Distribution Category UC-98

Consumption 

End-Use

A Comparison of Measures 

by Consumption and Supply Surveys

Energy information Administration

Office of Energy Markets and End Use

U.S. Department of Energy

Washington, D.C. 20585

General information concerning the contents of the report may be obtained from Lynda T. 

Carlson, Director of the Energy End Use Division (202/586-1112). Specific information 

regarding the contents or preparation of the publication may be obtained from Nancy L. Leach, 

Chief of the Residential and Commercial Branch (202/586-1114). The Residential Energy 

Consumption Survey manager and a major contributor to this report is Wendel Thompson 

(202/586-1119). The report was written by Gerald Peabody (202/586-6160).

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Energy Information Administration

Preface

This report was prepared in response to a request from the Office of Policy Integration in the 

U.S. Department of Energy for an analysis of how Energy Information Administration data from 

its consumption surveys compares with data from its supply surveys. The consumption surveys 

provide valuable details about energy use by the consumers, while the supply surveys provide 

valuable detail on trends in total consumption. The Office of Policy Integration, and other 

users of EIA data, often need to rely on supply surveys to understand trends and on 

consumption surveys to understand market forces. This report highlights those areas where the 

two types of surveys overlap and reinforce each other and those areas where they have 

differences. This report is a first step in making both sets of EIA data more useful to policy 

analysts who use E3A data in their work.

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Energy Information Administration

Introduction .................................................... 1

Comparison of Supply and Consumption Survey Methodologies ................. 5

Overview of Surveys ............................................. 5

Supply and Consumption ......................................... 7

Sources of Uncertainty or Error ..................................... 8

Sampling Techniques ............................................. 10

Sector Coverage by Survey Type .................................... 11

Residential Sector ................................................ 17

Sector Coverage by Survey Type .................................... 17

Energy Consumption by Fuel Type ................................... 19

Commercial Sector ................................................ 23

Sector Coverage by Survey Type .................................... 23

Energy Consumption by Fuel Type ................................... 25

Industrial Sector ................................................ 31

Sector Coverage by Survey Type .................................... 32

Energy Consumption by Fuel Type ................................... 33

Conclusion ..................................................... 39

Tables

1.

2.

3.

4.

5.

6.

7.

Number of Commercial and Industrial Electric

Accounts, 1966 - 1987 .......................................... 14

Residential Electricity Consumption and Supply .......................... 20

Residential Natural Gas Consumption and Supply ........................ 21

Residential Fuel Oil Consumption and Supply ........................... 22

Commercial Electricity Consumption and Supply ......................... 27

Commercial Natural Gas Consumption and Supply ........................ 28

Commercial Fuel Oil Consumption and Supply .......................... 29

Industrial Fuel Oil and Kerosene Consumption

and Supply ................................................... 35

auu ouppiy ourvey 

for Manufacturing Industries ....................................... 37

Energy Consumption by End-Use Sector 

Energy Information Administration

Energy policy makers-be they industry executives, members of utility commissions, or 

government officials require reliable data to make informed decisions. The need is particularly 

acute when the task is to forecast the future of energy markets. Making reasonable estimates 

of possible future prices, supply, and demand for energy requires accurate and detailed data 

about the current and historical situation of energy markets.

The Energy Information Administration (EIA) was mandated by Congress to be the agency 

within the Department of Energy that collects, analyzes and disseminates impartial, 

comprehensive data about energy-how much energy is produced, who uses it, and the purposes 

for which it is used. Energy data are also collected by a wide range of other groups; including 

other governmental agencies Federal, State and local; individual utility companies; and members 

of the energy industry, including individual companies and industry associations, such as the 

Edison Electric Institute.

To forecast energy market behavior, it is useful to bring together as much data as possible 

about the supply and demand of energy. The integration of data on the same subject from 

different sources, however, usually entails some difficulty since data collected by different groups 

and/or by different means are seldom completely compatible. Some effort must therefore be 

undertaken to reconcile the differences in data sets before the combined data can be used in an 

analysis.

EIA collects data from two distinct sources that, in their entirety, provide a comprehensive 

picture of energy production, marketing and use in the United States. The first set of surveystermed "supply" surveys in this report-are directed to the suppliers or marketers of specific fuels 

(including electricity). These surveys measure the quantity of the specific fuel produced and/or 

supplied to the market, along with other information related to the fuel's production and supply. 

Supply surveys are conducted for petroleum, natural gas, electricity, and coal. (The "supply" 

surveys for coal include surveys of consumers, which provide information on coal consumption; 

these surveys are discussed in the chapter on the industrial sector.)

The second group of surveys-termed "consumption" surveys in this report-collect data from 

samples of end-use consumers. These consumers use one, several, or all kinds of fuels. These 

surveys gather information on the types of fuels used by the consumer, the purposes for which 

each fuel is used, and the characteristics of the users. The end-use consumption surveys are 

conducted for the residential sector, commercial buildings, manufacturing establishments, and 

personal transportation.

Together, the uata from the supply and consumption surveys provide a ncn, aeianeu source or 

data on energy supply and use. The supply surveys have been conducted for many years, 

starting with predecessor agencies to EIA, The consumption surveys were started during the 

past decade under the auspices of EIA.

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Energy Information Administration

It is tempting to merge the time series data from the supply surveys with the detailed crosssectional data from the consumption surveys. However, there are important differences between 

the supply and consumption surveys which need to be taken into account in any analysis that 

uses both data sources.

This report discusses the relationship of EIA data from the supply surveys and from the 

consumption surveys. This comparison is made for three major end-use sectors: residential, 

commercial, and industrial. The discussion of industry is limited because the consumption survey 

covers manufacturing industries while the supply surveys (with the exception of coal) cover the 

entire industrial sector. No discussion is given of the transportation sector because the end-use 

consumption survey collects data only for personal transportation, and there are no comparable 

supply data available. Estimates of energy supply and consumption in each sector are compared 

for electricity, natural gas, petroleum fuels, and (for manufacturing industries) coal.

There are three important differences between the supply-based and consumption-based surveys:

 The supply surveys measure product supplied at some point in the supply chain, while 

the consumption surveys measure the actual quantity of fuel consumed (except for 

petroleum fuels for which the quantity delivered to the consumer is measured). Since 

fuels (except electricity) can be stored, the amount of product supplied to a sector in a 

given period is not necessarily equal to the amount consumed.

 The consumption surveys are based on a sample of the consumers in each economic 

sector, so there is a sampling error associated with the data from these surveys in 

addition to the nonsampling errors that are common to both sample and census surveys. 

In many cases, the supply surveys are a census of suppliers and so have no sampling 

error.1

« There are differences between the consumption and supply surveys in the coverage of 

each sector. The residential consumption survey, for example, does not cover the same 

set of residences as do the supply surveys. Further, there are differences among the 

various supply surveys in the coverage of each sector.

These differences are discussed further in the next chapter. It is important to note that the 

existence of differences between the two types of surveys does not mean that one or the other 

is incorrect or improperly conducted. In both types of survey, the decisions on the kinds of 

data to gather and the means to collect them have been based on sound statistical criteria and a 

full understanding of the types of data that could be collected without placing an undue burden 

on the respondent. For the most part, the differences between the two types of surveys reflect 

limitations imposed by efforts to minimize the burden of responding to the surveys and the need

'The term census, or census survey, in this report is used to mean a survey that covers all the members 

of the population from which data is being collected. A sample survey, on the other hand, collects data 

from a portion (a small portion in the case of the consumption surveys) of the total population being 

surveyed.

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2 Energy Information Administration

to limit the costs of data collection.

The result of the comparison in this report shows that, taking into account their differences, the 

two types of surveys present a consistent picture of energy consumption in the United States. 

Neither type of survey alone provides a complete description of energy consumption by 

economic sector. A fuller understanding of energy use by sector can be obtained by using data 

from the two sources, allowing for their differences.

Before comparing the methodologies used in the supply and consumption surveys, the sources of 

data used in this report will be described briefly. For each energy consumption survey, there 

are associated publications with detailed tables of findings from the survey. For the most part, 

data in this report have been obtained from these publications. In a few cases in which 

consumption figures were revised after the associated publication was released, the revised 

figures were obtained from the Annual Energy Review (AER), a composite report containing 

annual time series of data on energy production, price, and consumption.

For the fuel supply surveys, there are several sources of supply estimates. Preliminary estimates 

are obtained and published from weekly or monthly surveys. There are also annual reports, 

which publish results either from a separate annual survey or from a compilation of data 

received in the monthly surveys. In addition to data on quantities supplied and prices, reports 

based on the supply surveys provide a wealth of information about other factors related to the 

supply of each fuel,

Annual data on supply, consumption and prices for all fuels are also published in two 

consolidating reports the AER and the State Energy Data Report (SEDR). These two reports 

are generally the source of supply data quoted in this report, because they publish any revisions 

to the annual supply data that occurred after the associated annual report was published. The 

SEDR contains consumption and prices for a variety of fuels by economic sector for each State. 

In some cases, the data in SEDR may differ from that published for the supply surveys because 

of differences in the definitions of the end-use sectors. For this report, this difference is of 

importance primarily for commercial consumption of electricity, which will be discussed in more 

detail in the chapter on the commercial sector.

The next section compares the methodology of the supply and consumption surveys. Particular 

attention is paid to the three important differences between them noted above. Successive 

chapters discuss each end-use sector covered in this report (residential, commercial, and 

industrial), with separate sections for each fuel. The final chapter summarizes the report's 

findings.

Energy Consumption by End-Use Sector 

Energy Information Administration

Comparison of Supply and Consumption 

Survey Methodologies

The supply and consumption surveys conducted by EIA to measure energy use in the different 

economic sectors are based on different methods for collecting data, and they collect different 

kinds of data. This chapter gives a brief overview of each type of survey and discusses some of 

the important differences between the surveys that should be recognized in using the data from 

both types of survey to analyze energy demand or for other purposes.

Overview of Surveys

The consumption surveys collect information with a sample survey based on a relatively small 

number of users of energy in each sector. These surveys collect detailed information on the 

amounts of energy consumed, the purposes for which energy is used, and the characteristics of 

the users. The sample of consumers is selected using statistical techniques that allow the survey 

results to be generalized to the total population for the sector. These surveys are now 

conducted every three years.

The supply surveys use both census and sample surveys to collect data. There are a number of 

supply surveys for each fuel that are conducted at different frequencies and collect different 

types of data. The supply data used in this report are based on census surveys for electricity 

and natural gas, while the petroleum fuels survey is a sample survey.2

Energy Supply Data

Statistical data on the production and sale of the principal sources of energy have been 

collected and published for many years. The producers and/or primary suppliers of a specific 

type of energy generally number in the hundreds to thousands. This number allows for data 

collections from all the major suppliers and a substantial portion, if not all, of the smaller ones.

Data collected from suppliers provide a measure of the total amount of the specific type of 

energy supplied. These surveys also collect a range of other information related to the 

production and supply of each fuel. However, only the total quantity supplied to each end-use

2The petroleum data from the SEDR that are quoted here have, however, been benchmarked to total 

products supplied, figures calculated from census surveys.

Energy Consumption by End-Use Sector

Energy Information Administration 5

sector is relevant to this report, so the other types of data will not be discussed. The supply 

surveys considered in this report are for electricity, natural gas, petroleum fuels (kerosene and 

distillate and residual fuel oils), and coal.3

The data used in this report are from one survey for each of the fuels. Annual electricity sales 

data are currently collected on Form EIA-861, "Annual Electric Utility Report," which is sent to 

all electric utilities in the United States. The findings are reported in the Electric Power 

Annual. Annual natural gas data are collected on Form EIA-176, "Annual Report of Natural 

and Supplemental Gas Supply and Disposition," which is mailed to all natural gas pipeline 

companies and other companies that deliver natural gas directly to consumers, with results 

reported in the Natural Gas Annual. Petroleum fuel sales to end-use sectors are collected in a 

sample survey using Form EIA-821, "Annual Fuel Oil and Kerosene Sales Report," and reported 

in the Petroleum Marketing Annual The coal data used here are unique in that the "supply" 

data are from a survey of consumers rather than suppliers. Form EIA-3, "Quarterly Coal 

Consumption Report," is sent to all manufacturing plants that consume coal, and the findings 

are reported in the Quarterly Coal Report.

The production and sales data provide limited information about the users of energy. The 

supply data can be categorized into very broad groupings of types of customers (residential, 

industrial, and so on), generally based on rate classifications, and their location (state or region). 

These data provide no information on how the customers use the energy. For information 

about the purposes for which energy is used, data must be collected from the users themselves.

End-Use Consumption Data

Data collected from the final consumers of energy provide information about the amount of 

energy consumed by individual consumers and the purposes-end uses--for which it is used. 

Energy is needed for the services it can perform: heating homes or buildings, fueling vehicles, 

or powering a manufacturing process. End-use consumption data provide information about the 

ways energy is used to provide these services. End-use data for a home, for example, would 

provide information about the various types of energy used in the home, the purposes for which 

energy is used, and the amount of each fuel consumed. At the most detailed level, this 

information would specify how much fuel was used to perform a particular function-how much 

natural gas, for example, was used to heat a house.

To obtain consumption information at this level of detail, it is necessary to ask the consumers 

themselves what types of energy they use and the purposes for which they use it. The energy 

consumption surveys conducted by EIA are based on detailed information obtained from a 

sample of consumers in three major economic sectors-residential (including private vehicle use), 

commercial buildings, and manufacturing industries. Each of the consumption surveys are now 

conducted every three years. The Residential Energy Consumption Survey (RECS) is conducted

3Except for the industrial sector, the petroleum fuels are considered collectively in this report. RECS 

and NBECS do collect data on kerosene, as well as distillate and residual fuel oil, but for the purposes of 

this report it is sufficient to consider the petroleum fuels in total.

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6 Energy Information Administration

on a sample of full-time occupied residences, and has been conducted seven times starting in 

1978. The survey of commercial buildings, the Nonresidential Buildings Energy Consumption 

Survey (NBECS), is conducted on a sample of buildings in which over one-half the floorspace is 

devoted to commercial activities.4 NBECS has been conducted three times starting with 1979. 

The Manufacturing Energy Consumption Survey (MECS) is based on a sample of manufacturing 

establishments and was first conducted in 1985.

