• • PEM electrolyzers achieve minute-level startup and second-level response, enabling direct coupling with intermittent PV/wind without buffering batteries, as demonstrated by the 2.5 MW Ulanqab project directly coupled to wind power.
• • Low-iridium and non-noble metal catalysts, along with domestically produced proton exchange membranes, reduce material costs and mitigate supply chain risks associated with imported components, though long-term degradation rates under dynamic operation remain to be quantified.
• • Direct PV-PEM coupling requires matching the electrolyzer's voltage-current curve to the PV array's maximum power point; mismatches can lead to efficiency losses exceeding 15% under variable irradiance, necessitating advanced DC-DC converter control.
• • Hydrogen storage provides seasonal energy shifting (months-long storage) at a levelized cost that is currently 2-3 times higher than lithium-ion batteries for short-duration storage, but becomes competitive for durations exceeding 100 hours, addressing curtailment rates of 5-10% in high-renewable regions.