Two recent reports have highlighted expanding the transmission network as one of the most pressing issues to address in making the electricity system fit for the future. Alongside that they confirmed that some new gas-fired power plants would be required.
A new report from the Royal Academy of Engineering’s National Engineering Policy Centre (NEPC), ‘Rapid Decarbonisation Of The Gb Electricity System’, looked in depth at the transformation needed. Meanwhile a snapshot of the current situation came from the government-appointed Panel of Technical Experts (PTE), whose remit is to assess and challenge the Electricity System Operator’s proposals on the target procurement in the Capacity Market, as well as consider methodology issues that may affect the market in future.
The PTE said congestion across the networks was now “a material issue for significant periods of the year. While it used to be the Scottish generators who were mostly constrained off, the transfer capacities across southern boundaries .. can also now see extended periods with active constraints”. This refers to areas where large volumes of power are feeding in to limited network such as from offshore wind or interconnectors on the east coast or southeast coast. The PTE says, “it would be remiss to go on ignoring the potential impact of constraints on the ability of the networks to deliver energy from all available power stations or interconnectors in a stress event”.
The NEPC report also says, “This is one of the most significant and difficult constraints to rapid progress”. Its recommendation is that “NESO should undertake a rapid assessment of the gap between the transmission network that is currently slated to be in place by 2030 and what is now required, initially reporting by October 2024, and finalised by mid-2025 at the latest.”
Gas fired plat needed – with plans to decarbonise
On gas-fired power plant, the NEPC report notes that the new government has already committed to maintaining a supply of unabated gas to ensure security of supply and system resilience and says this is “crucial”. It says unabated gas will be the default until 2030, and modelling says it “may be called upon in at least 25% of hours across the year in 2030 even if only for a small proportion of total generation.
It adds, “Policy will need to ensure that short-term signals do not encourage existing gas-fired capacity to close down while still needed, extending the life of some, where possible. With this done, it may still be necessary to build new gas-fired capacity.” If so, new plant must be made ‘low-carbon-ready’, both technically and sited close to planned future hydrogen or carbon removal infrastructure. It says, “Government will need to close loopholes such as those which have seen plant built in unsuitable locations at 299MW, just beow the threshold at which CCS-readiness requirements apply.”
A PTE comment about constraint also reminds readers that gas plants may have their own weather -related issues, as “If we recall the “beast from the east”, where it was windy, but gas plants were struggling due to extreme cold”. However their main concern is their zero-carbon readiness. It notes that “the Capacity Market-eligible capacity requirement in future years seems optimistic around the transition to hydrogen”. The report says, “considering the economics, transportation issues, etc. it is not clear to us that hydrogen use will, at least initially, be widespread in power stations in addition to local industrial hubs. It seems more probable hydrogen will want to locate near customers such as chemicals producers. Further, if hydrogen is new build, as ESO considers it could be, then in addition to the usual new project development risks, it may be in a long connection queue and not able to join the market before the mid-2030s.”
That concern increases the importance of the availability of carbon capture and storage(CCS) for use on future gas plants and the NEPC report stresses the urgent need for government to take decisions on CCS clusters that have been pending. It refers to these projects “which have supply chains and contracts lined up ready for FID in September 2024, for delivery by 2030” and says, “green-lighting these projects would mean that the UK has finally started on CCS, after three failed attempts”, but warns “even a few months delay in deciding would require the projects to return to the supply chain for revised quotes leading to potentially much greater delays.”
It says work is needed to address limitations on how power-related CCS facilities can be operated variably to balance the system.
As in previous years, the actual data on the embedded capacity remains a concern. ESO assumes some over delivery, with plant staying open without a Capacity Market agreement. What would drive this behaviour is unclear, however, especially as this would now be gas plant which seems most likely to be in the Capacity Market. With tightening emissions standards, 13 increasing costs, concerns over running hours, and other detrimental factors, the Capacity Market income is crucial so that without it many of those plants may close. What seems more probable is that non-delivery will increase for the same reasons that are impacting wind of transmission connected plant developers; increased prices, supply chain risks and late delivery of connections
More than an acceleration
Overall, the NEPC report says the new government’s plan for a clean electricity system by 2030 “cannot simply be an acceleration of a 2035 plan”. It has to be “understood as a major infrastructure programme, a whole-systems challenge touching every part of society, and a different proposition from business-as-usual policy implementation…. Changing an existing system is not the same as building a new one from scratch, and the new electricity system must enable multiple other systems – of transport, heating, industrial processes, and much else – which are themselves complex, changing, and outside the control of the programme itself”.
It says, “Government will need to set out a compelling vision of a decarbonised electricity system, and create a “Chief Engineer for the mission, with a specific remit for systems integration, and a seat at the table at the most senior levels”.
It is probable that by 2050, less than 26 years away, most of the UK’s primary energy demand, presently around 2,200 TWh a year, will need to be delivered as electricity, with the balance as geothermal heat. At present, electricity production is only around 20% of primary energy, which suggests that it will need to be increased 4 times over the next 26 years. The probably outcry against 4 times as many overhead power lines and the cost of achieving this, requires that in future, new electricity production needs to be consumed where it is needed, to bypass the expensive electricity grid. During periods of low electricity demand, surplus electric power should be stored in batteries or converted into hydrogen which is urgently needed to power heavy transport.