For the RECS and NBECS, personal interviews are conducted with the home owner or building 

representative; for MECS, the survey questionnaire is mailed to the establishments. Data on 

the amount of fuels consumed are obtained from the companies that sell the fuels to the users 

for RECS and NBECS. The respondents list the quantities of fuel purchased and consumed in 

MECS.

The introduction noted three important differences between the supply and consumption 

surveys: the distinction between consumption and supply, sources of errors in the surveys, and 

the types of units covered within a sector by each survey. These differences are discussed in 

turn. In addition, the supply and consumption surveys use two different sampling techniques to 

draw samples for the surveys. RECS and NBECS are based on multistage area probability 

sampling techniques, while MECS and the petroleum supply survey, EIA-821 "Annual Fuel Oil 

and Kerosene Sales Report," use sampling from lists. These sampling techniques are also briefly 

described.

Supply and Consumption

A market is in balance when supply equals demand, or consumption. Consequently, the terms 

supply and consumption are sometimes used interchangeably in reports on energy use. For 

petroleum fuels, however, there are a number of steps in the chain of supply. It extends from 

the oil field where the crude oil is produced (or the receiving dock where the oil is imported), 

to the refinery where various fuels and other products are produced from the crude oil, and to 

the resellers and dealers who ultimately sell the fuels to the final consumer. Supply can be 

measured at several points along the supply chain, and these measures of supply will not 

necessarily be equal to measures of final end-use consumption.

Products held by a supplier need not be consumed in a given time period; they can be stored or 

exported. Further, a supplier may sell products from storage or products that have been 

imported. This is primarily true for petroleum fuels, where there are a number of products, 

storage at many points in the supply chain is common, and both crude oil and products can be 

imported and exported. 

Natural gas is also stored and imported, but this does not affect the supply data cited here.

4The next commercial buildings survey, conducted for 1989, will be termed the Commercial Buildings 

Energy Consumption Survey (CBECS). The acronym NBECS will be used throughout this report since that 

is the name of the surveys reported on here.

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Energy Information Administration 7

The annual survey based on Form EIA-176 Is sent to companies that deliver gas directly to 

consumers, so the measures of end-use sales from this survey should be compatible with end-use 

consumption data. For electricity, no storage is possible, so there is no distinction between 

supply and consumption.

Because the supply situation for petroleum fuels is complex, there are two types of surveys 

conducted in this area: supply surveys and marketing surveys. The supply surveys focus on field 

production of crude oil, refinery operations, and import/exports. The marketing surveys cover 

refiners, gas plant operators, suppliers, and resellers. The survey cited in this report is part of 

the petroleum marketing survey of retailers and resellers. The "Annual Fuel Oil and Kerosene 

Sales Report" (Form EIA-821) survey determines the quantity of product sold to end-use 

customers. Two types of findings are reported from this survey: the direct sales data are 

reported, along with data that have been adjusted to ensure that the PAD District total sales of 

distillate and residual fuel oils and kerosene equal the products supplied as published in the 

Petroleum Supply Annual. These adjusted figures are called supply and are the values used in 

SEDR for end-use consumption by sector. These figures are also used here to compare supply 

with consumption data.

In comparing the results from two different types of survey, it is important to account for errors 

in the data. The next section discusses the types of errors in the supply and consumption 

survey data.

Three sources of error respondent error, processing error, and sampling frame error are 

common to both types of surveys, census and sample. Another source of error, sampling error, 

is introduced when a sample of the target population is surveyed instead of the entire 

population.

Respondent, Processing, and Frame Errors

Respondent errors in survey data result from incorrect answers, or failure to answer a question, 

by the respondent. All the survey data quoted in this report are subject to this type of error. 

To minimize such errors, rigorous procedures have been developed and tested over time for 

each survey to screen responses for plausibility and to check with the respondent when an 

answer does not seem reasonable or when a question is not answered. Every effort is made to 

ensure that the answers provided are correct, to the extent that the respondent can answer the 

question. Nonetheless, not all errors will be corrected, so there remains an unknown level of 

rpsnnnr)e,nt e.rror in the survey data discussed in this report.

For the residential and commercial consumption surveys, data are obtained from the fuel 

supplier as well as from the householder or building representative, and respondent error by the

Energy Consumption by End-Use Sector 

8 Energy information Administration

fuel supplier can have an important effect on the quality of the survey results. For natural gas 

and electricity, only one supplier is available to the customer and the utilities keep good records 

on the quantities supplied to their customers. The quality of consumption data for these fuels is 

very high.

For fuel oil, on the other hand, the consumer can receive deliveries from several suppliers. 

When resp9nding to the survey, the respondent may fail to list all the fuel oil suppliers. In 

addition, many fuel oil dealers are relatively small businesses and may not keep records in a 

form that allow them to readily determine the total quantities delivered to a particular customer. 

They might overlook some deliveries and fail to report them when responding to the survey. 

Consequently, data on consumption of fuel oil for the residential and commercial surveys have 

higher uncertainty than do data on natural gas and electricity consumption. Also, the petroleum 

consumption data may be biased low. For MECS, all fuel consumption data in the survey are 

from the manufacturer's records of purchases and are expected to be of equal quality for all 

fuels.

Another source of error in survey data comes from mistakes in processing the data after they 

are received. The data must be coded and then entered into a computerized data base system, 

and mistakes can occur at each step of the data processing. All of the surveys have extensive 

edit checks and other procedures designed to minimize these types of errors so that the data 

base reflects as accurately as possible the data received from the respondents.

Frame errors can occur in both sample and census surveys. To conduct a census survey, it is 

necessary to have an accurate list of all the members of the population being surveyed, or have 

a method for conducting the survey that will ensure that the total population is covered. Since 

any population is always changing through the addition (a new business starts up or a person is 

born) and deletion (a corporation goes out of business or a person dies) of members, keeping 

track of the population to be surveyed is difficult. An incompleteness in the list of the 

population being surveyed results in frame error for the survey. Sample surveys have a complex 

sample frame that is used to select the sample. To the extent these procedures lead to the 

selection of a sample that is not representative of the entire population (by under or over 

sampling a particular types of units) there will be frame error.

Respondent, processing and frame errors are common to all surveys. It is difficult to quantify 

the magnitude of these errors, so in publishing its data, EIA does not present an estimate of 

the size of error from these sources. Since no estimate of their size is available, these errors 

aren't discussed further in comparisons of the results from the supply and consumption surveys. 

The magnitude of sampling errors, however, is quantifiable.

Sampling Error

All of the consumption surveys and the annual survey of fuel oil dealers based on Form EIAS21 aio aaiiiplc suivcys. Sample surveys are used wnen xhe population 01 interest is so large 

that it is not feasible to conduct a census survey. For example, there were 90.5 million 

households in the United States in 1987, while the Residential Energy Consumption Survey

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Energy Information Administration

(RECS) was -based OR about 6,000 households,

The statistical procedures followed in selecting the sample are designed to make the sample 

representative of the entire population. These procedures also determine how to make 

estimates for the entire population from the sample data, and how to estimate the uncertainty 

in these estimates, which is termed the sampling error.

For 1987, the year of the latest RECS, total energy consumption was estimated to be 9.13 

quadrillion Btu (quads) for the residential sector. The sampling error, one standard error, for 

this estimate is 0.19 quads, about 2 percent of the estimated value. The 95-percent confidence 

interval for the estimate is 9.13 +/-0.37 quads. Based on the sampling error, we can be 95- 

percent confident that the true value for total consumption lies within the range from 8.77 to 

9.51 quads. (The 95-percent confidence interval is the estimated value +/- 1.96 times the 

standard error.) The relative sampling error (RSE) will be cited in this report as the measure 

of uncertainty in the consumption surveys. (The RSE is the ratio of the standard error to the 

estimate expressed in percent.)

The standard error increases with decreasing size of the sample upon which an estimate is 

based. Consequently, for the consumption surveys, the standard errors are lower for fuels that 

are used by a large portion of the population, such as electricity, and higher for fuels used by a 

minority of the population, such as fuel oil for residential and commercial consumers.

The petroleum supply survey of annual fuel oil and kerosene sales is based on a sample of 

retailers, and sampling errors have been calculated for the sales data. The supply data quoted 

in this report are the sales data adjusted so that total sales equal total product supplied. The 

adjustment process redistributes sales among the end-use sectors. Standard errors aren't 

available for these supply figures, so only the standard errors from the consumption surveys are 

used in this report for making comparisons.

Sampling Techniques

Two types of sampling techniques are used to select the samples for the consumption and 

supply surveys: multistage area probability sampling and list sampling. RECS and NBECS use 

multistage area probability sampling techniques. MECS is based on a list of manufacturing 

establishments maintained by the Census Bureau, and the petroleum supply survey for Form 

EIA-821 uses a sample from list of fuel oil retailers and resellers. The NBECS sample is 

supplemented with a sample drawn from lists of large buildings. Each type of sampling 

technique is discussed in turn.

The sample selection process begins with a list of a!l the counties in the United States. 

Information about the county relevant to the particular survey, such as population size,

Energy Consumption by End-Use Sector 

to Energy Information Administration

lit'

geographic location, and main heating fuel for households, is used to select counties for the 

sample. The selection process is designed to make the sample representative of the various 

regions of the country and of other population characteristics. Within the selected counties, 

successively smaller areas are selected, until a very small geographic area is selected.

An interviewer is then sent to that area to list all the units to be surveyed (either housing units 

or commercial buildings). These small areas generally contain about 45 to 50 housing units for 

RECS, and about 100 commercial buildings for NBECS. The interviewer records the address of 

each unit and the characteristics that are relevant to the survey (building size and apparent 

usage for NBECS, for example). From this listing, a small number of units are selected to be 

included in the survey.

A representative for each unit selected from the sample is interviewed in person and a 

questionnaire is filled out that contains comprehensive information about the characteristics of 

the building, the energy-using equipment within the building, and the characteristics of the 

occupants (household characteristics for RECS and business activities for NBECS). The 

respondent is also asked to sign an authorization form that allows EIA to get information on 

the energy supplied to the building directly from the suppliers. Thus the energy consumption 

data are obtained from actual billing data maintained by the utilities supplying the buildings. 

The responses from the household or building interviews, combined with the energy use 

information from the energy suppliers, form the content of the energy consumption surveys.

List Sampling

The second method used by EIA to select a sample for surveys is sampling from a list of 

members of the population. The NBECS uses lists to supplement the sample drawn by the 

multistage area probability sampling technique, while the MECS sample is drawn entirely from a 

list of manufacturing establishments. For NBECS, lists of specialized buildings were used 

(hospitals, colleges and universities, schools, post offices, and Federal government buildings) as 

well as a list of large buildings in each metropolitan area. MECS is based upon a 

comprehensive list of manufactures that is maintained by the Census Bureau for its Annual 

Survey of Manufactures. The characteristics of the buildings or manufacturing establishments 

are used to draw a sample that is representative of all types of buildings or establishments. For 

example, for the MECS, the lists are stratified by industry groups and the drawing is made from 

within each manufacturing group to ensure that all manufacturers are represented. The annual 

survey of fuel oil dealers is a sample drawn from the list of dealers maintained for the sampling 

frame for the monthly petroleum marketing surveys. This list is also stratified by dealer 

characteristics so that the sample is representative of the universe of dealers.

Sector Coverage by Survey Type

The consumption surveys were designed to provide broad information about energy consumers

Energy Consumption by End-Use Sector 

Energy Information Administration 11
geographic location, and main heating fuel for households, is used to select counties for the 

sample. The selection process is designed to make the sample representative of the various 

regions of the country and. of other population characteristics. Within the selected counties, 

successively smaller areas are selected, until a very small geographic, area is selected.

An interviewer is then sent to that area to list all the units to be sun/eyed (either housing units 

or commercial buildings). These small areas generally contain about 45 to 50 housing units for 

RECS, and about 100 commercial buildings for NBECS. The interviewer records the address of 

each unit and the characteristics that are relevant to the survey (building size and apparent 

usage for NBECS, for example). From this listing, a small number of units are selected to be 

included in the survey.

A representative for each unit selected from the sample is interviewed in person and a 

questionnaire is filled out that contains comprehensive information about the characteristics of 

the building, the energy-using equipment within the building, and the characteristics of the 

occupants (household characteristics for RECS and business activities for NBECS). The 

respondent is also asked to sign an authorization form that allows EIA to get information on 

the energy supplied to the building directly from the suppliers. Thus the energy consumption 

data are obtained from actual billing data maintained by the utilities supplying the buildings. 

The responses from the household or building interviews, combined with the energy use 

information from the energy suppliers, form the content of the energy consumption surveys.

List Sampling

The second method used by EIA to select a sample for surveys is sampling from a list of 

members of the population. The NBECS uses lists to supplement the sample drawn by the 

multistage area probability sampling technique, while the MECS sample is drawn entirely from a 

list of manufacturing establishments. For NBECS, lists of specialised buildings were used 

(hospitals, colleges and universities, schools, post offices, and Federal government buildings) as 

well as a list of large buildings in each metropolitan area. MECS is based upon a 

comprehensive list of manufactures that is maintained by the Census Bureau for its Annual 

Survey of Manufactures. The characteristics of the buildings or manufacturing establishments 

are used to draw a sample that is representative of all types of buildings or establishments. For 

example, for the MECS, the lists are stratified by industry groups and the drawing is made from 

within each manufacturing group to ensure that all manufacturers are represented. The annual 

survey of fuel oil dealers is a sample drawn from the list of dealers maintained for the sampling 

frame for the monthly petroleum marketing surveys. This list is also stratified by dealer 

characteristics so that the sample is representative of the universe of dealers.

The consumption surveys were designed to provide broad informal ion about energy consumers

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Energy Information Administration
in specific economic sectors. The design of the sampling frame determines what portion of the 

sector is included in the sample. The supply surveys, on the other hand, were designed to 

survey suppliers of specific fuels to provide information about the quantities of fuel supplied and 

at what price. The supply surveys weren't necessarily designed to obtain information about enduse sectors, and what information is obtained about deliveries of fuels to individual sectors is 

obtained from responses to the questions on the survey form. The coverage of each sector 

varies between the supply and consumption surveys, and among the various supply surveys. The 

following sections give an overview of some of these differences in coverage and the reasons for 

them. More detailed discussions are provided in the individual chapters for each sector.

Consumption Surveys

The RECS sample is designed to cover all occupied residential units, but it explicitly excludes 

summer homes and other homes that are only occupied for part of the year. Farm houses and 

single family houses on military bases are included, as are apartments. Group housing, such as 

school dormitories, military barracks, and nursing homes are not covered.

