A feasibility study on production and storage of hydrogen with renewable energy resources at municipal scale

Sammanfattning: The feasibility of a PEM hydrogen storage system in a municipal setting using prosumer excess solar power has been investigated. The feasibility was determined upon key performance indicators payback time, internal rate of return (IRR) and net profit margin. The project was done as a case study on Södertälje municipality, Stockholm, Sweden. Different business models were compared to determine the optimal operation scheme. Potential showstoppers were also explored. Literature study and interviews were combined into a system model in Excel which breaks down costs and profits over a 20-year timeline. A sensitivity analysis was performed to measure the stability of yearly net profits during changes in electricity price and hydrogen market price. The available excess solar power was identified and used to size a system consisting of an electrolyser, storage tanks and fuel cells. A daily system was deemed best, where electricity is accepted during the day and discharged during the night. Hydrogen is also sold as a commodity for vehicular charging, and oxygen is compressed into a refill station for hospitals and manufacturers. The results were simulated in two operational scenarios; a Standard scenario and a Truck scenario, the latter which has no fuel cell and more hydrogen is sold at the expense of electricity. The payback time is 5 years for the Standard scenario and 4 years for the Truck scenario. They have an IRR of 4% and 32% after 5 years and a net profit margin of 63% and 86% respectively. The sensitivity analysis shows <6% change in yearly net profits for the Standard scenario and <12% change in the Truck scenario when electricity price and hydrogen market price fluctuatesby 50%.