Solar vs Grid: Running the Real Numbers
“Is solar worth it?” is the number one question we hear from homeowners. The answer depends on your electricity rate, sun exposure, available incentives, and how long you plan to stay in your home. We built detailed financial models for every US state and ran 25-year projections to give you a definitive answer.
The short version: Solar is financially worth it for homeowners in 35+ states who plan to stay in their home for at least 5 years. The average homeowner saves $25,000-$60,000 over 25 years compared to grid electricity, with a payback period of 5-8 years.
The Cost of Grid Electricity Is Rising
Before we talk about solar, let us look at what you are comparing against. US residential electricity rates have increased an average of 3.5% per year over the past decade, with some states seeing 6-8% annual increases.
| Year | National Avg Rate | Monthly Bill (1,000 kWh) |
|---|---|---|
| 2020 | $0.131/kWh | $131 |
| 2022 | $0.145/kWh | $145 |
| 2024 | $0.162/kWh | $162 |
| 2026 | $0.178/kWh | $178 |
| 2030 (projected) | $0.208/kWh | $208 |
| 2035 (projected) | $0.248/kWh | $248 |
If you do nothing, your electricity costs will approximately double over the next 20 years. Solar locks in your energy cost at installation day prices for 25-40 years.
Solar Cost: What You Actually Pay in 2026
Here is the real math for a typical 8kW solar system in 2026:
Gross system cost: $22,800 ($2.85/watt national average) Federal ITC (30%): -$6,840 Net cost to you: $15,960
Your net cost per kWh of solar electricity over 25 years:
- 8kW system produces approximately 11,000 kWh/year (national average)
- Over 25 years (with 0.4% annual degradation): 268,000 kWh total
- Cost per kWh: $0.060 ($15,960 / 268,000 kWh)
Compare that to grid electricity at $0.178/kWh today, rising to $0.25+ by 2035. You are locking in electricity at one-third the current rate.
25-Year Financial Comparison: Solar vs Grid
For a home using 10,500 kWh per year (US average):
Scenario: Stay on Grid Only
| Cost Element | Amount |
|---|---|
| Year 1 electricity cost | $1,869 |
| Total 25-year electricity cost (3.5% annual increase) | $71,400 |
| Total cost | $71,400 |
Scenario: Go Solar (Cash Purchase)
| Cost Element | Amount |
|---|---|
| System cost after ITC | $15,960 |
| Remaining grid costs (nighttime, winter) | $4,800 |
| Maintenance over 25 years | $1,200 |
| Total cost | $21,960 |
| Total savings vs grid | $49,440 |
Scenario: Go Solar (Loan at 5.5% APR, 15-year term)
| Cost Element | Amount |
|---|---|
| Total loan payments (15 years) | $23,800 |
| Remaining grid costs | $4,800 |
| Maintenance | $1,200 |
| Total cost | $29,800 |
| Total savings vs grid | $41,600 |
Even with financing, solar saves the average homeowner over $40,000 compared to 25 years of grid electricity.
The Payback Period Explained
Your payback period is how long it takes for solar savings to equal your upfront investment. Here is how it works:
Year 1 savings: You offset ~$1,650 in electricity costs (8kW system, national average rates)
Payback calculation: $15,960 net cost / $1,650 annual savings = 9.7 years at today’s rates
But electricity rates increase each year. Factoring in 3.5% annual rate escalation:
Adjusted payback: 7.2 years
In high-rate states, payback is even faster:
| State | Electricity Rate | Annual Solar Savings | Payback After ITC |
|---|---|---|---|
| Hawaii | $0.39/kWh | $3,800 | 4.2 years |
| California | $0.31/kWh | $2,950 | 4.8 years |
| Massachusetts | $0.29/kWh | $2,700 | 5.1 years |
| Connecticut | $0.28/kWh | $2,600 | 5.5 years |
| New Jersey | $0.22/kWh | $2,100 | 5.5 years |
| New York | $0.24/kWh | $2,250 | 6.2 years |
| National Avg | $0.178/kWh | $1,650 | 7.2 years |
| Texas | $0.14/kWh | $1,350 | 7.8 years |
When Solar is NOT Worth It
Solar does not make financial sense in every situation. Here are the cases where you should hold off:
Your roof needs replacement within 5 years. Removing and reinstalling panels costs $2,000-$5,000. Get the new roof first, then solar.
