THE inevitable global failure of renewables-based climate policies has led advocates to cover up their disastrously bad advice by calling for still more ambitious, Net Zero, emissions targets. To sustain the pretence of viability, policy makers find themselves obliged to call on hydrogen as an energy carrier for those sectors where it is most difficult to create the appearance of decarbonisation, namely electricity system balancing, heavy transport on land and on sea, industrial process heat, and peak domestic winter heating, when ground-source heat pumps will fail just as they are needed most. The United Kingdom, as ever, is truly a leader in this matter, and Mrs May’s Net Zero legacy could, unless abandoned, continue to poison our economy long after her deficiencies over Brexit are forgotten and perhaps even forgiven.
The problem is not simply one of unaffordable cost and ultimate infeasibility, though Net Zero is certainly expensive and will certainly fail. The marginal increment between an 80 per cent emissions reduction and the Net Zero target will certainly add a great deal more than 25 per cent in extra cost. Precise estimates are impossible, so extreme are the problems, but a doubling of total cost would not be at all surprising. And there can be no real question that it is ultimately unfeasible; at present the illusion of low-carbon transition can be maintained because intrinsically non-viable green technologies are essentially parasitic on the high productivity of carbon fuels, both domestically and particularly internationally. Wind and solar records get the headlines, but the UK system is ballasted and balanced by gas and nuclear, and indeed on occasion by coal, and the costs of renewables equipment are contained, though still high, because they are provided predominantly with fossil fuels. As our increasingly fragile electricity system is balanced with expensive batteries and with hydrogen fuelled peak electricity generation, and as the share of renewable energy in the manufacture of a solar panel and a wind turbine rises, the system costs and the capital costs will start to head for the skies.
In the inevitable debacle, the principal technological casualty will be the hydrogen economy itself. That is genuinely regrettable, since this difficult but interesting gas has clear and authentic promise as a universal energy carrier in a highly efficient and clean society. That promise, however, is dependent on the thermodynamic quality of the primary energy input. Only very advanced nuclear will do, a point that has been well understood since the visionary physicist Cesare Marchetti, then at Euratom, first recommended the idea in an engineerable form, using high temperature nuclear reactors and catalysts for the thermal decomposition of sea water to produce extremely cheap hydrogen with very few unwanted by-products. This brilliant concept presents immense and still unresolved difficulties in nuclear and chemical engineering. The temperatures are very high, requiring special materials to contain the process, and an optimal catalyst has yet to be found. But the promise is genuine, and far-sighted administrations with a clear and physically realistic long-term plan for energy independence, such as the government of Japan, are still committed to the idea and making quiet progress.
However, the desperate face-saving haste of the British government, amongst others in the West, is driving them to force hydrogen upon our economies in the short term, and this means that hydrogen must be generated by two relatively unsophisticated commodity production processes, namely the electrolysis of water, and the chemical reforming of natural gas using steam (Steam Methane Reforming). Both processes are acceptable if hydrogen is required for niche and non-energy purposes, but it is a simple mistake to suggest them for the production of energy carrying hydrogen in very large quantities, such as the 270 TWh a year proposed by the UK’s Committee on Climate Change in their Net Zero projections.
There are four principal disadvantages. Firstly, the costs will be huge. SMRs and electrolysers are expensive to build and to run – the CCC’s proposals imply a capital expenditure of £40billion on SMRs alone – and they do not have very long plant lives, implying a relatively short capital refreshment cycle, particularly for electrolysers.
Secondly, due to conversion and storage losses, hydrogen from electrolysis and SMR can never in principle compete economically with its own inputs, the electricity and natural gas, used to make it. The consumer will always be better served by using the electricity and natural gas directly.
Thirdly, Steam Methane Reforming emits large quantities of carbon-dioxide, compromising the Net Zero target unless the SMRs are equipped with carbon capture and sequestration (CCS), which is expensive and currently unavailable at scale. This leads to a further observation. Since the Net Zero target is critically dependent on hydrogen from SMRs, with the CCC predicting that 80 per cent of required quantity will be from this source, we can see that behind the clouds of rhetoric about falling renewables costs the UK’s Net Zero target is in fact a gamble on carbon capture. But if CCS becomes viable, and it might do, then it will be more effective to use methane directly in gas turbines and allow the consumer to use the resulting electricity directly, rather than make hydrogen with all the attendant costs, problems and dangers.
Finally, the production of hydrogen from both electrolysis and SMRs uses large quantities of clean, fresh water. The UK’s current hydrogen target would increase national water consumption by between 1 and 2 per cent at a time of what the CCC itself predicts will be constrained fresh water supply, with deficits in a quarter of the country’s resource zones.
The long-term promise of hydrogen, on Marchetti’s model, is excellent. Indeed, it is probably the only viable low carbon future that also preserves human well-being. Those jeopardising that future by forcing rapid and sub-optimal adoption of hydrogen in order to prolong the current mal-engineered renewables farce should hang their heads in shame.
Hydrogen: The once and future fuel? by John Constable is published today by the Global Warming Policy Foundation.