Richborough Energy Park has UK’s best carbon-saving battery in 2024

Richborough Energy Park 2 (REP2) has cut more carbon emissions than any other battery project in the UK this year, a Modo Energy analysis shows. 

The asset, one of two 50 MW, 50 MWh battery systems developed, managed and operated in the Richborough Energy Park by Pacific Green and optimised by Shell on behalf of clean energy asset management firm Sosteneo, had saved 12,945 tonnes of carbon emissions in 2024, as of September, Modo Energy said. 

Its twin, Richborough Energy Park 1, is also among the top 20 carbon-saving batteries in the UK this year, avoiding 6,403 tonnes of greenhouse gas emissions. 

This means the Richborough Energy Park project overall has saved more than 19,000 tonnes of carbon emissions in eight months, or an average of more than 2,400 tonnes a month. 

The UK’s second best-performing plant, West Gourdie in Dundee, Scotland, has saved 12,876 tonnes, and the third, Thurcroft in South Yorkshire, has saved 12,490, based on Modo Energy’s calculations. Both projects are about the same size as the Richborough Energy Park units, with 50 MW of power. 

Batteries can reduce grid-related carbon emissions by storing renewable energy when there is excess production, then releasing it back to the electricity network when needed. 

The UK’s best-performing battery project

However, most of the carbon impact at Richborough Energy Park 2 so far this year has come from providing grid stabilisation services that are normally performed by combined-cycle gas turbines (CCGTs). 

Grid operators such as the UK’s National Energy System Operator (NESO) must ensure the frequency of the electricity network stays at a roughly constant level—50 hertz in the case of Britain—to provide a reliable power supply. 

“As demand rises, we ask providers to turn up their energy sources to balance the system and keep frequency close to 50 hertz,” says NESO. “Equally, when demand drops, we might as an operator ask them to reduce generation to avoid frequency being too high.”

The turning up of energy sources has traditionally involved burning gas in CCGTs that provide relatively large amounts of power at short notice. But batteries can achieve the same effect, reducing the amount of gas that needs to be used and cutting the emissions linked to frequency response services.

The exact amount saved depends on the kind of frequency response service provided. In so-called dynamic containment low services, where output needs to be increased in less than a second to deal with unforeseen faults, the saving can be as much as 72 kilogrammes of CO₂ per megawatt of power, Modo Energy says. 

So far in 2024, Modo Energy says, Richborough Energy Park 2 has saved 12,200 tonnes of carbon—or 94% of its total emissions savings—by stepping in when CCGTs were required to provide mandatory frequency response services. 

Other batteries are doing the same, carrying out a vital mission as the UK moves to a low-carbon energy system. In old-style grids, dominated by coal plants, the frequency of the electricity network was held steady by the large mass of steam turbines all rotating in sync up and down the country. 

As those large rotating masses are lost from the system—remember the UK closed its last coal-fired plant, Ratcliffe-on-Soar, in September—it becomes harder to maintain grid frequency, so paradoxically there is a danger that emissions can rise in the energy transition because CCGTs have to be ramped up more often. 

Thanks to batteries, this is not happening. “NESO needs to manage grid inertia as it helps frequency remain stable during large outages,” Modo Energy explains. “However, this requirement has massively reduced since 2022, as NESO has reduced the target grid inertia from 140 GVAs [gigavolt-amperes] to 120 GVAs. 

“According to NESO, 30% of this can be attributed to batteries that perform dynamic containment.”

The impact on emissions is significant. In July 2024, according to Modo Energy’s calculations, the use of CCGTs to provide grid inertia produced almost 86,800 tonnes of emissions—but the use of batteries saved more than 300,500 tonnes. 

Compare that to the same month two years ago, when CCGTs spewed out almost 21,300 tonnes and batteries saved less than 1,100. All this is independent of when batteries store renewable energy that would otherwise be lost from the system. 

Over time, however, wholesale power trading—buying renewable electricity when it is cheap, because there is an excess, and selling it when demand outstrips supply and prices go up—is expected to become the dominant source of revenue for battery systems, and the main way they will cut emissions. 

Significant impact on emissions

This is important because not all frequency response actions reduce emissions. Take the example of a battery that is providing frequency response services but runs out of juice at a time when there is not much renewable energy on the grid. It will charge up on electricity produced by CCGTs, increasing emissions. 

Due to this, there have been 22 battery systems so far in 2024 that have increased UK grid emissions rather than saving CO₂. One battery system has emitted more than 4,000 tonnes of carbon so far. 

But overall, says Modo Energy: “Due to the link between wholesale trading and reduced carbon emissions, total carbon savings directly from battery actions have increased since the end of 2022. The energy exported from batteries participating in frequency response services caused 36,000 tonnes of carbon emissions in 2024. 

“However, this is offset by the 102,000 tonnes of carbon saved by batteries through wholesale trading.”

This is great news for the UK and the world at a time of growing alarm over the impacts of climate change. And the further good news is that more battery projects are in the offing. Pacific Green’s Sheaf Energy Park is currently under construction—another project for Sosteneo that will have 250 MW and 375 MWh of capacity. 

With the UK’s new government touting ambitious clean energy plans, we hope these projects will just be the first of many that will help deliver a clean, stable grid.