Thought of the Week
Could changing where we use electricity help us decarbonise the energy grid in a more cost effective way?
September 5, 2024 6 Minute Read
The Labour government is targeting a transition to a net zero energy grid by 2030. This will be supported by a newly formed mission control for clean power which aims to facilitate renewables projects and monitor progress towards the 2030 target.
The planning system has been identified as a barrier to renewables infrastructure growth. The new government seems intent on removing some of these planning barriers, lifting a de facto ban on new onshore wind farms in England and starting to ramp up consent to solar power.
This focus on upscaling onshore wind and solar production is likely to change where electricity is generated across the country. The areas with the most potential to generate renewable energy are not where demand is highest, notably the southeast of England and other large metropolitan areas. We will increasingly have to move energy around the country from where it’s generated to where it’s needed. Or start moving energy consumption closer to generation.
Where has the most onshore wind and solar generation potential?
Recent analysis has identified approximately 370,000 hectares of land in England that is most suitable for developing onshore wind and solar farms. If developed, the 10 local authority areas with the greatest generation potential could power almost 22 million households between them, equivalent to 76% of UK households as of 2023.
While the generation potential of these areas is huge, they tend to be more rural areas with relatively few homes and businesses. This lack of local demand represents a challenge to increasing renewable energy use.
Why can’t we just send electricity to where we need it?
The short answer is that we can, but it’s expensive. The infrastructure can take a long time to build, be delayed by planning or prevented entirely by fierce local opposition.
To transmit electricity over long distances, it must be transmitted at very high voltages. This relies on network of substations, cables and pylons which are very expensive to build and maintain.
Estimates of costs in the UK for high voltage overhead lines are between £2.2 million and £4.2 million per kilometre while underground cables are estimated to cost between £10.2 million to £24.1 million per kilometre (estimates for overhead and underground include installation and lifetime maintenance).
While renewable electricity can be connected to the existing transmission network, the network would need significant reinforcement to transmit future generation from renewables.
Taking the lowest cost estimates, new transmission infrastructure to send electricity the roughly 530 kilometres from Edinburgh to London, for example, would cost almost £1.2 billion. That’s assuming local communities don’t object.
The high cost of transmission infrastructure has been highlighted recently by a newly approved undersea transmission cable between Aberdeenshire and North Yorkshire estimated to cost between £3.4 and £4.3 billion.
While this plan should facilitate a quicker transition, using renewable energy close to where it is generated, could be the most cost-effective way of decarbonising the energy grid, with less time spent in the planning and construction of transmission infrastructure.
How could renewable energy be used near to where it is generated?
Firstly, distributing more renewable energy locally is not cost free. Integrating renewables into local grid infrastructure will still need to get through the planning system and require significant investment. However, the closer energy is consumed to where it’s generated the more cost effective it should be.
An obvious candidate for local renewables is housing. In the top 10 local authority areas, local renewables could provide all domestic electricity demand.
But this does not get close to using all potential renewable electricity. We estimate that by 2030, households in these areas would only consume 10% of local renewable generation potential, or 21% if all homes used heat pumps.
Co-locating energy intensive activities in areas with high renewable generation could promote more local energy use. However, the suitability of rural areas with high generation potential for data centres or manufacturing, for example, is limited. Without locally established workforces or supply chains it would likely take government intervention to make it a viable option.
This leaves us with a question. Do we have the time and money to enhance our transmission network, allowing us to move renewable electricity to where we want it? Or is it possible to promote more local energy use for a quicker and cheaper net zero transition?
