Solar Panel Cost: Per Watt, by System Size, and What Changed in 2026
Solar is priced per watt, so the size of the system is the whole equation. This calculator prices the installed system; batteries and panel removal are separate.
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No federal tax credit is applied. The residential ITC ended for customer-owned systems on 31 December 2025. State and utility incentives are not modelled.
What changed in 2026
The residential solar tax credit ended for customer-owned systems on 31 December 2025. Systems placed in service in 2026 or later no longer qualify for the 30% federal credit if you own them.
Third-party-owned systems — leases and power purchase agreements — may still qualify under commercial credits, with some of that passed through as a lower rate.
This matters because most solar cost pages still show an after-credit number. The gap between before and after is about $7,000 on a typical system. If a quote you are reading mentions the 30% credit, check the date on it.
Where the money actually goes
| Component | Share of price |
|---|---|
| Permitting and interconnection | 4% |
| Racking and mounting | 6% |
| Labour | 7% |
| Electrical wiring | 10% |
| Inverters | 10% |
| Solar panels (modules) | 12% |
| Customer acquisition | 15% |
| Other soft costs | 36% |
The panels are only 12% of the price. The largest single block is other soft costs at 36%, which covers design, engineering, insurance during construction, overhead and profit.
Customer acquisition at 15% is larger than the panels themselves. That is sales commission and marketing, and it is why the same equipment can be quoted at very different prices by different companies.
The practical implication: you are not shopping for panels. You are shopping for an installer, and the equipment is a minority of what you pay.
By system size
| System | Installed cost | Per kW |
|---|---|---|
| 3 kW | $9,100 | $3,033 |
| 4 kW | $12,200 | $3,050 |
| 5 kW | $15,200 | $3,040 |
| 6 kW | $18,200 | $3,033 |
| 7 kW | $21,300 | $3,043 |
| 8 kW | $24,300 | $3,038 |
| 9 kW | $27,400 | $3,044 |
| 10 kW | $30,400 | $3,040 |
| 11 kW | $33,400 | $3,036 |
| 12 kW | $36,500 | $3,042 |
| 13 kW | $39,500 | $3,038 |
Solar is unusually linear. Each kilowatt costs roughly the same as the last one, because the equipment scales with size and there is no large fixed cost to spread.
That is the opposite of the pattern on every other size page on this site, where the per-unit price falls. On solar, the discount for going bigger is real but modest.
The number that decides your system size
System size is set by your electricity consumption, not your house size. Two 2,000 sq ft homes can need very different systems if one has a heat pump and an EV and the other does not.
The states in the source data range from a 4.9 kW average system in Colorado to 11.2 kW in Vermont. That spread is consumption and climate, not house size.
The hidden costs
Roof condition. Panels should go on a roof with at least ten years of life left. If the roof needs work first, do it first — removing and reinstalling panels later costs about $3,800.
Electrical service. Older homes may need a 200-amp upgrade before solar can be connected.
Insurance. Solar raises home value, and premiums often follow.
Battery. $7,000 to $18,000, averaging about $15,000. It is not required, and it changes the payback maths more than any other single decision.
What it costs in six states
Material does not change at the state line. Labour does. These are the same 7 kW job priced with six different wage markets.
| State | Labour factor | Low | High |
|---|---|---|---|
| Oklahoma | ×0.79 | $19,505 | $22,263 |
| Kentucky | ×0.84 | $19,586 | $22,355 |
| West Virginia | ×0.92 | $19,690 | $22,475 |
| New Hampshire | ×1.08 | $19,904 | $22,719 |
| New Jersey | ×1.38 | $20,317 | $23,191 |
| Illinois | ×1.40 | $20,350 | $23,229 |
Only the labour line moves. That is a stated limitation of this model, not an oversight.
Frequently asked
Is solar still worth it without the tax credit?
It depends on your electricity rate and how much sun you get. Published payback figures around ten years assumed the credit; without it, expect longer in most states.
Should I lease instead of buy?
A lease lowers the upfront cost and lowers the lifetime saving too. Leases may still carry commercial credits, which is why they look better after 2025 than they did before.
How long do panels last?
Twenty-five to thirty years with output degrading slowly. The inverter usually fails first, typically at ten to fifteen years.
Updated October 2026