The range of fuels and energy products in broad categories covered by the Inventory are coal, natural gas, petroleum products and end-use electricity. There are cases where some measures in the Inventory benefit more than one type of fossil fuels. In this case, the OECD Secretariat allocated support to particular fuels where official government sources do not provide such a breakdown. Measures benefiting more than one fuel or energy product were allocated according to the relative value of production or consumption using the calculated shares derived from the national balances published in the IEA’s World Energy Balances.
For fuels such as coal, natural gas and petroleum, the allocation concludes with a simple allocation of shares calculated using the IEA World Energy Balances data. However, for end-use electricity, the allocation presents an additional methodological challenge as raw amounts include embedded support for electricity generated from non-fossil-fuel origin (e.g., nuclear, renewables, biofuels and wastes) and electricity from traded (i.e., imported) sources, (which can make it difficult to trace the ultimate origin and consequently the generation type of the electricity once joining the national grid). Both the share of electricity from non-fossil-fuel sources and electricity from traded sources must therefore be removed to isolate end-use electricity support to fossil fuels alone.
To isolate the share of electricity domestically generated in the country (i.e., excluding imported electricity), the following formula was used: