Britain’s clean-energy construction pipeline is creating new work for general contractors, groundworks firms and mechanical and electrical contractors across Essex, Kent and London. Utility-scale solar farms, rooftop photovoltaic systems and battery energy storage systems are no longer specialist projects carried out only by a small group of energy contractors.
Many established construction businesses are now being asked to install cable routes, foundations, fencing, plant, inverters, panels, battery containers and grid infrastructure. That creates a commercial opportunity, but it also creates an insurance problem when a contractor accepts work that falls outside the basis on which its policies were written.
The market is moving quickly. Government and Ofgem reporting on connections reform shows that 221 gigawatts of projects have been removed from the main connection queue, while battery projects progressing through the process still exceed the Government’s 2030 range by 14.8 gigawatts. The scale of the pipeline is considerable, but it is not yet clear whether every project will be commercially viable or whether the insurance market can provide capacity at the speed required.
At the same time, insurers are becoming more selective. Allianz UK has expanded its battery-storage underwriting proposition, while Howden has expanded its renewable-energy facility across its UK network. These developments show that specialist capacity is being built, but they do not mean every solar or BESS project will receive broad, unrestricted cover.
In my experience, the biggest problem is often not that a contractor has no insurance. It is that the contractor has the wrong insurance for the work being undertaken.
1. Battery fire and thermal runaway may be restricted under standard policies
Standard contractors’ all risks and public liability policies are not automatically designed for lithium-ion battery storage.
Battery energy storage systems present a different fire risk from ordinary construction materials or electrical plant. A damaged, defective or overheated cell can enter thermal runaway, causing heat and fire to spread through adjacent cells. Fires can be difficult to control, may reignite and can require significant emergency-response planning.
Some standard policies may exclude battery storage altogether. Others may restrict cover for fire, explosion, thermal runaway, commissioning, testing or the storage of high-energy battery units. The wording can also distinguish between damage to the battery system itself and damage that the system causes to surrounding property.
That means a contractor may assume that its contract works policy covers a BESS installation, only to discover that the key battery-related loss is excluded or subject to a low sub-limit.
The same concern applies to rooftop solar. Research reported by Insurance Business, based on QBE information from UK fire services, found that fires involving solar panels increased from 91 in 2022 to 212 in 2025. DC cabling and connectors were the leading recorded source in 2025, while battery banks and inverters were also significant causes.
Insurers are therefore asking more questions about fire engineering, equipment separation, thermal monitoring, detection, suppression, emergency access and maintenance. A well-designed BESS with clear documentation may still be insurable, but the risk needs to be presented properly from the start.
2. Contractual liability and design responsibility can fall between two policies
Renewable-energy contracts frequently use EPC or design-and-build structures. A general contractor may be responsible not only for installing equipment but also for selecting components, preparing layouts, coordinating suppliers, producing calculations or warranting that the completed system will perform.
That creates a boundary between construction work and professional design.
Public liability insurance generally responds to legal liability for injury or property damage. It is not usually intended to cover every contractual obligation a contractor accepts. If the contract imposes a wider liability than would exist under ordinary law, the policy may not respond to that assumption of responsibility.
Professional indemnity insurance may be needed where the contractor designs, specifies, surveys, advises, certifies or provides engineering input. But a contractor’s existing PI policy may have been written for ordinary building work, not for electrical design, battery integration, grid compliance or energy-performance guarantees.
There is also a common misunderstanding around contract works cover. Construction policies may cover accidental physical damage during the project, but design defects and the cost of correcting defective work are often restricted. This is where LEG clauses, or defects clauses dealing with design and workmanship, become relevant. The exact wording matters and should not be reduced to the simple assumption that “all risks” means everything is covered.
Before signing an EPC-style contract, a contractor should ask:
- Who is responsible for the system design?
- Who selects the battery, inverter and control equipment?
- Is the contractor giving a performance guarantee?
- Does the contract require fitness for purpose rather than reasonable skill and care?
- Does the PI policy cover the relevant engineering or electrical design?
- Does the construction policy respond to resulting damage caused by a defect, and under what LEG wording?
These questions should be resolved before the work starts, not after a loss has occurred.
3. Delay in start-up can be more expensive than the construction loss
A fire or defect on a grid-connected project can cause a loss far greater than the cost of replacing damaged equipment.
Solar farms and BESS projects often depend on a particular grid-connection date, subsidy arrangement, power purchase agreement or revenue start date. If commissioning is delayed, the project may lose expected income, incur additional borrowing costs and face contractual penalties.
This is where delay in start-up, also known as advance loss of profits in some arrangements, becomes important. The cover can protect anticipated revenue and additional expenditure following insured physical damage that delays the project’s planned start of operations.
It is not an automatic extension of ordinary contract works insurance, and it is rarely bought by smaller contractors unless the developer, funder or main contract requires it. That can leave a significant gap in the project insurance programme.