NBECS covers commercial activities that take place in buildings, but excludes the limited 

number of commercial sector activities that are not located in buildings (street lighting, for 

example). NBECS also picks up a small amount of consumption by residences or industrial 

establishments that are located in buildings that are primarily commercial, and it misses 

consumption by commercial establishments located in buildings that are primarily noncommercial.

The MECS is explicitly designed to cover manufacturing industries, and since it is based on a 

comprehensive list of manufacturing establishments, it provides complete coverage of the 

manufacturing sector. However, there is no consumption survey that covers the other segments 

of the industrial sector-construction, mining, and agriculture.

Supply Surveys

For each fuel, annual data are collected on sales or deliveries to end-use consumers. However, 

there is some variation among the surveys in the way the end-use sectors are defined. The 

quality of the data on end-use sector sales depends on the response to the question by the 

utility or supplier. In many cases, suppliers will classify their end-use sales by rate classification 

which may not be consistent with other definitions of the sectors,

Electric and natural gas utility companies have different rate structures for different categories 

of customers. They will typically have one rate schedule for residential customers, with 

relatively low consumption levels; a second rate schedule for commercial customers, with 

intermediate levels of consumption; and an industrial rate schedule for large consumers. The 

rates reflect any number of considerations that are important to the economic welfare of the 

'*<?!?!p?ny »nc! -wwv mflwt nthrr interests as well such «s life-line rales that nrovide economic 

service to low-income families.

Energy Consumption by End-Use Sector 

12 Energy Information Administration

The utility specifies how much fuel it supplied to residential, commercial, industrial, and other 

customers by totaling the quantity supplied under these rate classes. Utilities are not required 

to maintain records on the economic activities of their customers, so their rate structures may 

not correspond to economic definitions of the end-use sectors. To the extent there is not a oneto-one correspondence between the economic activity of the customers and the rate schedule at 

which they are billed, there will be a misclassification of end-use sector supply data.

The instructions for Form EIA-861, the EIA form for collecting annual supply information from 

electric utilities, specify that the utility should list sales to five categories of end users. These 

categories include the major end-use sectors (residential, commercial, and industrial) as well as 

two categories specific to the survey (street and highway lighting and other). The instructions 

for the form are intended to allow the utilities to use their preferred bases for categorizing 

consumers. Thus utilities are allowed to use discretion to determine which customers are 

classified in what end-use sector.

The form for the natural gas survey, Form EIA-176, provides definitions of the different sectors. 

A study of a small number of respondents found there is some misclassification in the natural 

gas data due to the way records are kept, but the misclassification is highly consistent over 

time.5 For example, a large master-metered apartment building may be classified as commercial 

if it is billed at commercial rates.

It is possible for a customer's classification~or rate schedule-to change over the course of the 

year as its consumption varies. For example, a very large commercial building may have a high 

electricity load in the summer when it runs its air-conditioning equipment and be billed at 

industrial rates. In the winter, if it is heated with gas, the buildings electricity consumption 

might be substantially lower and be billed at commercial rates. This is most likely to be a 

concern for electric utilities, where consumption for summer months can increase markedly to 

air condition a building, and then be much lower in the fall and spring, when much less heating 

or air conditioning is required.

There are no data available that would enable EIA to determine how much misclassification 

there might be in end-use sector supply data supplied by the utilities. There are, though, some 

limited data that suggest that the problem is not negligible.6

The Edison Electric Institute (EEI) recognizes this situation and consequently combines 

commercial and industrial sales data when they make comparisons with EIA data. This is done 

to minimize changes that may be caused by changes in classification. Concerning the published

5An intensive study was conducted by EIA's Office of Oil & Gas on a small sample of respondents to 

Form EIA-176.

*In 1978, Southern California Gas had 8,000 customers they classified as industrial. Following a 

reclassification that was designed to have their classification conform to the standard industrial classification 

(SIC) codes, the number of industrial customers increased tn ^DOOn <Tint3 minted in » IQ&d letter from 

Paul Schaffer, Senior Editor for Statistics, Energy Daify News, to Lynda Carlson, Director of the Energy End 

Use Division of EIA.)

Energy Consumption by End-Use Sector

Energy Information Administration 13

counts of commercial and industrial customers, the Efcl notes in the 1986 edition of its 

Statistical Yearbook (p. 53) that "commercial and industrial are not wholly comparable on a 

year-to-year basis due to changes from one classification to another."

Evidence that customers are not consistently classified from year to year appears in the 

historical trends of the number of accounts classified as commercial and industrial (Table 1). 

The 3EEI data indicate that commercial accounts have shown a steady increase every year from 

1966 through 1987. The number of industrial accounts has shown more variation in their 

growth. In 1982, the number of industrial accounts reached a peak which has not been reached 

since.

Table 1. of Commirelal and

1966 - 1987

Year

1966

1967

1968

1969

1970

1971

1972

1973

1974

1975

1976

1977

1978

1979

1980

1981

1982

1983

1984

1985

1986

1987p

Commercial

7,536,066

7,579,626

7,706,779

7,744,851

7,865,073

8,002,572

8,200,033

8,361,847

8,472,817

8,591,108

8,750,949

8,943,732

9,148,399

9,386,572

9,698,809

9,847,260

9,976,274

10,266,449

10,565,239

10,920,861

11,114,300

11,358,420

Percent 

Change

4-0.6

+ 1.7

+0,5

+ 1.6

+ 1.7

+2.5

+2.0

+ 1.3

+ 1,4

+ 1.9

+2.2

+2.3

+2.6

+3.3

+ 1.5

+ 1.3

+2.9

+2.9

+3.4

+ 1.8

+2.2

industrial

316,098

324,222

333,650

348,648

352,993

355,967

369,952

413,383

422,736

414,665

427,403

448,009

464,637

477,874

484,652

516,996

533,635

500,215

525,692

499,728

498,254

494,545

Percent 

Change

+2.6

+2.9

+4.5

+ 1.2

+0.8

+3.9

+ 11.7

+2.3

-1.9

+3.1

+4.8

+3.7

+2.8

+ 1.4

+ 6.7

+3.2

-6.3

+ 5.1

-4.9

-0.3

-0.7

p: preliminary data 

Source: Edison Electric Institute, Statistical Yearbook of the Electric Utility 

Industry/1986, Table 10; customer count is for December 31 of year indicated.

There are three aspects to the ways utilities are likely to classify consumption by sector that 

affect comparisons between consumption and supply data and studies of variations in supply data

14

Energy Consumption by End-Use Sector 

Energy Information Administration

over time. First, as has been discussed, some utilities use rate schedules for commercial, 

industrial, and other customers that do not provide a distinction between these customers that is 

consistent with the economic definitions of the sectors in which the customers are located.

Second, the rate schedules for different utilities are not necessarily the same, so it is likely that 

the characterization of customers will vary across utilities. This can be important for studies of 

regional differences in consumption that are based on supply data. To the extent that 

differences of energy supplied to a specific sector reflect differences in utilities' classification 

rather than actual differences in consumption, the analysis will be adversely affected.

Finally, within a utility the classification of customers may shift over time for two reasons. First, 

a company may change its consumption level over the course of time, or even over the course 

of one year, and therefore move between different rate classifications. Then the customers' 

consumption would be shifted back and forth between commercial and industrial categories, 

even though the business of the customer did not change. Secondly, a utility may change its 

rate structure and therefore change the distribution of its supply among the sectors even though 

the nature of the customers did not change.

For these reasons, the time series of supply-based consumption data do not present a clean time 

series of consumption by economic sector. There are unknown shifts of consumption among 

sectors that will occur because of changes in rate structures or movements between rate 

structures by firms that have changes in consumption. Since there are no data available that 

would enable EIA to determine to what extent these changes are taking place, the supply-based 

consumption data must be used with some caution in time series analyses of consumption by 

sector. Further, care must be taken in attempting to integrate supply-based data and 

consumption-based data. Since it is likely that these two sources of consumption data are not 

measuring consumption by the same population of consumers, care must be taken in any 

analysis that is based on the joint use of these data.

The situation for each end-use sector will be discussed in more detail in the following chapters. 

These chapters consider each sector individually, and discuss the degree of overlap of coverage 

in the consumption and supply surveys for each fuel. The discussion in these chapters should 

prove to be an aid to analysts who are studying energy demand through the joint use of supply 

and consumption data series.

MS,

Energy Consumption by End-Use Sector 

Energy Information Administration 15
over time. First, as has been discussed, some utilities use rate schedules for commercial, 

industrial, and other customers that do not provide a distinction between these customers that i,;> 

consistent with the economic definitions of the sectors in which the customers are located.

Second, the rate schedules for different utilities are not necessarily the same, so it is likely that 

the characterization of customers will vary across utilities. This can be important for studies, of 

regional differences in consumption that are based on supply data To the extent that 

differences of energy supplied to a specific sector reflect differences in utilities' classification 

rather than actual differences in consumption, the analysis will be adversely affected.

Finally, within a utility the classification of customers may shift over time for two reasons. First, 

a company may change its consumption level over the course of time, or even over the course 

of one year, and therefore move between different rate classifications. Then the customers' 

consumption would be shifted back and forth between commercial and industrial categories, 

even though the business of the customer did not change. Secondly, a utility may change its 

rate structure and therefore change the distribution of its supply among the sectors even though 

the nature of the customers did not change.

For these reasons, the time series of supply-based consumption data do not present a clean time 

series of consumption by economic sector. There are unknown shifts of consumption among 

sectors that will occur because of changes in rate structures or movements between rate 

structures by firms that have changes in consumption. Since there are no data available that 

would enable EIA to determine to what extent these changes are taking place, the supply-based 

consumption data must be used with some caution in time series analyses of consumption by 

sector. Further, care must be taken in attempting to integrate supply-based data and 

consumption-based data. Since it is likely that these two sources of consumption data are not 

measuring consumption by the same population of consumers, care must be taken in any 

analysis that is based on the joint use of these data.

The situation for each end-use sector will be discussed in more detail in the following chapters. 

These chapters consider each sector individually, and discuss the degree of overlap of coverage 

in the consumption and supply surveys for each fuel. The discussion in these chapters should 

prove to be an aid to analysts who are studying energy demand through the joint use of supply 

and consumption data series.

iftEnergy Consumption by End-Use Sector 

Energy Information Administration
There is no well-established definition of the residential sector as there is for the other sectors. 

The residential sector is generally considered to consist of all private residences, including single 

family homes (both owned and rented), multifamily housing units, apartments, and mobile 

homes. Secondary homes, such as summer homes, are also included. Institutional housing, such 

as school dormitories, hospitals and military barracks, are generally not included in the 

residential sector. Since there is no standardized definition of this sector, there will be variation 

in which dwelling units are included in it in different studies or data sources. Residential 

housing units consume energy for space heating, water heating, air conditioning, lighting, 

refrigeration, cooking, clothes drying, and other appliance operation.

The Residential Energy Consumption Survey (RECS) provides a direct measure of energy 

consumption in individual housing units, along with detailed information about the housing unit, 

its energy consuming equipment, and the characteristics of the unit residents. The various EIA 

supply surveys provide estimates of the total amount of individual fuels supplied to the 

residential sector in total The consumption survey and the various supply surveys differ 

somewhat in the types of housing units that are included in their respective definitions of the 

residential sector, as will be discussed in the following section.

Sector Coverage by Survey Type

All surveys cover the major portion of the residential sector, private housing units. However, 

there are some significant differences in the way certain portions of the sector are handled. 

RECS covers occupied, primary residences, but does not include vacant and secondary housing 

units. These units tend to be covered by the supply surveys. On the other hand, the supply 

surveys vary in their coverage of apartments and farm houses.

Consumption Survey

The sampling frame for RECS is explicitly designed to cover all residential housing units that 

are primary residences. It excludes units that are vacant or that are secondary homes, such as 

vacation homes, as well as migratory housing. The sample includes apartment buildings, farm 

homes, and single family homes on military bases (but not housing in military barracks). Other 

forms of institutionalized housing, such as college dormitories and hospitals, are not included.

Aiic impact Ol excluding migiaiuty and secuiiuaiy liuusmg t^aaiiul uc aisa^S; without data

the levels of consumption in these units. Migratory housing may use little energy. However, 

vacation homes could have a full complement of appliances. Those homes that are used for a

Energy Consumption by End-Use Sector 

Energy Information Administration 17
There is no well-established definition of the residential sector as there is for the other sectors, 

The residential sector is generally considered to consist of all private residences, including single 

family homes (both owned and rented), multifamily housing units, apartments, and mobile 

homes. Secondary homes, such as summer homes, are also included. Institutional housing, such 

as school dormitories, hospitals and military barracks, are generally not included in the 

residential sector. Since there is no standardized definition of this sector, there will be variation 

in which dwelling units are included in it in different studies or data sources. Residential 

housing units consume energy for space heating, water heating, air conditioning, lighting, 

refrigeration, cooking, clothes drying, and other appliance operation.

The Residential Energy Consumption Survey (RECS) provides a direct measure of energy 

consumption in individual housing units, along with detailed information about the housing unit, 

its energy consuming equipment, and the characteristics of the unit residents. The various ETA 

supply surveys provide estimates of the total amount of individual fuels supplied to the 

residential sector in total. The consumption survey and the various supply surveys differ 

somewhat in the types of housing units that are included in their respective definitions of the 

residential sector, as will be discussed in the following section.

Sector Coverage tsa* by J> Survey fi Type iff a

All surveys cover the major portion of the residential sector, private housing units. However, 

there are some significant differences in the way certain portions of the sector are handled. 

RECS covers occupied, primary residences, but does not include vacant and secondary housing 

units. These units tend to be covered by the supply surveys. On the other hand, the supply 

surveys vary in their coverage of apartments and farm houses.

Consumption Survey

The sampling frame for RECS is explicitly designed to cover all residential housing units that 

are primary residences. It. excludes units that are vacant or that are secondary homes, such as 

vacation homes, as well as migratory housing. The sample includes apartment buildings, farm 

homes, and single family homes on military bases (but not housing in military barracks). Other 

forms of institutionalized housing, such as college dormitories and hospitals, are not included.

