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Amounts are to be reported in terajoules, except charcoal and liquid biofuels that are to be reported in 1000 tonnes. All values have to be rounded to zero decimal places and negative values are not allowed.

Group II and Group III renewables and waste fuels are subject to losses during storage and transportation. For example, solid materials like wood chips, municipal waste and agricultural wastes are subject to dispersal by wind and water while being held at storage sites and/or transported. Similarly, biogas transport facilities are subject to leaking.

Biogases which are vented should be reported in distribution losses. Biogases which are flared (burned rather than consumed in other sectors) should not be reported in distribution losses but in the energy sector.

Final energy consumption is all Group II and Group III renewables and waste fuels delivered to consumers in the industry, transport and other sectors. It does not include any fuels used for transformation or in the energy-producing industries.

In the industry sector, the bulk of the consumption occurs in two sub-sectors: paper pulp and print, and wood and wood products (Table 3). For instance, these two sub-sectors account for about 80% of the renewables and waste final consumption of all OECD member countries.

The consumption of renewables and waste in the transport sector is still very limited, less than 1% of the global transport consumption. However, the share of renewables in transport dramatically varies from country to country, with for instance over 15% in Brazil owing to a large methanol programme.

The largest part (over 80%) of the final consumption of renewables and waste occurs in the other sectors, mainly in residential and services. Moreover, over 90% of this consumption occurs in non-OECD countries. Biomass, and for a large part fuelwood, accounts for the largest share of this consumption.

To be complete, it should be added that there are several elements (such as wind for sail boats, or free heat from the sun for heating houses) which are not considered in the final consumption. Should they be considered, the overall share of renewables and waste would then be higher.

The discussions on climate changes have undoubtedly stimulated the development of renewable energy in order to reduce the emissions of greenhouse gases from Annex 1 Parties to the UNFCCC; therefore, there is a strong need for better monitoring this development and consequently to strengthen the reporting and dissemination of timely and reliable information on renewables and waste. This is a major challenge since a large part of renewable energy is not commercially marketed and/or is located in remote areas.

As a consequence, there is a need to collect more specific information on some of these products in order not only to monitor their annual development but also to make comparison with other countries.

The complement of information concerns some technical characteristics of three types of installations (power plants, solar collectors and liquid biofuels plants), the average net calorific values of liquid biofuels and charcoal, and the production of wood and other solid wastes.

With the growing importance of the environmental debate, it has become essential to identify total consumption of fuels in each respective industry and consuming sector, so that for each sector appropriate measures can be developed to conserve energy and reduce greenhouse gas emissions.

Prior to the initiation of the annual Renewables and Waste Questionnaire, some renewables and waste statistics were collected on the annual Coal Questionnaire. These data, for wood, wood wastes and other solid wastes were disaggregated in more detail than on the current Renewables and Waste Questionnaire. In order to permit member countries to maintain the data series that were collected, Table 6 has been included for the collection of more detailed statistics on these commodities.

In the case of CHP plants, reporting separate figures for the amounts of fuel used for the production of electricity and heat requires a method of dividing the total fuel use between the two energy outputs.

The presentation of energy statistics expressed in natural units in the form of commodity balances between the supply and use of the energy commodities provides a check on the completeness of the data and a simple means of assembling the main statistics of each commodity so that key data are easily obtained. However, because fuels are mainly bought for their heat-raising properties and can be converted into different fuel products, it is also helpful to present the supply and use data in energy units.

The energy balance is also the natural starting point for the construction of various indicators of energy consumption (for example consumption per capita or per unit of GDP) and of energy efficiency. The statistician also uses the energy balance as a high-level check on the data accuracy as apparent energy gains in conversion processes or large losses indicate data problems.

The commodity balance and its main parts have been largely described in Chapter 1, Fundamentals , Section 9, How are Energy Data Presented? Commodity balances should be constructed at national level for every energy commodity in use, however minor, and even if some commodities are aggregated for working purposes. They should be considered as the basic framework for the national energy statistics and a valuable accounting tool used to construct energy balances, higher aggregates and indicating the data quality through the Statistical Difference row.

