Commercial solar, and what it actually changes
Solar reduces the energy you buy. It does not, on its own, reduce every charge on a commercial bill. Understanding which parts it touches is the difference between a project that pays back and one that disappoints.
Solar tools
Work out the size, the output and the return before anyone quotes you.
Generation estimator
How many kilowatt-hours an array would produce at your location, what share of your usage that covers, and what it is worth at your state's rate.
Open the estimator →Incentives guide
The federal credit and depreciation, every incentive type explained, and where solar is worth most by state on price and sunshine.
See incentives →Payback calculator
Installed cost against first-year value, after the federal credit, to give a simple payback period in years.
Jump to calculator →What decides whether solar works for a site
Four things matter far more than the panel price a salesperson quotes.
Your daytime load
Solar generates during the day. A business that draws most of its power while the sun is up consumes what it generates; one that runs at night exports it, usually for far less than it costs to buy.
Your roof or land
Usable area, orientation, shading and the age of the roof. Re-roofing after an array is installed is expensive, so roof condition often sets the timeline.
What you pay now
The higher your all-in rate, the more each self-generated kilowatt-hour is worth. This is why the same array pays back quickly in one state and slowly in another.
Your demand charges
Solar reliably cuts energy charges. It only cuts demand charges if it happens to be generating at the moment your peak occurs — which is not guaranteed.
Simple payback calculator
You supply the cost, because installed price varies too much by region, roof and installer for us to assume one honestly.
Solar and your supply contract
These two decisions are usually made by different people, months apart, and they interact.
You still buy power at your contracted rate; you simply buy fewer units. Shopping a better supply rate and installing solar are complementary, not alternatives.
Some commercial contracts assume a usage band. If solar drops you well below it, check whether the contract carries a penalty for under-consumption before you sign a long term.
Your utility still owns the wires and still bills for them. Solar reduces the supply side of the bill far more than the delivery side.
If an array is going in next year, a shorter supply term keeps you free to re-shop once your real post-solar usage profile is known.
Solar tools we have not built yet
We publish figures only where we have a primary source behind them. We do not yet have one for solar, so these modules are described rather than guessed at.
Live incentive values
Current rebate amounts and certificate prices per state, kept fresh automatically. Until there is a maintained feed behind it, we explain how each incentive works and point at DSIRE for the numbers.
Site-specific modelling
Roof pitch, azimuth and shading, rather than a state-level average. This is what an installer's proposal does, and what turns an estimate into something financeable.
Load-shape matching
Hour-by-hour generation against your own consumption, to show how much you would use on site rather than export — the figure that decides the return in states without full retail credit.
What the numbers on this page are: the calculators here use published methods with every input exposed, and value production against the state rates we already publish. That makes them useful for sizing and for sanity-checking a quote. It does not make them a site assessment — no state-level average can tell you what your particular roof will do.
Commercial solar questions
Will solar cancel my electricity bill?
Almost never for a commercial account. It offsets the energy you would otherwise buy, but delivery charges, demand charges and fixed service charges continue. A large reduction is realistic; elimination generally is not.
Should I sign a supply contract before or after installing?
If the array is close, a shorter term keeps your options open, because your usage profile will change. If it is a year or more away, shop the best rate you can now — there is no benefit to overpaying in the meantime.
Does solar help with demand charges?
Only when it is generating at the moment your peak demand occurs. A late-afternoon or evening peak may see little benefit. Pairing with storage is what reliably addresses demand charges, and that changes the economics of the project.
Can I still choose my supplier with solar installed?
Yes. In a deregulated market you continue to buy your remaining supply from whichever supplier you choose, and your utility continues to deliver it. Solar does not remove your right to shop.
Start with what you pay today
Your current rate sets the value of every kilowatt-hour solar would replace. See where your state stands.
See rates by state