Is solar cheaper than utility electricity?

In most US states, the levelized cost of solar (LCOE) is now $0.06–$0.10/kWh over 25 years — well below the national average retail rate of $0.17/kWh. In high-rate states like California ($0.30+/kWh) or Hawaii ($0.40+/kWh), the economics are overwhelmingly in solar's favor. Even in low-rate states, solar is typically cost-competitive after incentives.

How long does it take for solar to be cheaper than the grid?

Solar typically becomes cheaper than the grid within the first year of operation in high-rate states. Over time, as utility rates rise 3–5% annually, the advantage grows. By year 10, your effective solar rate (annualized system cost) is often 50–70% below what you'd pay the utility. After the system is paid off, electricity is essentially free.

At what utility rate does solar make financial sense?

Solar generally makes strong financial sense when your utility rate exceeds $0.12–0.14/kWh. Above $0.20/kWh (the national average), solar is compelling in virtually every US market with adequate sun. States like California ($0.30+/kWh), Hawaii ($0.40+/kWh), and Massachusetts ($0.25+/kWh) have the most favorable economics.

What happens to my solar savings if electricity rates drop?

Electricity rates have historically risen on average 2.5–3% per year nationally and rarely drop significantly long-term. However, rate structures can change — some utilities have added fixed charges, demand charges, or reduced net metering rates. A battery system provides a hedge against rate structure changes by maximizing self-consumption rather than relying on grid exports.

Solar vs Utility Cost Calculator

Compare the total 25-year cost of solar against staying on the utility grid with rising rates. This side-by-side comparison shows exactly how much solar saves — and when solar's total cost drops below the utility's.

Monthly Bill ($)

Solar Monthly Cost ($)

Utility Increase (%/yr)

About This Calculator

The Solar vs Utility Cost Calculator presents the most direct financial comparison a homeowner can make: the total amount of money going to the utility over 25 years versus the total amount spent on solar over the same period. Both costs escalate at different rates — utility bills grow with annual rate increases, while a solar loan or lease typically has a fixed payment or a modest escalator. The gap between these two growing curves represents your cumulative savings from going solar, which typically reaches $25,000–$50,000 over 25 years for average U.S. households.

The "solar monthly cost" input should reflect your actual net monthly solar expense: if you paid cash, enter zero (the system is already paid off) or spread it over 25 years; if you have a loan, enter your monthly payment; if you have a lease, enter your lease payment. The "solar annual increase" applies if you have a lease or PPA with an escalator — for a fixed loan or cash purchase, enter 0%. This flexibility allows the calculator to model any financing scenario accurately against the escalating utility alternative.

One nuance worth understanding: after a solar loan is paid off (say, year 12 on a 12-year loan), your monthly solar cost drops to near zero — just occasional maintenance. But this calculator uses a steady escalation model. For paid-off systems, enter a small maintenance-only cost (perhaps $10–$15/month) as your solar monthly cost to reflect realistic long-term expenses. This avoids overstating solar savings in later years. For lease holders, your payment continues through the full term at the escalating rate.

The most powerful insight from this comparison is the Year-25 utility bill — seeing that a $150/month bill today becomes $250–$370/month in 25 years (at 3.5% annual escalation) makes the case for solar viscerally clear. Every year of delay means one more year of paying that escalating utility bill rather than locking in a lower, predictable solar cost. This calculator is the best single tool for explaining the solar value proposition to a skeptical spouse, parent, or financial advisor.

Calculations based on NREL solar modeling data and industry-standard assumptions, built and maintained by the independent SolarToolsOnline research team.

Estimates only — not financial, tax, or legal advice. Verify important results with a licensed solar installer or financial professional before making decisions.