National statisticians should pursue large statistical differences in order to establish which data are wrong or incomplete. Unfortunately, it will not always be possible to correct the data and, in this case, the statistical difference should not be changed but left to illustrate the size of the problem.

Deciding whether a statistical difference should be pursued with the reporting enterprise(s) is a matter of judgement. The percentage difference which one might consider acceptable will depend upon the magnitude of the supply of the commodity. For major supplies, like natural gas or electricity, efforts should be made to keep the statistical differences below one per cent. On the other hand, for a minor commodity like tars and oils from coke ovens, a 10% error can be tolerated.

When the commodity balances are constructed from the data reported to the statistician, it may also show a statistical difference which is zero (a “closed” balance). This apparently ideal position should be regarded with suspicion as, in almost all situations, it indicates that some other statistic in the balance has been estimated to balance the account. This usually occurs when the data come from a single reporter (for example a refinery or an iron and steel works) who has all the data making up the balance and is therefore able to adjust figures to close the balance. For information and an appreciation of the data problems encountered by the enterprise concerned, the statistician should discover what element(s) has (have) been estimated to balance the account.

It is essential to construct energy balances from the commodity balances both to check the data further and to enable users to find important relationships in the data which are concealed in the commodity balances.

The transformation of the commodity balances to an energy balance is illustrated schematically in Figure 7.1 below.

The first step is to convert the natural units in the commodity balances to the chosen energy unit by multiplying by the appropriate conversion equivalent for each of the natural units. Major international energy organisations, such as the IEA and Eurostat, use energy units of tonnes of oil equivalent for their balances, where one tonne of oil equivalent (toe) is defined to be 41.868 gigajoules (see Annex 3 for a discussion of units and conversion equivalents). Many countries use the terajoule as the unit for their national energy balance.

The reformat operation consists of arranging the converted commodity balances alongside one another, rearranging certain of the rows and introducing a sign convention in the transformation sector. There are different ways an organisation can present its energy balances depending on conventions and emphasis. For instance, the differences between the IEA and Eurostat’s format will be explained more fully at the end of this chapter.

the form of the primary energy for the energy accounts. For example, the gross electricity production from hydro plants is used as the primary energy form rather than the kinetic energy of the falling water because there is no statistical benefit from pursuing the adoption of the kinetic energy as the primary energy form. It does not, however, say how the amount of energy to be attributed to the primary energy form is calculated but in this case it is natural to adopt the amount of electricity generated as the measure.

In the earlier days of energy balance methodology, a partial substitution method was used to value primary energy production. This gave the electricity production an energy value equal to the hypothetical amount of the fuel required to generate an identical amount of electricity in a thermal power station using combustible fuels.

The principle now adopted is the “physical energy content” method in which the normal physical energy value of the primary energy form is used for the production figure. For primary electricity, this is simply the gross generation figure for the source.

In these cases, no estimation is required. The non-EU countries which are members of the IEA and ECE do not, in general, have similar information and for these countries the IEA imputes the primary heat production value for nuclear plants from the gross electricity generation using a thermal efficiency of 33%.

As stated in Chapter 1, Fundamentals, Section 8, where some of the steam direct from the reactor is used for purposes other than electricity generation, the estimated primary production value must be adjusted to include it.

In this case, however, the thermal efficiency used is 10%. The figure is only approximate and reflects the generally lower-quality steam available from geothermal sources. It should be stressed that if data for the steam input to geothermal power plants are available, they should be used in determining geothermal heat production.

However, the procedure is economic when the costs avoided by not using less efficient thermal power stations to generate a similar amount of electricity exceed the cost of the pumped storage procedure.

The principle of using the steam from nuclear reactors as the primary energy form for the energy statistics has an important effect on any indicators of energy supply dependence. Under the present convention, the primary nuclear heat appears as an indigenous resource. However, the majority of countries which use nuclear power import their nuclear fuel and if this fact could be taken into account, it would lead to an increase in the supply dependence on other countries.

Pumped storage generation with natural flow hydroelectricity would double count the energy content of the pumped storage generation in Gross Inland Consumption(Eurostat) or TPES (IEA). The pumped storage generation is therefore omitted from hydroelectricity generation in the energy balance.

