The Lead-to-Install Conversion Math Most Solar Installers Get Wrong

Most solar and heat pump installers measure lead-to-install conversion as a single number: leads in, installs out. That single number hides where the funnel actually breaks — and almost every shop is reporting conversion 30-50% higher than reality because they exclude the leads that died early.

Here's the funnel math that operators need, the stages where most contractors lose 60%+ of their leads, and what to do about it.

The single number that lies

The standard solar installer metric: "we close 18% of our leads." What that usually means: of the leads that made it to a sit-down consultation, 18% signed a contract. Of those, 80% completed install. So the headline 18% is actually 18% × the percentage of leads that made it to consultation.

In most shops, only 35-45% of leads make it to consultation. So the true lead-to-install conversion is closer to 6-8%, not 18%. That number changes everything about what you should be optimizing.

The real funnel for residential solar/heat pump

True lead-to-install conversion: 3-13%. Most shops report 12-20% because they're reporting from the consultation-booked stage, not from the lead stage.

Where the biggest leaks are

Leak 1: Contact rate (30-45% of leads never reach a human)

This is by far the biggest funnel leak and it's rarely measured. Most installers call back a lead within 24-48 hours. Industry data is consistent: lead-to-contact rate drops 50%+ if first attempt is >6 hours after the lead came in, and 80%+ if >24 hours.

Fix: 5-minute callback SLA on inbound leads during business hours, voice AI handling after-hours intake. See after-hours call recovery.

Leak 2: Qualification false negatives

A lot of installers qualify too aggressively. The CSR asks 8 questions, the lead doesn't fit perfectly, the CSR marks unqualified. Half of those are actually viable — they just had a unique scenario the CSR wasn't trained on.

Fix: audit your unqualified leads quarterly. Pick 20 randomly, have a senior rep recontact. The conversion rate on the "unqualified" bucket is usually 8-12% — meaning 1-in-12 of your "unqualified" leads would have been an install if anyone followed up.

Leak 3: Consultation no-show

15-25% of booked consultations don't happen. The customer flakes, reschedules, or the rep's day got rearranged and the consultation moved without confirming with the customer.

Fix: automated confirmation 48 hours, 24 hours, 2 hours before. Personal call 2 hours before from the rep doing the consultation. Drops no-show rate to 8-12%.

Leak 4: Proposal-to-close gap

Even with a held consultation, only 25-40% sign. The proposal-to-close rate is the most rep-dependent metric in the funnel. Top reps close 45-55%. Bottom reps close 15-20%. Same leads, same pricing.

Fix: track close rate per rep monthly. Pair bottom reps with top reps for 2-3 weeks of joint consultations. Same playbook as the crew productivity variance fix.

Leak 5: Signed-to-install dropoff

10-25% of signed contracts don't actually become installs. Customer changes mind during permitting (3-6 week wait), HOA blocks, financing falls through, life happens.

Fix: weekly customer touch from contract signing through install. Don't let the customer go silent for 4 weeks while permits process.

The economic implication

Most solar installers spend $1,200-2,500 per lead (paid leads, marketing CAC, etc.). If true conversion is 6% and you think it's 14%, your effective CAC per install is 2.3x what you think. That changes every marketing decision.

For a 200-install/year installer, fixing the funnel math from 6% to 9% (a modest improvement) is worth roughly $1.8M-2.4M in annual revenue. Same lead budget, more installs.

The OBBBA reality check

The 25D residential solar credit died December 2025. Lead volume in residential solar dropped 35-55% in the first half of 2026 depending on geography. The shops that survived are the ones who tightened the funnel — every leak matters more when leads cost more and there are fewer of them.

Heat pump leads (25C credit still alive) and EV charger leads are picking up but at different conversion patterns. The same funnel diagnosis applies; the bucket sizes shift.

The visibility layer

Most installers can't produce this funnel report from their CRM or field service software. The data exists; the standard reports don't roll it up this way. You either build the report in Excel monthly (most do) or put an AI ops layer above that watches the funnel in real-time and flags when any stage drops below baseline.

The benefit of real-time: catching a 20% drop in contact rate on day 3 instead of day 30 means you save the next month's 200 leads. See AI layers above field service software.

The diagnostic to run this month

1. Pull every lead from the past 90 days, regardless of source
2. For each: time-to-first-contact, qualified Y/N, consultation booked Y/N, consultation held Y/N, proposal sent Y/N, signed Y/N, installed Y/N
3. Calculate conversion at each stage
4. Compare to the benchmark ranges above
5. Identify your worst-performing stage
6. Focus 30 days of effort on that single stage

Do this monthly. The shops that close the funnel leaks systematically outperform shops that focus only on lead generation by 2-3x revenue per dollar of marketing spend.

Bottom line

Per Solar Power World's 2026 installer benchmarking study, the top quartile of residential solar installers convert leads to installs at 11-14%, versus the median of 5-7%. The difference isn't lead quality — it's funnel discipline. Most installers think their conversion is the consultation-to-close number. The real conversion is lead-to-install, and most shops are losing 60%+ of leads before the consultation ever happens.