Charging ahead

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Charging ahead: building on the success of the UK’s grid flexibility market. By Alan Greenshields

Renewables made up a record 41.5% of electricity generation in the UK during 2022, as both wind and solar reached record levels. This success can be attributed to the increasing availability and decreasing cost of renewable energy sources, but also the increasingly mature ecosystem of energy storage that has enabled grid operators to collaborate in the efficient deployment of wind and solar power.   

Although the desire to transition to renewable energy has been growing for many years, re-configuring the grid to accommodate increased wind and solar power is a challenge. Renewables improve energy security and support net-zero targets, but their intermittent nature poses challenges to the grid.

The UK is also experiencing interconnection issues related to the growth in new applications from renewables and energy storage projects, which has led up-to a 15 year wait. Much-needed reforms are finally being considered and National Grid has just announced that it is accelerating the connection of up to 20GW of storage projects. Although this is welcome, the reality is that the UK is still struggling to connect large-scale renewable projects to the grid fast enough to curb reliance on fossil fuels and meet energy demands.  

New solutions and technologies must be identified and deployed to modernise the grid and achieve new levels of flexibility. The UK must meet both its ambitious 2050 grid net-zero target through the deployment of renewables, but also power the surge in need for electric vehicle (EV) charging stations.  

Enabling an era of renewables 

Currently, the UK generates much of its electricity from unsustainable energy sources, with 38.5% of energy coming from gas in 2022. However, since 2010, the cost to deploy wind and solar energy has declined substantially. Today, they are among the lowest-cost options for new generation capacity. As a result, there are an increasing number of viable renewable projects, with installed capacity growing from 117.3GW to 255GW in the past decade.   

The challenges for these projects no longer lie in the renewable technology, but rather in the availability of interconnections and the architecture of the grid. The UK must build on the success of its local market flexibility by increasing the percentage of power coming from renewables through increased use of energy storage. This means rethinking the grid’s topology and interconnect process entirely.  

The bureaucracy that evaluates and approves new grid interconnections needs reform to keep pace with the volume of requests. Projects must be approved based on viability, not today’s “first come, first served” structure, where nonviable projects that are unlikely to ever be built may be prioritised at the expense of viable projects. 

Delays are worsened by other administrative issues, such as demands for comprehensive environmental assessments for each project, and the increasing cost of booking grid capacity in advance. These costs for connection can stymie projects that would otherwise be viable, with fees reaching up to five times construction costs. This includes application fees, feasibility study charges, connection charges, and one-off costs. 

These challenges stem from the original architecture of the grid and associated regulations, which were designed around a small number of large-scale fossil fuel generators. Where there were once 40-50 applications for connections a year, this has risen to about 400 per year with 234 GW of renewable energy capacity currently waiting to be connected to the grid.

Grid upgrades  

What makes the challenge more difficult is that the grid needs to adapt to renewable sources and at the same time cope with increased demand for reliable electricity, from the electrification of buildings and transportation. The transition from petrol- and diesel- powered cars to EVs will require a rapid reimagining of grid infrastructure, as studies have shown that the transition to EVs will result in a 25% increase in electricity demand over current levels by 2040. 

Today’s grid was designed for large, centralised generating stations and relatively predictable residential and light commercial energy loads. However, as the energy mix shifts to decentralised renewable generation and EV charging increases, outdated grid infrastructure will need to adapt. 

Ultimately, the UK must rely on sophisticated energy solutions to overcome the increased peak demand volatility and reduced reserve margins caused by mass EV charging alongside renewable deployments. 

Energy storage 

One way to accelerate renewable deployment while enabling grid upgrades to meet growing demand caused by trends toward electrification is to take advantage of new innovations that are commercially available today. For example, by prioritising new projects that include long-duration energy storage (LDES) technology, transmission congestion can be eased, as excess energy can be stored during periods of over-generation and deployed when needed (for example, to power EV charging infrastructure during periods of high demand). 

Long-duration batteries can store 6-12 hours of electricity and feed this back into the gird, enabling energy from renewables to be stored and then discharged when customers need power most, even if the wind is not blowing and the sun isn’t shining. Renewable power can thus be relied upon to meet increased demand for electricity. For example, by deploying LDES as ‘buffers’ at EV charging stations, surges in demand by drivers charging can be smoothed, reducing strain on the grid.  

By integrating storage both into the grid and giving priority to those new renewable projects with storage components, it will be possible to improve the flexibility of the grid while also reducing emissions. 

Galvanising the grid for a renewable revolution 

Addressing obstacles, such as a lack of project prioritisation and high connection costs, can facilitate the UK's transition to cost-effective and clean energy. Growing demand for electricity and EV charging is motivating the grid to identify solutions which can alleviate transmission congestion and ensure stability.  

By establishing regulations and harnessing innovative technologies, network infrastructure can be revamped to align with the UK’s looming climate objectives, increasing deployment rates of renewables and curbing dependence on fossil fuels. 

Alan Greenshields is director of Europe at ESS


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