From generators and CHP into battery storage

The UK had 7.5 GW of grid-scale battery storage at the end of 2025, according to DESNZ. A record 2.3 GW of that was energised in 2025 alone. The government’s Clean Power 2030 Action Plan puts the range needed by 2030 at 23 to 27 GW.

Starting from 7.5 GW, reaching even the bottom of that range by the end of 2030 means adding about 3.1 GW a year, every year. That’s well above the best year so far, and 2026 has been slower: Modo Energy counted 397 MW added in the first quarter and 209 MW in the second. Every one of those sites has to be commissioned, maintained and looked after when something trips.

So where do the engineers come from?

There’s no official headcount, so be wary of anyone quoting one

I haven’t found a credible UK figure for how many BESS engineers there are, or how many are needed. The government’s Clean Energy Jobs Plan puts electricians and electrical engineers on its list of 31 priority occupations, but it has no battery-specific numbers.

What I can talk about is what I’ve seen while recruiting for these roles. Two recent hires came from outside batteries altogether. One was a generator hire engineer who moved into a BESS service role in Scotland. The other came from CHP in East Anglia. In both cases the employer wanted the electrical background and trained the HV and battery-specific side itself.

What carries over

A generator or CHP engineer already does a lot of what a BESS service engineer does:

• Fault finding on running plant, often alone, often against the clock.
• Safe isolation, permits to work and working on remote, unmanned sites.
• Control systems and protection. CHP engineers in particular are used to plant that runs in parallel with the grid.
• Reading load data and understanding why a system behaves differently at 20% load than at 90%.

What’s new

The gap is real, but it’s specific. A typical BESS engineer spec asks for:

• Battery chemistries, mainly LFP, with NMC on some older sites.
• Power conversion systems (PCS), battery management systems (BMS) and energy management systems (EMS).
• Factory and site acceptance testing, and commissioning.
• Grid connection requirements, usually G99, or the Grid Code for transmission-connected sites.
• HV commissioning experience.

The hazards are different too. DESNZ’s health and safety guidance for grid-scale storage highlights thermal runaway, which can lead to fire, explosion and toxic gases, and arc flash, including on the DC side. It notes that lithium-ion fires can give off hydrogen fluoride, which is corrosive and acutely toxic. It says plant “should only be operated by skilled personnel”.

The rules have caught up, and that helps

There’s more formal guidance to train against than there used to be:

• There’s no BESS-specific law, but the HSE sets out what applies. The Health and Safety at Work Act, the Electricity at Work Regulations, DSEAR, CDM and the Management Regulations all cover battery sites.
• The IET Code of Practice for Electrical Energy Storage Systems was updated in 2024 (third edition). It covers storage in buildings and at low voltage, from specification and design through to operation and maintenance.
• BS 7671:2018+A4:2026 adds a new chapter on stationary secondary batteries. The previous version is withdrawn on 15 October 2026, so installations designed from then on should follow A4.

For an engineer moving across, that’s good news. There’s a clear body of knowledge to learn, and an employer can build training around it.

Generators aren’t going away, they’re getting company

Red diesel ended for construction, plant hire and most other sectors in April 2022. In London, generators on sites covered by the Non-Road Mobile Machinery rules must now meet Stage V, unless the site gets an exemption. The GLA’s own guide says battery alternatives “can remove the need for a generator entirely” for some site power.

Film and TV is moving the same way. BAFTA albert reported that UK productions burned more than 3 million litres of fossil fuel in generators in 2024. Its SPARK roadmap, backed by broadcasters and studios including the BBC, ITV, Sky and Netflix, calls for fossil fuels and standalone generators to be phased out before 2030, using hybrid generators and HVO along the way where needed.

Hire companies already offer hybrid units that pair a generator with a battery. Plenty of generator engineers are working on batteries already, whether their job title says so or not.

On-call looks different

The BESS service roles I’ve recruited for run on-call differently from most generator work. Sites are monitored remotely, so the first response is usually phone triage, and a site visit follows only when it’s needed. The DESNZ guidance says safe operation will include continuous monitoring of equipment across the site.

For engineers who’ve spent years on a traditional call-out rota, that’s worth asking about.

If you’re an engineer thinking about the move

Ask:

• Which chemistry and which PCS and EMS platforms you’ll be working on.
• What HV training is included, and the route and timescale to authorisation.
• How on-call works, and how often you’ll actually attend site.
• How big the patch is.

If you’re hiring

• Widen the net. Generator, CHP and UPS engineers bring the electrical and fault-finding base. The battery-specific side can be taught.
• Budget for HV training and authorisation from the start, rather than asking for it on day one.
• Write the advert around the background you need, not “three years’ BESS experience”. There aren’t enough of those people to go round yet.

If you’re weighing up the move or hiring for it, get in touch.

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Sources: DESNZ Energy Trends, grid-scale battery statistics (30 June 2026); Clean Power 2030 Action Plan (Dec 2024, updated Apr 2025); Modo Energy, GB BESS buildout Q1 2026 and Q2 2026 (Apr and July 2026); Clean Energy Jobs Plan (Oct 2025); DESNZ, Health and safety in grid-scale electrical energy storage systems (Apr 2024); HSE, Battery energy storage systems; IET Code of Practice for Electrical Energy Storage Systems, 3rd edition (2024); IET/BSI, BS 7671:2018+A4:2026; HMRC, Reform of red diesel entitlements; GLA, NRMM Practical Guide (2024); BAFTA albert, SPARK: Clean Temporary Power by 2030 (Dec 2025).