broschuere ee zahlen en bf

ANNEx: METhODOLOGICAL NOTES
100 Renewable Energy Sources in Figures
4. Calculating avoidance factors and avoided emissions for renewables­based
heat generation
The emissions of greenhouse gases and air pollutants that are avoided by using renewable
energy in the heat sector are calculated in three stages:
First, the substitution factors are determined for each of the renewable heat supply paths.
These indicate which fossil primary and also secondary energy sources such as district heating
or electricity would have to take over the renewable heat supply if the latter were not
available. Important information for this purpose is provided by the findings of an empirical
survey on the use of solar thermal energy, heat pumps and wood-burning systems in private
households [87]. Use was also made of information from the Working Group on Energy Balances
(AGEB) on energy consumption by the sectors: processing of mined and quarried products,
the paper industry, and other industries (including timber industry) and private households.
In the case of supplies of renewable district and local heating from wood, biogenic
components of waste and geothermal energy, it is assumed that these are a 100 % substitute
for fossil district heating and that the distribution losses are comparable.
In a second step, emission factors for renewable heat supplies in private households, agriculture
and industry, and also for the relevant savings in fossil heat supplies, are taken from or
deduced from UBA [92], Öko-Institut [90], Ecoinvent [84], Vogt et al. [89], Ciroth [83], Frick et
al. [86]. The emission factors used take account of the entire upstream chain for supplies of
fossil and renewable energy sources. In the case of combined heat-and-power generation, allocation
to heat and power is in accordance with the “Finnish method” laid down in EU
Directive 2004/8/EC.
In the final step, the fossil emissions avoided are compared with the emissions arising from
the use of renewables to determine the net avoidance of greenhouse gases and air pollutants.
Detailed information on the calculation methods and data sources can be found in UBA [75].
Substitution factors for renewables­based heat
Heating oil Natural gas Hard coal lignite District heat Elec. heating
[%]
Wood – stand-alone stoves (hh) 41 50 0 1 2 6
Wood – central heating systems (hh) 65 20 2 3 0 10
Solid biomass (industry) 13 54 10 14 9 0
Solid biomass (hP/ChP) 0 0 0 0 100 0
Liquid biomass (industry) 7 67 10 3 13 0
Liquid biomass (hh) 29 51 1 1 9 9
Biogas, sewage gas, landfill gas (BChP) 58 37 5 0 0 0
Biogenic fraction of waste (hP/ChP) 0 0 0 0 100 0
Deep geothermal energy (hP/ChP) 0 0 0 0 100 0
Solar thermal energy (hh) 45 51 0 0 1 3
heat pumps (hh) 45 44 1 2 5 3
Total 35 38 3 3 17 4
Sources: UBA [75], [92] on the basis of AGEE-Stat and Frondel et al. [87]; AGEB [2], [4]