The energy lost in pumping, that is, the difference between the quantity of electricity used for pumping and that generated at pumped storage plants, is included in “Consumption of the energy branch” (Eurostat) under the Electrical Energy column.

Heat production from heat pumps does not usually raise problems related to the definitions of the energy flows. Any data collection problems usually arise when trying to find heat pump use and establishing reporting.

Production of blast-furnace gas, produced during the manufacture of iron in blast furnaces, is a by-product fuel from the process and is consumed at the blast furnace, elsewhere on the manufacturing site, and sometimes sold to other enterprises.

Section 9 of Chapter 1 illustrates and discusses the differences between the commodity balances used by the IEA and Eurostat. The major difference is in the presentation of the production of primary and secondary fuels.

The IEA commodity balance, on the other hand, has both primary and secondary production reported in the “production” row of commodity balances. This has the advantage of presenting all commodities identically without requiring the user to know that there are two locations in which production information is presented.

As noted above, the Eurostat energy balance has a format identical to that of the commodity balance with its transformation part (sometimes called “transformation matrix”) divided between inputs and outputs. All quantities are positive in the transformation matrix. Like the commodity balance, the production is limited to primary production.

The IEA energy balance places only indigenous production (primary production) in the “production” row. Production of a secondary energy commodity appears as a positive quantity in the transformation matrix against the heading for the relevant transformation industry.

Each organisation's balance must transfer the figures from the column for the primary electricity produced (for example hydro) into the electricity column of the balance so that its disposal, together with all other electricity, can be accounted for according to the sectors of consumption.

The IEA transfers the primary electricity by entering it into the transformation matrix as an input with a negative sign and an identical amount is included in the total electricity production in the Electricity column.

After reviewing the text, I found no full sentences or paragraphs that are not part of a table. The text appears to be a statistical report with various categories and numerical data, which does not contain complete sentences or paragraphs in the classical sense.

The annual questionnaires classify electricity and heat generating plants into three groups: Electricity-only plants – which generate electricity only; Heat-only plants – which generate heat only; and Combined heat and power plants (CHP) – which generate heat and electricity in a combined process.

The majority of electricity generation without heat supply is obtained from alternators driven by turbines that are propelled by steam produced from combustible fuels (including wastes), or nuclear heat. Smaller electricity-only plants also use gas turbines or internal combustion engines.

Steam may also be obtained directly from geothermal reservoirs although geothermal steam and/or hot water may need upgrading by heating with fossil fuels to produce steam of sufficient quality (temperature and pressure) to operate the turbines.

Heat may be supplied to consumers through a pipe network or through a boiler installed in or near a building containing the dwellings and serving only that building. In all cases, the heat is sold to the consumer with direct payment or indirect payment through accommodation charges.

Combined heat and power (CHP) units provide simultaneous supplies of electricity and heat from one or sometimes several items of generating equipment.

The operating conditions under which electricity output from a CHP unit may be classified as CHP electricity are currently under review by Eurostat to ensure that only bona fide CHP operation is included. Therefore, statisticians can expect the definitions affecting the reporting of this activity to evolve in the near future.

The simplest co-generation power plant is the so-called backpressure power plant where CHP electricity is generated in a steam turbine, and backpressure exerted on the steam in the turbine maintains the temperature of the steam exiting the turbine. The steam is then used for process steam or district heat.

Recently, natural gas-fired combined cycle power plants consisting of one or more gas turbines, heat recovery boilers, and a steam turbine have become quite common.

Instead of a gas turbine, a reciprocating engine, such as a diesel engine, can be combined with a heat recovery boiler, which in some applications supplies steam to a steam turbine to generate both electricity and heat.

Although technology is evolving to a point where reciprocating engines and combustion turbines are used in CHP applications, steam turbine plants remain themost common type used for combined production of electricity and heat.

The efficiency of electricity production requires a method for estimating the amount of heat used for electricity generation.

The index of energy saving (S) evaluates the quantity of energy saved because a conventional power station, with efficiency R p, has not been used to produce the electricity.

Low-temperature exhaust provides little useful energy from the steam leaving the turbine and most remaining heat is usually exhausted into cooling water or the air.

