Is the UK doing enough to reduce the use of sulphur hexafluoride (SF6)?
The characteristics of this gas make it highly effective for use in electrical switchgear – but it one of the most potent greenhouse gases, with an effect around 24,000 times that of carbon dioxide. So managing small leaks is important and finding alternatives is a priority – and the pressure must be maintained to ensure that the gas is driven out of the industry at high voltage, where replacements are more difficult, as well as local networks.
The industry aims to reduce leaks and, long term, to find replacements for SF6. But Sustainability First argues that the regulator is doing too little to drive the electricity networks to move faster towards less-polluting alternatives, even at low voltage.
In a response to Ofgem’s consultation on draft business plans for distribution networks in England and Wales, SF described the DNOs’ SF6 strategies as a “material but neglected area” in asset management and said the networks’ strategies were “of highly variable quality”.
Describing as “wholly inadequate” Ofgem’s plans for a reputational incentive, with progress reports, instead of financial penalties and rewards, it called for a “change of gear”.
First, SF wants the distribution networks to put in place a common reporting methodology, – something that has been proposed by Ofgem. It said, “Otherwise, it remains impossible to fully understand the bigger picture – not just on leakage but also to gain a clearer view of the 200,000 equipment items that contain SF6 held right across DNO networks.” Then it wants Ofgem to use financial incentives to drive networks to make better, faster changes to their use of SF6, whether that is reducing leaks, changing assets or having active engagement with the supply chain.

More pressure needed to address higher voltage
Whatever the limitations of the ED2 proposals, distribution networks have the benefit that alternatives to SF6 are being developed and are becoming more commonly used. But at higher voltage, satisfactory replacements are more difficult to find – and the high-voltage network is expanding rapidly, both on and offshore. What is more, the regulators will have fewer opportunities to put pressure on new high-voltage network operators.
Although the problem is acknowledged in a new draft of the National Policy Statement (NPS) on energy, where SF6 is singled out as “an extraordinarily potent greenhouse gas”, it leaves large loopholes that could see the gas in use for decades.
In the draft NPS BEIS says “The climate-warming potential of SF6 is such that applicants should, as a rule, avoid the use of SF6 in new developments.” But it says, “Where no proven SF6-free alternative is commercially available… the continued use of SF6 is acceptable.”
Project developers are expected to consider “at the design stage” whether the development could be “reconceived” without SF6 and explain the reasons and costs if they believe it cannot. But the Secretary of State can approve SF6 applications if there is no proven commercially available alternative, if a “bespoke SF6-free alternative would be grossly disproportionate in terms of cost” and “provided that emissions monitoring and control measures compliant with the F-gas Regulation and/or its successors are in place”.
Under the price review process, incumbent transmission networks will have a new hurdle to cross every five years as incumbent and regulator settle on a price determination. As Sustainability First’s call regarding distribution networks shows, the review offers an opportunity to reset the baseline in response to new options on SF6.
But offshore connections are given a licence lasting two decades or more and – if the regulator expands onshore network competition as planned – an increasing number of onshore high-voltage links will operate under similar long licences.
As the number of such links increases, it is more important than ever that the licence requires SF6 management and reduction over the long term – and not an approach that was ‘best available technology’ at a design stage 20 years ago.

Further reading
The worst greenhouse gas: why the electricity industry has to grapple with SF6
Greater Gabbard OFTO ‘could not have forseen’ seal failure that released SF6