Workshop on Energy Balances and Energy related Greenhouse Gas Emission InventoriesCopenhagen 24-25 June 2003 CO2 Emission Inventories HarmonisationThe Strategy and Work in DenmarkBy Peter Dal, Danish Energy Authority
Contents • Possible reasons for divergence • Why revisions of the statistics are needed • Example 1: Firewood in households • Example 2: Domestic air transport • Example 3: CHP by autoproducers • Effective reporting systems are necessary
Possible Reasons for Divergence between Eurostat and EEA on Energy Data • Lack of co-ordination between two separate reporting institutions: Not the case in Denmark • Revision of historical data are not carried out to the same extent due to differences in the facilities for revision of time series
Why Revision of Energy Statistics is Needed • Revised national account statistics (ISIC-Nace) • Changes in calorific values etc. • Improved statistics on renewable energy • Re-evaluation of the transformation sector • Change in definitions of final energy consumption • Re-estimation of components in final energy cons.
Eurostat / IEA requirements for Statistics in the Transformation Sector
An Assumption of 200 % Heat Efficiency in Danish CHP-production In 2000, it was decided in the Danish energy statistics to assume a heat-efficiency of 200 % in CHP-production. Previously, fuel use was proportionally split between heat and electricity according to the corresponding heat and electricity production. This shift has had a significant effect on fuel consumption in the transformation sector as well on final energy consumption (especially in manufacturing where CHP-production is very widespread).
CHP by Autoproducers: An Example Fuel use: 100 TJ natural gas in a CHP-producing industry company Production: 40 TJ electricity 40 TJ heat, of which 20 TJ is sold for district heating Loss: 20 TJ Before - proportionally fuel split: Natural gas used for electricity production: 50 TJ Natural gas used for heat production: 50 TJ Used for district heat production 25 TJ Used in the company: 25 TJ (final consump) Now - 200% heat-efficiency: Natural gas used for electricity production: 80 TJ Natural gas used for heat production: 20 TJ Used for district heat production 10 TJ Used in the company: 10 TJ(final consump)
Conclusions on Autoproducers’ CHP • The assumption how to treat fuel consumption in CHP units may differ from country to country • Regarding autoproducers: Eurostat and IEA has no knowledge about the split between the transformation sector and final energy consumption • The Danish assumption means the more auto-producers’ CHP, the higher the energy efficiency
Effective Reporting Systems Are Necessary • Before: Completing paper questionnaires • IEA’s electronic reporting system • But, still all figures to the nearest whole number • Time series should be in focus • New reporting system for Danish energy statistics