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So, the key to viable wind and solar is not in direct generation of electricity, but in using them to create a storable form of energy that can be used as needed by big power plants. Most are looking at hydrogen gas.
According to this wiki article, storage of hydrogen gas for stationary power plants (as opposed to the mobile car engine) is not especially problematic:
By this scheme, the grid and all its power plants remain intact, but they would burn hydrogen instead of natural gas and coal. Wind and solar farms would not be directly connected to the grid: all their output would be used to split water, and the resultant hydrogen conveyed to power plants much like natural gas is now.
https://en.wikipedia.org/wiki/Hydrogen_storage
According to this wiki article, storage of hydrogen gas for stationary power plants (as opposed to the mobile car engine) is not especially problematic:
Unlike mobile applications, hydrogen density is not a huge problem for stationary applications. As for mobile applications, stationary applications can use established technology:
Underground hydrogen storage[edit]
- Compressed hydrogen (CGH2) in a hydrogen tank[61]
- Liquid hydrogen in a (LH2) cryogenic hydrogen tank
- Slush hydrogen in a cryogenic hydrogen tank
Underground hydrogen storage is the practice of hydrogen storage in underground caverns, salt domes and depleted oil and gas fields. Large quantities of gaseous hydrogen have been stored in underground caverns by ICI for many years without any difficulties.[62] The storage of large quantities of liquid hydrogen underground can function as grid energy storage. The round-trip efficiency is approximately 40% (vs. 75-80% for pumped-hydro (PHES)), and the cost is slightly higher than pumped hydro.[63] The European project https://en.wikipedia.org/w/index.php?title=Hyunder&action=edit&redlink=1[64] indicated in 2013 that for the storage of wind and solar energy an additional 85 caverns are required as it can't be covered by PHES and CAES systems.[65]
By this scheme, the grid and all its power plants remain intact, but they would burn hydrogen instead of natural gas and coal. Wind and solar farms would not be directly connected to the grid: all their output would be used to split water, and the resultant hydrogen conveyed to power plants much like natural gas is now.
Power to gas is a technology which converts electrical power to a gas fuel. There are two methods: the first is to use the electricity for water splitting and inject the resulting hydrogen into the natural gas grid; the second, less efficient method is used to convert carbon dioxide and hydrogen to methane, (see natural gas) usingelectrolysis and the Sabatier reaction. The excess power or off peak power generated by wind generators or solar arrays is then used for load balancing in the energy grid. Using the existing natural gas system for hydrogen Fuel cell maker Hydrogenics and natural gas distributor Enbridge have teamed up to develop such a power to gas system in Canada.[66]
Pipeline storage of hydrogen where a natural gas network is used for the storage of hydrogen. Before switching to natural gas, the German gas networks were operated using towngas, which for the most part (60-65%) consisted of hydrogen. The storage capacity of the German natural gas network is more than 200,000 GW·h which is enough for several months of energy requirement. By comparison, the capacity of all German pumped storage power plants amounts to only about 40 GW·h. The transport of energy through a gas network is done with much less loss (<0.1%) than in a power network (8%). The use of the existing natural gas pipelines for hydrogen was studied by NaturalHy[67]
https://en.wikipedia.org/wiki/Hydrogen_storage