Assessing hydrogen production from wind and solar power with an LCA

One option to reduce the environmental problems induced by the transport sector is its electrification with fuel cell electric vehicles (FCEV) as they produce locally only water emissions and are much quieter than conventional vehicles with an internal combustion engine. However, for a real environmental benefit of hydrogen not only its usage in a FCEV has to be cleaner. Also its production and distribution has to be taken into account. In particular solar and wind power are often discussed as energy sources for renewable hydrogen production due to its large energy potential all over the world. Due to the unequal local distribution of these energy sources not every country in the world is able to cover their needs of renewable energy on its own, like Japan or Germany. Other regions instead, like North Africa, have very large renewable energy potentials [1]. That is why for Germany next to the production of hydrogen from wind power with electrolysis the import of hydrogen produced with the help of concentrated solar power (CSP) is one future option. By using the high temperatures generated by a CSP plant different hydrogen production options can be of interest, i.e. high temperature electrolysis and thermochemical cycles.Within such a scenario a mayor challenge is the transport: For short and medium distances hydrogen is transported in a gaseous state. The storage density of gaseous hydrogen, however, is quite low. Thus, for longer distances hydrogen is transported as a liquid. However the liquefaction of hydrogen consumes around 30 % of the energy content of hydrogen [2]. As an innovative alternative liquid organic hydro carriers (LOHC) can be used as a carrier fluid. They can be handled much easier than liquid hydrogen with respect to temperature or losses [3]. Against this background the goal of this paper is it to compare three different future hydrogen production and distribution pathways from renewable energies by means of a life cycle assessment: 1. Hydrogen production with alkaline electrolysis powered by wind energy directly at the site of the hydrogen refueling station.2. Hydrogen production with high temperature electrolysis powered by a concentrated solar power plant in North Africa and transported to Germany within liquid organic hydrogen carriers by ship and truck to a hydrogen refueling station.3. Hydrogen production with a thermochemical cycle powered by a concentrated solar power plant (CSP) in North Africa and transported to Germany within liquid organic hydrogen carriers by ship and truck to a hydrogen refueling station.As a fossil reference system the hydrogen production with steam reforming of Natural Gas and its transport by truck to a hydrogen refueling station will be investigated. In all analyzed pathways the functional unit will be 1 kg of hydrogen with 700 bar ready for dispensing at a hydrogen refueling station in Germany. References[1] C. M. Salazar, An Overview of CSP in Europe, North Africa and the Middle East, CSP today, 2008[2] idealhy, Design for Demonstration of Efficient Liquefaction of Hydrogen idealhy: Enabling liquid hydrogen as a means of distribution of low-carbon energy, 2013[3] T. Harada, Ichikawa, H. Takagi, H. Uchida, in; Compendium of Hydrogen Energy Volume 4: Hydrogen Use, Safety and the Hydrogen Economy. M. Ball, A. Basile and T. N. Veziroglu (Ed.), Woodhead Publishing, Cambridge, 201