CO2 Intensity of Electricity Generation

• Not applicable

The CO₂ intensity of total electricity generation is taken as the ratio of CO₂ emissions from all electricity production, both from public main activity producers and autoproducers, against total electricity generation including electricity from nuclear plants and renewable sources. The CO₂ emissions used in this indicator (the numerator, expressed in TgCO₂) were derived from the reported total CO₂ emissions from public electricity and heat generation from the EEA greenhouse gas data viewer (code: 1A1a). As the 1A1a category shows CO₂ emissions for all energy production from Public Electricity Generation, Public Combined Heat and Power and Public Heat Plants, the following estimations were performed:

- First, the CO₂ emissions of gross electricity production were calculated. This was done by multiplying total CO₂ emissions (1A1a), with the ratio of electricity production (plus energy losses) from public conventional thermal power stations (ESTAT:TI_EHG_MAPE_E, TI_EHG_MAPCHP, TI_EHG_MAPH and GHP were used together with ‘SIEC’ C0000X0350-0370, O4000XBIO, G3000, C0350-0370, P1000, S2000, R5110-5150, R5300, W6100_6220) versus all electrical energy production from public power stations (ESTAT: GEP_MAPE) and combined heat power station (GEP_MAPCHP). The ratio for calculating the share of CO₂ emissions of electricity production was calculated as (electrical energy + energy losses)/(electrical energy + derived heat + energy losses).

To calculate (electrical energy + derived heat + energy losses), which is the total output from public conventional power plants, the sum of energy input of public power plants (ESTAT:TI_EHG_MAPE_E, TI_EHG_MAPCHP and TI_EHG_MAPH) from combustion fuels (C0000X0350-0370, O4000XBIO, G3000, C0350-0370, P1000, S2000, R5110-5150, R5300, W6100_6220) was taken as approach. 

• Transformation input — Main Activity Producer Electricity Only; nrg_bal_c; TI_EHG_MAPE;
• Transformation input — Main Activity Producer Combined Heat and Power; nrg_bal_c; TI_EHG_MAPH;
• Transformation input — Main Activity Producer Heat Only; nrg_bal_c; GHP_MAPH
• Solid fossil fuel; C0000X0350-0370;
• Oil and petroleum products (excl. Biofuel); O4000XBIO;
• Natural Gas; G3000;
• Manufactured gases; C0350-0370;
• Peat and peat products; P1000;
• Oil shale and Oil sands; S2000;
• Primary solid biofuels; R5110-5150_W6000RI;
• Biogases; R5300;
• Non-renewable waste; W6100_6220.

To calculate (electrical energy + energy losses), it was assumed this equals to (electrical energy + derived heat + energy losses)–(derived heat), which in turn equals to (energy input – derived heat). This approach was used since the energy transition losses are unknown. For energy input, the sum of the energy input of power plants (ESTAT:TI_EHG_MAPE_E, TI_EHG_MAPCHP and TI_EHG_MAPH) were used again, for combustion fuels (C0000X0350-0370, O4000XBIO, G3000, C0350-0370, P1000, S2000, R5110-5150, R5300, W6100_6220). To calculate derived heat, the sum of gross heat production from public power plants (GHP_MAPH) and combined heat plants (GHP_MAPCHP) was used.

• Gross heat production — Main Activity Producer Heat Only; nrg_bal_c; GHP_MAPH;
• Gross heat production — Main Activity Producer Combined Heat and Power; nrg_bal_c; GHP_MAPCHP.

- Second, the reported CO₂ emissions in class 1A1a do not include CO₂ emissions from autoproducers. Emissions from autoproducers were therefore estimated by multiplying the electricity output of autoproducers (nrg_bal_c, TI_EHG_APE_E, TI_EHG_APCHP_E were used for the calculations) by a calculated CO₂ emission ratio for main activity producers. This CO₂ emission ratio was calculated as the CO₂ emissions from public electricity production (as derived above), against the amount of electricity produced in public conventional power plants.

A zero CO₂ emission factor was applied to nuclear power and to renewables, including to biomass energy. In the case of the former, this is because the method does not take into account life-cycle greenhouse gas emissions. For the latter, this is because — according to the United Framework Convention on Climate Change (UNFCCC) Reporting Guidelines — biomass-related emissions have to be reported as a memorandum item in greenhouse gas inventories, with the assumption being that biomass harvesting would be shown as changes in carbon stocks in the Land Use, Land Use Change and Forestry (LULUCF) sector, and thus not in the energy sector. This should not be interpreted, however, as an endorsement of default biomass sustainability or carbon neutrality. 

The denominator of the CO₂ intensity of total electricity production is the sum of electricity produced from public power stations (ESTAT: GEP_MAPE, GEP_MAPCHP) and from autoproducer power stations (ESTAT: GEP_APE, GEP_APCHP). These data are presented by ESTAT category GEP (Gross electricity generation).

Care is needed when using estimates for the CO₂ emission intensity of total electricity production. Assumptions are used to estimate these intensities, given that the CO₂ emissions data from the EEA greenhouse gas data viewer (category 1A1a, Public Electricity and Heat production) include both the emissions from power and heat generation. Specifically, for the allocation of CO₂ emissions from combined heat and power (CHP) plants, the EEA has chosen a proportionality approach based on the electricity and heat output data from Eurostat. This implies an equal average efficiency for both heat and electricity generation, which is likely to overstate the electricity efficiency and to understate heat efficiency for CHP plants.  

Percentages (gCO₂/kWh)

Dataset based on EEA greenhouse gas data viewer and Eurostat energy database.