Cost & Financing

Read this part first: incentives changed

The 30% federal residential clean energy credit — IRC §25D, the one every solar brochure printed for a decade — was terminated for systems placed in service after 31 December 2025, under Public Law 119-21, enacted in July 2025.

That means a great deal of solar material still circulating is wrong in a way that flatters the numbers. Any calculator, flyer, or sales page still subtracting 30% from an installed cost is showing you a payback period shorter than the real one. Our own estimator was corrected for exactly this on 16 August 2026; it now applies no credit at all.

We are a referral service, not your tax adviser, and this is a fast-moving area. Confirm the current position with a tax professional and against irs.gov before you rely on it either way. (Verified 2026-08-16; owner to re-confirm against irs.gov before launch.)

One knock-on effect worth naming, because the older documents get it wrong: the advice that a roof replacement or tree removal done to enable an installation could be folded into the credited system cost depended on that credit existing. Budget for that work as a plain cost, and ask a professional before assuming any program covers it.

What actually drives the price

System cost is usually discussed per watt of installed capacity, which makes proposals comparable. The things that move it:

Size

Driven by your consumption and how much of it you want to offset. The single biggest factor, and the one you have most influence over.

Mounting surface

A simple south-facing shingle roof is the cheap case. Multiple faces, tile, ground frames, and carports each add labour and hardware.

Electrical work

A service panel upgrade, a long conduit run, or a meter relocation are common surprises. Ask early whether any are expected.

Component choice

Microinverters or optimizers over a plain string inverter; premium panels; a battery. Each is a defensible choice and each costs more.

Grid-tied or off-grid

Off-grid needs enough storage to carry you through the dark, which is a different order of expense from a grid-tied system.

Who does the work

Labour, overhead, and how the sale reached you all land in the price. This is exactly why proposals for the same roof differ.

Four ways to pay, and the one distinction that matters

Cash, a loan, a lease, and a power purchase agreement are the usual options. Underneath them is a single question: who owns the system?

With cash or a loan, you own it. You hold whatever incentives and renewable energy credits attach to it, you carry the maintenance relationship, and the asset is yours when you sell the house. A loan spreads the cost and adds financing charges; that is the trade.

With a lease or a PPA, a developer owns the equipment on your roof. You pay a monthly amount, or a per-kilowatt-hour rate, usually for twenty years or so. Any tax benefits and renewable energy credits belong to them, not you. It can still be the right answer for someone who wants no capital outlay — but going in knowing you are buying electricity rather than an asset is the point.

Two things to read carefully in any of them: what happens if you sell the house, and any escalator clause that raises the payment annually.

State, county, and utility programs

Below the federal level, incentives vary sharply — by state, sometimes by county, and by utility. Virginia, Maryland, and DC each treat this differently, and net metering terms sit with your specific provider.

DSIRE, the Database of State Incentives for Renewables and Efficiency, is the free public register of these programs and is the sane starting point for finding what applies where you live.

SRECs are the other piece. One Solar Renewable Energy Credit is issued per megawatt-hour a system produces, and in states with a market for them they can be sold. Their value moves with that market, so treat any projected SREC income as a projection, not a promise — and check who owns them under a lease or PPA.

What a calculator can and cannot tell you

A calculator — ours included — takes a bill, an assumed rate, average regional sun hours, and a typical cost per watt, and does arithmetic. It is useful for deciding whether solar is worth a conversation. It is not a quote, and it does not know your roof.

What it cannot see: your actual roof geometry and shading, the condition of your electrical service, current equipment pricing, your utility's current net-metering terms, or your tax position. Every one of those can move the real number substantially in either direction.

Getting more than one proposal remains the single most effective thing a homeowner can do. And a proposal that requires an answer today is telling you something about the seller.