Electrolysis splits water into hydrogen and oxygen using electricity. Next-gen proton exchange membrane (PEM) electrolyzers achieve 80% efficiency, with costs dropping from $1,000/kW to $400/kW by 2025. Scaling renewable-powered electrolysis is key, targeting $1/kg hydrogen by 2030.

Cryogenic tanks store hydrogen at -253°C, enabling transport over long distances. NASA’s expertise is adapting for commercial use, though boil-off losses (1% daily) require improved insulation. Solid-state options like metal hydrides are emerging alternatives.

FCVs like Toyota’s Mirai offer 400-mile ranges and 5-minute refueling, ideal for heavy-duty transport (trucks, planes). Infrastructure lags, with only 600 global stations, but Japan and Germany are expanding networks.

Microalgae produce lipids convertible to biodiesel, yielding 10-100 times more per hectare than crops like corn. Projects like ExxonMobil’s trials aim for 10,000 barrels daily by 2030. Costs remain high ($5/gallon), but co-products (e.g., animal feed) improve economics.

Gasification or pyrolysis converts trash into syngas, then synthetic fuels. Fulcrum BioEnergy’s Nevada plant processes 200,000 tons of waste yearly into jet fuel. Scaling requires consistent waste streams and emissions controls.