•mo impact (ji cxciuuuig Ulijjj.i»ujiy aim aeixjiiucuy ut- aaaCadi.ii MH.HJUI UULU

the levels of consumption in these units. Migratory housing may use little energy. However, 

vacation homes could have a full complement of appliances. Those homes that are used for a

Energy Consumption by End-Use Sector 

Energy Information Administration
substantial length of time over the course of a year could be expected to have consumption 

levels that approach that of a full-time occupied housing unit.

Supply Surveys

The treatment" of apartment buildings varies among the various supply surveys. Instructions for 

Form EIA-861, the current electricity survey form for collecting annual sales data, allows utilities 

some discretion in how they classify customers. Consequently, some utilities use rate schedules 

to determine sectoral sales and may therefore misclassify some residential consumption. In 

particular, large apartment buildings that are billed at commercial rates could be included under 

commercial sales.

Apartment buildings are listed as being part of the residential sector on Form EIA-176 for the 

natural gas survey. However, in some cases, natural gas utilities use the billing rate classification 

for determining consumption by sector. Gas delivered to large apartment buildings that are 

billed under commercial tariff schedules would then be classified as commercial rather than 

residential sales.

Apartment buildings are explicitly excluded from the residential sector in the petroleum surveys. 

The respondents are instructed to include apartment building consumption of fuel oil in the 

commercial sector.

Farm homes are a second type of housing unit that is difficult to handle properly in the supply 

surveys. The electricity survey in particular is likely to have difficulty with farms. The survey 

will measure all sales to farms, but sales for the farm house and for other farm operations will 

not be distinguished in all cases. On a farm, some energy is consumed in the farm house for 

household purposes, while other energy is consumed for farm operations. The later 

consumption should be counted in the agriculture sector (as part of industry) while the former 

is part of residential consumption.

A farm family that uses electricity for farm buildings and other farm operations, as well as for 

their house, may receive only one bill from the electric utility. The utility would not be able to 

separate out consumption that was for residential purposes from that for agricultural purposes. 

Therefore, the total amount of consumption for the farm is likely to be assigned either to 

residential or to industry, depending upon how the farm is listed in their accounts. Neither 

assignment will give the correct amount of residential consumption.

Sales to farms are included in a separate category on the fuel oil and kerosene forms. Because 

this category contains multisector consumption (farm home use-residential and farm operation 

use-industrial or agriculture), this separate category does not help in making the proper 

assignment of this consumption. However, because of the separate category, we can identify 

that the farm consumption is not assigned to the residential sector for the supply surveys.

RECS does not identify farm homes per se, but it does identify homes that use energy for some 

farm operations. With this information, it is possible to estimate what portion of the energy is

Energy Consumption by End-Use Sector 

18 Energy Information Administration
substantial length of time over the course of a year could be. exoecied to have consumptic-y 

levels that approach thai of a full-time occupied housing unit.

The treatment'of apartment buildings varies among the various supply surveys. Instruction;; reForm EIA-861, the current electricity survey form for collecting annual sales data, allows utilii.i;: 

some discretion in how they classify customers. Consequently, some utilities use rate schedules 

to determine sectoral sales and may therefore misclassify some residential consumption. In 

particular, large apartment buildings that are billed at commercial rates could be included unct:>: 

commercial sales.

Apartment buildings are listed as being part of the residential sector on Form EIA-176 for the 

natural gas survey. However, in some cases, natural gas utilities use the billing rate classifies-.! io 

for determining consumption by sector. Gas delivered to large apartment buildings that are 

billed under commercial tariff schedules would then be classified as commercial rather than 

residential sales.

Apartment buildings are explicitly excluded from the residential sector in the petroleum survey;:'. 

The respondents are instructed to include apartment building consumption of fuel oil in the 

commercial sector.

Farm homes are a second type of housing unit that is difficult to handle properly in the supply 

surveys. The electricity survey in particular is likely to have difficulty with farms. The survey 

will measure all sales to farms, but sales for the farm house and for other farm operations will 

not be distinguished in all cases. On a farm, some energy is consumed in the farm house for 

household purposes, while other energy is consumed for farm operations. The later 

consumption should be counted in the agriculture sector (as part of industry) while the former 

is part of residential consumption.

A farm family that uses electricity for farm buildings and other farm operations, as well as for 

their house, may receive only one bill from the electric utility. The utility would not be able t 

separate out consumption that was for residential purposes from that for agricultural purpose-,, 

Therefore, the total amount of consumption for the farm is likely to be assigned either to 

residential or to industry, depending upon how the farm is listed, in their accounts. Neither 

assignment will give the correct amount of residential consumption.

Sales to farms are included in a separate category on the fuel oil and kerosene forms. Becaus 

this category contains multisector consumption (farm home use residential and farm operation 

use industrial or agriculture), this separate category does not help in making the proper 

assignment of this consumption. However, because of the separate category, we can identify 

that the farm consumption is not assigned to the residential secior for the supply surveys.

RECS does not identify farm homes per se, but it does identify :io;rnes that use energy for ;;orrH. 

farm operations. With this information, it is possible to estimate what portion of the energy is

Energy Consumption by End-Use Sectc' 

18 Energy Information Administration
used for residential purposes and how much for agricultural. REGS thus attempts to include 

only the consumption associated with farm homes that is for residential purposes. Based on the 

RECS, it appears that this issue is primarily a problem only for electricity.

'%£' ^ Consumption • by & Fuel Type 9 a

In the following sections, the total consumption of energy for each fuel type as measured by the 

consumption and supply surveys will be compared and discussed.

Electricity

The EIA supply survey for electricity includes vacant and second homes, which comprise about 

8 percent of the housing stock. The supply survey also includes consumption from seasonal and 

migratory housing units. These differences between the supply and consumption surveys would, 

by themselves, lead to a higher consumption level in the supply survey.

On the other hand, RECS includes some residential consumption that is not included in the 

supply survey-consumption in farm homes, in private homes on military bases, and some large 

apartment buildings. Electricity consumption in farm houses may not be listed under residential 

consumption in all cases in the supply survey. Consumption on military bases is not included in 

the supply survey.

There is no a priori basis for determining whether the supply or consumption survey will give a 

higher estimate of electricity use for the residential sector. If the apartments that are included 

in RECS, but not the supply survey, have a higher tota! consumption than the second and 

migratory homes, which are included in the supply survey but not RECS, then RECS will show 

a higher use for electricity. RECS electricity consumption is less than the supply values after 

1982 (with the differences for 1984 and 1987 being statistically significant at the 95-percent 

confidence level), but not for earlier years (Table 2). The differences between RECS and the 

supply survey are not statistically significant for 1978, 1980, and 1982.

The number of seasonal and migratory homes, and vacant and second homes, surged after 1982.

The 1985 American Housing Survey estimates an increase of 72 percent in migratory and

seasonal units, 50 percent in second homes, and 10 percent for vacant homes over the two-year 

ftp; period from 1983 to 1985.7 Consequently, these types of housing, which are the major difference

between REGS and the supply survey were probably more significant for 1984 and 1987 than 

lia for earlier years.

7American Housing Survey for the,United States in 1985, U.S. Department of Census, HS-150-85, 

(Washington, D.C., 1989)

Energy Consumption by End-Use Sector

Energy Information Administration 19
used for residential purposes and how much for agricultural. !.-VSC"3 thus attempts to include 

only the consumption associated with farm homes that is for reside :n:al purposes. Based on thf; 

RECS, it appears that this issue is primarily a problem only i'o-: : electricity.

In the following sections, the total consumption of energy for each fuel type as measured by the 

consumption and supply surveys; will be compared and discussed.

Electricity

The EIA supply survey for electricity includes vacant and second homes, which comprise about 

8 percent of the housing stock. The supply survey also includes consumption from seasonal and 

migratory housing units. These differences between the supply an<. consumption surveys would, 

by themselves, lead to a higher consumption level in the supply survey.

On the other hand, RECS includes some residential consumption that is not included in the 

supply survey-consumption in farm homes, in private homes on military bases, and some large 

apartment buildings. Electricity consumption in farm houses may cot be listed under residential 

consumption in all cases in the supply survey. Consumption on military bases is not included in. 

the supply survey.

There is no a priori basis for determining whether the supply or consumption survey will give a 

higher estimate of electricity use for the residential sector. If the apartments that are included 

in RECS, but not the supply survey, have a higher total consumption than the second and 

migratory homes, which are included in the supply survey but not RECS, then RECS will show 

a higher use for electricity. "RECS electricity consumption is less than the supply values after 

1982 (with the differences for 1.984 and 1987 being statistically significant at the 95-percent 

confidence level), but not for earlier years (Table 2). The dilicrerces between RECS and the 

supply survey are not statistically significant lor 1978, 1980, and 1982,

The number of seasonal and migratory homes, and vacant and sect met homes, surged after 1982, 

The 1985 American Housing Survey estimates an increase of 72 percent in migratory and 

seasonal units, 50 percent in second homes, and 10 percent for vacant homes over the two-year 

period from 1983 to 1985. 7 Consequently, these types of housing, which are the major difference:: 

between RECS and the supply survey were probably more significant for 1984 and 1987 than 

for earlier years.

7American Housing Survey for ihe United_States_in_J_985, U.S. Department of Census, HS-15G-85. 

(Washington, D.C., 1989)

Energy Consumption by End-Use SSR^C?

Energy Information Administration lii
Natural Gas

The types of homes that are not included in RECS-second homes and migratory housing-are 

less likely to be serviced by natural gas companies than are primary housing units. Vacation and 

migratory homes tend to be located in areas where there is no natural gas available. The 

housing units included in RECS that may not be fully counted in the supply survey include 

homes on military bases, farm homes, and some apartment buildings. Farm homes and houses 

on military bases add a very small amount to the RECS consumption; the approximate number 

of farm homes using natural gas is 0.3 million.

Table 2. Residential Electricity Consumption and Supply

1978 1980 1982 1984 1987

RECS Consumption

(mttften kilowatthours) 724 721 710 728 808

I . '

EIA Supply Data , , 

million kilowatthours) 674 717 730 778 850

Supply data as 

Percent of RECS 93.1% 99.4% 102.8% 106.9%* 105.2%*

One RSE 

(RECS sampling error) 4.3% 1.9% 2.9% 2.6% 1.7%

*Statistically different from 100% using 2 standard errors.

Source: Residential Energy Consumption Survey: Consumption and Expenditures, 

DOE/EIA-0321/1, various years. Supply data: State Energy Data Report, Consumption 

Estimates 1960-1987, DOE/EIA-0214(87). The data for 1978 through 1982 were 

collected on Form EIA-826, and data for 1984 and 1987 were collected on Form EIA861. , ,._ . /-. r ',.- -' ,''

Based on the known differences in the coverage of the two surveys, the difference between the 

natural gas use estimates from the supply and consumption surveys will depend on the number 

of apartments not included in the supply survey. An examination of the results from the two 

surveys shows that RECS has higher consumption estimates than does the EIA supply survey in 

all years (Table 3). However, the differences are statistically significant at the 95-percent

*~ * * -^ -"*. <*.. . -i r^o _ ^.i -100^ 

CU1111UC1JCC iOVCl UlUj iAJl JL.//O uuu JLVO,.

An EIA study has compared the two sets of data and concluded that much of the difference 

can be attributed to the exclusion of large apartment buildings from the EIA supply data; a

Energy Consumption by End-Use Sector 

20 Energy Information Administration
The types of homes that arc not included in RECS-second homes and migratory housing-arc 

less likely to be serviced by natural gas companies than are primary housing units. Vacation ?.i 

migratory homes tend to be located in areas where there is no natural gas available. The 

housing units included in RECS that may not be fully counted in the supply survey include 

homes on military bases, farm homes, and some apartment buildings. Farm homes and house;; 

on military bases add a very small amount to the RECS consumption; the approximate number 

of farm homes using natural gas is 0.3 million.

Table 2. Residential Electricity Consumption and Supply

1978 1980 1982 1984 1987

RECS Consumption

{rfrfrrten kilowatthours) 724 721 710 728 808

I

EIA Supply Data 

V^ (million kilowatthours) 674 717 730 778 850

Supply data as

Percent of RECS 93.1% 99.4% 102.8% 106.9%* 105.2%*

One RSE

(RECS sampling error) 4.3% 1.9% 2.9% 2.6% 1.7%

*Statistical!y different from 100% using 2 standard errors.

Source: Residential Energy Consumption Survey: Consumption and Expenditures, 

DOE/EIA-0321/1, various years. Supply data: Sfafe Energy Data Report, Consumption 

Estimates 1960-1987, DOE/EIA-0214(87). The data for 1978 through 1982 were 

collected on Form EIA-826, and data for 1984 and 1987 were collected on Form EIA861.

Based on the known differences in the coverage of the two surveys, the difference between the 

natural gas use estimate?; from the supply and consumption surveys will depend on the number 

of apartments not included in the supply survey. An examination of the results from the two 

surveys shows that RECS has higher consumption estimates than does the EIA supply survey b 

all years (Table 3). However, the differences are statistically significant at the 95-percent

An EIA study has compared the two sets of data and concluded that much of the difference 

can be attributed to the exclusion of large apartment buildings rrom the EIA supply data; a

Energy Consumplion by End-Use Secto/ 

20 Energy Information Administration
small part of the difference could also be attributed to a difference in the months covered.8 

(The supply survey is based on a calendar year, while RECS up through 1984 has been based 

on a 12-month period spanning a full winter April 1 of the first year through the end of March 

for the next year; for 1987, the RECS is based on the calendar year.)

Tabie 3. Residential Natural Gas Consumption and Supply

1978 1980 1982 1984 1987

RECS Consumption 

(billion cubic feet)

EIA Supply Data 

(billion cubic feet)

Supply Data as a 

Percent of RECS

One RSE 

(RECS sampling error)

5,461 4,840 4,680 4,830 4,687 

4,903 4,752 4,633 4,555 4,315 

89.8%* 98.2% 99.0% 94.3% 92.1%* 

5.5% 3.8% 3.9% 3.3% 3.4%

*Statistically different from 100% using 2 standard errors.

Source: Residential Energy Consumption Survey: Consumption and Expenditures, 

DOE/EIA-0321/1, various years. Supply data: Sfafe Energy Data Report, Consumption 

Estimates 1960-1987, DOE/EIA-0214(87). The supply data are collected on Form EIA176.

