Why Hydrogen Is Not The Answer
By Paul Homewood
The Telegraph article, which I posted on yesterday, noted:
A Government spokesman said: “A low carbon hydrogen sector here in the UK will be critical to delivering energy security, economic growth, and our net zero ambitions.
“We expect to have up to two gigawatts of low-carbon hydrogen projects in construction or operation by 2025.
“Hydrogen could play an important role in helping decarbonising heat in buildings, but the Government has been clear that a decision on this will not be made until 2026, allowing for full consideration of relevant evidence.”
The government’s Hydrogen Strategy aims at 5 GW by 2030. No firm decisions have been made about the balance between steam reforming and electrolysis yet, although it seems inevitable that the former will dominate. 5 GW amounts to about 4% of UK gas consumption.
But the real question is where the energy will come from in the first place, as hydrogen is not an energy, but an energy carrier.
Steam reforming, of course, typically needs natural gas to convert to hydrogen, but it is an extremely energy inefficient process. You would only get back about 60% of the energy you put into the process at the start. If it is to be low carbon, which is the whole idea, you will also need to add carbon capture, which also wastes energy. All in all, you would probably need to put in 2 units of gas, to get the equivalent of 1 unit back out.
At a time when natural gas is difficult to buy, as well as very expensive, it is plainly ridiculous to turn gas into hydrogen, which you will then burn instead of gas anyway.
But the alternative of electrolysis is also a dead end, certainly for the next couple of decades. The theory is that electrolysis will only use surplus wind power or other renewable electricity. But there is no such surplus currently, as all wind and solar power is sent to the grid. (The only exception is where it is constrained off, but this is usually due to the inability of transmission networks to handle it, meaning it would not available for electrolysis anyway).
Any demand for electricity for electrolysis, therefore, would have to come from a marginal source, which for many years to come will usually be gas generators. So the hydrogen will not be green at all, and production of hydrogen will simply end up increasing the consumption of gas. Again, because of the energy inefficiencies of both the electrolyser process and CCGT, more gas will be consumed to make hydrogen than will be saved by it being replaced by hydrogen.
None of this makes any sense from an energy policy perspective. Eventually of course we may have so many wind farms that there is theoretically enough renewable electricity to produce all the hydrogen we need, albeit hopelessly intermittently. But this prospect seems to be decades away.
To put things into perspective, a single 1 GW electrolyser would need all the output from a 3 GW wind farm. The new Dogger Bank wind farm project currently being developed is rated at 3.6 GW, and will be the biggest wind farm in the world with 277 turbines.
Even without all of the infrastructure and storage problems highlighted by the MPs, the idea that hydrogen will play more than a minor role in the foreseeable future is not a realistic one.
Comments are closed.
NOT A LOT OF PEOPLE KNOW THAT 
Hydrogen is not the answer to any sensible question, unless it is what’s the best way to waste billions of $.
The hydrogen scam is part of the carbon pricing strategy to make energy expensive so the plebs use far less of it. There is no other way that hydrogen can be competitive. It seems that the threat of hydrogen in the stratosphere as a major ozone depleting gas is being covered-up as the trough gets bigger!
Hydrogen is the Houdini of the gas world.
What is even more perverse is that Hydrogen is a (indirect) greenhouse gas allegedly far more devastating than CO2.
https://www.rechargenews.com/energy-transition/hydrogen-twice-as-powerful-a-greenhouse-gas-as-previously-thought-uk-government-study/2-1-1200115
Meanwhile, OFGEM authorises brown-outs:
https://www.current-news.co.uk/news/ofgem-approves-first-of-a-kind-class-energy-system-to-save-britain-millions-on-its-energy-bills
Another boondoggle. Electrolysis is incredibly expensive and consumes about 1.5 kW of power for each kWh of hydrogen, and that is the best case. Also 20 mt of denin water is required for each tonne of hydrogen. As for CCUS good luck. THe carbob dioxide needs to be super critical and could induce eathquakes. It is not dissimilat toe hydraulic fracturing. Total non starter.
Stupid question from a non-scientist.
I understand that Hydrogen can be produced from water by electrolysis – thus some water is destroyed; but is there a process, natural or synthetic, by which water can be created?
Yes. by burning hydrogen.
Right. So electrolysis produces Hydrogen by separating out the Oxygen and combustion of the resulting Hydrogen produces water – H2O.
So the whole process, whatever the expenditure of energy, is ‘water-neutral’?
Not exactly neutral. Burning hydrogen produces water vapor. So the whole process converts liquid water to water vapor.
The biggest greenhouse gas? WATER VAPOR.
A point that is little appreciated is the implications of intermittency for attempting any sensible economic operation of electrolysis. In Orkney, the O2 Orbital project takes the intermittent, very flickery generation from the tidal turbines and feeds into a vanadium flow battery system, which is much better placed to handle the flicker and the tidal intermittency. The battery is in turn connected to the electrolyser to try to provide a more constant rate of operation. Of course, the battery will consume ~20% of the output from the turbine in its round trip (different sections of the battery can be configured to charge while others discharge, with swap over during slack tide). Then the PEM electrolyser gets to work on the remaining 80% of the output, already taking the efficiency overall below 50%. Where hydrogen is used to generate electricity you are down to ~25% round trip efficiency.
Batteries can be employed on Heath Robinson toy projects like tidal stream, but they are completely impractical for large scale wind – that’s why they are looking at hydrogen in the first place. Wind surpluses at present do occur very sporadically when it is windy overnight: no-one needs the power when demand is at its lowest, and the prices go to zero or are negative. The frequency and size of those surpluses will increase as more capacity is added, and there will be more demand hours where a smaller surplus is generated. Very intermittent operation is not good for electrolyser yields, so it only begins to make some kind of sense if you have a reasonable guarantee of a big enough surplus to keep the plant running at least all night. Even so, the number of economic hours remains low, and the resultant low utilisation kills the economics.
Moreover, there will be some hours with larger surpluses that occur infrequently, and are thus not worth providing electrolyser capacity to utilise. That means curtailment. All this low and negative value production eats into the economics of the wind farms which can no longer rely on getting an income from all their output. That means they need to charge higher prices for the output that is useful in order to break even. LCOE calculations become nonsense.
Paul: I would just like to remingd you that the ICI steam reforming process was developed, and became the basis for UK domestic gas for a decade, using light distillate (referred then to as naphtha) as the feed and the fuel.
Reblogged this on Climate Collections.
Esso are in the process of building a steam-methane reforming hydrogen plant at their Fawley Refinery, linked to the new diesel hydrotreater that’s part of the same project. There seem to be plans afoot to produce some additional hydrogen with carbon capture for local distribution:
https://exxonmobil.co/3Xv078H
Of course the project economics won’t work without significant subsidies.