Heavy shading. If your roof receives less than 4 hours of direct sunlight daily due to trees or buildings, solar output drops dramatically. A site assessment with shade analysis (free from most installers) will tell you if your location works.
You are moving within 3 years. While solar adds home value (3-4% on average), the transaction costs and hassle of transferring solar agreements may not be worth it for very short stays. Cash purchases transfer easily; leases and PPAs can complicate home sales.
Very low electricity rates. In areas with rates below $0.10/kWh (parts of the Pacific Northwest, Tennessee Valley), the payback period stretches beyond 12 years. Solar still works, but the financial case is weaker.
Roof geometry issues. North-facing roofs (in the Northern Hemisphere), very steep or very flat pitches, and heavily dormered roofs may not have enough suitable area for a cost-effective system.
Solar + Battery vs Grid + Generator
Many homeowners also weigh backup power options. Here is how the costs compare:
Solar (8kW) + Battery (13.5kWh Tesla Powerwall 3):
- Installed cost: $32,000
- After 30% ITC: $22,400
- Annual savings: $2,200 (electricity + TOU optimization)
- Payback: 10.2 years
- 25-year savings vs grid: $38,000
- Backup power: Yes, automatic, silent, solar-rechargeable
Grid + Standby Generator (22kW Generac):
- Installed cost: $8,000-$12,000
- Annual fuel and maintenance: $400-$800
- 25-year total cost: $18,000-$30,000
- Does not reduce electricity bills
- Backup power: Yes, automatic, requires fuel
The solar + battery combination costs more upfront but eliminates electricity bills and provides fuel-free backup. Over 25 years, it wins financially by a wide margin.
The Environmental Angle
If environmental impact matters to you, the numbers are compelling:
An 8kW solar system in the US prevents approximately 7.5 metric tons of CO2 emissions per year, equivalent to:
- Driving 18,750 fewer miles in a gas car
- Planting 125 trees annually
- Removing 1.6 cars from the road
Over 25 years, your solar system prevents roughly 188 metric tons of CO2 emissions. This is one of the single most impactful climate actions an individual can take.
How Net Metering Affects the Math
Net metering — the policy that lets you sell excess solar energy back to the grid — significantly impacts solar economics. Here is how the three common structures compare:
Full retail net metering (NJ, MA, NY): You receive full retail credit for every kWh exported. This is the best scenario and produces the fastest payback.
Reduced rate net metering (CA NEM 3.0, some utilities): You receive 50-75% less for exported energy than you pay for consumed energy. Adding a battery to maximize self-consumption becomes important.
No net metering (some rural co-ops, TN, AL): You receive wholesale rates ($0.03-$0.05/kWh) or nothing for exports. Solar is still viable if you size the system for self-consumption and add battery storage.
Making the Decision: A Simple Framework
Ask yourself these four questions:
- Do you pay more than $0.12/kWh for electricity? If yes, solar likely makes sense.
- Does your roof get 4+ hours of direct sun daily? If yes, proceed.
- Will you stay in your home for 5+ years? If yes, you will pass the payback period.
- Can you use the federal tax credit? If you owe $5,000+ in federal taxes, you can capture the full benefit.
If you answered yes to all four, solar is almost certainly worth it. Get 3-5 quotes through a marketplace like EnergySage to see your specific numbers.
FAQ
How much do solar panels save per month? The average US homeowner saves $100-$180 per month on electricity with solar, depending on system size, electricity rate, and sun exposure. In high-rate states like California and Massachusetts, monthly savings of $200-$300 are common.
Do solar panels work in winter? Yes. Solar panels produce less energy in winter due to shorter days and lower sun angles, but they still generate meaningful power. Snow typically slides off panels within a day or two. Annual production estimates already account for seasonal variation.
What happens to solar panels after 25 years? Solar panels do not stop working at 25 years — that is just when the performance warranty expires. Most panels continue producing 80-85% of original output well beyond 30 years. At that point, you have a fully paid-off energy source generating free electricity.
Will solar panels damage my roof? Properly installed solar panels actually protect the roof surface beneath them from UV exposure and weather. Reputable installers use flashed mounting feet that maintain roof integrity. Most installer warranties cover roof penetration for 10-25 years.
Is it better to buy or lease solar panels? Buying (cash or loan) provides 2-3x more total savings than leasing because you capture the tax credit and own the asset. Leasing makes sense only if you cannot use the tax credit and want zero upfront cost. We recommend purchasing whenever financially possible.