by Tim Storer
Norway currently generates over 95% of its power from hydroelectric dams, making it one of the most climate friendly energy systems on the planet. In efforts to bring Norway carbon neutral by 2050, the government aims to eliminate emissions from the transportation sector. Konrad Meier of the Stuttgart University of Applied Sciences examines the possibility of using a hypothetical 100 megawatt offshore wind farm to generate hydrogen fuel via electrolysis. Because water hydrolysis uses only electricity and water, it offers an emissions-free means to generate hydrogen as long as the electricity is generated from a renewable source, such as wind power. This could achieve Norwegian political goals of carbon neutrality by providing the hydrogen necessary to transform their transportation sector. Unlike other proposed wind-to-hydrogen technologies, Meier examines an off-grid operation, rather than producing hydrogen at the fuel refill site. The analysis was conducted under three scenarios, and the hydrogen from this proposed operation is profitable in the energy market under only the “best case” scenario.
This is a clever use of wind power for several reasons. First, if this operation were integrated into the power grid, wind variability would become an issue. Keeping the production off-grid avoids costs of transmission infrastructure and variable supply. Second, the variability also makes exporting excess power to the E.U. infeasible. The remaining 5% of domestic power is more likely to come from untapped hydroelectric resources, so wind has no use in Norway either. Using wind power for hydrogen synthesis circumvents these issues that have previously prevented wind production from being a viable energy source in Norway.
To examine costs, Meier used a location proximal to an operational German wind farm, Alpha-ventus, and incorporated its data. He uses 2010 data as his “worst case” scenario, which is a very conservative baseline considering how much lower the power output had been in previous years and how the proposed system would not be subject to transmission losses. The “best case” scenario was calculated simply by the predicted estimates. Given the likely increases in electrolysis efficiency in upcoming years, this scenario also yields conservative estimates of overall output costs. Meier discusses four types of electrolysis, but focuses on proton exchange membrane electrolysis cell (PEMEC) and solid oxide electrolysis cell (SOEC) that require water as the only input material. Unfortunately, research on the efficiency of PEMEC and SOEC is unable to offer precise estimates, and herein lies a major source of ambiguity in the study.
Because there is currently no market for hydrogen transportation fuel, this study is limited by the assumption of a future in which infrastructure has been implemented to support a hydrogen market. Unfortunately, given how variable the results are (dependent on optimistic/pessimistic assumptions), it is unclear whether such an investment is worthwhile at all. However, in as much as the best and worst case scenarios were estimated in a very conservative way, it is possible that such an operation could be an economic way to transform the transportation sector. Further research is needed on the efficiency of the PEMEC and SOEC processes to indicate whether the proposed wind farm is an economically viable solution to attaining a carbon neutral transportation sector.
Konrad Meier, 2014. Hydrogen production with sea water electrolysis using Norwegian offshore wind energy potentials. International Journal of Energy and Environmental Engineering Vol. 5: 1–12. http://link.springer.com/article/10.1007/s40095-014-0104-6/fulltext.html#CR1