Techno-economic analysis of a wind-photovoltaic-electrolysis-battery hybrid energy system for power and hydrogen generation

The techno-economic feasibility of the wind-photovoltaic-electrolysis-battery (WPEB) power system and its capability for curtailment reduction are studied. The WPEB system (wind:120 MW, PV:80 MW, electrolyzer: 60 MW, battery bank: 20 MW) located in Damao Banner, China is taken as a case study. The main conclusions are summarized below: First, the WPEB system annually generates 584.62GWh renewable electricity. The generation accommodation capability requirement of the power grid decreases from 57.56% to 28.72% by raising the electrolysis ratio from 0% to 22.31%. WPEB system successfully applies the Power-to-Hydrogen technology to utilize the curtailed electricity. Second, a flexible hydrogen demand curve is well suited to boost the hydrogen production of the WPEB system which adapts to the seasonal and diurnal variation of renewable power generation. 77.30% of the hydrogen load is met by the WPEB system at a constant hydrogen demand of 24000 kg/day because of the low renewable generation from July to September. Third, the economic performance of the WPEB system benefits from increasing hydrogen production because the hydrogen/oxygen selling revenue is superior to that of selling electricity to the grid. The NPV of the WPEB system exceeds the wind-photovoltaic -battery (WPB) system when the hydrogen production is no less than 12000 kg/day. The net present value (NPV), internal rate of return (IRR), return on investment (ROI), levelized cost of electricity (LOCE), levelized cost of hydrogen (LCOH) and payback period of the WPEB-H24000 condition are 1781.22 million yen , 13.19%, 80.86%, 0.2503 yen /kWh, 13.1665 yen /kg, 9 years.