By Paul Homewood
https://www.neso.energy/publications/clean-power-2030
You will recall the NESO’s Clean Power 2030 report to Ed Miliband a couple of weeks ago, which made it absolutely clear that we would need to retain our full fleet of gas power stations, in order to provide power when the wind does not blow.
The report made it clear that this would continue to be necessary well beyond 2030, until enough low carbon dispatchable capacity came on stream. That effectively means either CCGT with carbon capture, or hydrogen burning plants.
Carbon capture is still not proven at commercial scale, and even if it could be introduced, it would make the cost of generation much higher, as well as increasing the amount of gas used, which makes zero sense to anybody outside of Ed Miliband’s little bubble.
But what about hydrogen?
In 2020, John Constable wrote a report on hydrogen use for GWPF, analysing the CCC’s proposals. It contained this section::
In other words, most of the hydrogen would have to be made via steam reforming natural gas. With an assumed fuel efficiency of 80%., that would need 282 TWh of natural gas supply, nearly half the current annual usage of just over 700 TWh. However, 80% efficiency is extremely optimistic – 65 to 75% is deemed to be the norm at the moment, and that does not take carbon capture into account. A gas requirement of 500 TWh would not be unrealistic.
Coming back to the NESO proposals, they reckon we would need at least 15 TWh in a “typical” weather year, but plainly we would need to build a much larger margin of safety.
During the first week of this month, gas plants were supplying half our power, when winds were low. During midwinter, if wind power was a low as it was in that week, we would need the full 35 GW capacity churning out nearly 1 TWh a day, particularly given the fact that NESO say demand will be 11% higher by 2030.
A month or more of that weather would mean at least 30 TWh of gas power, all of which would have to be stored for winter months.
To produce this amount of hydrogen would not be an insurmountable problem in itself, requiring about 4 GW of steam reforming capacity. John Constable suggests a capital cost of about £5 billion for this. But the hydrogen would then need to be distributed and stored, and a fleet of hydrogen burning power stations built at a potential cost of £50 billion. (It seems unlikely that it would be viable for older CCGTs to be adapted to burn hydrogen).
Given the continued dependence on imported natural gas, with all the upstream emissions involved, of the steam reforming option, it can hardly be regarded as Net Zero! There can be no justification for imposing a cost of tens of billions on the public for what would be no more than a box ticking exercise. And it’s not just a matter of cost. To waste massive amounts of gas converting it to hydrogen and then capturing the carbon would be an obscene misuse of a valuable and sparse commodity.
What about electrolysis though?
Constable’s study reckons fuel efficiency of 73% – 44 TWh from 60 TWh of electricity. As we could potentially need at least 30 TWh, we would need to input roughly 60 TWh of hydrogen, given the operating efficiency of thermal power stations.
That would mean 82 TWh of electricity to feed the electrolysers, probably more if line losses are taken into account. In turn, you would therefore need about 25 GW of offshore wind power capacity, which is more than we currently have.
All that just to supply 5% of our electricity demand. And we have not even started with all the other uses of natural gas that will have to be catered for.
Does anybody still believe this is a good idea?