In backpressure power plants (Figure A1.1), the purpose is not to maximise electricity production, but to satisfy heat demand of an industrial process or a district heating network.

The energy content of the exhaust steam depends mainly on its pressure, and by changing the exhaust pressure it is possible to control the heat-to-power ratio of a backpressure turbine.

The electricity generation of a total backpressure turbine can be considered completely CHP production.

characterised by high thermal efficiencies, which can reach and sometimes exceed 90%. The efficiency of electricity generation is usually in the range of 15% to 25%.

Extract-and-condense turbines are generally used in large power plants. This is especially the case in northern Europe where they can generate electricity and district heat in winter and operate in a fully condensing mode in summer, producing only electricity.

The term “condensing electricity” is sometimes used also for the electricity generation of other types of cycles, when the generation does not fulfil the definition of simultaneous exploitation of the thermal energy for electricity and heat production by co-generation. Especially in steam turbines, even if a small part of the steam is condensed, the portion of the generated electricity corresponding to the amount of wasted heat should not be considered CHP generation.

Since the heat recovered from gas turbines is almost totally concentrated in its exhaust gas, thermal recovery is limited to only a single heat exchanger. Despite this operational simplicity, the exchanger must be large because of the volume of gas involved.

The result is to further upgrade thermal quality of the exhaust gas and raise heat recovery. Thermal efficiency achieved by this approach reaches close to 100% because the heat lost before the heat recovery boiler is practically zero. It should be noted, however, that heat generated by post-firing is not CHP heat, and both the input fuel and the output heat should be considered a “heat-only” system.

Gas turbines can be operated while by-passing all or part of the heat recovery system. In this case, thermal energy remaining in the exhaust gases is not used for heat production, and the electricity generation corresponding to the by-passed exhaust gases is considered "condensing power" and not CHP generation.

The efficiency of the electricity generation of a simple stand-aside gas turbine unit is typically lower than that of a condensing steam unit. However, the construction costs of a simple gas turbine power plant per kW are relatively modest, and currently only a fraction of the cost of a condensing steam unit. Thus, stand-alone gas turbine units are often used for covering the demand for electricity during peak load conditions because they can be installed economically and they can be brought on line quickly.

An important characteristic of diesel-cycle reciprocating engines is their high efficiency when generating electricity. This ranges from 35% to 41% for the smaller and large sizes respectively.

Heat is recovered by exploiting exhaust gas, cooling water, lubricants and, in supercharged engines, the heat available in the supercharge air.

There is a range in the quality of heat recovered in internal combustion engine systems. About 50% of the heat is recovered from engine exhaust gases, which are high-temperature and have high thermal value.

Internal combustion engines can be combined with some other cycles, for example with steam or gas turbines, and have a variety of applications. They are popular as reserve capacity in hospitals, nuclear power stations, etc., and are also used in regular power production. Gaseous and traditional liquid fuels can be used in internal combustion engines.

when converting primary energy into heat and electrical energy, since there is an actual temperature change of close to 1 000°C over the entire system as compared to a change of 550°C to 600°C achieved in the most modern steam and gas turbine system when operating as electricity-only facilities.

The thermal efficiency of the electricity segment approaches, and with most recent larger units, may exceed 50%. The benefits of this system is fuller exploitation of exhaust heat which would otherwise be lost.

Recently, the combined gas/steam cycle has been adopted more widely, especially in some sectors of industry, and also in the medium range and the medium-small range power sector. The increased availability of efficient and proven gas turbines should stimulate further expansion of this technology.

By allowing flowing water to pass through a specially designed turbine connected to an electricity generator, the energy in the flowing water is converted to electricity.

The water may be taken from a reservoir constructed to supply the turbines. These plants are usually large generating units. Small hydro plants exploit the natural flow from rivers and are referred to as “run of river” schemes.

Hydroelectricity may also be produced from water flow taken from special reservoirs filled by pumping water from a river or lake at lower levels. At pumped storage plants, electricity (taken from the national grid) is used during periods of low demand (usually at night) to pump water into reservoirs for release during times of peak electricity demand when the marginal cost of electricity generation is higher.

