EA-i

ENVIRONMENTAL ASSESSMENT FOR PROPOSED ENERGY CONSERVATION 

STANDARDS FOR SMALL ELECTRIC MOTORS 

TABLE OF CONTENTS 

EA.1 INTRODUCTION ........................................................................................................EA-1 

EA.2 METHODOLOGY .......................................................................................................EA-2 

EA.3 RESULTS .....................................................................................................................EA-3 

EERE-2007-BT-STD-0007 COMMENT 07.2
EA-1 

 

ENVIRONMENTAL ASSESSMENT FOR PROPOSED ENERGY CONSERVATION 

STANDARDS FOR SMALL ELECTRIC MOTORS 

EA.1 INTRODUCTION 

 The U.S. Department of Energy (DOE) will conduct an environmental assessment as part 

of the notice of proposed rulemaking. DOE will assess the impacts of proposed energy 

conservation standards for small electric motors on certain environmental indicators using a 

variant of the U.S. DOE/Energy Information Administration (EIA)’s National Energy Modeling 

System (NEMS).a

 EIA uses NEMS to produce the Annual Energy Outlook (AEO).1 DOE will 

use a variant known as NEMS-BT to provide key inputs to the analysis, based on the 2008 

version of the AEO (AEO2008). Results of the environmental assessment will be similar to those 

provided in AEO2008. 

 DOE intends the environmental assessment to provide emissions results to policymakers 

and other stakeholders, and to fulfill requirements that the environmental effects of all new 

Federal rules be properly quantified and considered. The environmental assessment considers 

three criteria pollutants—sulfur dioxide (SO2), nitrogen oxides (NOx), and mercury—as well as 

carbon emissions. The only form of carbon emissions tracked by NEMS-BT is carbon dioxide 

(CO2), so the carbon discussed in this report is only in the form of CO2. For each of the trial 

standard levels, DOE will calculate total emissions using NEMS-BT, using additional, external 

analysis as needed. 

 Although DOE intends to consider only SO2, NOx, mercury, and CO2 in its 

environmental assessment, there are other air pollutants that are of concern. Specifically, the 

Clean Air Act requires the Environmental Protection Agency (EPA) to set National Ambient Air 

Quality Standards for the following six common air pollutants, also know as “criteria pollutants”: 

(1) ozone, (2) particulate matter (PM), (3) carbon monoxide (CO), (4) nitrogen dioxide, (5) SO2, 

and (6) lead.2 EPA recently added mercury to this list. Some of the “criteria pollutants” (i.e., 

ozone, PM, CO, and lead) are not driven significantly by either electric utility power plants or 

fuel-fired appliances. Therefore, DOE does not intend to address them in the environmental 

assessment. In the case of ozone and particulate matter, other pollutants are precursors to their 

formation and atmospheric conditions are the driving force behind their formation. Also, SO2

and NOx are the primary precursors to ozone and PM, respectively, and will already be addressed 

by the environmental assessment. In the case of CO, electric utilities and fuel-fired appliances 

are not significant sources. For electric power plants, almost all carbon emissions are in the form 

a For more information on NEMS, please refer to the U.S. Department of Energy, Energy Information 

Administration documentation. A useful summary is National Energy Modeling System: An Overview 2000, 

DOE/EIA-0581(2000), March 2000. See http://tonto.eia.doe.gov/bookshelf/SearchResults.asp?title=modeling. EIA 

approves use of the name NEMS to describe only an official version of the model without any modification to code 

or data. Because this analysis entails some minor code modifications and the model is run under various policy 

scenarios that are variations on EIA assumptions, DOE refers to the model as NEMS-BT (BT is DOE’s Building 

Technologies Program). 

EERE-2007-BT-STD-0007 COMMENT 07.2
EA-2 

of CO2 as the combustion process is lean enough not to yield CO in significant amounts. For 

fuel-fired appliances, proper appliance maintenance, installation, and use can prevent dangerous 

levels of CO. A well-designed and properly functioning heating or cooking appliance should not 

produce toxic or lethal levels of CO, as, most often, CO poisoning occurs in the home as a result 

of malfunctioning appliances. Finally, with regard to lead, the ban on the use of leaded gasoline 

has resulted in a dramatic decrease in lead emissions since the mid 1970s. In general, industrial 

processes (not electric utilities), particularly primary and secondary lead smelters and battery 

manufacturers, are responsible for most of lead emissions and all violations of the lead air quality 

standards. 

EA.2 METHODOLOGY

 DOE will conduct the environmental assessment as a policy deviation from the 

AEO2008, using the same basic set of assumptions. For example, the emissions characteristics 

of an electricity generating plant will be exactly those used in AEO2008. The NEMS reference 

case and alternative growth scenarios are as described in the utility impact analysis (see 

preliminary Technical Support Document (TSD) chapter 13). 

