Exerciseon Building Energy Balances

The purpose of the IEA Balance Builder is to build a country’s energy balance following the IEA methodology. This can be done by filling by hand the “Data in physical units”and“Conversion factors” worksheets or by uploading data from the IEA data questionnaires.

You are presented with a partially filled balance builder (file BalanceBuilder_Statisland.xls), follow the instructions below to complete the data and answer the questions regarding the aggregated and disaggregated balance worksheets.
Note that yellow cells indicate errors (as explained in the “Main Menu” worksheet).

Before starting, open the “Data in physical units”worksheet. You will note that:

there is an arithmetic error for other bituminous coal,
natural gas is missing and
there is a problem with double counting for non-energy use of other kerosene, fuel oil, white spirit, lubricants, bitumen and paraffin waxes.

Now do the following:

Upload the natural gas questionnaire (file: STATISLAND_Gas.xls) to fill in the missing natural gas data.
Update the “Data in physical units”worksheet according to the following. Cells modified in the “Data in physical units” worksheet will turn orange if the change is correct.

The ideal way is to correct the errors in the questionnaire directly and reload the questionnaire in the balance builder. Make the participants correct the coal questionnaire.

Anthracite previously reported as stocked was actually exported.

Change C15 to zero and C12 to -142

The amount of Non-metallic minerals for other bituminous coal was accidentally left out. It should be 913 kt.

Insert 913 in cell E65

Blast furnace gas used in main activity producer electricity plants generated 1300GWh of electricity.

Insert 1300 in cell O94

Open the “Disaggregated Balance”worksheet. You will notice that there are no numbers for anthracite, biogasoline and biodiesels. This is because some of the net calorific values are missing on the “Conversion factors”worksheet. Update the following:
Anthracite:26700 kJ/kgfor production, 26500 kJ/kg for exports and 26750 kJ/kg for all other flows
Biogasoline: 26800 kJ/kg
Biodiesels: 36800 kJ/kg

Anthracite row 6, biogasoline cell C39, biodiesels C40
Now when you go into the “Disaggregated Balance” worksheet you will see numbers that were previously missing for anthracite, biogasoline and biodiesels.

Fix the non-energydouble counting issue for oil in the “Data in physical units” worksheet as described in the Main Menu.

This needs to be done in transformation/energy/industry/ transport/other. The non-energy in AE89-92 should never be set to zero.

Disaggregated balance

What is the difference between a negative and a positive number in stock changes (row12)?

A negative number represents a stock build(closing stock > opening stock) and a positive number represents a stock draw (closing stock < opening stock).

Production of motor gasoline equals 12570 kt in the “Data in physical units” worksheet, why is it zero in the aggregated balance?

In the production row we only show primary energy production not secondary products. That is why it appears as a zero in production. Oil products production appears as a transformation output in the balance (and will appear as a positive number in the transformation sector).

Why does other bituminous coalappear as a negative number on the main activity producer electricity plants row of the disaggregated balance?

Because it is used as an input to produce electricity.

What is the difference between a negative number in transformation processes (rows1737) and a negative number in energy industry own use (rows 39-55)?

A negative number in the transformation sector shows an input to a transformation process and in the energy industry own use indicates energy consumption in that industry.

Are coking coal and lignite transformed or consumed directly? If transformed, into what other products? If consumed, by which sector? In which cases will the numbers be positive, and in which cases will they be negative?

Coking coal is transformed into coke over coke, coal tar, and coke oven gas in coke ovens. The inputs to these processes are negative.
Lignite is transformed into electricity in electricity only and CHP plants, into BKB in BKB plants(all negative) and consumed directly by the non metallic minerals in industry sub sector (positive).

Aggregated balance

What is the efficiency (as percentage) of coal and natural gasmain activity producer electricity plants? (1GWh = 0.086 ktoe)

Coal 34.9%
Gas 41.9%

Is this country energy self sufficient? For all fuels?
(self sufficiency is calculated as production over TPES)

Self sufficiency is calculated as production over TPES (less than 1 means the country is not self sufficient and depends on imports). Since the value for Statisland is 2.58, that means that overall, it is self sufficient.
The country is not self sufficient for oil (sum of crude oil and oil products). It is 0.63.

What does the negative number in the total column of main activity producer electricity plants indicate?The oil refineries row has a positive number in the total column. Is this correct?

It represents the transformation loss of the electricity production process.
No it is not correct – you cannot get out more energy than you put in. It may be a problem with the underlying data in physical units or it could be a mismatch of the NCVs used to calculate the crude oil and oil products.

Bonus question

Look at the nuclear, hydro and geothermal columns in the “Data in physical units”worksheet, numbers are reported in electricity output for the three of them but only geothermal has data in production and transformation, why?
Looking at nuclear, hydro and geothermal in the “aggregated balance” worksheet we find numbers in production, how are they calculated? What are their efficiencies?

Physical Units Data
In hydro plants, the energy of the falling water is used directly to produce electricity. It cannot be used elsewhere. Therefore, the most logical measure of the energy production is the electricity output from the turbines.
For nuclear plants, the heat from the reactors is the primary energy form selected by the IEA because the heat can either be used to generate electricity (the usual case) or can be used directly.
For geothermal plants, it is possible thatmost is used for electricity generation in transformation, some heat may be used directly (e.g. in district heating) in transformation, and some may be used directly by final consumers. Because of the way that the IEA questionnaires are set up, to represent this in physical units, you need to have the amount of electricity produced, the amount of heat produced that is sold to third parties and the amount of heat produced that is used directly by final consumers. In the IEA questionnaires, this is stored by converting the electricity output to TJ and then applying the efficiency (default 10%), applying the efficiency for heat (around 50%) and putting the direct use and losses into the consuming sectors. Production is the sum of these elements.
Aggregated Balance Data
To estimate an input to electricity plants that do not use fossil fuels the following conventions are used when using the Physical Energy Content Method.

For hydro plants, 100% efficiency is assumed. This is because there is no benefit in calculating the energy of the falling water, as unlike heat, it has no other useful application. So the data in physical units are multiplied by 0.086 to convert from GWh to ktoe.
For nuclear, when data on the heat input to the turbines is unavailable, then it can be estimated by assuming a turbine efficiency of 33% (this is based on the European average). Any heat that is produced that is used directly should have been measured. So, the electricity output in physical units is multiplied by 0.086 and then divided by 0.33. The heat output used directly is converted from TJ to ktoe by multiplying by 0.02388.
For geothermal plants, the efficiencies were already applied to the data in physical units to estimate the inputs so the whole column can be converted directly to ktoe by multiplying by 0.02388