Fuel Oil

The biggest difference between RECS and the petroleum supply survey is the exclusion of 

apartment buildings and farm homes from the residential sector from the supply survey. These 

units comprise about 16 percent of the total housing stock. The secondary and migratory 

homes, which are excluded from RECS, comprise a smaller portion of the total housing stock.

Since the petroleum survey covers a smaller portion of the residential sector, it would be 

expected to have lower consumption estimates than RECS. This expectation is weakly 

supported in the data (Table 4). (The expectation is more strongly supported when the data 

are analyzed at the Census Division level.) In all but one year, the RECS estimate of total 

consumption is higher than the supply survey data. However, the difference is statistically

BAn Assessment of the Quality of Selected EIA Data Series: Energy Consumption Data, DOE-EIA-0292(85), 

April 1986, pp. 63-72.

Energy Consumption by End-Use Sector 

Energy Information Administration 21
small part of the difference could also be attributed to a difference in the months covered.8 

(The supply survey is based on. a calendar year, while RECS up through 1984 has been based 

on a 12-month period spanning a full winter April 1 of the first year through the end of March 

for the next year; for 1987, the RECS is based on the calendar year.)

Table 3, Residential Natural Gas Consumption -snd Supply

1978 1980 1982 1984 1987

RECS Consumption 

(billion cubic feet) 5,461 4,840 4,680 4,830 4,687

EIA Supply Data 

(billion cubic feet) 4,903 4,752 4,633 4,555 4,315

Supply Data as a 

Percent of RECS 89.8%" 98.2% 99.0% 94.3% 92.1%*

One RSE 

(RECS sampling error) 5.5% 3.8% 3.9% 3.3% 3.4%

*Statistically different from 100% using 2 standard errors.

Source: Residential Energy Consumption Survey: Consumption and Expenditures, 

DOE/EIA-0321/1, various years. Supply data: State Energy Data Report, Consumption 

Estimates 1960-1987, DOE/EIA-0214(87). The supply data are collected on Form EIA176.

Fuel Oil

The biggest difference between RECS and the petroleum supply survey is the exclusion of 

apartment buildings and farm homes from the residential sector from the supply survey. These 

units comprise about 16 percent of the total housing stock. The secondary and migratory 

homes, which are excluded from RECS, comprise a smaller portion of the total housing stock

Since the petroleum survey covers a smaller portion of the residential sector, it would be 

expected to have lower consumption estimates than RECS. This expectation is weakly 

supported in the data (Table 4). (The expectation is more strongly supported when the data 

are analyzed at the Census Division level.) In all but one year, the RECS estimate of total 

consumption is higher than the supply survey data. However, the difference is statistically

*An Assessment of the. Qualify' of Selected EIA Data Series: Energy Consumption Data, DOE-EIA-0292(8:P) 

April 1986, pp. 63-72.

Energy Consumption by End-Use Sector

Energy information Administration '.'."',
significant only for 1984 at the 95-percent confidence level. (If the standard error associated 

with the petroleum supply survey were included in the standard error for the comparison in 

Table 4, the standard error for the comparison would be somewhat larger and none of the 

differences would be statistically significant at the 95-percent confidence level.)

Table 4. Residential Fuel Oil Consumption and Supply

1978 1980 1982 1984 1987

RECS Consumption

(million gallons) 15,802 11,220 8,230 9,080 8,850

ElA Supply Data

(million gallons) 15,204 10,290 8,274 7,602 8,106

Supply Data as a

Percent of REGS 96.2% 91.7% 100.5% 83.7%* 91.6%

One RSE 

(REGS Sampling Error) 7.6% 5.7% 5.8% 5.4% 5.4%

*Statistically different from 100% using 2 standard errors (based only on REGS 

sampling error; the sampling error from the petroleum survey has not been included).

Source: Residential Energy Consumption Survey: Consumption and Expenditures, 

DOE/EIA-0321/1, various years. Supply data: Sfafe Energy Data Report, Consumption 

Estimates 1960-1987, DOE/EIA-0214(87); data from Form EIA-821.

Considering the 1987 data, if the supply data from EIA-821 were increased by 16 percent (the 

number of households in apartments as measured by RECS) and the RECS data increased by 8 

percent (cited above as the proportion of secondary housing) to account for the missing 

"housing stock," the supply data as a percent of RECS would be 98.4 percent-very close 

agreement.

Energy Consumption by End-Use Sector 

22 Energy information Administration
significant only for 1984 at I he 95-percent confidence level (If the standard error associate 

with the petroleum supply :;urvey were included in the standard error for the comparison is 

Table 4, the standard error for the comparison would be somewhat larger and none of the 

differences would be statistically significant at the 95-percent confidence level.)

Table 4. Residential Fuel Oil Consumption ard Supply

1978 1980 1982 1984 1987

REGS Consumption

(million gallons) 15,802 11,220 8,230 9,080 8,850

EIA Supply Data

(million gallon:;) 15,204 10,290 8,274 7,602 8,106

Supply Data as &

Percent of RECS 96.2% 91.7% 100.5% 83.7%* 91.6%

One RSE 

(RECS Sampling Error) 7.6% 5.7% 5.8% 5.4% 5.4%

*Statistically different from 100% using 2 standard errors (based only on RECS 

sampling error; the sampling error from the petroleum survey has not been included).

Source: Residential Energy Consumption Survey: Consumption and Expenditures, 

DOE/EIA-0321/1, various years. Supply data: State Energy Data Report, Consumption 

Estimates 1960-1987, DOE/EIA-0214(87); data from Form EIA-821.

Considering the 1987 data,, if the supply data from EIA-821 were increased by 16 percent (i.h;: 

number of households >n. apartments as measured by RECS) and the RECS data increased by 

percent (cited above as the proportion of secondary housing) to account for the missing 

"housing stock," the supply data as a percent of RECS would be 98.4 percent-very close 

agreement.

Energy Consumption by End-Use Sector 

22 Energy Information Administration
The commercial sector, as defined economically, consists of business establishments that are not 

engaged in manufacturing or other type of industrial activity (agriculture, mining or 

construction).9 These establishments include hotels, motels, restaurants, wholesale businesses, 

retail stores, laundries, and other service enterprises; office buildings; religious and nonprofit 

organizations; health, social, and educational institutions; and Federal, State, and local 

governments. Street lights, pumps, bridges, and public services are also included. Energy in the 

commercial sector is generally used for the same purposes as in the residential sector: space 

heating and cooling, cooking, water heating, and electrical equipment and appliance operation 

including lighting. However, the relative amounts of energy used for these purposes can vary 

substantially from use in the residential sector, depending on the specific activities of the 

commercial consumer.

The consumption survey, the Nonresidential Buildings Energy Consumption Survey (NBECS), 

and the various supply surveys produce measures of energy consumed by commercial customers. 

But the types of activities included as being in the commercial sector by these surveys vary, and 

no survey covers precisely the commercial sector as defined economically.

Sector Coverage by Survey Type 

Consumption Survey

The NBECS estimates the energy consumed in buildings in which the activities are 

predominantly (i.e., using over one-half the floorspace) commercial. The survey measures only 

energy consumption that takes place in buildings. Commercial activities that do not take place 

in buildings, such as street lights, bridge operations, and lights in parking lots, are not included 

in the NBECS consumption data. The NBECS sample frame includes all buildings in which 

over half the floorspace is devoted to commercial activities and (for the most recent 1986 

survey) that have floorspace greater than 1,000 square feet.

The NBECS is based on a sample of such buildings. The sample includes buildings that are 

occupied by industrial establishments that use the building primarily for commercial activities. 

For example, a building occupied by a manufacturing company that uses it as an office building

definition is based on the Standard Industrial Classification (SIC), which is a comprehensive set

Of ratf><mrtfl<! rtfMwMnrvo^ Vnr tfco <~<WTM ^,f \ ,»"„,--, „„»„„,,<. nr.J T>,.J, — » c-,- «1«-.:c.:_ „ »,----•.- , .-„ -_».».u_v. — „--»-

-~ ~ - o^*- .j ^v. *..-j Lt*~*A tjj ..A**. ^i*i~v vyi A» j.*^l*lt £,^111^*11 1 tAltl* ijtA^itl^i *.\Jl l*l<4OOlk> ***£ tyuotli^oo ^o KAUliOAlltLl/illO.

For the commercial sector, the term business is used broadly to include government agencies, religious 

organizations and other nonprofit corporations. The SIC categories are described in Office of Management 

and Budget, "Standard Industrial Classification Manual, 1987" (Washington, D.C.).

Energy Consumption by End-Use Sector

Energy Information Administration 23
The commercial sector, as defined economically, consists of business establishments that are .act 

engaged in manufacturing or other type of industrial activity (agriculture, mining or 

construction).9 These establishments include hotels, motels, restaurants, wholesale businesses, 

retail stores, laundries, and other service enterprises; office buildings; religious and nonprofit 

organizations; health, social, and educational institutions; and Federal, State, and local 

governments. Street lights, pumps, bridges, and public services are also included. Energy in the 

commercial sector is generally used for the same purposes as in the residential sector: space 

heating and cooling, cooking, water heating, and electrical equipment and appliance operation 

including lighting. However, the relative amounts of energy used for these purposes can vary 

substantially from use in the residential sector, depending on the specific activities of the 

commercial consumer.

The consumption survey, the Nonresidential Buildings Energy Consumption Survey (NBECS), 

and the various supply surveys produce measures of energy consumed by commercial customers. 

But the types of activities included as being in the commercial sector by these surveys vary, and 

no survey covers precisely the commercial sector as defined economically.

Sector Coverage by Survey Type 

Consumption Survey

The NBECS estimates the energy consumed in buildings in which the activities are 

predominantly (i.e., using over one-half the floorspace) commercial The survey measures only 

energy consumption that takes place in buildings. Commercial activities that do not take place 

in buildings, such as street lights, bridge operations, and lights in parking lots, are not included 

in the NBECS consumption data. The NBECS sample frame includes all buildings in which

||; over half the floorspace is devoted to commercial activities and (for I he most recent 1986

if: survey) that have floorspace greater than 1,000 square feet.

The NBECS is based on a sample of such buildings. The sample includes buildings that are 

occupied by industrial establishments that use the building primarily for commercial activities, 

For example, a building occupied by a manufacturing company that uses it as an office building

9This definition is based on the Standard Industrial Classification (SI 1 ,"), which is a comprehensive :;ci.

of r-afpnr.r'"=c H^,,^i^»,^^ t,,. . T, „ ,r»«v~,-> C f ~* *"~ -•" — "-* ~ - •' T) -- J -^~ |' ; ' :i" : -~ <----'--••- ----'<••>

----- Q — ..-— ~j .. . —- ^, £^ ~ . ^ j O.B-. —**. .**-.. w i iii.JijL^^.n^tik »,, *!•** U t*^l£,*^ 1. ., I • - , * . o,./ > S.J Lit fe C1 ttOi **^OO WiJ LLAU'fB^lllLi'L'l! l^

For the commercial sector, the term business is used broadly to induck government agencies, religious 

organizations and other nonprofit corporations. The SIC categories arc described in Office of Managemcni 

and Budget, "Standard Industrial Classification Manual, 1987" (Washington, D.C.).

Energy Consumption by End-Use Sector

Energy Information Administration 23
for managerial staff would be included in the NBECS sample.

A small amount of industrial consumption for manufacturing activities is included in NBECS, 

along with some residential consumption. A manufacturing establishment can be located in a 

building classified as commercial for the purposes of NBECS. The energy used by that company 

for manufacturing will be included in the NBECS consumption. Similarly, a building that is 

predominantly commercial but that also has some residential units will have the residential 

consumption included in the NBECS data. There are no data available on how much industrial 

and residential consumption are included in the NBECS figures.

On the other hand, NBECS will not capture the energy consumption of commercial 

establishments that are located in buildings not classified as commercial for the purposes of 

NBECS. Shops on the ground floor of an apartment building, or in a building that is primarily 

industrial, will not be covered in the NBECS sampling frame.

NBECS does not cover a small amount of consumption for other activities that are properly 

considered to be part of the commercial sector. Any activity that does not take place in a 

building, such as street or parking lot lighting or pumps and bridge operation, is -not included. 

(One small study estimated this consumption in the neighborhood of three percent of total 

commercial consumption.)10 The exclusion of buildings under 1,001 square feet in size 

eliminates some additional commercial consumption (estimated to be in the neighborhood of 2 

percent of the total)."

Because NBECS is based on a sample of buildings, it includes some residential and industrial 

consumption and fails to measure some commercial consumption. Alternative approaches to 

designing a sample for NBECS were considered, but none proved to be feasible. One 

possibility explored was to survey commercial establishments directly, but no list of commercial 

establishments could be located that had the information needed to draw a sample for energy 

consumption purposes. Further, a commercial establishment itself does not necessarily purchase 

energy (since the cost of energy may be included in the rent the establishment pays for leasing 

floorspace), so sampling establishments would not necessarily provide useful energy consumption 

data. A sample based on buildings has the advantage that a building is a natural unit for 

determining energy consumption. The building's characteristics and the purposes for which it is 

used are major determinants of the energy consumed in the building.

The initial NBECS was designed to cover all buildings that were not almost entirely residential. 

Since the first survey, the type of building covered by the survey has gradually changed. After 

the report on the 1979 building characteristics was issued, industrial buildings were dropped 

from the sample base for the 1979 reports on consumption and expenditures. Further 

restrictions were imposed on the 1986 sample by removing buildings that (1) had commercial 

activity in them but were primarily (more than 50 percent of floorspace) residential or industrial,

on a Muuy ui * icw uiuiiics iii the Northwest Region. See Energy Ir.fcrrr.stier. Adrr!!ri?tr?">". 

"Nonresidential/Commercial Buildings Energy Consumption Survey Feasibility Study," Vol I, 1982.

"Eugene M Burns, "The Edge of NBECS, Part 1: Little Buildings," NBECS Technical Note, Number 

65, April 5, 1988.

Energy Consumption by End-Use Sector 

24 Energy Information Administration
for managerial staff would be included in the NBECS sample,

A small amount of industrial consumption for manufacturing activities is included in NBECS, 

along with some residential consumption. A manufacturing establishment can be located in a 

building classified as commercial for the purposes of NBECS. The energy used by that company 

for manufacturing will be included in the NBECS consumption. Similarly, a building that is 

predominantly commercial but that also has some residential units; will have the residential 

consumption included in the NBECS data. There are no data available on how much industrial. 

and residential consumption are included in the NBECS figures.

