A commercial solar proposal is read by somebody who never met you and never saw the roof. It has to survive being forwarded, summarized badly, and argued about in a room you’re not in.
Think about what actually happens after you hit send. The facility director reads it, forwards it, and then repeats a version of it to a finance person who has never spoken to you. Whatever survives that retelling is your proposal. Everything else was formatting.
Most solar proposals are built for the wrong reader. They open with company history, run to twenty pages, and bury the number on page eleven next to a shading diagram nobody in the approval chain can interpret.
In short
- Write for the person who wasn’t on the roof. They’re the one who approves it.
- If you gave a planning range earlier, tie the firm number back to it in one sentence anyone can repeat.
- Price the real scope. A low range to get a project approved works exactly once.
- Federal credit rules moved, and the safe harbor most installers still quote no longer applies to most projects. Get that right or leave it out.
It has to travel without you
Write the first page so a finance director can defend it to a board without calling you. That means the system size, the total cost, the net cost after incentives, the annual savings estimate and the assumption behind it, all on one page in that order.
Then say what you need from them and when. A proposal that ends without a specific next action becomes a document instead of a decision.
The sentence that has to survive retelling: “Two hundred and forty kilowatts on the warehouse roof, one point one million before incentives, roughly forty thousand a year off the electric bill, and the roof is good for it.”
If your proposal can’t be compressed into one sentence like that, the person forwarding it will invent their own, and theirs will be worse.
The planning range and the firm number are different documents
Most commercial solar starts with a range given months before anybody asked for a proposal. That range is how the line got into a budget. The proposal that arrives later is being read beside it, whether or not you remember giving it.
So connect them explicitly. One sentence, near the top.
“The planning range we gave you was 1.0 to 1.2 million. The firm number is 1.14 million. The difference is the transformer upgrade the utility confirmed in August.”
That sentence does something no amount of design detail can. It tells a finance person that the estimate held, that you track your own numbers, and that the variance has a named cause. Contractors who skip it force the reader to work out whether they have been quoted the same project twice.
The federal credit changed, and most proposals haven’t caught up
This is the part worth getting exactly right, because a lot of what is circulating in the industry is now wrong.
Under the One Big Beautiful Bill Act, the Section 48E credit terminates for applicable wind and solar facilities placed in service after December 31, 2027. Facilities whose construction begins after July 4, 2026 are subject to that termination date. That much is widely known.
What is less known is how you establish that construction began. IRS Notice 2025-42 is direct about it.
“Except as provided in section 6 of this notice, the Physical Work Test described in section 3.02 of this notice is the sole method that a taxpayer may use for these purposes.”
Section 6 is the exception, and it’s narrow. The Five Percent Safe Harbor survives only for what the notice calls a low output solar facility, defined as one with maximum net output of not greater than 1.5 megawatts measured in alternating current. Above that, spending five percent of project cost establishes nothing.
The notice is blunt about why. The Physical Work Test “focuses on the nature of the work performed, not the amount or the cost,” and there’s “no fixed minimum amount of work or monetary or percentage threshold” that satisfies it.
Plenty of installers are still telling commercial customers that committing five percent of the project cost locks in the credit. For a two megawatt rooftop, that advice is wrong, and the owner finds out at the worst possible moment.
Say this, not more. You’re a solar contractor, not the customer’s tax advisor, and proposals that read as tax advice create a liability you don’t want.
State the deadlines and cite the notice. Say which test the project would rely on and why. Then put in writing that the customer’s tax professional confirms eligibility and timing, and that rules continue to change. That’s the responsible position and it’s also the one that sounds most competent in the room.
More roofs to assess
Abstrakt sets appointments with the facility directors, owners, and finance leaders who approve commercial solar spending, so your team is assessing roofs instead of chasing lists. The assessment, the number, the proposal, and the contract are yours.
What belongs in it, and what doesn’t
| Include | Why the finance reader needs it | Leave out |
|---|---|---|
| System size and total cost | The two numbers every other line is judged against | Company history |
| Net cost after incentives, with the assumption named | Lets them test the case if the assumption moves | Unlabelled net figures |
| Annual savings and the rate it assumes | A savings number with no rate behind it reads as marketing | Twenty-five year cumulative totals |
| Roof condition and remaining life | The question that kills projects late, so answer it early | Shading diagrams as evidence |
| Interconnection status and what is outstanding | The most common source of schedule slip | Vague timelines |
| What you need, from whom, by when | Turns a document into a decision | “Let us know if you have questions” |
The roof row matters more than installers expect. A twenty-five year array on a roof with eight years left is a conversation somebody will eventually have, and it’s much cheaper to have it in the proposal than after the racking is ordered.
Why the early installer is hard to beat
The contractor who gave the planning range has advantages that have nothing to do with price. Their number is the one in the budget. Their assumptions are the ones the finance team already accepted. When a competing proposal arrives, it’s not being read on its own merits, it’s being read as a deviation from an existing plan, and deviations have to be justified.
Which is the real argument for being early. Early proposals don’t win on merit. The early number becomes the baseline, and everybody else spends their proposal explaining why they differ from it.
Frequently Asked Questions
What should a commercial solar proposal include?
System size, total cost, net cost after incentives with the assumption stated, annual savings and the utility rate behind it, roof condition and remaining life, interconnection status, and a specific next action with a name and a date. All of it readable on the first page by somebody who never saw the building.
Who actually reads a commercial solar proposal?
Rarely the person you walked the roof with. It gets forwarded to finance, and the decision is usually made by somebody who reads a summary of it. Write the first page for that reader.
When does the federal commercial solar tax credit end?
Under the One Big Beautiful Bill Act, the Section 48E credit terminates for applicable wind and solar facilities placed in service after December 31, 2027, and facilities that begin construction after July 4, 2026 fall under that termination date. Timing and eligibility for any specific project should be confirmed by the customer’s tax professional, and the rules have been changing.
Does spending five percent of project cost still lock in the credit?
Not for most commercial projects. IRS Notice 2025-42 states that the Physical Work Test is the sole method for establishing beginning of construction, except for what it defines as a low output solar facility with maximum net output of not greater than 1.5 megawatts alternating current. The notice also says the test focuses on the nature of the work and sets no monetary or percentage threshold.
Should a proposal mention solar incentives?
Yes, with the assumption named and a clear statement that the customer’s tax professional confirms eligibility. Give a net figure without saying what it assumes and you have handed a finance reader a number they can’t test, which is the fastest way to have your proposal set aside.
What if the firm number comes in above the planning range?
Say so in one sentence, near the top, with the cause named. A variance with a reason attached is a normal part of a capital project. A variance the reader has to discover by comparing two documents is what makes them question both numbers.
Keep going
- Solar lead generation
- Commercial roof maintenance agreements
- What to say when you cold call a facility manager
- Outsourced SDR services
- Cold calling services
About this article
Jeff Winters is Chief Executive Officer at Abstrakt. Reviewed by Neil Erker, Chief Marketing Officer. Abstrakt sets appointments for commercial solar installers and contractors across the trades. Nothing here is tax advice, and federal credit rules continue to change.