 The NEMS-BT model tracks carbon emissions using a detailed carbon module; this 

approach provides good results because of its broad coverage of all sectors and inclusion of 

interactive effects. Past experience with carbon results from NEMS suggests that the NEMSgenerated emissions estimates are somewhat lower than estimates based on simple average 

factors. One of the reasons for this divergence is that NEMS tends to predict that conservation 

displaces renewable generating capacity in the later years of its forecast. On the whole, NEMSBT provides carbon emissions results of reasonable accuracy, at a level consistent with other 

published Federal results. 

 The NEMS-BT model reports the two airborne pollutant emissions that DOE has reported 

in past analyses: SO2 and NOx. The Clean Air Act Amendments of 1990 set an SO2 emissions 

cap on all power generation.3

 The attainment of this target, however, is flexible among 

generators through the use of emissions allowances and tradable permits. The NEMS-BT model 

includes a module for SO2 allowance trading and delivers a forecast of SO2 allowance prices. 

Accurate simulation of SO2 trading tends to imply that physical emissions effects will be zero, as 

long as emissions are at the ceiling. There is an SO2 benefit from conservation in the form of a 

lower allowance price but, since the impact of any one standard on the allowance price is likely 

small and highly uncertain, DOE does not plan to monetize the SO2 benefit. 

 Also, the NEMS-BT model has an algorithm for estimating NOX emissions from power 

generation. The impact of these emissions, however, will be affected by the Clean Air Interstate 

Rule (CAIR), which the U.S. Environmental Protection Agency (EPA) issued on May 12, 2005.4

 

CAIR will permanently cap emissions of NOx in 28 eastern States and the District of Columbia. 

As with SO2 emissions, a cap on NOX emissions means that equipment efficiency standards may 

have no physical effect on these emissions. When NOx emissions are subject to emissions caps, 

EERE-2007-BT-STD-0007 COMMENT 07.2
EA-3 

DOE’s emissions reduction estimate corresponds to incremental changes in the prices of 

emissions allowances in cap-and-trade emissions markets rather than physical emissions 

reductions. Therefore, while the emissions cap may mean that physical emissions reductions 

will not result from standards, standards could produce an environmental-related economic 

benefit in the form of lower prices for emissions allowance credits. However, as with SO2

allowance prices, DOE does not plan to monetize this benefit because the impact on the NOx

allowance price from any single energy conservation standard is likely small and highly 

uncertain. 

 With regard to mercury emissions, NEMS has an algorithm for estimating these 

emissions from power generation. However, the impact on mercury emissions will be affected 

by the Clean Air Mercury Rule (CAMR), which the EPA issued on May 18, 2005.5

 CAMR will 

permanently cap emissions of mercury for new and existing coal-fired plants in all States. As 

with SO2 and NOx emissions, a cap on mercury emissions means that equipment efficiency 

standards may have no physical effect on these emissions. When mercury emissions are subject 

to emissions caps, DOE’s emissions reduction estimate corresponds to incremental changes in 

the prices of emissions allowances in cap-and-trade emissions markets rather than physical 

emissions reductions. Therefore, while the emissions cap may mean that physical emissions 

reductions will not result from standards, standards could produce an environmental-related 

economic benefit in the form of lower prices for mercury emissions allowance credits. However, 

as with SO2 and NOx allowance prices, DOE does not plan to monetize this benefit because the 

impact on the mercury allowance price from any single energy conservation standard is likely 

small and highly uncertain. 

EA.3 RESULTS

 The results for the environmental assessment are similar to a complete NEMS run, as 

published in the AEO2008. These include emissions for SO2, NOx, mercury, and CO2 in fiveyear forecasted increments, extrapolated to the year 2045. DOE will report the outcome of the 

analysis for each trial standard level as a deviation from the AEO2008 reference case results. 

EERE-2007-BT-STD-0007 COMMENT 07.2
EA-4 

 

REFERENCES

1

 U.S. Department of Energy-Energy Information Administration. Annual Energy Outlook 

2008 with Projections to 2030, June, 2008. Washington, DC. DOE/EIA-0383(2008). 

2

 U.S. Environmental Protection Agency. Six Common Air Pollutants. Washington, DC. 

<http://www.epa.gov/air/urbanair/> 

3

 U.S. Environmental Protection Agency. Clean Air Act. Washington, DC. 

<http://www.epa.gov/air/caa/> 

4

 U.S. Federal Register. Rule To Reduce Interstate Transport of Fine Particulate Matter and 

Ozone (Clean Air Interstate Rule); Revisions to Acid Rain Program; Revisions to the NOX

SIP Call, Final Rule, May 12, 2005. 70 FR 25162. 

5

 U.S. Federal Register. Standards of Performance for New and Existing Stationary Sources: 

Electric Utility Steam Generating Units, Final Rule, May 18, 2005. 70 FR 28606. 

EERE-2007-BT-STD-0007 COMMENT 07.2