Cogeneration of green hydrogen in a cascade hydropower plant

•Among renewable energy sources, hydropower plants are the most suitable for cogeneration of electricity and green hydrogen.•The cogeneration in a cascade hydroelectric power plant is possible to a limited extent.•The cogeneration can be already economically viable today.•The scenario for the use of green hydrogen for heating and mobility needs in the local community is presented.•The article supports hydrogen strategies in harmony with renewable energy policies. Hydrogen is today an indispensable feedstock in various process industries, but the method of its production is mostly not in line with accepted environmental guidelines. With emerging electro-energetic systems with a large share of renewable sources, hydrogen is also becoming an important energy carrier, which with the possibility of storing surplus energy ensures greater stability of power system operation and energy supply. Therefore, the use of electricity from renewable sources is important for the production of green hydrogen using electrolysis. The first part of the article describes the possibilities for hydrogen cogeneration in one of the run-of-river hydropower plants in Slovenia. The implementation costs of the necessary equipment for hydrogen production in the case-study power plant, its production costs and the profitability of hydrogen production compared to the sale of electricity are estimated. The criteria according to which the production of hydrogen is more profitable than the sale of electricity at current prices and guaranteed sales is also defined. In the second part of the article, a scenario for the use of hydrogen for heating and mobility needs in the nearby local community is presented. For the regular supply of hydrogen in the range of up to 30 kg/h, the necessary investment costs for the installation of the appropriate equipment in the hydropower plant are calculated along with an estimation of the payback period of the investment.