Solar acquisition cost is forecast to rise 40% into a market contracting 19% — after the credit expired

Two forecasts describe the same year. Customer acquisition cost, which had fallen to a five-year low of $0.60 per watt in 2025, is expected to rise 40% to $0.84. The market itself is expected to contract 19% following the expiry of the residential credit under Section 25D at the end of 2025. Those are not two separate problems. Fewer buyers with the same number of installers bidding for them is the mechanism by which acquisition cost rises, and the marketplace data confirms the demand side has not gone quiet: a 205% year-on-year increase in homeowners actively working with an installer, and an all-time high in customer enquiries.

Acquisition cost up 40%, the market down 19%, and enquiry volume at an all-time high. All three are true in the same year.

1. 01

   As a share of the installed price, acquisition goes from about a quarter to about a third

   At $0.60 per watt against an average installed price of $2.49 per watt, acquisition was roughly 24% of the price of the system in 2025. At the forecast $0.84 it is roughly 34%, if price holds. Those two figures come from different publishers over different windows and holding price flat is an assumption, so treat the ratio as a direction rather than a measurement. The direction is the entire story.

2. 02

   A contraction does not reduce acquisition cost, it raises it

   This is the part that catches operators who have only traded through growth. Demand falling and acquisition cost rising are the same sentence said twice, because the installer base does not contract at the same speed as the market it serves. The 40% and the 19% are one forecast, not two.

3. 03

   There is no published paid-media benchmark for this sector, and the proxy must be labelled every time

   No credible published Google Ads cost per click, click-through rate, conversion rate or cost per lead for residential solar. No published Meta cost per lead. No local search benchmark, no lead-to-sale rate, no speed-to-lead study. The closest defensible proxy is the Home and Home Improvement category at $8.33 per click and $90.92 per lead, and it is a proxy: home improvement pools fast, low-consideration jobs with a purchase that in solar is financed, permitted and takes weeks. Every appearance of that figure in this model carries the word proxy attached.

4. 04

   Demand is not the constraint, so media is not the lever

   Record enquiry volume arriving into a contracting market means the year is decided by what happens to an enquiry after it arrives: how fast it is qualified, how many appointments become proposals, and how many proposals are signed. A media budget increase into that situation buys more of something the installer already has more of than it can process.

Residential solar CAC **$0.60/W in 2025** (five-year low) → forecast **$0.84/W in 2026 (+40%)** as the market contracts **19%**; installed price **~$2.49–2.60/W** (marketplace basis). **The Section 25D 30% residential credit expired 31 Dec 2025** (OBBBA); only leased/third-party-owned systems keep federal support via Section 48E.

The model spends on conversion before it spends on media, because the published forecast says the price of a lead is rising and the marketplace data says leads are abundant. Phase one instruments the funnel end to end — enquiry, qualified, assessed, proposed, signed — since none of those rates are published for this sector and all of them are measurable. Phase two works on the qualification and appointment layer where the abundant volume is being lost. Phase three sizes media against cost per signed watt rather than cost per lead, so the metric being managed is the one the acquisition-cost forecast is denominated in. Proxy benchmarks are used only as a floor and are labelled as proxies wherever they appear.

1. 1

   Weeks 1–3

   Funnel instrumentation

   Enquiry to signed contract measured at every stage; no published rate exists for any of them

   Owner: OmniFlow

2. 2

   Weeks 3–6

   Qualification layer

   Qualifying questions before the appointment, three routes out, answers written to the CRM

   Owner: OmniFlow + installer sales

3. 3

   Weeks 5–10

   Appointment and proposal work

   Assessment booking, proposal turnaround and follow-up measured as stages rather than as activity

   Owner: OmniFlow

4. 4

   Weeks 8–16

   Media against cost per signed watt

   Spend sized on cost per signed watt; proxy benchmarks used as a floor and labelled as proxies

   Owner: OmniFlow

5. 5

   Month 6

   Review

   Cost per signed watt against the $0.60 and $0.84 reference points, stage conversion reported throughout

   Owner: OmniFlow

The model reports cost per signed watt, which is the unit the published acquisition forecast is denominated in and the unit almost no installer measures. At $0.60 per watt against a $2.49 price, acquisition consumed roughly 24% of the installed price; at the forecast $0.84 it consumes roughly 34% if price holds. Those two figures come from different publishers over different windows, so the model treats the ratio as a direction and the installer's own cost per signed watt as the number that matters. No solar-specific media benchmark is used anywhere, because none is published.

Modelled. Inputs: Wood Mackenzie, US residential solar customer acquisition costs, March 2026; EnergySage, Marketplace Report #22 (data July – December 2025); WordStream by LocaliQ, Google Ads Benchmarks 2026 (13,474 US search campaigns, April 2025 – March 2026). Modelled outputs are not a forecast or a guarantee of results. Cited: Wood Mackenzie (Mar 2026); Congressional Research Service; EnergySage.

Every figure below is published research, not a client result. They are the inputs to the arithmetic above, listed so it can be checked rather than taken on trust. The bracketed number points to the full citation at the end of this page.

These are the surfaces this engagement is run and measured from, shown with representative figures built around the benchmarks cited on this page. Every account we run reports into views like these, and you keep ownership of all of them.

Each figure on this page, the system it is read from, and the definition and window it is measured over.

Not applicable — this is a modelled engagement. Its weakest input is that the 2026 acquisition figure is a forecast made before anybody had observed a full year of the post-subsidy market, and the installed price it is compared against comes from a marketplace panel rather than from the whole market. Dividing one by the other compounds both weaknesses into a single ratio, which is why the model states it as a direction and instruments the installer's own cost per signed watt in the first three weeks.

A modelled capability, not a client account. Figures illustrate what the model produces and are labelled as modelled wherever they appear. See all our work

Full citations for everything cited on this page, with the sample and period each study covers, so you can go and read the original.