On the other hand, NBECS will not capture the energy consumption of commercial 

establishments that are located in buildings not classified as commercial for the purposes of 

NBECS. Shops on the ground floor of an apartment building, or in a building that is primarily 

industrial, will not be covered in the NBECS sampling frame.

NBECS does not cover a small amount of consumption for other activities that are properly 

considered to be part of the commercial sector. Any activity tha(: does not take place in a 

building, such as street or parking lot lighting or pumps and bridge operation, is -not included 

(One small study estimated this consumption in the neighborhood of three percent of total 

commercial consumption.) 10 The exclusion of buildings under 1,001 square feet in size 

eliminates some additional commercial consumption (estimated to be in the neighborhood of 2 

percent of the total).11

Because NBECS is based on a sample of buildings, it includes some residential and industrial 

consumption and fails to measure some commercial consumption .Alternative approaches to 

designing a sample for NBECS were considered, but none proved to be feasible. One 

possibility explored was to survey commercial establishments directly, but no list of commercial 

establishments could be located that had the information needed to draw a sample for energy 

consumption purposes. Further, a commercial establishment itself does not necessarily purchase 

energy (since the cost of energy may be included in the rent, the establishment pays for leasing 

floorspace), so sampling establishments would not necessarily provide useful energy consumption 

data. A sample based on buildings has the advantage that a building is a natural unit for 

determining energy consumption. The building's characteristics and the purposes for which, it i<; 

used are major determinants of the energy consumed in the building.

The initial NBECS was designed to cover all buildings that were not almost entirely residential. 

Since the first survey, the type of building covered by the survey has gradually changed. After 

the report on the 1979 building characteristics was issued, industrial buildings were dropped 

from the sample base for the 1979 reports on consumption and expenditures. Further 

restrictions were imposeci on the 1986 sample by removing buildings that (1) had commercial 

activity in them but were primarily (more than 50 percent of floorspace) residential or industri?-..

"r>aseu un a siuu_y uf a iV/* uuliiux> iii tuC i'crtli'rvc:;i "cgic,",. Cc; Energy "

"Nonresidential/Commercial Buildings Energy Consumption Survey Feasibility Study," Vol I, 1982.

"Eugene M Burns, "The Edge of NBECS, Part 1: Little Buildings," NBECS Technical Note, Nurntx 

65, April 5, 1988.

Energy Consumption by End-Use Sector 

24 Energy Information Administration
or (2) had less than 1,001 square feet of floorspace.

Supply Surveys

For the supply surveys, the activities that are included in the commercial sector vary by the type 

of fuel. The situation for electricity is complicated because there are three categories that 

include commercial sales. One of these categories, "other," includes sales to transportation and 

possibly other end-use sectors as well as commercial. Another of the three categories is 

"commercial sales," which is likely to include consumption for some sales billed at commercial 

rates by customers in other sectors.

For natural gas, the supply survey provides an explicit definition of the commercial sector, which 

is slightly broader in scope than the economic definition. Natural gas utilities are asked to 

include the consumption of agriculture, fishery, and forestry establishments as part of 

commercial consumption. Some apartment building and industrial consumption is also included 

because these customers are billed at commercial rates. The fuel oil supply survey includes 

apartment buildings in the commercial sector.

It is likely that some portion of the energy measured in NBECS that is consumed by industrial 

establishments engaged in commercial-related activities in buildings may also be included in the 

various supply surveys. In many cases, this consumption takes place in buildings that are leased 

by the industrial companies and may appear as commercial accounts to the utilities. This 

consumption would then also be included as commercial consumption by the supply survey. 

There are no data that would enable us to determine how much overlap there might be in these 

cases.

Energy Consumption by Fuel Type

The amount of each fuel measured by the consumption and supply surveys for the commercial 

sector is discussed in the following sections. Differences between the two surveys are discussed 

in light of the preceding discussion of differences in the universe of coverage.

Electricity

The current form for collecting annual electricity sales, Form EIA-861, contains five categories 

for listing end-use sales. Of these five, three include sales to the commercial sector as defined 

above: commercial sales, public street and highway lighting, and "other." (The remaining 

categories are residential sales and industrial sales.) The "other" category includes sales to

municipalities or divisions and agencies of Federal or State governments. Some of the "other" 

category is clearly commercial-a substantial portion of the sales to governmeHt is likely to be

Energy Consumption by End-Use Sector

Energy Information Administration 25
or (2) had less than 1,001 square feet of floorspace.

Supply Surveys

For the supply surveys, the activities that are included in the commercial sector vary by the type 

of fuel. The situation for electricity is complicated because there a e three categories that 

include commercial sales. One of these categories, "other," includes sales to transportation and 

possibly other end-use sectors as well as commercial. Another of the three categories is 

"commercial sales," which is likely to include consumption for some sales billed at commercial 

rates by customers in other sectors.

For natural gas, the supply survey provides an explicit definition of chc commercial sector, which 

is slightly broader in scope than the economic definition. Natural gas utilities are asked to 

include the consumption of agriculture, fishery, and forestry establishments as part of 

commercial consumption. Some apartment building and industrial consumption is also included 

because these customers are billed at commercial rates. The fuel o'<\ supply survey includes 

apartment buildings in the commercial sector.

It is likely that some portion of the energy measured in NBECS that is consumed by industrial 

establishments engaged in commercial-related activities in buildings may also be included in the 

various supply surveys. In many cases, this consumption takes place in buildings that are leased 

by the industrial companies and may appear as commercial accounts to the utilities. This 

consumption would then also be included as commercial consumption by the supply survey. 

There are no data that would enable us to determine how much overlap there might be in these: 

cases.

The amount of each fuel measured, by the consumption and supply surveys for the commercial 

sector is discussed in the following sections. Differences between the two surveys are discussed 

in light of the preceding discussion of differences in the universe of coverage.

Electricity

The current form for collecting annual electricity sales, Form EIA-861. contains five categories 

for listing end-use sales. Of these five, three include sales to the commercial sector as defined 

above: commercial sales, public street and highway lighting, and "other." (The remaining 

categories are residential sales and industrial sales.) The "other" category includes sales to

municipalities or divisions and agencies of Federal or State governments. Some of the "other" 

category is clearly commerdal-a substantial portion of the sales to ^overnmeHt is likely to be

Energy Consumption by End-Use Secto? 

Energy Information Administration
iiggagaE-saassiSfflBBs^

commercial-while other is transportation, and some can't be categorized without further 

information. The "commercial sales" category is likely to include most sales at commercial rates 

not included in the "other" or "lighting" categories.

The "public street and highway lighting" category is a commercial use of electricity that is 

included in the supply survey but not included in NBECS. The "commercial sales" category is 

likely to consist of commercial accounts that would have a high degree of overlap with NBECS 

coverage, apart 'from misclassifications of high consumption apartment buildings and relatively 

low-consuming industrial establishment which are billed at commercial rates. The "other" 

category will include consumption by governments that takes place in buildings, which will also 

be included in NBECS. However, the remaining portion of the "other" category will not be 

included in NBECS, and not all of it is commercial. There are no data available that can be 

used to distinguish government, other commercial, and the remainder.

Because of the complexity of the data, it is difficult to compare the supply data with NBECS. 

There are alternative combinations of the data from the supply survey that can be compared to 

NBECS. Two variations of the supply data are compared here with NBECS. The first is the 

value for commercial consumption obtained from the State Energy Data Report (SEDR). SEDR 

sums electric sales for public street and highway lighting, commercial sales, and other less an 

estimated amount of sales to the transportation sector. This number for consumption might be 

expected to be higher than the NBECS value, since it includes street and highway lighting that 

aren't included in NBECS. However, the inclusion of misclassified residential and industrial 

customers, and the omission of commercial customers billed at noncommercial rates, will have an 

unknown effect on the comparison.

The SEDR commercial consumption estimate is slightly lower than the NBECS estimate for 

1979 and 1983, and slightly higher for 1986 (Table 5). The relative drop in NBECS 

consumption in 1986 is consistent with the reduced number of buildings covered by NBECS in 

1986. None of the differences are statistically significant at the 95-percent confidence level, so 

these two measures are not statistically different.

A second comparison is with the commercial sales figures alone from the supply survey with 

NBECS (Table 5). In this case, the supply figure is substantially lower than NBECS, with the 

difference being statistically significant for 1979 and 1983. It would appear that enough 

government building consumption is included in the "other" sales category so that the 

"commercial sales" category for the supply survey is not comparable with NBECS.

Natural Gas

The delivery data for natural gas cover more economic units of activity than does NBECS: 

agriculture, fishery, and forestry establishments are included in the supply survey but not in 

NBECS. The NBECS estimates of commercial natural gas consumption are lower than the 

supply estimates coiieiiicu on JTUHU EIA-176 iui tac LHHJU y^aia tlic NIjIZCG liao uCCil 

conducted (Table 6). The differences are statistically significant at the 95-percent confidence 

level for 1979 and 1986. The difference between the two was larger in 1986 when the NBECS

Energy Consumption by End-Use Sector 

26 Energy Information Administration
commercial while other is !.rari.:;portaiiort, and some can':: :>. 

information. The "commercial sales" category is likely to j^i 

not included in the "other" cr "lighting" categories.

•<:.'. ;fs>:dzed without further

a; most sales at commercial rat

The "public street and highway lighting" category is a commercia 

included in the supply survey but not included in NBECS, The 

likely to consist of commercial accounts that would have a High 

coverage, apart 'from misclassifications of high consumption apar 

low-consuming industrial establishment which are billed at com 

category will include consumption by governments that takes pl 

be included in NBECS. However, the remaining portion of the 

included in NBECS, and. not all of it is commercial. There aio: 

used to distinguish government, other commercial, and the rema

l use of electricity that is 

"commercial sales" category is 

degree of overlap with NBECS' 

tment buildings and relatively 

ercial rates. The "other" 

ce in buildings, which will also 

"other" category will not be 

no data available that can he 

inder.

Because of the complexity of the data, it is difficult to compare the supply data with NBECS. 

There are alternative combinations of the data from the supply survey that can be compared to 

NBECS. Two variations of the supply data are compared here with NBECS. The first is r.lie 

value for commercial consumption obtained from the Slate Energy Data Report (SEDR). SED'f 

sums electric sales for public street and highway lighting, commercial sales, and other less an 

estimated amount of sales to the transportation sector. This number for consumption might '.K; 

expected to be higher than the NBECS value, since it includes street and highway lighting that 

aren't included in NBECS. However, the inclusion of misclassilicd residential and industrial 

customers, and the omission, of commercial customers billed at noncommercial rates, will have ;: 

unknown effect on the comparison.

The SEDR commercial consumption estimate is slightly lower i.iars the NBECS estimate for 

1979 and 1983, and slightly higher for 1986 (Table 5). The reblive drop in NBECS 

consumption in 1986 is consistent with the reduced number of -Holdings covered by NBECS in 

1986. None of the differences are statistically significant at the 9.5-percent confidence level, ; : ,c 

these two measures are not statistically different.

A second comparison is with the commercial sales figures alone from the supply survey with 

NBECS (Table 5). In this case, the supply figure is substantially lower than NBECS, with the 

difference being statistically significant for 1979 and 1983. U would appear that enough 

government building consumption is included in the "other" sab;.?.; category so that the 

"commercial sales" category for the supply survey is not comparable with NBECS.

The delivery data for natural gas cover more economic unks oi activity than does NBECS: 

agriculture, fishery, and forestry establishments are included in .he supply survey but not in 

NBECS. The NBECS estimates of commercial natural gas consumption are lower than the 

supply estimates CUHCCLCU uu ;:uuu _i_j./-i.-1 /o iui uiu uu^- vi..ci.- > >.u-^ I<UU.LJWU> nao u^^m 

conducted (Table 6). The differences are statistically sigrm'ican. c.i the 95-percent confidence 

level for 1979 and 1986.. The difference between the two -/a,1; areer in 1986 when the NBEC

26

Energy Consumption by End-Ls^; >at;< >r 

Energy Information
estimate no longer included some apartment buildings and some small buildings (smaller than 

1,001 square feet).12

Tab!© 5. Commercial Electricity Consumption and Supply

1979 1983 1986

N8ECS Consumption 

(billion kilowatthours)

SEDR Commercial Consumption 

(billion kilowatthours)

SEDR as Percent of NBECS

Commercial Sales from Supply 

Survey (billion kilowatthours)

Commercial Sales as 

Percent of NBECS

One RSE 

(based on NBECS 

sample variance)

589 656 701

543 621 721 

92.2% 94.7% 102.9%

473

80.3%*

7.0%

544

82.9%*

8.3%

641

91.4%

5.4%

Note: The 1979 and 1983 NBECS included some smaller buildings (less than 

1,001 square feet) and some apartment buildings that were not included in 1986. 

*Statistically different from 100% using 2 standard errors.

Sources: NBECS: Commercial Buildings Consumption and Expenditures 1986, 

•DOE/EIA-0318(86); 1979 and 1983 data are from Annual Energy Review 1986, 

DOE/EIA-0394-(86), Table 30. NBECS data for 1979 in the AER are revised from the 

data originally published. Supply Data: State Energy Data Report 1960-1987, 

DOE/EIA-Q214(87) for SEDR commercial consumption; Annual Energy Review 1988, 

DOE/EIA-0384(88), Table 89 for-Commerciat Sales. Supply data for 1986 are from 

Form EIA-861, and earlier yeaiyfrim Form EIA-826

Presumably, an important factor in the difference between NBECS and the natural gas supply 

survey is the inclusion of agricultural consumption in the supply survey. However, there are no 

independent measures of natural gas consumption in this industry to check whether the 

differences between the supply and consumption survey estimates correspond to consumption in 

this industry.

12In the early NBECS, the coverage of small buildings was probably not complete so the term "some 

small buildings" has been used. See Eugene M. Burns, "The Edge of NBECS, Part 1: Little Buildings," 

NBECS Technical Note 65, April 5, 1988.

Energy Consumption by End-Use Sector 

Energy Information Administration 27
estimate no longer included, some apartment buildings and some small buildings (smaller than 

1,001 square feet). 12

Table 5. Commerces Electricity Consumption and Supply

NBECS Consumption 

(billion kilowatthours)

SEDR Commercial Consumption 

(billion kilowatthours)

SEDR as Percent of NBECS

Commercial Sales from Supply 

Survey (billion kilowatthours)

Commercial Sales as 

Percent of NBECS

1979 1983

589

473

656

544

1986

701

543 621 721 

92.2% 94.7% 102.9%

641

80.3%* 82.9%* 91.4%

One RSE 

(based on NBECS 

sample variance) 7.0% 8.3% 5.4%

Note: The 1979 and 1983 NBECS included some smaller buildings (less than 

1,001 square feet) and some apartment buildings that were not included in 1986.