However, the procedure is economic when the costs avoided by not using less efficient thermal power stations to generate a similar amount of electricity exceed the cost of the pumped storage procedure. The methodology for the inclusion of pumped storage electricity generation in the energy balance is discussed in Chapter 7, Section 3.

Heat pumps are devices for transferring heat from a cold source to a warmer source and may be used to draw heat from outside a building to warm the inside. They are usually driven electrically and can provide an efficient means of heating. They are not, however, in widespread use and make only a small contribution to national energy supplies.

Petroleum refineries are complex plants where the combination and sequence of processes are usually very specific to the characteristics of the raw materials (crude oil) and the products to be produced.

A refinery takes crude oil and separates it into different fractions, then converts those fractions into usable products, and these products are finally blended to produce a finished product.

In addition, differences in owner’s strategy, market situation, location and age of the refinery, historic development, available infrastructure and environmental regulation are among other reasons for the wide variety in refinery concepts, designs and modes of operation.

The production of a large number of fuels is by far the most important function of refineries and will generally determine the overall configuration and operation. Nevertheless, some refineries can produce valuable non-fuel products such as feedstocks for the chemical and petrochemical industries.

Refining crude oil into usable petroleum products can be separated into two phases and a number of supporting operations.

The second phase is made up of three different types of “downstream” processes: combining, breaking and reshaping fractions. These processes change the molecular structure of hydrocarbon molecules either by breaking them into smaller molecules, joining them to form larger molecules, or reshaping them into higher-quality molecules.

Market demand has for many years obliged refineries to convert heavier fractions to lighter fractions with a higher value.

The simplest conversion unit is the thermal cracker by which the residue is subjected to such high temperatures that the large hydrocarbon molecules in the residue convert into smaller ones.

Several types of coal may be blended to improve blast furnace productivity, to extend coke battery life, etc.

The actual yields of products from a coke oven depend on the coals charged and the length of the heating period. However, typical figures are illustrated in Figure A1.7 and represent the outputs expressed as percentages of coal input by mass.

Patent fuels and briquettes Manufactured solid fuels are generally reported as two separate types of products. One is patent fuel. It is nominally a smokeless fuel and is derived from fines, or residual dust of hard coal. This finely divided coal is pressed into a briquette with or without a binding agent. Sometimes the binding agents are other fuels like petroleum or agglomerating renewable products like pitch. In addition, the process may involve low-temperature heating or carbonisation of the briquette during its forming. A number of patent fuels are also low-temperature cokes.

In general, patent fuels have net calorific values which are similar to but slightly higher than the fuel from which they are derived. In some cases, this is due to the addition of binders (when needed) but is mostly the result of removing impurities and moisture from the finely divided particles existing before processing into briquettes.

The iron and steel activities in some countries are limited to just the treatment and finishing of steel, without the manufacture of coke or the operation of blast furnaces. Plants which combine the coke production and iron manufacturing stages as well as the treatment and finishing of steel are known as integrated steel plants.

Other materials are not injected into the blast air at every plant. The purpose of injection is to provide additional carbon to the process and reduce the need for coke. Most, but not all, of the injected materials are recognised in the questionnaires as fuels.

The reporting of blast-furnace fuel use is dependent on the statistics of the process as provided by the iron and steel plants.

It is clear from the above, and from the discussion of coke manufacture, that integrated steel plants are large energy consumers and important parts of the energy economy.

Consequently, most enterprises keep careful accounts of fuel and energy use which are very similar to the balances described in this Manual.

This implies that large plants, at least, should be able to report the fuels used for each process provided that the data collection formats are well matched to their internal operating returns.

Under ideal reporting conditions, statisticians would have figures for different types and quantities of fuels used at blast furnaces as well as figures for the blast-furnace gas produced.

However, it is unlikely that the quantities of fuels used for blast air heating and as feedstock for the blast furnace will be separately identified.

In the absence of this information, reporting should assume that all blast-furnace gas and coke-oven gas used at blast furnaces is for blast air heating and should be considered as energy sector consumption.

Occasionally, natural gas use may be reported but the nature of its use is less clear as it could be consumed for either purpose.