As part of the funding initiative „Energiewende im Verkehr“ (energy turnaround in transport), the Federal Ministry of Economical Affairs and Energy (BMWi) is funding research and development into the production and application of synthetic fuels. Together with DLR and izes gGmbH, among others, the FfE accompanies this funding initiative with the accompanying research project BEniVer and is responsible for the ecological evaluation in the form of life cycle assessments.
One of the key technologies in the production of synthetic fuels is the electrolysis. In order to be able to compare analyses relating to fuel synthesis, it is important to have access to consistent data for the electrolysis. These consistent data sets were provided in /FFE‑29 20/ and /FFE 57 20/, the first source containing the operating data of the electrolysers and the second source describing environmental impacts for the production and disposal of stacks and balance of plant (BOP) for facilities with 1 MW installed capacity. Data were provided for Alkaline Electrolysis (AEL), Proton Exchange Membrane Electrolysis (PEMEL) and Solid Oxide Electrolysis (SOEL).
This blog post now describes the system formation of the three electrolyser technologies with a capacity of 285 MW each. The operating data sets are taken from the source mentioned above. It is assumed that the expenditure for the production of the stack can be scaled with the electrical capacity. In accordance with /FFE‑29 20/, it is assumed for the scaling of the BOP that with a doubling of the electrical capacity, the expenditure is 1.8 times the original expenditure. The results are calculated for the years 2020, 2030 and 2050. For electricity generation, /FFE‑55 20/ is used. In the case of SOEL, it is assumed that the available steam from waste heat is available and thus no expenditure is incurred for provision. All other data were taken from the ecoinvent database.
Figure 1: Greenhouse gas emissions of different electrolyser technologies for different years; contributions of electrcity supply, water supply, production and end-of-life of stack and balance of plant for each technology and year.
At this point, it should be noted that the hydrogen at the outlet of the various electrolyser technologies has different purity and pressure and is therefore not directly comparable (see also /FFE 29 20/). This is deliberately kept undefined at this point for further use, as the requirements for pressure and purity for further use may also differ.
Furthermore, the present results show an advantage of SOEL technology over the other two technologies. This only applies in this form to the assumption that the technology benefits from waste heat utilisation and that this waste heat is provided without any associated environmental impact. This may be the case for integration into an existing industrial park. In a greenfield application, the energy for providing the water steam would have to be provided, for example, by electrical energy.
Sources:
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FFE‑29 20 |
Pichlmaier, Simon et al.: Ökobilanzen synthetischer Kraftstoffe – Methodikleitfaden zum Projekt: Begleitforschung Energiewende im Verkehr (BEniVer). München: Forschungsstelle für Energiewirtschaft e.V., 2020. |
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FFE‑55 20 |
LCIA Environmental Indicators for the Electricity Production – Dynamis fuEL Scenario (Germany): http://opendata.ffe.de/dataset/lcia-environmental-indicators-for-the-electricity-production-dynamis-fuel-scenario-germany/; München: Forschungsstelle für Energiewirtschaft e. V. (FfE), 2020. |
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FFE‑57 20 |
LCIA Environmental Indicators for the Construction and End-of-Life of Electrolysers (Germany): http://opendata.ffe.de/dataset/lcia-environmental-indicators-for-the-construction-and-end-of-life-of-electrolysers-germany/; München: Forschungsstelle für Energiewirtschaft e. V. (FfE), 2020. |