House without grid connection
An energy consultant at the other end of the telephone wants to tell me, that a normal house will have in the future no grid connection. Here the truth about this nonsens.
There is a manufacturer of inverters who wants to make hydrogen with excess electricity and to make later when the demand is with a fuel cell electric power.
And so, houses in the future have no grid connection.
For the supply of an one family house including electric mobility have to be saved 3000 kWh summer excess to the winter.
Let's ignore todays fuel cells, let's be total optimistic, let's assume 50% electric efficiency can be reached. So 6000 kWh hydrogen had to be strord to produce 3000 kWh electric power.
But how looks a storage for 6000 kWh hydrogen like? Hydrogen has as a gas 90 g/m². Best high pressure tanks are for 700 bar suitable. 63 kg hydrogen in 1 m³. 1 kg has 33 kWh chemical energy. The 6000 kWh require 182 kg hydrogen. This makes around 3m³ high pressure storage.
Just right now, an house in Austria exploed by a natural gas accident. When a high pressure tank becomes leaky and 183 kg hydrogen explode, also the whole neighborhood would be flat.
Hydrogen is something for existing underground gas storage, existing CCPP combined cycle power plants, but sure not for the cellar.