Savings and payback
See your 25 year savings total across five different rate inflation scenarios at once, so you know how much your projection depends on the assumption.
For planning purposes only, not financial or tax advice; confirm figures with a licensed installer or tax professional before making a purchase decision.
How it works
Step 1
Use the result from the solar savings calculator as your starting point.
Step 2
The tool runs your starting figure through 1%, 2%, 3%, 5%, and 7% rate inflation assumptions over 25 years, showing the full range side by side. For a deeper look at any single scenario, see the rate inflation projection tool. For the official overview, the US Department of Energy's homeowner's guide to going solar covers buying, leasing, and system sizing.
Starting from $1,800 in year-one savings, a 1% inflation scenario totals about $50,838 over 25 years, while a 7% scenario reaches $113,848, a spread of over $63,000 depending entirely on which rate assumption proves closest to reality, more than tripling the total from the 25 year lifetime savings calculator's flat baseline in the high scenario alone. That's a striking range for the same starting point and time horizon. The US Energy Information Administration's electricity data show how retail rates have moved, which is the starting point for any savings estimate.
No one knows future utility rates with certainty, and a single projection can create a false sense of precision. Seeing the full spread from conservative to aggressive gives a more honest picture of how much your long-term total could genuinely vary, rather than anchoring on one figure that might turn out to be wrong in either direction. Over 25 years, upkeep adds up, and the total maintenance cost 25 year projection shows what to budget for it.
The 2 to 3% scenarios track closest to the historical US average and make reasonable baseline choices. Treat the 5 and 7% scenarios as upside cases rather than expectations, and the 1% scenario as a deliberately conservative floor for stress-testing your numbers. The 3% rate inflation calculator gives that middle scenario more detail on its own. Output varies by roof and weather, and the real world vs nameplate output gap calculator shows what your site should produce in a typical year.
This tool isolates rate inflation only, consistent with the rate inflation projection tool. For a version that also nets in panel degradation, use the 25 year lifetime savings calculator with your own degradation assumption alongside whichever rate scenario you find most credible.
Questions
A great deal over 25 years. Starting from $1,800 in year-one savings, a 1% inflation scenario totals about $50,838, while a 7% scenario reaches $113,848, a spread of over $63,000 depending entirely on which rate assumption proves closest to reality.
No one knows future utility rates with certainty, so a single projection can create false confidence. Seeing a full range side by side, from conservative to aggressive, gives a more honest picture of how much your long-term total could vary.
The 2 to 3% scenarios track closest to the historical US average and are reasonable choices for a baseline plan. Treat the 5 and 7% scenarios as upside cases rather than expectations, and the 1% scenario as a deliberately conservative floor.
No, it isolates rate inflation only, consistent with the rate inflation projection tool. For a version combining both rate growth and degradation, use the 25 year lifetime savings calculator with your own degradation assumption.