Understanding your PPA rate comparison
Why the starting rate alone doesn't tell the full story
Compare the PPA rate's starting point and escalator against your utility rate and its own historical escalation, not just the first-year price. A PPA at $0.09/kWh with 3% annual escalation against a utility rate of $0.11/kWh rising 2.5% a year saves about $84,384 over a 20-year contract, even though the PPA's escalator is higher than the utility's. The lower starting point does most of the work here, but that gap narrows every year the PPA escalator outpaces the utility's. For real-world PPA pricing benchmarks, Lawrence Berkeley National Laboratory's PV PPA prices data tracks actual contracted rates across the country, useful for gauging whether your proposal is in line with the market. A size estimate is only half the decision for a business. The loan payment calculator in our Financing section can help you work out which way to pay for the system costs less.
The crossover risk hiding in a high escalator
Yes, if the PPA's annual escalator is high enough relative to actual utility rate increases, the PPA rate can eventually cross above the utility rate later in the contract term. This is a real risk with PPAs that carry a 4% or higher escalator, since utility rates don't always rise that fast every year. Run this tool with a higher escalator input to see how sensitive your specific deal is to that risk, and the PPA escalator rate calculator isolates that variable further from a residential angle.
What counts as a competitive PPA escalator
Most commercial PPA contracts carry a 1% to 3% annual escalator, and it matters quite a bit over a 20 to 25-year term, since even a 1-point difference compounds into a meaningfully different total cost. Always compare the escalator, not just the starting rate, when evaluating competing PPA proposals from different developers. The power purchase escalator tool breaks this piece out on its own. The loan term comparison tool covers the financing angle of the same decision.
How contract length changes the math
Most commercial PPAs run 15 to 25 years, often matching the expected useful life of the solar system. Some contracts include an option to buy out the system at a predetermined price partway through the term, which is worth checking for if you might want to own the system eventually. Run the PPA vs. ownership tool to compare this proposal against buying the system outright from day one, or the lease vs. loan comparison for another ownership path, and check the 10-year grid-only comparison for the no-solar baseline. The Department of Energy's guide to going solar covers these ownership tradeoffs at a more general level, and the loan term comparison tool in our financing section breaks down how contract length affects a loan the same way it affects a PPA.