Doug Parr, Chief Science Officer for Greenpeace, exposes how the Government is using unreasonably pessimistic assumptions about storing renewable energy to bolster the case for its scenarios which involve large amounts of nuclear power and fossil generation with carbon capture and storage
How is UK government continuing to justify continued emphasis on nuclear power development when the cost of renewables has fallen so far? The answer is about the weather – government will point out (although this will not be a shock to most people, or renewables energy experts) that the sun doesn’t always shine and the wind doesn’t always blow. In other words, what can manage the gaps in electricity supply when there isn’t enough solar or wind power? We can max out on electrical connection to other countries, demand response and batteries and there’s still a gap. So to fill that ‘gap’ we need some form of long term storage for renewable power.
Enter hydrogen as the storage fuel that could fill the gap.
Hydrogen produced from renewable power (known commonly as ‘green hydrogen’) is producing a lot of excitement in lots of countries. Notably Germany is planning €7bn spending to expand it, Sweden have plans to use green hydrogen for steel production rather than power system balancing, there are even massive plans in Australia as it seeks to diversify from fossil fuels, and major plans from the EU.
In UK there is some enthusiasm but it’s mixed in with more vigorous support for hydrogen derived from fossil gas. That said, hydrogen became a mainstay of Climate Change Committee modelling and the scenarios from their 6th Carbon Budget report, producing 90TWh hydrogen (not just from renewables), or about one third the energy of the current electricity system by 2035 in their ‘balanced’ scenario. CCC scenarios overall show a mix of between 5GW and 10GW nuclear capacity by 2050.
Note that the 5GW level of nuclear would mean no additional capacity is required, assuming Hinkley Point C eventually works, and Sizewell B gets life extension. In other words, in 3 of the 5 CCC scenarios no more nuclear capacity is required other than that under construction or already built. Obviously it is possible to imagine scenarios with less nuclear, but that’s what UK government’s official adviser says.
However, that’s not the perspective of UK government, as informed by their Modelling 2050 study, released 2 days before Christmas last year. This suggests more nuclear is required, and informed Secretary of State Kwasi Kwarteng at Commons select committee hearing in saying
“nuclear power is essential. We have done all the modelling. We need what is called firm or dispatchable power in order to balance the system …. The sun is not always shining for solar power generation; nor is the wind always blowing …About 15% of power generation will probably come from this firm power, and nuclear power baseload is the most effective non-carbon source of that power.”
And went on to say that the cost of 100% renewables systems was very high.
However, a look at the modelling study suggests that with a burgeoning hydrogen sector, the cost difference between ‘high nuclear’ and ‘low nuclear’ scenarios is low to non-existent, because the ‘firm power’ that Mr Kwarteng wants is provided by the stored hydrogen. So the Modelling 2050 study does not require nuclear in the way he implies.
Further, the Modelling 2050 study seems weighted against the uptake of hydrogen to provide this ‘balancing’ service to the grid. The modelled assumption on hydrogen availability and price, which is the basis of the scenarios explored, is found on p6, where it says:
“the main part of the paper we consider a scenario where the total amount of hydrogen-fired generation is constrained to 20 TWh or less, and hydrogen is twice as expensive as natural gas”
In footnote 6 on that page we discover that:
“overall costs of the necessary hydrogen infrastructure are included in our assessment of the hydrogen price. Our central gas price assumption in 2050 is 19.5£/MWh (2012 prices). In our core hydrogen scenario (hydrogen price = 2x gas price) this equates to a hydrogen price of approximately 39 £/MWh [c. 1.2 £/Kg in 2020 prices]” (emphasis added)
Thus the viability of green hydrogen to contribute to a very high renewables system is constrained by 2 assumptions of only 20TWh being available in 2050, and the cost being £1.2/kg in 2020 prices (or $1.68/kg at today’s exchange rate)
These 2 critical assumptions contrast sharply with Climate Change Committee where their central ‘balanced pathway’ scenario reaches nearly 100TWh by 2050, with other scenarios going higher still.
Meanwhile cost assumptions from the Head of BloombergNEF, the leading analysts in this space, say
“By 2050, therefore, extrapolating long-standing trends in renewable power and electrolyzer costs….BloombergNEF estimates that green hydrogen will be available at between $0.8 and $1.0 per kilo. I would not be surprised to see it go below that.”