The cause of the delay also needs careful attention. A policy may respond to an insured fire, machinery breakdown or transit loss, but not to every delay caused by the grid operator, planning process, connection queue or commercial dispute. Waiting periods, maximum indemnity periods, assumptions about the commissioning date and the calculation of expected revenue all need to be agreed.
Imported batteries create another issue. Damage during overseas transport may fall outside a standard construction policy, requiring marine cargo or transit cover. If the damaged equipment delays commissioning, the transit policy and DSU section need to work together.
Howden’s renewable-energy facility is an example of the specialist market developing around these combined exposures, with renewable construction, operational, transit, business interruption and delay-related covers considered within a wider programme.
4. The subcontractor and competence chain can decide who carries the claim
A main contractor may not install the panels or battery units itself. It may appoint an electrical contractor, specialist PV installer, battery integrator or commissioning engineer.
That is normal, but subcontracting does not automatically transfer the main contractor’s exposure.
If an uninsured subcontractor connects DC cabling incorrectly and a fire follows, the property owner may still pursue the main contractor under the contract. The main contractor may then need to recover from the subcontractor, which is difficult if the subcontractor has inadequate insurance, has ceased trading or has accepted a liability limit that does not match the project.
Competence evidence is becoming increasingly important. For solar installations, clients and insurers may ask for MCS certification and installer details. They may also want evidence of electrical testing, inspection, commissioning, maintenance and handover procedures.
For battery projects, the questions are more detailed. The contractor should understand who is responsible for:
- Battery cell and container specifications.
- Fire detection and suppression.
- Thermal monitoring and alarm signalling.
- Emergency isolation and first-responder access.
- Site security and protection from impact.
- Commissioning and testing.
- Ongoing inspection and maintenance.
A certificate of insurance alone does not demonstrate competence. Main contractors should check that subcontractors are insured for the actual work, that their limits are adequate, and that their policy wording does not exclude battery storage, high-voltage work or design responsibility.
5. Declared values and building warranties may no longer reflect the real risk
Solar panels, inverters, transformers and battery units can have volatile prices and long replacement lead times. A declared project value prepared six months ago may no longer reflect the cost of replacing equipment, importing it or completing specialist commissioning.
Underinsurance can affect more than the physical damage section. It may reduce the amount available for debris removal, professional fees, expediting expenses, business interruption or delay in start-up.
Contractors and developers should review values when:
- Equipment specifications change.
- Battery capacity increases.
- Imported components are substituted.
- The project is delayed.
- Replacement costs or lead times rise.
- The scope expands from installation into design and commissioning.
There is also a property-insurance issue when a solar array is retrofitted onto an existing warehouse, office, school or industrial building. The building owner’s policy may contain occupancy, alteration, electrical installation, roof-loading or fire-protection warranties. Adding solar equipment or battery storage without notifying the property insurer can create a separate coverage dispute.
The contractor should not assume that the building owner has dealt with this. The contract should clearly allocate responsibility for notifying insurers, obtaining surveys and confirming that the existing property policy remains suitable.
What contractors in Essex, Kent and London should do now
The clean-energy pipeline will continue to create opportunities for general contractors and M&E firms, but insurance needs to be included in the project design rather than treated as paperwork at the end.
Before accepting solar or battery-storage work, contractors should:
- Review the full policy wording, not only the insurance certificate.
- Confirm whether BESS, lithium-ion batteries, thermal runaway and commissioning are covered.
- Check whether the contract creates design, performance or fitness-for-purpose obligations.
- Arrange professional indemnity cover where design or engineering responsibility is accepted.
- Review LEG clauses and defective-workmanship exclusions under the construction policy.
- Check subcontractor insurance, MCS evidence, competence and responsibility for testing.
- Consider marine transit and delay-in-start-up cover for imported equipment.
- Recalculate project values and replacement-cost assumptions before binding cover.
- Confirm that the building owner’s property insurer has accepted any rooftop solar or battery alterations.
- Engage with a broker early, particularly where the project involves BESS, shared grid infrastructure or unusual contractual terms.
Allianz’s expanded BESS underwriting and Howden’s renewable-energy facility are positive developments, but the market is clearly selective and fire-mitigation dependent. The projects most likely to secure workable terms will be those with clear designs, competent installers, documented emergency procedures and early insurer involvement.
If you need Construction Contractor Insurance, General Contractor Liability Insurance, Business Insurance Essex or Business Insurance London for renewable-energy work, speak to Moyak Insurance Services before signing the contract. We can review the work you are taking on, identify where liability sits and approach suitable insurance markets for your business and budget.
Call 01375 392087, email info@moyakinsurance.co.uk or visit Moyak Insurance Services. You can also request a review through our commercial combined insurance service.
Further reading: