Backup power for every UK mobile mast could cost £1.8 billion
Key Points
- The government told Parliament it does not hold data on what proportion of rural mobile masts have battery back-up or alternative power for unplanned outages.
- The answer was given by Kanishka Narayan (DSIT) on 28 May 2026 to a written question from Plaid Cymru MP Ben Lake.
- Ofcom estimated one hour of back-up at every UK mobile site would cost the industry £900 million to £1.80 billion.
- Mobile operators have no specific legal duty to provide power back-up, so battery cover varies by network.
- Rural areas face the greatest exposure, with consequences for reaching 999 during storms and power cuts.
The government cannot say what proportion of rural mobile phone masts have battery back-up or alternative power to keep working during an unplanned outage.
The admission came in a written answer on Thursday (28 May). Kanishka Narayan, Parliamentary Under-Secretary of State at the Department for Science, Innovation and Technology, was responding to Ben Lake, the Plaid Cymru MP for Ceredigion Preseli.
Lake had asked what share of rural mast sites carry power that can be drawn on when the grid fails. “Government does not hold this level of detailed information,” said Narayan in his written answer.
Narayan said mobile network operators carry legal obligations to keep their networks resilient. The measures must be appropriate and proportionate. Ofcom oversees compliance, with powers to investigate, issue penalties and enforce remedial action.
The minister acknowledged that storms and power cuts land hardest on rural communities. He pointed to an Ofcom consultation on power back-up for mobile services that reached the same conclusion.
Ofcom has already put a price on fixing the problem. In a technical report published on 10 February 2025, it estimate the costs of one hour of back-up at every UK mobile site, finding that the bill would run to between £900 million and £1.8 billion across the industry.
Ofcom weighed that against the risk that any single mast could lose power in an outage. It found the high cost of a universally available solution made it hard to judge whether the measure would be proportionate.
The work traces back to a consultation Ofcom opened in January 2024. That consultation asked what power back-up operators can and should provide.
It also proposed wider resilience rules covering single points of failure and automatic failover, so traffic diverts to another site when equipment fails. The regulator has said the amount of battery back-up in place varies by mobile network operator. No single standard applies across the industry.
Mobile operators have no specific legal duty to install power back-up. They must instead manage risks to the security of their networks and services under broader resilience rules. That leaves battery support varying from one operator to the next. Rural communities are most exposed.
Weaker signal, heavier reliance on a single network and longer grid restoration times can cut people off for longer when the power fails.
More households are dropping their landlines and relying on a mobile to reach 999. A mast that loses power during a storm can leave a community unable to call for help. Ofcom has flagged this shift before as a central reason for examining mast resilience. Rural and remote areas carry the greatest risk.
Narayan noted that Ofcom published an update on its work in February 2025 and is completing further analysis to set the measures needed to give consumers adequate resilience.
The government wants Ofcom to conclude that work as soon as possible.
He also pointed to closer collaboration between the electricity and telecommunications sectors. The aim is to cut the chance of disruption during power cuts, and to limit how many people are affected and for how long where it occurs.
