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A team of German researchers has compared the economic performance of a decentralised photovoltaic system with electrolyser and fuel cells with that of a stand-alone solar-plus-storage system on a building in Niger. Their analysis showed that decentralised hydrogen powered by photovoltaics could achieve a significantly lower levelised cost of energy and levelised cost of storage than the battery-powered photovoltaic system, with values ??reaching €0.12 ($13.1)/kWh and €0.35/kWh, respectively.
A group of researchers from the University of Applied Sciences in Germany has investigated how PV-electrolyzer-fuel cell systems could replace solar plus storage systems as stand-alone power supply solutions for decentralized off-grid electrification and found that the fuel cell variant could provide significantly cheaper power and lower stored energy costs than the solar plus storage combination.
The scientists studied the possibility of installing both configurations in a two-storey, 14-room academic building in Niamey, Niger. The average annual radiation is about 2000 kWh/m2.
The building uses 19 air conditioners, 75 lamps, 23 fans, 26 computers, 2 laptops, 4 video projectors, 1 television, 5 printers, 2 refrigerators, 2 photocopiers, 3 scanners and 1 outdoor lamp. “The operating hours of all appliances are between 06:00 and 21:00, except for the refrigerators, the outdoor lamp and the standby load,” the scientists specify, noting that the nominal load during operation is constant, around 66.8 kW. “As the building is closed on Sundays, only the refrigerator load and the standby load are taken into account during the day.”
The photovoltaic hydrogen system consists of a 150 kW solar panel, a 50 kW polymer exchange membrane (PEM) electrolyzer, a hydrogen tank with a total storage capacity of 50 kg, a 20 kW fuel cell, and a 5 kWh battery that covers a small load during the night for practical reasons. “Every day, the battery would be fully charged before producing hydrogen, ensuring sufficient electricity availability during the night,” the group noted. “The amount of hydrogen remaining at the end of the day after fuel cell operation will be accumulated in tanks every day.”
The performance of this hydrogen system was compared, through a series of simulations, to that of a stand-alone solar-plus-storage counterpart consisting of a 150 kW PV array, a 513 kWh battery storage system, and an energy management system. The analysis took into account the overall cost structure of the systems, the levelized cost of energy (LCOE) and levelized cost of storage (LCOS) of both systems, as well as the levelized cost of hydrogen for the PV-electrolyzer-fuel cell system.
The economic analysis showed that the photovoltaic-powered hydrogen system is an “optimal option” compared to the classic photovoltaic battery system, despite its slightly higher initial costs. “Although the battery storage system delivers a slightly higher amount of electricity than the hydrogen storage system, the difference is marginal compared to the higher profitability of the hydrogen option,” the scientists say.
They found that the hydrogen system achieved an LCOE of €0.12 ($13.1)/kWh and an LCOS of €0.35/kWh, while the solar plus storage system achieved values ??of €0.17/kWh and €0.71/kWh. The LCOH of the hydrogen installation also ranged from €8.21/kg to €4.78/kg.
The reason for the better performance of the hydrogen PV system was attributed to the relatively high cost of the system’s battery over the project’s lifetime. “Considering the future manufacturing challenges associated with the battery storage system, investing in the hydrogen storage system today could be a favorable option,” the researchers stated. “From the results of this study, it can be concluded that the proposed project can be feasibly installed at the chosen site.”
Their findings can be found in the study “ Standalone electricity supply system with solar hydrogen and fuel cell: Possible to get rid of storage batteries? ”, recently published in the International Journal of Hydrogen Energy . “The consistent message emerging from these results is the economic viability of hydrogen production and its use for electricity storage applications,” the academics conclude. |
