The Leighty Foundation, United States
pp. 63 - 66
Keywords: renewables, transmission, storage, integration, pipelines, cavern
Electricity systems will be inadequate to humanity's urgent task of rebuilding its largest industry -- energy -- from ~85% fossil today to 100% renewable sources by Year 2100. To supply all energy, from all sources for all uses, from diverse renewables -- and perhaps some nuclear -- we must conceive, design, and build complete, optimized, energy systems to solve the Big Three problems of renewables: 1. Gathering and transmission 2. Annual-scale firming storage 3. Distribution, integration, and end-use The most technically and economically attractive alternatives to electricity systems move and store carbon-free fuels in underground pipelines of multi-GW capacity: 1. Gaseous hydrogen, GH2 2. Liquid anhydrous ammonia, NH3 GH2 storage is in deep, man-made salt caverns, storing ~ 100,000 MWh each at Capex ~ $ 0.20 / kWh. NH3 storage is in ~ 30,000 ton refrigerated "atmospheric" surface tanks, storing ~ 200,000 MWh each at Capex ~ $ 0.10 / kWh The renewables-source GH2 and NH3 fuel is distributed and sold for stationary CHP, industrial and residential, and transportation fuels, or for regeneration for wholesale grid feed. GH2 and NH3 fuel transmission costs less per GW-km than electricity. Underground infrastructure is protected.