*Statistically different from 100% using 2 standard errors.

Sources: NBECS: Commercial Buildings Consumption and Expenditures 1986, 

"DOE/EIA-0318(86); 1979 and 1983 data are from Annual Energy Review 1986, 

DOE/EIA-0394-(86), Table 30. NBECS data for 1979 in the AER are revised from the 

data originally published. Supply Data: State Energy Data Report 1960-1987, 

DOE/EIA-0214(87) for SEDR commercial consumption; Annual Energy Review 1988, 

DOE/EIA-0384(88), Table 89 for-Commerciai Sales. Supply data for 1986 are from 

Form EIA-861, and earlier yeai^frim Form EIA-826

Presumably, an important factor in the difference between NBECS and the natural gas supply 

survey is the inclusion of agricultural consumption in the supply survey. However, there are nc 

independent measures of natural gas consumption in this industry to check whether the 

differences between the supply and consumption survey estimates correspond to consumption in 

this industry.

12In the early NBECS, the coverage of small buildings was probably not complete so the term "some 

small buildings" has been used. See Eugene M. Burns, "The Edge of NBECS, Part 1: Little Buildings,,'1 

NBECS Technical Note 65, April 5, 1988.

Energy Consumption by End-Use Sector 

Energy Information Administration
Table 6. Commercial Natural Gas Consumption and Supply

1979 1983 1986

NBECS Consumption

(billion cubic feet) 2,270 2,160 1,674

El A Supply Data

(billion cubic feet) 2,786 2,433 2,318

Supply Data as a

Percent of NBECS 122.7%* 112.6% 138.0%*

One RSE 7.9% 8.2% 5.6% 

(based on NBECS 

sampling variance)

Note: The 1979 and 1983 NBECS included buildings smaller than 1,001 square 

feet and some apartments that were not included in 1986,

*Statistically different from 100% using 2 standard errors.

Source: NBECS: Commercial Buildings Consumption and Expenditures 1986, 

"DOE/EIA-0318(86); 1979 and 1983 data are from Annual Energy Review 1986, 

DOE/EIA-0394-(86), Table 30. NBECS data for 1979 in the AER are revised from the 

data originally published. The 1979 data in the AER were converted to physical 

units using 1,109 Btu per cubic foot. Supply Data: State Energy Data Report 1960- 

1987, DOE/EIA-0214(87), Table 14, (data from Form EIA-176).

Fuel Oil

As noted in the second chapter, fuel oil is the fuel most difficult to measure either by the 

supply or consumption approach. The EIA supply data include fuel oil delivered to apartment 

buildings that is not included in NBECS.

Total commercial fuel oil deliveries measured by NBECS are substantially lower than the values 

from the supply survey (Table 7). Indeed, the quantities measured in NBECS are about onehalf those measured by the supply survey.

The fuel oil supply data are so much larger than the consumption estimates that some reason 

not yet considered must be affecting the comparison between these data sources. One factor 

that may account for some part of the difference is that power plants located on campus type 

facilities are typically not included in NBECS because they are not considered to be commercial 

buildings. This consumption is likely to be included in the supply surveys as commercial. 

NBECS would measure the steam or electricity delivered to the NBECS buildings, but would

Energy Consumption by End-Use Sector 

28 Energy Information Administration
Table §, CommerefaS Natural Gas Consui/notsor: and Supply

1983 1986

NBECS Consumption

(billion cubic feet) 2,270 2,160 1,674

EIA Supply Data

(billion cubic feet) 2,786 2,433 2,318

Supply Data as a

Percent of NBECS 122.7%* 112.6% 138.0%*

One RSE 7 9% 8.2% 5.6% 

(based on NBECS 

sampling variance)

Note: The 1979 and 1983 NBECS included buildings smaller than 1,001 square 

feet and some apartments that were not included in 1986

*Statistically different from 100% using 2 standard errors.

Source: NBECS: Commercial Buildings Consumption and Expenditures 1986, 

•DOE/EIA-0318(86); 1979 and 1983 data are from Annual Energy Review 1986, 

DOE/E!A-0394-(86), Table 30. NBECS data for 1979 in the AER are revised from the 

data originally published. The 1979 data in the AER were converted to physical 

units using 1,109 Btu per cubic foot. Supply Data: State Energy Data Report 1960- 

1987, DOE/EIA-0214(87), Table 14, (data from Form EIA-'76).

Fuel Oil

As noted in the second chapter, fuel oil is the fuel most difficult to measure either by the 

supply or consumption approach. The EIA supply data inclm'e fuel oil delivered to apartrriec:. 

buildings that is not included in NBECS.

Total commercial fuel oil deliveries measured by NBECS are substantially lower than the v;:.lu: 

from the supply survey (Table 7). Indeed, the quantities measured in NBECS are about orx; 

half those measured by the supply survey.

The fuel oil supply data are so much larger than the consumption estimates that some reasor. 

not yet considered must be affecting the comparison between these data sources. One facto: 

that may account for some part of the difference is that power plants located on campus type: 

facilities are typically not included in NBECS because they arc not considered to be common" 1 . buildings. This consumption is likely to be included in the supply surveys as commercial, 

NBECS would measure the steam or electricity delivered to l'ic NBECS buildings, but wodr.i

Energy Consumption by End-U:=s Seo-or 

28 Energy Information Administrator;
not count the fuel used to produce the steam or electricity.13

Table 7. Commercial Fuel Oil and

1979 1983 1986

NBECS Consumption

(million gallons) 5,465 2,526 3,168

EIA Supply Data 

(million gallons) 8,148 6,930 6,216

Supply Data as a

Percent of NBECS 149.1%* 274.3%* 196.2%*

One RSE

(based on NBECS 8.9% 13.7% 8.6% 

Sampling Variance)

Note: The 1979 and 1983 NBECS included some smaller buildings (less than 

1,001 square feet) and some apartment buildings that were not included in 1986. 

Fuel oil includes distillate fuel oil, residual fuel oil and kerosene.

*Statisticatty different from 100% using 2 standard errors (based only on NBECS 

sampling error; the sampling error from the petroleum survey has not been included).

Source: NBECS data for 1986, NBECS: Commercial Buildings Consumption and 

Expenditures 1986, DOE/EIA-0318(86), 1979 and 1983 data are from "Annual Energy 

Review 1986," DOE/EIA-0394-(86), Table 30. NBECS data for 1979 in the AER are 

revised from the data originally published. The 1979 data in the AER were converted 

to physical units using 140.898 Btu per gallon. Supply Data: State Energy Data 

Report 1960-1987, DQE/EIA-Q214(87).

About 75 percent of the district heat counted in the 1986 NBECS was produced onsite by 

power plants that were part of a company facility. If we assume that this nonpurchased district 

heat was produced at 60 percent efficiency through the use of fuel oil, that would represent 

3,849 million gallons of fuel oil-an amount more than large enough to explain the difference 

between NBECS and the supply survey. Of course, other fuels such as coal and natural gas are 

also used to produce district heat, and there are no data available that can be used to 

determine how much of it is produced by fuel oil.

There are other reasons why NBECS could be short in its measurement of fuel oil consumption.

"A pilot study is oemg eonuuctea as part ot tne iy<sy ctuics to see now wen sucn central plant 

consumption can be measured, and to try to quantify how much such consumption contributes to the 

difference between supply-side and demand-side estimates. For multibuilding facilities that have central 

plants, consumption and production data by fuel type are being collected from the plants.

Energy Consumption by End-Us* Sector

Energy information Administration 29
not count the fuel used to produce the steam or electricity, 13

1979 1983 1986

NBECS Consumption

(million gallons) 5,465 2,526 3,168

EIA Supply Data

(million gallons) 0,148 6,930 6,216

Supply Data as a

Percent of NBECS 149.1%* 274.3%* 196.2%*

One RSE

(based on NBECS 8.9% 13.7% 8.6% 

Sampling Variance)

Note: The 1979 and 1983 NBECS included some smaller buildings (less than 

1,001 square feet) and some apartment buildings that were not included in 1986. 

Fuel oil includes distillate fuel oil, residua! fuel oil and kerosene.

*Statistically different from 100% using 2 standard errors (based only on NBECS 

sampling error; the sampling error from the petroleum survey has not been included).

Source: NBECS data for 1986, NBECS: Commercial Buildings Consumption and 

Expenditures 1986, DOE/EIA-0318(86), 1979 and 1983 data are from "Annual Energy 

Review 1986," DQE/E-IA-0394-(86), Table 30. NBECS data for 1979 in the AER are 

revised from the data originally published. The 1979 data in the AER were converted 

to physical units using 140.898 Btu per gallon. Supply Data: State Energy Data 

Report 1960-1987, D(5E/FIA-0214{87).

About 75 percent of the district heat counted in the 1986 NBECS was produced onsite by 

power plants that were part of a company facility. If we assume that this nonpurchased district 

heat was produced at 60 percent efficiency through the use of fue': oil, that would represent 

3,849 million gallons of fuel oii an amount more than large enough to explain the difference 

between NBECS and the supply survey. Of course, other fuels such as coal and natural gas are 

also used to produce district heat, and there are no data available that can be used to 

determine how much of it is produced by fuel oil.

There are other reasons why NBECS could be short in its measurement of fuel oil consumption.

"/\ pnoi stuay is oemg conuuoea as pan or tne iy»y Cbtus to see now wen. sucn central piaru 

consumption can be measured, and to try to quantify how much such consumption contributes to the 

difference between supply-side and demand-side estimates. For multibvilding facilities that have centrrd 

plants, consumption and production data by fuel type are being collected from the plants.

Energy Consumption by End-Uss Seeloir

Energy Information Administration ?.'.'.
The building representative who is interviewed for the survey may fail to list all the fuel oil 

suppliers in response to the survey questions. Also, a fuel oil dealer may not list all the 

deliveries to the building.

Energy Consumption by End-Use Sector 

30 Energy Information Administration
The building representative who is interviewed for the survey may fail to list all the fuel oil 

suppliers in response to the survey questions. Also, a fuel oil <\ealer may not list all the 

deliveries to the building.

Energy Consumption by End-Use Seel or 

30 Energy Information Administration
The industrial sector is much more diverse, and more complex in its energy use, than either the 

residential or commercial sector. It comprises manufacturing industries-which make up the 

largest part of the sector-along with mining, construction, agriculture, fisheries, and forestry. 

Establishments in the sector range from a steel mill, to a small farm, to a company assembling 

electronic components.

The principal uses for energy in this sector are powering manufacturing processes and carrying 

out other types of industrial activities. The energy used to space condition buildings (heating or 

cooling them), a major component of energy use in the residential and commercial sectors, is 

relatively unimportant for industry. Energy is used for a wide range of industrial processes, 

which use a large number of different types of equipment. Because of this diversity, it is 

difficult to measure the end uses of energy for industry.

It is even complex to determine how much energy is "consumed" by a manufacturing plant.14 

During the course of an industrial process, byproducts can be produced which are usable as a 

fuel. A boiler used in manufacturing can also cogenerate electricity which can either be 

consumed at the plant or sold back to a utility. Some energy sources are also used as raw 

material~or feedstock-input to a production process; the output of the process may be a fuel of 

another form or may no longer be usable as a fuel.

Comparing industrial energy consumption estimates from a survey of industrial users with data 

on energy supplied to industrial customers, must be done with these complexities of industrial 

energy use taken into consideration. The measure of energy consumption from a consumption 

survey that would most closely correspond with data from a supply survey would be total fuels 

purchased. However, care should also be taken to make sure that both types of survey are 

dealing in the same way with fuels purchased as feedstocks.

Only one consumption survey is conducted for the industrial sector, the Manufacturing Energy 

Consumption Survey (MECS), which covers manufacturing. There is no end-use survey of 

mining, construction, or agriculture. The supply surveys vary in their coverage of the industrial 

sector, so each survey will be discussed individually in the next section.

The industrial sector provides an additional element for consideration. Coal is an important fuel 

for the industrial sector, where only scant amounts of it are consumed in the residential and 

commercial sectors. Therefore, coal is added to the list of fuels discussed in this chapter.

14See Manufacturing Energy Consumption Survey: Consumption of Energy 1985, DOE/EIA-0512(85) for 

a discussion of different measures of energy consumption in the manufacturing industries sector.

Energy Consumption by End-Use Seel 

Energy Information Administration 31

Consumption Survey

MECS is based on a sample of manufacturing establishments, selected from a complete list of 

manufacturers maintained by the Census Bureau for its Annual Survey of Manufactures. MECS 

is designed to provide complete coverage of the manufacturing sector. The sample of 

establishments is stratified so that each industry is covered, and those industries with high energy 

consumption levels are selected at a higher sampling rate to ensure the data will be reliable for 

industries with high energy consumption.

Very small establishments are the only exclusion from the survey. The consumption of the small 

establishments excluded from MECS is estimated to be about 3 percent of the total 

consumption of the manufacturing sector.15

The sample element for MECS is similar to that for RECS and NBECS-it is the unit in which 

energy is consumed. For MECS, that unit is an establishment-.-a site where manufacturing 

occurs. The site has geographical boundaries and may encompass several buildings, be one 

building or part of a building, or not be located in a building at all. Energy collection from 

establishments is feasible because companies manage energy on an establishment level, data are 

maintained at the establishment level rather than for individual buildings within an 

establishment, and supplementary economic data are available for establishments.

MECS is conducted by a mail questionnaire sent to each establishment selected for the survey. 

The questionnaire asks detailed questions about each type of fuel consumed by the 

establishment. The data on energy consumption is based on the records of fuel purchases 

maintained by the establishment.

From these responses, several measures of consumption of each type of fuel have been 

developed. These measures distinguish purchased energy, energy used as feedstocks, and total 

energy consumption, which includes the use of fuels produced onsite as a byproduct of the 

industrial process.

