Assessment of green hydrogen production and hybrid renewable energy system for seasonal residential area

Abstract

Global energy consumptions and environmental issues keep increasing with growing population and technologic advancements; therefore, development of alternatives to fossil fuels which have depleting resources as well as negative environmental impacts becomes a necessity. Combining with the global economic and energy crises, sustainable and emission free renewable energy sources such as wind and solar energy has become important in this transition over the last decades. Moreover, rising greenhouse gas emissions and reliance on fossil fuels are compelling arguments for shifting to alternative sources and for motivating industrial actors to invest in different technologies. One promising solution to reduce greenhouse gas emission is green hydrogen, since it can be used as a replacement of fossil fuels in various industrial applications along with heating and mobility sectors. In this study, feasibility of green hydrogen production from an electrolyzer that is supplied by off-grid hybrid wind and solar energy with battery storage is investigated. Hybrid system will be used to meet electricity demand of a seasonal residential area consisting 100 homes that is located in Foça, Izmir/Turkey. The area is suitable for summer vacation mostly, therefore, electricity demand is much higher during summer than winter. Accordingly, an off-grid hybrid system is designed based on the peak demand and load profiles. Considering the seasonal variations and fluctuation of energy generation from renewable sources, there will be excess energy throughout the year, especially from fall to spring seasons. Among various technologies, the excess energy will be supplied to the 250 kW proton exchange membrane (PEM) electrolyzer for green hydrogen production in order to add value to overall system. Since Izmir has a developed industry and ports, applications of the produced green hydrogen in several industries such as steel, mobility and ammonia is examined while analysing the entire supply chain from production to storage and transportation. Electricity generation and hydrogen production simulations were performed in the HOMER Pro software. Results of the study showed that most feasible configuration of the proposed off-grid hybrid renewable energy system is determined as which consisting solar energy, wind energy and battery storage with a levelized cost of electricity as 0.265 $/kWh. On the other hand, considering the aim of this study, most feasible configuration with the integration of an electrolyzer to an off-grid hybrid renewable energy system, which includes 303 kW solar energy, 12 kW wind energy and 822 kWh battery storage capacities, offers the levelized cost of electricity as 0.389 $/kWh with total of 5,946 kg hydrogen production and levelized cost of hydrogen as 4.5 $/kg. Examining the application of hydrogen on different sectors, up to 35.2 tons of CO2 emission reduction has been observed while the costs are increasing up to 8.28 $/kg. The findings can be considered aligned comparing with literature and future targets. This study provides an overview for evaluating implementation of an integrated system with hybrid renewable energy sources and electrolyzer to meet energy demand of a region while producing green hydrogen. Even though it is a sustainable approach, current costs of green hydrogen applications are higher comparing to traditional methods. As green hydrogen can become an unrivalled tool to replace fossil fuels, it is crucial to implement suitable national strategies, policies, incentives, laws and taxes which accounts for important part of developing a hydrogen market to achieve future energy targets.