Abstract
In the perspective of using fuel cells for integration of fluctuating renewable energy the SOFCs are the most promising. These cells have the advantage of significantly higher electricity efficiency than competing technologies and fuel flexibility. Fuel cells in general also have the advantage of fast regulation abilities combined with excellent part-load efficiencies. Additionally scaling the cells from W to kW to MW is possible and does not influence the efficiencies of the cells. The feasibility of the scaling however depends on the market at hand and the fuel cells characteristics.
Wind integration can also be preformed with other types of fuel cells than the SOFCs such as PEMFC in micro-CHP. These however have the disadvantage that the efficiency is lower and require pure hydrogen. PEMFCs have advantages for mobile applications replacing internal combustion engines and batteries were feasible. For mobile applications the PEMFCs have the advantages that they can compete with internal combustion engines with fast start-up, fast regulation abilities and better efficiencies. In comparison with batteries fuel cells have the advantage that they have higher energy densities and can be refilled instantly, however the storage problems have yet to be solved. As storage and energy carriers methanol and ethanol are the most promising in regards to mass and volume. These can be used directly in SOFCs but have to be reformed for use in PEMFC.
New technologies that can provide energy system flexibility, such as SOFCs, heat pumps and heat storage technologies are more important than storing electricity as hydrogen via electrolysis in energy systems with high amounts of wind [12]. Unnecessary energy conversions should be avoided. However in future energy systems with wind providing more than 50% of the electricity and with the best measures for improving flexibility have already been taken, making fuels via electrolysis is one of the alternatives to integrate more renewable energy. Creating the road map to a 100% renewable energy systems require difficult choices between balancing fluctuating renewable with hydrogen production or electric cars, and on the other hand using biomass and bio fuels [11]. Fuel cells can have an important role in these future energy systems.
Wind integration can also be preformed with other types of fuel cells than the SOFCs such as PEMFC in micro-CHP. These however have the disadvantage that the efficiency is lower and require pure hydrogen. PEMFCs have advantages for mobile applications replacing internal combustion engines and batteries were feasible. For mobile applications the PEMFCs have the advantages that they can compete with internal combustion engines with fast start-up, fast regulation abilities and better efficiencies. In comparison with batteries fuel cells have the advantage that they have higher energy densities and can be refilled instantly, however the storage problems have yet to be solved. As storage and energy carriers methanol and ethanol are the most promising in regards to mass and volume. These can be used directly in SOFCs but have to be reformed for use in PEMFC.
New technologies that can provide energy system flexibility, such as SOFCs, heat pumps and heat storage technologies are more important than storing electricity as hydrogen via electrolysis in energy systems with high amounts of wind [12]. Unnecessary energy conversions should be avoided. However in future energy systems with wind providing more than 50% of the electricity and with the best measures for improving flexibility have already been taken, making fuels via electrolysis is one of the alternatives to integrate more renewable energy. Creating the road map to a 100% renewable energy systems require difficult choices between balancing fluctuating renewable with hydrogen production or electric cars, and on the other hand using biomass and bio fuels [11]. Fuel cells can have an important role in these future energy systems.
| Original language | English |
|---|---|
| Title of host publication | Long-term perspectives for balancing fluctuating renewable energy sources |
| Place of Publication | Kassel |
| Publisher | University of Kassel |
| Publication date | 2007 |
| Pages | 93-103 |
| Publication status | Published - 2007 |