Residential solar costs about $2.60 per watt in 2026, according to EnergySage’s marketplace quote data (page updated June 30, 2026). That is before any incentive, and no federal credit applies to a system placed in service after December 31, 2025, per the IRS (page updated July 4, 2026). Two other widely cited datasets give higher figures: $3.36 per watt from SEIA and Wood Mackenzie for the second quarter of 2026, and $4.00 per watt from Lawrence Berkeley National Laboratory (LBNL) for 2024 installs. All three can be right, because they measure different things. This guide explains the gap, then shows how system size, panel brand and the equipment-versus-labor split move the number.
Three Per-Watt Numbers, Three Meanings
Cost per watt is the installed price divided by system size in watts. An 8 kW system is 8,000 W, so $2.60 per watt means $20,800 (our arithmetic). The trouble is that each source collects prices differently.
| Source | $/W | What it measures |
|---|---|---|
| EnergySage marketplace | $2.60 | National figure from quotes on its platform, 2026, before incentives |
| SEIA / Wood Mackenzie | $3.36 | Residential turnkey average, Q2 2026 |
| LBNL Tracking the Sun | $4.00 | Median reported installed price of 2024 installs, in 2024 dollars |
SEIA and Wood Mackenzie’s Q3 2026 US Solar Market Insight, reported on September 25, 2026 by pv magazine USA, put the Q2 2026 residential turnkey price at $3.36 per watt, down 1.4% from a year earlier. LBNL’s October 2025 data update reports a residential median of $4.0 per watt, with the 20th percentile at $3.0 and the 80th percentile at $5.2. LBNL’s figure includes the dealer fees built into many solar loans, which pushes the median up.
Applied to an 8 kW system, the three figures give $20,800, $26,880 and $32,000 (our arithmetic). The EnergySage number is a marketplace price where homeowners compare multiple bids, so it is a handy benchmark when you compare bids. Treat the LBNL figure as what typical homeowners actually paid in 2024, not as a 2026 quote.
For a fuller breakdown by system type and a ten-state comparison, see our solar panel installation cost guide.
The Federal Credit Is Gone
Older articles often quote a lower “after incentive” cost per watt. They applied the 30% residential clean energy credit. The IRS says that credit is not available for property placed in service after December 31, 2025. Applying 30% to $2.60 would have given $1.82 per watt (our arithmetic), but that number no longer describes a 2026 purchase. If an article still shows it, the article is out of date.
State and utility incentives still exist in some places. We cover how they shape state prices in our solar cost by state guide.
Cost Per Watt by System Size
Larger systems cost less per watt because fixed costs, such as the site visit, permits, inverter setup and sales effort, are spread over more panels. EnergySage’s size data (June 2026) shows the pattern.
| System size | Cost per watt |
|---|---|
| 4 kW | $2.89 |
| 5 kW | $2.78 |
| 6 kW | $2.68 |
| 8 kW | $2.62 |
| 10 kW | $2.58 |
| 12 kW | $2.56 |
| 14 kW | $2.54 |
| 15 kW | $2.47 |
From 4 kW to 15 kW the price per watt falls $0.42, or about 14.5% (our arithmetic). Most of that drop happens early. Going from 4 kW to 8 kW takes off $0.27, while going from 8 kW to 12 kW takes off only $0.06.
There is a practical lesson here. At EnergySage’s figures, a 5 kW system costs $2.78 per watt, or $13,900, and a 10 kW system costs $2.58 per watt, or $25,800 (our arithmetic). The extra 5 kW adds $11,900, which is $2.38 per added watt. If your electric use justifies a larger array, the added panels are cheaper than the first ones. If it does not, a bigger system just takes longer to pay back. Our solar system cost by size guide has total prices for common sizes.
Where the Money Goes: Equipment Versus Install
EnergySage breaks down a 12 kW system priced at $31,135 (about $2.59 per watt, our arithmetic) like this.
| Cost item | Share of price | Per watt (our arithmetic) |
|---|---|---|
| Panels | 12% | $0.31 |
| Inverters | 10% | $0.26 |
| Racking | 3% | $0.08 |
| Wiring | 9% | $0.23 |
| Supply chain | 9% | $0.23 |
| Sales tax | 2% | $0.05 |
| Labor | 7% | $0.18 |
| Sales and marketing | 18% | $0.47 |
| Overhead | 11% | $0.28 |
| Profit | 11% | $0.28 |
| Permitting and interconnection | 8% | $0.21 |
Grouping those lines ourselves, hardware, wiring, supply chain and tax add up to 45%. Labor, sales and marketing, overhead and profit add up to 47%. Permitting and interconnection is the remaining 8%. Put simply, about half of what you pay is not metal and glass.
