This Thursday, 23rd March, the Government is holding an Inquiry to explore its efforts to decarbonise the power sector – i.e. producing all electricity from "zero and low carbon" means. It has set itself a deadline to achieve this objective by 2035 – a laudable but nevertheless challenging aim when you consider that currently only around 55% of energy is produced by zero and low carbon means.


Decarbonising electricity generation is an essential part of, but is of course different to, reaching Net Zero. The move to Net Zero is itself causing an increased demand for electricity: electric cars and air source heat pumps, for instance, put an additional load on the electricity generation systems. Demand is anticipated to increase by 60% by 2035. This, in turn, puts increased stress on efforts to achieve the 2035 target.


How much progress is the UK making towards this? And how will it achieve it?


The National Audit Office has released a report that is the result of its examination of what the Government is doing, and what it needs to overcome in order to achieve a “secure, affordable and decarbonised supply of power by 2035”.


Points made in the report include the need for:

  1. A “step-change in both private investment and the pace at which new generating capacity is built”.
  2. A substantial modernisation of the power system so that it can accommodate different kinds of generations. This relates not only to meeting electricity needs when the intermittent nature of the wind blowing and the sun shining means there is no guarantee of supply from renewables, but also how electricity is charged for. The current charging system does not factor in the cheaper running costs of renewables.
  3. A delivery plan. The Government set up the Department for Energy Security & Net Zero (DESNZ) in 2021 and gave it the remit of achieving its power sector ambitions. Achieving decarbonisation of the power sector will involve many stakeholders, both public and private sector, and the stakeholders the NAO spoke to said there needs to be, “a delivery plan that recognises the time required to decarbonise all aspects of the power sector, including expanding generation and developing technologies ahead of 2035”. In its report, dated February 2023, the NAO states that the DESNZ, “told us it still has more work to do to develop a delivery plan”. It further says, “The lack of a delivery plan means DESNZ cannot be confident its ambition to decarbonise power by 2035 is achievable”.
  4. Flexibility. The NAO says DESNZ has to factor in the need for flexibility because, “While DESNZ needs a delivery plan, it will need to remain flexible because new technologies could emerge that alter the most cost-effective pathway towards a decarbonised power system”. Although not a new technology, SSE’s announcement this week that it would like to develop a huge hydro project in Scotland is an excellent case in point in how there may be changes to how the target will be met.


The report summary makes it clear that to meet the target DESNZ considers that “new generation, including wind, solar and nuclear, [need] to deploy at, or close to, the maximum level which is technically feasible in that time.” (emphasis added). It acknowledges that time has been lost by the unavoidable need to deal with the immediate problems of both supply and cost of electricity that were presented by the war in Ukraine.


The Public Accounts Committee Inquiry on Thursday, which is based on the NAO’s report, will question senior officials at DESNZ on “how it is set up to achieve power sector decarbonisation while maintaining security of electricity supply and affordability for consumers and taxpayers”.


In the circumstances, DESNZ clearly has a difficult job to do.