Supply Surveys

The electricity supply surveys, conducted with EIA Form-861, includes the entire industrial 

sector in its industry category. There is a likelihood that some industrial establishments with 

low consumption are billed at commercial rates by electric and/or natural gas utilities and their 

consumption consequently counted as commercial. Similarly, some large commercial accounts

"Energy Information Administration, Manufacturing Energy Consumption Survey: Methodological Report 

1985, DOE/EIA-0514(85), November 1988, pp. 7-11.

Energy Consumption by End-Use Sectof 

32 Energy Information Administration

could be billed at industrial rates and included in industrial consumption. There are no data 

available with which the effect of this kind of misclassificadon can be measured. There is no 

basis for estimating whether the net effect would be positive or negative, let alone estimating its 

magnitude.

As noted earlier in this report, agriculture, fisheries, and forestry are included in the commercial 

sector in the natural gas survey, Form EIA-176. Mining and construction are included in the 

industrial sector, along with manufacturing industries.

For petroleum products, the situation is a bit more complex. One reason petroleum fuels are 

more difficult to track in industrial consumption is that the petroleum and chemical industries 

use substantial amounts of petroleum fuels as inputs to their production process. The output of 

the process may be another fuel, as is the case for refineries, or another product that is not an 

energy source.

With both the MECS and the petroleum supply data, it is possible to separate petroleum 

establishments from other manufacturers. The balance of the petroleum supply data are 

principally for manufacturers, although some mining operations are included in the data. This 

situation will be discussed in more detail in the section on petroleum fuels.

The coal supply survey provides data on products supplied to specific industry categories. 

Therefore, it is possible to compare directly the coal supply data with the MECS consumption 

data for specific industries.

Energy Consumption by Fuel Type

For electricity and natural gas, the supply surveys cover a broader range of the industrial sector 

than just manufacturers, the subject of the consumption survey. For these fuels, then, we 

expect the supply figures to be larger than those from MECS, and that is what the data show. 

For petroleum and coal, the coverage of the two surveys is closer to being the same. However, 

as we shall see, there are still apparently differences of coverage in some cases so that a direct 

comparison cannot be made.

Electricity

As expected, the MECS figure for electricity consumption is substantially lower than the supply 

figure for 1985:16

16MECS distinguishes electricity "consumption," which includes electricity generated and consumed on 

site, from "purchased electricity," which is comparable to data collected in the supply survey. The MECS 

data are from Manufacturing Energy Consumption Survey: Consumption of Energy, 1985, and the supply data 

are from Annual Energy Review 1988, DOE/EIA-0384(88), May 1989, Table 89; data from Form EIA-861.

Energy Consumption by End-Use Sector

Energy information Administration 33

MECS Purchased Electricity 654 billion kilowatthours

Industrial Safes of Electricity 825 billion kilowatthours

Supply as a Percent of MECS 128 percent

One RSE (MECS Sampling Error) 4 percent

There are no independent measures of electricity consumption in the agriculture, mining or 

construction industries to use to determine whether the difference between the MECS and 

supply figures is a reasonable estimate for the consumption in these industries.

Natural

As with electricity, the supply measure of natural gas consumption for industry is larger than 

from MECS:"

MECS 5,012 billion cubic feet

Supply Survey (EIA-176) 5,901 billion cubic feet

Supply as Percent of MECS 118 percent

One RSE (MECS Sampling Error) 1 percent

The larger value for supply is expected because the supply survey includes mining and 

construction in addition to manufacturing industries. There are no independent estimates of 

natural gas consumption in these industries to determine whether or not the difference between 

MECS and the supply measure can be reasonably attributed to them.

Fuel Oil and Kerosene

The supply data on sales of fuel oil and kerosene to manufacturing industries are contained in 

two categories sales for industrial use and sales for oil company use. Industrial use as defined 

in the supply form, EIA-821, includes manufacturing industries and some mining operations, but 

excludes oil company use. On the supply form, sales to oil companies includes sales to drilling 

companies, pipelines, other related oil companies not engaged in the selling of petroleum 

products, and fuel used by the reporting oil company for refinery operations.

In the MECS data, it is possible to separate consumption by oil companies themselves from 

other manufacturers. The MECS data for oil companies do not include consumption by 

pipelines and drilling companies, so it covers a slightly smaller range of companies than does the 

supply survey. Both the supply and MECS data can be further broken into type of fuel oil

"Data Sources: Manufacturing Energy Consumption Survey: Consumption of Energy, 1985, DOE/E1A0514(85), November 1988; for the supply data, Natural Gas Annual 1986, DOE/EIA-0131(86)/1 October 1987, 

Table 27. The EIA supply data do not include 966 billion cubic feet of lease and plant fuel which are used 

by the natural gas companies and are not included in MECS.

Energy Consumption by End-Use Sector 

34 Energy information Administration

consumed, distillate (Including kerosene), and residual.

Since the MECS includes slightly fewer categories of companies for both industrial use (mining 

included in supply) and oil company use (drilling companies and pipeline included in supply), 

the MECS consumption figures are expected to be less than the supply figures. Both the supply 

survey and MECS collect data on deliveries rather than consumption of the products, so the 

two surveys are consistent in what they measure.

The MECS figures are lower, but the differences are far larger than would be expected on the 

basis of the differences in coverage of the two surveys (Table 8).

Table 8. industrial Fuel Oil and Kerosene Consumption

Distillate Fuel Oil 

and Kerosene

Residual Fuel Oil

MECS Consumption 

(thousand barrels)

EIA Supply Data 

(thousand barrels)

Supply as Percent 

of MECS

One RSE

(MECS Sampling Error)

Oil Comppanies

752

20,869

2,775%*

12%

Other Man 

ufactures

34,987

67,790

194%*

6%

Oil Comppanies

15,731

18,477

117%*

7%

Other Man 

ufactures

71,277

95,509

134%*

3%

Note: Supply data for oil company use includes drilling and own company refining.

* Statistically different from 100% using 2 standard errors (based only on NBECS 

sampling error; the sampling error from the petroleum survey has not been included).

Source: Manufacturing Energy Consumption Survey: Consumption of Energy, 1985. 

Supply data: Petroleum Marketing Monthly June 1988, DOE/EIA-0380(88/06). pp.200- 

201; Data based on Form EIA-821.

Apart from residual fuel oil consumption for oil company use, where the MECS and supply data 

are fairly close (though not quite in agreement at a 95-percent confidence level), the supply 

estimates are substantially larger than the consumption estimates. The differences are so large 

as to suggest that the supply data are measuring something different than is being measured by

Energy Consumption by End-Use Sector 

Energy Information Administration 35

MECS.18 For example, the distillate fuel oil use by oil companies is so much larger than the 

MECS estimate that the supply data may be including some sales for refinery charging stocks 

rather than consumption. The instructions for Form EIA-821 request that oil companies 

exclude sales for use as refinery charging stocks, but the seller may not always know what use 

will be made of the product sold and so will not be able to respond accurately to the survey. 

Without further data, it is not possible to determine what factors underlie these extreme 

differences between MECS and the petroleum supply data.

The EIA coal "supply" survey and MECS both cover manufacturing industries, so the two can 

be compared more directly than is possible for other industrial fuel consumption. The "supply" 

survey, based on Form EIA-3, is a census of all plants using coal and measures consumption in 

a manner very similar to MECS. The MECS sample is drawn from a list maintained by the 

Census Bureau of manufacturing establishments, and it is a sample of manufacturers based on 

SIC classifications. The coal survey is a census of coal consuming companies, and the 

companies themselves specify the nature of their business on the survey form. The supply 

survey respondents may not classify their business consistently with the SIC categories, so it is 

possible there are some differences between the two surveys in the industrial classifications of 

the companies surveyed.

Since the coal survey is a census, it is not subject to sampling error as is MECS. Both surveys 

provide consumption estimates for specific industries, collect information about the same four 

types of coal, and ask how much coal is consumed, not just purchased or delivered. The supply 

survey is conducted quarterly, so the results from the four quarters of 1985 have been summed 

for these comparisons with MECS.

Total coal consumption measured by the supply survey is 12 percent higher than measured by 

MECS (Table 9), Much of the difference is believed to be a result of differences in coverage 

by the two surveys. Specifically, the supply survey includes some coal consumption by 

companies which are not included in MECS because their SIC code is not included in the codes 

for manufacturing industries. The industries most affected by this difference in coverage are 

Primary Metal and Petroleum.

Comparing the consumption estimates from the two surveys for individual industries shows a 

large number of differences (Table 9). Of the 15 manufacturing industries where comparisons 

could be made, the consumption estimates for 11 were different and 4 had the same 

consumption levels (at a 95-percent confidence level).

For primary metals, the MECS estimate is lower than the supply estimate by 6,504 thousand 

short tons. Up to half of this difference could be due to the exclusion of "auxiliary"

18See the article by Kelly and Wier, "A Comparison of Selected EIA-782 Data With Other Sources," 

Petroleum Marketing Monthly, DOE/EIA-0380(89/08), August, 1989, pp 5-17 for a discussion of some of the 

issues involved in measuring petroleum supply.

Energy Consumption by End-Use Sector 

36 Energy Information Administration

establishments from the MECS sampling frame, -which are probably included in the supply 

survey. In some cases, an auxiliary establishment will provide electric power to the 

establishment'it'supports. In this situation, the auxiliary establishment will transfer in, rather 

than sell, the electricity to the establishment with which they are connected.

Industry MECS Supply

(1,000 short tons)

Difference

(S-M)

(1,000 short

tons)

Supply/

MECS

RSE

(Industries where differences are statistically significant)

Primary Metal

Petroleum

Paper

Chemicals

Food

Rubber

Transportation

Fabricated Metal

Furniture

Machinery

Electric

41,676

339

14,015

14,957

5,571

328

1,860

329

89

741

373

48,180

5,875

11,808

15,966

4,948

553

2,041

508

240

670

426

6,504

5,536

-2,207

1,009

-623

225

181

179

151

-71

53

116%

1733%

84%

107%

89%

169%

110%

154%

270%

90%

114%

5%

9%

5%

3%

5%

7%

4%

6%

15%

5%

5%

Stone

Tobacco

Textile

(Industries where differences are not statistically significant) 

14,635 15,152

463

1,687

517

56

56

104% 

114% 

103%

5% 

8% 

7%

Leather 

All Manufacturers

32 26 

97,981 109,526

-6

11,545

81% 33% 

112% 3%

Note: Data for Primary Metal include 41,056 thousand short tons consumed by 

coke plants which is collected on Form EIA-5. The total for all manufacturers 

includes consumption for industries not listed.

Source: Manufacturing Energy Consumption Survey: Consumption of Energy, 1985, 

DOE/EfA-QS12(85);Suppiy Data: Quarterly Coal Report October-December 1986, 

DOE/EIA-0121(86/4Q), p.55 (Form EIA-3).

The MECS data indicate that 5,990 million kWh of electricity were transferred in by primary 

metal manufactures. If all this electricity were produced by coal, it would represent 3 thousand 

short tons of coal. Adding this quantity of coal to the MECS total would mfean there is no

Energy Consumption by End-Use Sector 

Energy Information Administration 37

longer a statistically significant difference between the supply and consumption survey estimates. 

Not all of the electricity that is transferred in is necessarily produced by coal, of course, but a 

substantial amount of it is. This difference between the two surveys is an important reason for 

the differences in their findings for primary metals industries.

For the petroleum industry, the MECS consumption estimate is lower than the supply estimate 

by almost a factor of 20. The difference of 5,536 short tons is probably due to the inclusion of 

coal gasification plants in this category in the EIA-3 sample frame. These plants account for 

about 5,000 short tons of coal consumption. These plants are not considered manufacturing 

plants in the SIC classification, which is the basis for the MECS sample frame.

For the paper and allied products industries, the difference between the consumption survey and 

supply survey estimates is 2,207 short tons. There is no difference in coverage of establishments 

that we are aware of that could account for this difference. There is currently no explanation 

for the difference.

For chemicals, the MECS estimate is 1,009 short tons lower than from the supply survey. 

MECS does not include government owned and government operated plants. Nuclear 

processing plants are part of this industry and would be included in the supply survey but not 

MECS. There may also be auxiliary establishments that supply electricity generated from coal 

that are included in the supply survey but not MECS. There were 1,983 million kWh of 

electricity transferred in to chemical establishments, which is equivalent to about 1 thousand 

short tons. So this explanation could account for the discrepancy.

For the remaining industries, Food, Rubber, Transportation, Fabricated Metal, Furniture, 

Machinery and Electric, the consumption levels are lower, as are the magnitudes of the 

differences. There are no explanations for the differences, although there could be differences 

between the two surveys in the coverage of establishments included in the surveys, as was noted 

above for industries with higher consumption levels.

Energy Consumption by End-Use Sector 

38 Energy Information Administration

A typical analyst studying energy demand sees the combination of the rich cross-section detail in 

the consumption data and the longtime series of historical data available from the supply surveys 

as a valuable source of data for analysis. The data, however, don't fit quite so tightly together 

as we might hope. In some cases, the differences are relatively small, while in others the 

coverage of the two data sources is sufficiently different that they effectively cannot be used 

together. Further research and data collections will be required to reconcile the differences.

The two data sources do provide a consistent picture of energy use in the end-use sectors where 

both types of data have been collected. For the most part, though, the consumption and supply 

surveys are covering either slightly different, or substantially different, groups of energy 

consumers. Combining the two types of data in any analysis therefore requires that allowance 

be made for the differences of coverage.

Residential

The supply and consumption surveys come closest to covering the same set of consumers in the 

residential sector. The Residential Energy Consumption Survey (REGS) does not cover second 

homes and unoccupied housing. The electric and natural gas supply surveys have some 

misclassification resulting from utilities using rate classes rather than the economic activity of the 

consumer to allocate sales in response to the survey. Apartment buildings are explicitly 

excluded from the fuel oil supply survey. The effect of these factors was difficult to observe in 

the data. For most of the years that RECS has been conducted, there was no statistically 

significant difference between the RECS estimate for electricity consumption and the residential 

supply figures. The natural gas and fuel oil figures were also not statistically significantly 

different for most years. Consequently, the effects of differences in coverage between the 

surveys are smaller than the standard error due to sampling variance in the consumption survey.

From the results of the comparison then, we can conclude that the two types of survey appear 

to be measuring close to the same thing. The standard error in the RECS data is sufficiently 

large that it is not possible from these data to estimate the likely size of the differences in 

consumption resulting from the differences in coverage of the two types of surveys.

Energy Consumption by End-Use Sector

Energy Information Administration 39