Does solar increase home value? What the research shows

If you are weighing a system in 2026, a fair question is whether you would get some of the money back when you sell. The honest answer is “often something, but less certain than the headlines suggest.” This post walks through what the best-known research found, how old that research is, and why who owns the system matters as much as whether you have one.

Key takeaways

• The largest U.S. study of solar and sale prices (Lawrence Berkeley National Laboratory, 2015) found buyers paid a premium for owned systems, averaging about $4 per watt, or roughly $15,000 for a 3.6 kW system.
• That study used sales from 2002 to 2013. Costs, incentives and buyer awareness have changed since, so treat it as evidence of direction, not a price you can bank.
• Zillow’s 2019 analysis found about a 4.1% premium nationally, with a range by metro. It matched listings by keyword, which is a looser method than a research appraisal.
• Leased and power purchase agreement (PPA) systems are treated differently. Under current Fannie Mae rules, their value cannot be added to the appraised value.
• Use this as a reason to ask questions, not as a reason to expect your payback to be paid off by a sale.

What the Berkeley Lab study actually measured

The most-cited work comes from Ben Hoen and co-authors at Lawrence Berkeley National Laboratory (LBNL), working with appraisers and university researchers. The report, dated January 13, 2015, looked at 22,822 home sales across eight states, of which 3,951 were homes with solar. The sales span 2002 to 2013, and homes priced above about $900,000 were not included. The states were California, Connecticut, Florida, Massachusetts, Maryland, North Carolina, New York and Pennsylvania.

The researchers used regression models that compare sale prices while accounting for features such as size, location and market conditions. Their headline finding: across the full sample, average premiums equaled approximately $4 per watt, or about $15,000 for an average-sized 3.6 kW system.

A few details from the report are worth keeping in mind.

• California dominates the data. California homes made up 97% of the solar homes in the sample. The California estimate was about $4.21 per watt, with a 95% confidence interval of roughly plus or minus $0.64 per watt.
• Florida and other states are thinly covered. For the seven states outside California combined, the estimate was about $3.11 per watt. The authors note the smaller sample gives a much less precise estimate, though it was not statistically different from California’s.
• Bigger is not proportionally better. The authors found hints that larger systems earn an increment per watt that shrinks, and that buyers might pay something for having any system at all.
• Value fades with age. In the first ten years, the market appeared to discount the system faster than either panel efficiency loss or simple straight-line depreciation would suggest. The authors say their data are not robust for systems in their second decade.
• New homes were similar. Premiums on newly built homes and existing homes were not statistically different, though the report saw some evidence of builder discounting on new homes.

One more point for 2026 readers. The report found that estimates based on net system cost, meaning cost after government and utility incentives, may be the best proxy for market premiums. Those studied systems were installed when the federal residential credit existed. For installs in 2026 and later it does not apply, so we would not assume the same dollar-per-watt figure carries over.

What Zillow found, and what it did not

In April 2019, Zillow reported that homes with solar-energy systems sold for 4.1% more on average than other homes nationwide over the prior year. By metro, it cited 5.4% in New York, 4.4% in San Francisco and 3.6% in Los Angeles. A Zillow senior economist said in the release that the premium is largely reflective of expected energy cost savings.

Read this one with care:

• It covers homes sold between March 1, 2018 and February 28, 2019, so it is also a few years old.
• The footnote says homes were identified by keywords such as “solar panel” or “photovoltaic” in the listing description. That can mix owned and leased systems, and the release does not describe which other home features were controlled for.
• It is a company press release, not a peer-reviewed or lab-reviewed study.

The direction agrees with LBNL, but the two numbers are not directly comparable. One is a dollar-per-watt premium from regression models on appraisal-style data, the other is a percentage from listing keywords. If you want to cite either, cite both dates.

How appraisers handle solar

A premium in a study does not automatically appear in your appraisal. For loans sold to Fannie Mae, the Selling Guide says special energy items, including solar panels, must be noted in the appraisal and compared with comparable properties. It also says appraisers cannot adjust value simply by dollar-for-dollar equipment cost or by the discounted value of expected savings, and must consider how the local market actually reacts to the feature.

In practice this means:

• Value depends on comparable sales near you. If few nearby homes with solar have sold, there is less evidence for the appraiser to use.
• Your installation cost is not your appraised value. Paying a given amount for a system does not mean the home appraises for that much more.
• Documentation helps. Permits, production data, warranty papers and ownership records make it easier for an appraiser and lender to understand what is on the roof.

Owned, financed and leased: why it changes the answer

The LBNL study only included homeowner-owned systems. The authors say studies of third-party-owned systems are needed. So the research above does not tell you what a leased system adds to a sale price.

Fannie Mae’s current guide sets out how ownership affects things:

• Owned outright, or financed and repaid, or secured by the existing first mortgage: standard requirements apply, and a lender can count the panels in the appraisal.
• Separately financed panels: these must not add value unless the documents show the panels cannot be repossessed if the loan defaults.
• Leased panels or PPAs: the guide says their value cannot be included in the appraised value, and the lender must review the lease or PPA terms.

Selling a home with a lease also means the buyer has to qualify for, and agree to take over, the contract, or the seller has to resolve it. That is a practical step we cannot size for you, so ask the provider what their transfer process and any fees are before you sign. For the wider trade-offs, see our guide on solar lease vs buy.

Property taxes: a separate piece of the sale

Added value does not have to mean a higher tax bill, at least on paper.

• Florida: the statute says the just value attributable to a residential renewable energy source device may not be considered in assessing the property. It applies to residential devices installed on or after January 1, 2013. The 2017 amendments to the relevant subsections expire December 31, 2037, per the statute’s text.
• California: the State Board of Equalization’s August 26, 2024 letter said the new-construction exclusion applied to active solar systems in process or completed before January 1, 2027, and that a system already excluded stays excluded until the property changes ownership. That was the rule as of that letter. Legislation may have changed it since, so check the current text with your county assessor or the BOE before relying on it.

Neither rule tells you what a buyer will pay. They only affect assessed value. See our utility pages for FPL, Duke Energy Florida, TECO, PG&E, SCE and SDG&E for how rates affect the savings side.

What this means for your decision

Think of resale value as a possible bonus, not as part of the base case. Here is a cautious way to use the research:

1. Run the payback first. Our calculators for Florida and California show a low, likely and high range without counting any resale premium. See our methodology for the assumptions.
2. Treat the studies as a range of “something.” The sources point to a premium that varies by market, system size, age and ownership. They do not give a number for your street.
3. Prefer ownership if resale matters to you. Owned systems have the research and the appraisal rules behind them. If you are still deciding, read is solar worth it without the tax credit.
4. Ask a local agent and a local appraiser. Ask for recent sales of homes with and without solar nearby, which is the evidence that actually moves an appraisal.

Next steps

• Get a personal range from the Florida calculator or California calculator.
• If you are collecting offers, compare solar quotes side by side, including who will own the system.
• If you want help from installers, you can request quotes, with no obligation to buy.

Related reading: what residential solar costs per watt in 2026.