Hydrogen, seasonal storage key to UK 2050 goals: study
The UK power sector could reach its net zero carbon emissions target before 2050 and more cheaply than otherwise using a renewables-led energy system supported by decarbonised gas and long duration storage.
But electricity market reform to allow some plants to run longer and network co-ordination would also play a part, according to a study by LCP commissioned by utility SSE and published July 26: Net Zero Power without Breaking the Bank.
The report says technically the GB power system could become net-negative from 2027 with significant volumes of bio-energy with carbon capture and storage (BECCS) but it might not be cost effective compared with other carbon savings elsewhere in the economy or the best use of a limited bioresource.
So policy-makers will have to decide on a trade-off between earlier achievement at higher cost or later achievement at lower cost. For example, "the early closure of unabated gas and [building] new low-carbon thermal resulted in a reduction in emissions of 22 metric tons CO2e over the 2035-2050 period, but led to an increase in system costs of £4bn ($5.5bn) which equates to a cost of abatement of around £180/mt CO2e in discounted terms." That is about four times today's carbon price. However that price is set to rise as the governmind reduces the number of emissions.
The report flags up a big problem with support needed for offshore wind: "With high levels of renewable penetration, wholesale power prices fall during times of high renewable output, often to as low as zero. This means 'wind-captured' power prices fall significantly, and unsupported wind plant may be unable to make sufficient returns to cover their high ongoing fixed costs. In some cases this would imply early closure of plant," it says.
New-build gas peaking capacity installed from 2030 is assumed to be hydrogen ready, requiring little change to re-configure or upgrade to run on low-carbon hydrogen.
The paper expects gas CCS capacity to be built between 2028 and 2050 both to replace nuclear capacity and to displace hydrogen and unabated gas peaking capacity. Combined-cycle gas turbines close early as they are displaced in the overall merit order by gas CCS plant which is less exposed to higher carbon prices.
Apart from offshore wind and extending low-carbon power plant life, the study sees three major elements necessary: supporting CCS and hydrogen power generation to complement renewables and help deploy infrastructure to support new clean industrial clusters; long duration storage and green hydrogen production to balance a renewable-led system, with early deployment of strategic storage assets required; and co-ordinating the offshore power grid to reduce network costs significantly, and reduce impacts on local communities and the environment.
SSE CEO Alistair Phillips-Davis said decarbonisation "is non-negotiable but doing so quickly and affordably is critical." A high-renewables system centred on offshore wind backed up by technologies like CCS, hydrogen and long duration storage can achieve a faster and cheaper route to net zero than one including any more new nuclear projects.