Wednesday 14 July 2021

'Green' hydrogen?


"Natural gas – you poke a hole in the ground and capture the gas which gushes out.
    "'Green' hydrogen 
 you build expensive solar arrays, use uncompetitively expensive electricity to crack water, capture and compress the hydrogen. Or you use steam reforming, in which water mixed with coal or natural gas is heated and pressurised so much it burns, releasing vast quantities of CO2 which somehow have to be sequestered.
    "And then there is the difficulty of actually handling pure hydrogen – the cost of containing a gas with molecules so small, only high spec pipes can contain it, the risk of handling a gas which ignites easily over an extraordinary range of conditions, the danger of working with a gas whose flame burns so hot it is all but invisible.
    "I’m guessing we might have to wait a little longer than 2030 for green hydrogen to become price competitive."
          ~ Eric Worrall from his post on 'Green Hydrogen'

1 comment:

rotator said...

Since green hydrogen requires ~50 kw-hrs of electricity per kilogram of H2 that sets a lower limit on its cost. Very few sources of electricity are priced under $0.04/kw-hr and most utility scale power is a bit to a lot higher. Added costs for compressors/piping/storage/transport. 1 kg of H2 approximates the energy content of a gallon of petrol.