When solar tax incentives overheated, the residential solar market became scorched

By Steve Swedberg of CEI.

"Residential solar has long been sold as a win-win for consumers and the environment. It was marketed as an affordable way for homeowners to reduce energy costs and support clean energy goals. What’s not to like? Yet the latest Solar Market Insight Report shows US residential solar installations slowed by 2 percent in 2025, which reveals that the market is not immune to economic and policy pressures.

At the same time, some Republican lawmakers are now pushing to reinstate federal clean energy tax credits. This sign of political uncertainty underscores how reliant the residential solar market has been on government incentives.

In a previous piece, I covered how the Residential Clean Energy Credit (RCEC) and related financing structures spurred rapid market growth alongside unintended consequences. Introduced under the Inflation Reduction Act, the RCEC was intended to jumpstart the residential solar market with a substantial federal tax credit for installing panels. By lowering upfront costs for homeowners, it created a strong financial incentive for consumers and developers to invest in residential solar at an unprecedented pace.

While the credit expanded solar panel adoption, it also accelerated bankruptcies, contributed to at least one alleged fraud case, cost taxpayers millions, distorted energy markets, and funneled investment into subsidy-driven projects rather than economically efficient ones. Because residential solar economics have been tied more to federal incentives than to market fundamentals, these vulnerabilities are now impossible for policymakers and investors to ignore.

Why residential solar is vulnerable without subsidies

Incentives to maximize the fair market value and favor certain financial instruments over others shape how residential solar companies operate, as recent solar industry bankruptcies illustrate.

Sunnova and Mosaic, for instance, grew rapidly using heavily leveraged financing structures. Sunnova carried over $10 billion in debt at the time of its bankruptcy, while Mosaic built its business on long-term loans for residential solar installations. Similarly, SunPower was structured on a loan-based business model, whereas PosiGen focused on no‑upfront-cost leases or loan‑based financing.

These strategies reveal a pattern of overvaluation and aggressive expansion. By structuring operations to maximize RCEC benefits, companies were incentivized to overvalue systems, take on excessive debt, and chase growth divorced from economic reality. Such models leave residential solar particularly vulnerable when interest rates rise, consumer credit tightens, or the RCEC expires and the easy money disappears.

The RCEC’s influence on upfront costs and financing structures means the residential market likely would not have reached its current size without this federal incentive. Its expiration is therefore expected to have significantly adverse effects on the US residential solar sector.

Residential solar is less economically efficient than advertised

Financial advisory firm Lazard’s 2024 report shows that rooftop residential solar has a higher levelized cost of electricity (LCOE) than utility-scale solar and many conventional generation options. LCOE averages total costs over a system’s lifetime electricity output. While a higher LCOE does not automatically mean higher consumer prices, it signals that rooftop solar is less economically efficient per unit of electricity produced.

As my colleague Paige Lambermont pointed out, the RCEC rewards upfront capital investment over efficient or economically sound energy production. Lazard’s findings illustrate how subsidies can distort investment incentives and encourage deployment that may not follow the lowest-cost or most efficient path to meeting US electricity demand.

How the RCEC reshapes capital markets

The RCEC affects more than electricity costs; it also distorts energy finance. As a large, upfront, non-refundable tax credit, it incentivizes solar developers to prioritize projects that maximize tax benefits.

Because developers and homeowners cannot use the RCEC directly, projects rely on tax equity investors, which are large corporations or banks with substantial tax liabilities, to provide the upfront capital in exchange for credit. These investors use financing structures such as partnership-flips, sale-leasebacks, and inverted leases to convert future tax benefits into immediate funding.

Without the RCEC, tax-equity investors would likely have directed capital to other tax-advantaged opportunities or conventional energy projects. The RCEC therefore does more than subsidize residential solar. It channels investment toward projects that maximize subsidy capture, illustrating how federal incentives can reshape financial markets and capital allocation in ways that do not necessarily produce economic efficiency.

Time to test residential solar’s viability

In summation, the RCEC has highlighted the financial vulnerabilities and structural challenges within the residential solar sector. From overleveraged companies to misaligned investment incentives, the program illustrates how federal subsidies can reshape markets in ways that do not always promote economic efficiency.

Whether it is residential solar or the Trump administration recently giving a $625 million subsidy to the struggling coal industry, the RCEC is a fine reminder that the government should not pick winners and losers.

If solar power can succeed in the residential sector, it should be able to do so on its own merits and without government assistance. If subsidies are the only thing keeping residential solar market solvent, then the RCEC is less a bridge for a clean energy revolution than a taxpayer-funded crutch. It is time to see if residential solar can survive without a government handout."