The UK’s renewable energy generation capacity has increased hugely in recent years. In Q1 2023, the sector’s share of total electricity generation hit a record 47.8%, according to the Department for Energy Security and Net Zero. But that proportion would be even higher if it weren’t so difficult for new renewable generators to plug into the national grid.
Before exploring how, it’s important to be clear about the terminology. National Grid, the company, has been two entities since April 2019: National Grid Electricity Transmission (NGET) and National Grid Electricity System Operator (NGESO). NGET owns the transmission network in England and Wales – the high-voltage infrastructure linking the main generators to the biggest consumers and to the lower-voltage local distribution networks that supply homes and businesses. Both the transmission and distribution networks are usually referred to collectively as the national grid. NGESO is the transmission system operator for Great Britain, constantly adjusting the grid’s output to ensure that the demand for electricity is always matched.
Traditionally, big generators such as nuclear power stations and offshore wind farms feed into the transmission network. About 70% of Great Britain’s electricity is connected this way. Smaller projects will tend to plug into the local distribution networks.
The big problem is that there’s a lengthy waiting list for new projects seeking a connection, wherever that may be on the grid. Some applicants are being told that they’ll have to wait as long as 15 years for the infrastructure to be upgraded to a level at which they would be able to join it safely.
“The connections process was originally designed for a small number of large generators, whereas today it’s handling a huge number of applications from a wide range of smaller green projects,” explains Roisin Quinn, director of customer connections at National Grid.
A lack of foresight and funding over many years has been one of the main causes of this problem, according to Nikki Pillinger, specialist connections manager at independent grid consultancy Roadnight Taylor.
“Over the past few decades there hasn’t been enough pre-emptive investment in our electrical infrastructure to allow for the current level of expansion of renewable generation,” she says.
But Pillinger adds that awareness of the issue is at least growing, largely because some influential players in the industry have been pushing it up the agenda.
The UK’s new plan for connecting renewable generators
Other nations, especially in Europe and North America, are also finding it hard to connect renewable generators quickly enough to meet their sustainability commitments.
“The US has a huge backlog of low-cost renewable generators trying to connect to its transmission network.” So says Mathias Einberger, a manager focusing on carbon-free electricity at the Rocky Mountain Institute, a not-for-profit body working to accelerate the clean energy transition.
He cites recent research by the Lawrence Berkeley National Laboratory indicating that there’s about 2TW of mostly renewable generation and storage waiting to join the US grid. For comparison, the nation’s total installed generation capacity is roughly 1.25TW.
“The best and least costly sources of electricity in the US, which happen to be zero-carbon resources, are to be found far from where most people live and consume electricity – for example, wind on the Great Plains and solar in the Desert Southwest,” Einberger says. “We must therefore modernise and expand the grid, especially the long-distance transmission lines that span several regions.”
Many industry insiders are calling for an urgent upgrade along similar lines in the UK. That’s why NGESO and trade body the Energy Networks Association (ENA) revealed new plans in Q1 2023 aimed at slashing connection waiting times.
One of NGESO’s original assumptions was that all projects seeking a connection would join the grid eventually, but experience has told it that planning and/or funding problems will cause several withdrawals. Given this fact and the scale of capacity stuck in the queue – 345GW at the last count – NGESO has revised its assumptions. It now expects only about a third of applications to culminate in a connection. Its radical editing of the waiting list with this in mind should result in faster connections for those projects that make the cut.
The ENA is pioneering a new approach by which it hopes that some new generators will be able to join the grid before reinforcement work is completed and leapfrog other projects in the queue that aren’t advancing as quickly.
Pre-emptive investment is also set to increase, with NGESO’s Holistic Network Design report setting out a more joined-up, strategic approach that would link parts of the country with significant generation capacity to higher-demand areas.
“This coordinated design will take longer, but it will prove more efficient in the long run and have the potential to reduce investment costs and, ultimately, household and industry bills,” predicts Catherine Cleary, a Roadnight Taylor engineer specialising in grid connections.
Achieving net zero will require more investment
Although some headway is being made, the connection backlog is still too big for the liking of many renewable developers in the UK, which are calling for such initiatives to be implemented more quickly. But NGESO is defending its timetable.
“The actions we are taking have the potential to identify 40GW of capacity by the end of 2023 that could be allocated to contracted customers in the next six months,” Quinn says. “This is the equivalent of 12 Hinkley Point Cs.”
But more investment is still urgently required, according to Dr Jon Hiscock, CEO of Fundamentals, a consultancy specialising in grid technology. While he notes that private sector investors remain eager to back renewable generation projects, he has a stark message for policy-makers and others with the power to improve the situation.
“The inescapable fact is that decarbonising UK electricity needs significant investment now – and the cost will need to be borne by government borrowing, taxation, higher tariffs or some combination of the three,” Hiscock argues. “Dodging this issue for fear of upsetting electors in the immediate future will only lock the UK into further dependence on insecure, dirty and expensive fossil fuels.”