Executive Summary

• More than four in five grid-scale BESS appeals in the UK are allowed, according to analysis from GapSense, with even more – perhaps surprisingly – in the Green Belt
• In many cases, appeals on Green Belt sites were allowed because inspectors saw them as grey belt, following a change to the National Planning Policy Framework
• “The energy-transition balance – grid stability, net zero, a demonstrable unmet need for storage capacity – now outweighs moderate landscape and openness harm almost by default,” GapSense noted

More than 80% of grid-scale battery energy storage system (BESS) appeals in the UK have been allowed, with the number rising to 85% for Green Belt land, according to a new analysis from GapSense, a provider of AI agents for planning policy.

This makes for a particularly interesting analysis compared with the all-development average for planning appeals in England, which stands at 31.1%. The largest scheme allowed at appeal was for a 1.025GW site in Derbyshire in December 2025.

In terms of specific issues that were more likely to be found for the developer, highway and access and flood and drainage (eight out of nine, 89%) were the safest bets, alongside the issue of alternative sites (83%) and noise (80%). Fire safety, meanwhile – certainly a concern when it comes to BESS – had a lower success rate at 60%, but GapSense noted a caveat. Where it was the decisive factor, in two dismissals, for one of them the fire service itself did not object. They were more ‘questions of design detail and site choice’ rather than the principle of battery storage itself.

“The technical objections councils lean on rarely survive scrutiny,” GapSense noted. “Only landscape and Green Belt findings usually hold – and even they lose the final balance.”

Tipping that balance, GapSense argued, is through the revised paragraph 155 in the National Planning Policy Framework (NPPF) at the end of 2024, which found that ‘previously developed or weakly contributing Green Belt land, a demonstrable unmet need, and a sustainable location can now make storage not inappropriate at all.’

In other words, inspectors found the supposedly Green Belt sites as grey belt. One 49.35MW proposal in Walsall was allowed for this exact reason, with the documents confirming the ‘relevant criteria contained in framework paragraph 155 are met’. Of the 13 grid-scale decisions which came down to grey belt, 10 were won by the developer. Seven more went the way of the Walsall case; two saw the council withdraw mid-appeal, while only one, in Burnley, ended in dismissal.

“The energy-transition balance – grid stability, net zero, a demonstrable unmet need for storage capacity – now outweighs moderate landscape and openness harm almost by default,” GapSense noted, adding the Green Belt was now a ‘weaker shield for refusing storage than most committees assume’.

GapSense itself is an interesting entity, and aims to be an example of AI agents adding genuine value. The company’s story notes how recent the use case is. Two years ago, a model could not hold a planning corpus end-to-end and reason about it in a single pass. Today, it can; and such capability could potentially dramatically free up a planning consultant’s workload.

Hence the results that the company is showing with regard to battery storage. It is worth noting that these figures come only from the share of refusals that were appealed, rather than all battery storage refusals that were wrong. GapSense concluded that what is not in doubt is the direction of travel. “Battery storage appeals succeed at a multiple of the all-development average,” the company added.