Financing
Enter your system price, size, and loan terms. See your cash and financed cost per watt, useful for comparing quotes of different sizes.
How it works
Step 1
Use the cash price and system size in kW from your quote, both listed on any standard installer proposal, or check the total cost including fees calculator if you want to confirm nothing is hidden outside the headline price first.
Step 2
Include your quoted APR and term to see the gap between cash and financed cost per watt. The loan payment calculator can help confirm your monthly payment separately.
Step 3
This strips out financing terms so you're comparing equipment and installation pricing directly, even between systems of different sizes.
Total system price alone doesn't tell you whether a quote is competitive, since a larger system naturally costs more in absolute dollars. Cost per watt normalizes for size, letting you compare an 8.5 kW quote against a 6 kW quote on equal footing. On an 8.5 kW, $26,000 system, that works out to about $3.06 per watt in cash terms, a useful figure to compare against typical market pricing in your area. The CFPB's issue spotlight on solar financing covers general pricing and financing considerations worth reviewing alongside this comparison.
Once loan interest is included, the same system's financed cost per watt rises substantially, to about $5.69 per watt on the example system at 6.99% APR over 20 years, notably higher than the $3.06 cash figure, which reflects the real cost of borrowing over two decades. No federal tax credit currently applies to reduce that figure for a new purchase. The DOE's homeowner's guide to solar financing covers this same tradeoff in more general terms.
Use cash cost per watt to compare pricing between different installers, since it isolates equipment and installation cost from financing terms that vary based on your personal loan choice. Once you've picked an installer, financed cost per watt becomes useful for understanding your actual total cost under your specific loan. The cost per kWh produced calculator can help you translate this into an ongoing production value comparison too.
A cost per watt well above typical market range could reflect premium equipment, complex installation conditions, or simply a less competitive quote worth comparing against others. A cost per watt well below typical range is worth scrutinizing too, since it could indicate lower-quality equipment or corners cut elsewhere. The total cost including fees calculator can help confirm nothing is hidden outside the headline price, and the dealer fee impact calculator checks for one specific hidden cost that can inflate a financed quote.
Cost per watt is one useful comparison point, but it shouldn't be the only factor in choosing an installer or financing option. Equipment quality, warranty terms, and installer reputation all matter alongside price, and the cash vs financed payback comparison covers the broader financing decision in more depth. The kW to panel count converter can also help you sanity-check whether your system size itself is reasonable for your usage before focusing too much on price alone.
Questions
The cash cost per watt is the standard figure to compare against typical market pricing, often in the $2.50 to $3.50 per watt range depending on location and system type. On an 8.5 kW, $26,000 system, that's about $3.06 per watt cash, rising to about $5.69 per watt once financed at 6.99% APR over 20 years.
Cost per watt normalizes the price across systems of different sizes, letting you compare a smaller and larger quote on equal footing rather than just comparing total dollar amounts, which can be misleading if the systems aren't the same size.
Compare cash cost per watt across installers first, since that reflects the actual equipment and installation pricing without financing terms mixed in. Then look at financed cost per watt separately to understand your specific total cost once your chosen loan terms are applied.
The gap reflects loan interest accumulating over the loan term, which is a real cost even though it doesn't change the physical system you're getting. A large gap between the two figures is a useful reminder of how much a loan's rate and term affect total cost beyond the base equipment price.
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