Life Cycle Inventories of solid fossil fuels : updates for electricity generation from hard coal, lignite and peat
Creators: name: Itten, René
name: Oberschelp, Christopher
name: Kröhnert, Hanna
name: Stucki, Matthias
Publisher: name: ZHAW Zürcher Hochschule für Angewandte Wissenschaften
Year: 2023
Subjects: LCI
LCA
LCIA
Solid fossil fuel
Mining
Coal
Electricity
Hard coal
Lignite
Peat
333.79: Energie

description: The power sector, and especially coal power generation, is of high importance for Life Cycle Assessment (LCA) studies due to its high contributions across a wide range of environmental impact categories. Up to this update, the underlying Life Cycle Inventory (LCI) data of the supply chain for electricity generation from solid fossil fuels in the UVEK:2018 database was largely based on raw data from the year 2007 and older. Since then, environmental regulation in most countries has become substantially more strict and novel technologies have been introduced to abate emissions, while technological advances have improved on the efficiencies of the coal power generation. 
This comprehensive update of the LCI models for the complete solid fossil fuel supply chain in the UVEK database includes the actualisation of a total of 87 LCI datasets, the introduction of 35 new heat datasets as well as structural changes due to new and obsolete LCI datasets. The update of the solid fossil fuel supply chain for the UVEK database focuses on coal mining, hard coal supply mixes, solid fossil fuel combustion in power plants and electricity generation. Furnaces fired by solid fossil fuels as well as related infrastructure like coal mine storage facilities as well as power plant infrastructure are not updated and remain unchanged as described in Röder et al. (2007). The full report of Röder et al. (2007) in German is attached as annex to this report.
The update of LCI models for the solid fossil fuel supply chain in the UVEK database is a collaborative effort of Zürich University of Applied Sciences (ZHAW) and the Swiss Federal Institute of Technology (ETH) and was carried out in accordance with the data quality guideline of ecoinvent v2.0 (Datenqualitätsrichtlinie ecoinvent Daten V2.0, DQRv2) according to Frischknecht et al. (2007).
Electricity generation from solid fossil fuels is among the technologies with the highest environmental impacts per kWh of electricity generated. The greenhouse gas emissions caused by the generation of 1 kWh of electricity from hard coal ranges from 0.861 to 1.32 kg CO2-eq with generation in the Czech Republic causing the highest greenhouse gas emissions with 1.32 kg CO2-eq followed by Russia and India with 1.15 and 1.23 kg CO2-eq, respectively. The greenhouse gas emissions caused by the generation of 1 kWh of electricity from lignite ranges from 1.0 to 1.35 kg CO2-eq with generation in the Bosnia Herzegovina causing the highest greenhouse gas emissions with 1.35 kg CO2-eq followed by Greece and Slovakia with 1.33 and 1.28 kg CO2-eq, respectively.
The primary energy demand caused by the generation of 1 kWh of electricity from hard coal ranges from 9.53 to 14.7 MJ oil-eq with generation in the Czech Republic causing the highest primary energy with 14.7 MJ oil-eq followed by India and Russia with 14.2 and 13.5 MJ oil-eq, respectively. The primary energy demand caused by the generation of 1 kWh of electricity from lignite ranges from 9.34 to 22.9 MJ oil-eq with generation in the Greece causing the highest primary energy with 22.9 MJ oil-eq followed by North Macedonia and the Serbia with 15.3 and 14.9 MJ oil-eq, respectively. 
The total environmental impacts caused by the generation of 1 kWh of electricity from hard coal ranges from 1’010 to 1’830 eco-points with generation in the India causing the highest total environmental impacts with 1’830 eco-points followed by Czech Republic and the Russia with 1’600 and 1’570 eco-points, respectively. The total environmental impacts caused by the generation of 1 kWh of electricity from lignite ranges from 1’150 to 1’910 eco-points with generation in the North Macedonia causing the highest total environmental impacts with 1’910 eco-points followed by Bosnia Herzegovina and the Serbia with 1’690 and 1’670 eco-points, respectively. 
Most relevant processes in supply chain for electricity generation from solid fossil fuels are the combustion process, the conversion efficiencies in the power plants and coal mining. The conversion efficiency is not reflected in the contribution analysis and only influences the overall magnitude of results. The detailed contribution analysis for electricity from hard coal generated in Germany revealed, that most important contributor for greenhouse gas emissions with more than 84 % are the direct emissions from combustion of hard coal, followed by the coal supply with 15 %. The contribution of flue gas treatment and power plants only have a minor contribution to the total greenhouse gas emissions of 0.5 and 0.2 %, respectively. 
Most important contributor for primary energy demand with more than 98 % is the hard coal supply. The contribution of flue gas treatment and power plants only have a minor contribution to the primary energy demand of 0.7 and 0.2 %, respectively. Most important contributor for total environmental impacts with more than 73 % are the direct emissions from combustion of hard coal, followed by the coal supply with 25 %. The contribution of flue gas treatment and power plants only have a minor contribution to the total environmental impacts of 1.4 and 0.3 %, respectively. 
This update of the LCI models for the solid fossil fuel supply chain in general leads to lower environmental impact assessment results caused by the electricity generation from solid fossil fuels mainly due to (1) the update of the power plants efficiencies, (2) the update of the emission profiles of the solid fossil fuel combustion datasets (3) the update of the methane emissions from the coal mining processes and (4) the update of the hard coal supply mixes (sorted in descending order according to importance). 
The highest changes occur for the total environmental impacts assessed with the Ecological Scarcity Method 2021. The changes in total environmental impacts ranges from +8 % to -42 % per kWh of electricity generated from solid fossil fuels. This reduction is mainly due to the updated key emissions, methane in case of coal mining, CO2 and priority air pollutants like, NOx, SO2, PM as well as trace elements (heavy metals, volatile organic compounds) in case of the solid fossil fuel combustion. The changes for the greenhouse gas emissions according to IPCC 2021 per kWh of electricity generated range from +19 % to -24 % and can mainly be attributed to the change in power plant conversion efficiencies. The changes in primary energy demand per kWh of electricity generated range from +14 % to -20 % and result exclusively from the change in power plant conversion efficiencies, since the heating values and coal input into the combustion process has not been changed compared to the last version of the UVEK database. 
In general, the update leads to a harmonisation of inventory models and differences in the impact assessment results from different electricity generation datasets were reduced. However, with greenhouse gas emissions of 0.861 kg CO2-eq. – 1.35 kg CO2-eq. per kWh electricity from hard coal, lignite and peat power generation solid fossil fuels remains among the technologies with the highest contribution to the global climate crisis.