Techno-economic assessment of renewable hydrogen production for mobility: A case study

Abstract

Renewable hydrogen produced by water electrolysis from intermittent energy sources (i.e. sun and wind) is considered one of the most promising energy carriers for the decarbonisation of the so-called “hard-to-abate” sectors, especially heavy-duty transport and industry. To this reason, several new projects are currently under development and public fundings are widely available to boost the renewable hydrogen market. In this fast-changing scenario, this paper presents the techno-economic analysis of an integrated system where renewable power generation, electrolytic hydrogen production and final hydrogen use are closely integrated within a specific site, allowing higher efficiency as well as a containment of hydrogen production and handling cost. The analysis here presented considers a specific case study that includes a 12.5 MWP photovoltaic plant, a 5 MW electrolyser capable to produce nearly 300 t/yr. of renewable hydrogen, and a compression and storage system, all located in Sardinia (Italy). Differently from previous studies, this work faces the analysis from two opposite perspectives: on the one hand, it allows the assessment of the levelized cost of hydrogen during the whole project’s life, making the results comparable to those from other similar analyses; on the other hand, it presents the calculation of project’s profitability in terms of net present value, internal rate of return and payback time from the perspective of a potential investor. The analysis shows that a whole investment of about 20.3 M€ is required, which allows to achieve a levelised cost of hydrogen of 4.09 €/kg, which can decrease to 2.97 €/kg considering the revenues from selling oxygen and the overproduction of electricity. The potential use of renewable hydrogen in urban public transport (by means of fuel cell electric vehicles) has been considered as well, in comparison with conventional diesel buses. Despite the lower cost for fuel (0.41 €/km for hydrogen buses vs. 0.72 €/km for diesel buses) and maintenance and repair (0.20 €/km vs. 0.27 €/km), as well as the lower CO2 emission (some 76 t/yr. saved per bus), the very high investment cost for hydrogen-fuelled buses (up to 720,000 €) makes hydrogen still not competitive with diesel for urban transport, being hydrogen buses characterised by a whole specific transport cost of 1.45 €/km, to be compared with 1.04 €/km for diesel buses.