LBNL reaches a similar conclusion from a different angle: in its 2024 data, soft costs plus balance-of-system costs make up roughly 80% of the residential price, with the modules themselves a small part. SEIA and Wood Mackenzie put distributed module prices at $0.37 per watt in Q2 2026, down 16% from a year earlier. That is about 11% of the $3.36 turnkey price (our arithmetic). Cheaper modules help, but they cannot move the total much on their own. The report also pointed to higher freight and logistics costs and Section 232 metals tariffs as pressures on other parts of the price.
Does Panel Brand Change the Price?
Yes, but less than shopping around does. EnergySage’s brand ranking (July 1, 2026) lists per-watt prices from about $2.13 for CertainTeed to $2.89 for Silfab, with Maxeon at $2.73 and REC at $2.45. We cannot confirm from the page whether those figures are panel-only or full quotes with each brand, so read them as a relative spread, not a price list. The spread is $0.76 per watt, which is $6,080 on an 8 kW system (our arithmetic).
LBNL reports a median module efficiency of 20.9% for its 2024 sample. Higher-efficiency panels need fewer panels for the same output, which matters when roof space is the limit, so compare the total quote and not just the brand.
Cash Versus Loan, and Installer Spread
Two choices matter more than brand. First is how you pay. LBNL’s 2024 data shows a median of $3.5 per watt for cash purchases and $4.7 per watt for loans. Part of that $1.2 gap is the dealer fee that lenders charge the installer and installers pass through. On an 8 kW system the difference is $9,600 (our arithmetic). A loan can still make sense, but compare the loan’s total cost against a cash quote before signing.
Second is who installs. LBNL found that the median prices of the top 100 residential installers ranged from $2.7 to $6.5 per watt. On LBNL’s median system size of 7.2 kW, that spread is $19,440 to $46,800 (our arithmetic). Getting several quotes is the cheapest way to avoid the high end. For lease options, see our solar lease versus buy guide.
Using Cost Per Watt Correctly
Cost per watt is a comparison tool, not a final price. Three checks keep it honest.
- Confirm the quote is total installed price, including inverters, permits and interconnection.
- Divide by DC system size in watts, not by the number of panels.
- Compare quotes on the same basis, either cash or financed.
To turn a quote into a payback estimate, use our solar panel payback calculator.
The Bottom Line
Solar costs about $2.60 per watt in EnergySage’s 2026 marketplace data, $3.36 in SEIA and Wood Mackenzie’s Q2 2026 turnkey average, and $4.00 in LBNL’s 2024 install data. The gap comes from methodology, financing and timing. The federal credit no longer lowers any of these for 2026 installs. Bigger systems cost less per watt, with most of the drop between 4 and 8 kW, and about half of the price goes to labor, sales, overhead and profit, not hardware. Get several quotes, compare them on one basis, and run the numbers in our payback calculator before you sign.
FAQ
What is a good price per watt for solar in 2026?
EnergySage’s national figure is about $2.60 per watt, so a quote near or below that is competitive. SEIA and Wood Mackenzie’s Q2 2026 average of $3.36 is a reasonable upper reference for a turnkey system. Quotes well above that deserve a second bid.
Why is LBNL’s cost per watt higher than EnergySage’s?
LBNL reports the median price of 2024 installs, including loan dealer fees, in 2024 dollars. EnergySage reports marketplace quotes from 2026 that homeowners are comparing against each other. Different years, different samples and different financing treatment explain most of the $1.40 gap.
Is cost per watt lower for bigger solar systems?
Yes. EnergySage’s data shows $2.89 per watt at 4 kW falling to $2.47 at 15 kW. Fixed costs like permitting and sales are spread across more watts, so each added kilowatt is cheaper than the first ones.
Does the federal solar tax credit still lower the cost per watt?
Not for 2026 installs. The IRS says the 30% credit is not available for property placed in service after December 31, 2025. Any per-watt price you see in 2026 should be treated as the price you pay, before any state or utility incentive.