Insurance for DER: costs and coverage

Battery property cover is priced on chemistry, spacing, fire testing and the operator’s record. Solarif’s guide to storage requirements puts yearly premiums at 0.3% to 1.2% of project value, with lithium iron phosphate (LFP) cells usually getting better terms than nickel manganese cobalt (NMC). Severe-weather zones add 20% to 50%. Solar property rates in the US went from about 10 cents to as much as 30 cents per $100 of insured value during the last hard market. In the Finance hub example, insurance for a 100 kW battery can cost as much as routine upkeep.

Prices are now falling for many renewable buyers as more insurers compete, but the hard market left higher deductibles behind. A solar farm deductible that was once $25,000 might now be $250,000, one underwriter told Insurance Business. The head of kWh Analytics warned that rates have dropped across property insurance while the underlying risks haven’t changed. For a 15-year model, that argues for an insurance line that rises faster than inflation in the base case.

Hail accounts for 73% of insured solar losses by dollars from about 6% of incidents, according to PV Tech’s report on kWh Analytics data. The 2026 Solar Risk Assessment found that standard 2 mm glass modules aren’t enough on their own to keep hail risk acceptable across 52% of the contiguous US. An AXIS review found hail made up about 55% of weather and catastrophe claim dollars from about 1% of claims. Fire is drawing more attention too: most solar fire events start inside the plant, not from wildfires.

For rooftop and commercial DER, the lesson is about concentration. A portfolio of rooftop systems spread across states has less hail exposure than one large array in the plains, but it still needs to know how much of its value sits in high-hail counties.

Battery fires are rare but large. After the January 2025 fire at Moss Landing in California, Vistra claimed against policies with combined property and business interruption limits of $500 million and had collected all of it by February 2026, according to its SEC filing on the incident. Underwriters responded by asking for more evidence. The sixth edition of UL 9540A, the main fire test for battery systems, published in 2026, adds installation-level fire testing of how fire spreads between units, and underwriters want results that match the installed spacing and protection (Swiss Re).

For commercial and residential batteries, the practical points are the same at smaller scale: a listed system, installation to fire code and the manufacturer’s spacing, LFP chemistry where possible, and monitoring that can shut the system down early. Each one shows up in the premium or in whether the policy is written at all.

Tax credit insurance protects a credit buyer or tax investor if the credit is reduced, disallowed or recaptured. Premiums usually run 2% to 5% of the insured limit, and coverage of 90% to 140% of the credit is most common, per Crux’s transfer guide. But minimum premiums dominate small deals. Carrier premiums ran $150,000 to $350,000 per policy in 2024, plus $50,000 to $90,000 of underwriting fees, and rose in early 2025.

That’s why only 11% of solar ITC deals under $10 million carried insurance in early 2025, against 67% of larger deals, and why insured or investment-grade deals earned about 3 cents more per credit dollar. Brokers describe credits under about $5 million as hard to insure and sometimes left as “orphan credits” (Tax Notes reporting via Reunion). Pooling many small DER assets into one fund is the usual fix, as our tax equity guide explains.

An owned rooftop system is usually covered as part of the home, but a homeowner policy generally won’t pay for mechanical breakdown, poor workmanship or lost electricity production (Amica’s coverage guide). A home battery attached to the house may count as part of the dwelling, while a detached one may fall under the lower other-structures limit. With a lease or PPA, the provider owns and insures the equipment, though contracts vary on what the homeowner must carry. Home premiums themselves are rising fastest in storm-exposed states, as the Finance hub covers.