Trinasolar

How Residential Solar Installers Can Build a Lower-Cost Growth Engine

September 14, 2026

Breaking down where residential solar customer acquisition costs are actually heading and how installers can influence them.

Despite a slight decline in residential solar customer acquisition costs (CAC) in the first quarter of 2026, these costs remain one of the biggest variables impacting profitability for installers. Further complicating matters, this year's forecasts and data depict a more nuanced equation than first glance might suggest. Understanding where acquisition costs are actually heading, and how installers can influence them, has become essential for any solar business trying to grow.

Residential Solar Market Still Absorbing the Loss of 25

The ripples from the loss of the Section 25D investment tax credit (ITC) for homeowners continue to shake up the residential solar market, and 2026 customer acquisition cost numbers reflect that disruption. Earlier this year, following the 25D elimination, Wood Mackenzie forecast a 40% increase in solar customer acquisition costs, driven by an expected contraction in the residential market. After falling to a five-year low of roughly $0.60 per watt in 2025, Wood Mackenzie projected residential solar CAC would jump to $0.84 per watt in 2026.

That forecast hasn't played out evenly — it wouldn’t be the solar coaster otherwise, right? — and the early data tells a more complicated story than just a simple spike. In Q1 2026, the residential segment installed 1,179 MWdc of solar capacity, up 6% year over year but down 15% quarter over quarter, though enough to make it the strongest quarter in the past two years, trailing only Q4 2025.

Solar Demand Pull-Forward Masked the Real Trend

SEIA and Wood Mackenzie's Q1 2026 Quarterly Market Report found that residential system pricing actually fell 7% year over year, to an average of $3.21 per watt direct current, down from $3.44/Wdc in Q1 2025. The report attributes that decline to two factors: falling module prices, which dropped as domestic supply increased, and lower customer acquisition costs, which declined as the looming expiration of Section 25D drove a surge in sales activity before the deadline. Since homeowners could still lock in the 25D credit by getting their systems installed, though not necessarily interconnected, by the end of last year, it pushed many installations and demand into this year and created a pull-forward effect that propped up volumes and pricing in Q1, typically a slow time of year due to poor weather conditions.

Now that that pulled-forward demand has dried up and the buyer pool diminished, the residential sector is starting to feel a more competitive acquisition environment along with rising forecasted costs. The newly released Q3 2026 report noted that Q2 2026 residential installations fell to just 995 MWdc, a 12% YoY and 10% QoQ drop, marking its lowest quarterly level in five years. SEIA and Wood Mackenzie now project the residential segment will contract by 23% over the full year, up from 21% forecasted last quarter. After this contraction plays out, the segment is expected to begin recovering in 2027 with a forecast 6-7% annual growth rate.

Beyond the interconnection numbers, the Q2 report noted that installers are reporting longer sales cycles and falling close rates, a clear sign that the cushion provided by pulled-forward demand is gone.

What Do Residential Solar Customer Acquisitions Actually Cost Installers

Residential solar customer acquisition costs vary by method used and location, with per-installation CAC averages ranging from $3,000 to $5,900 and reaching $10,000 in mature markets. Door-to-door canvassing is often the most expensive approach, followed by digital advertising and paid lead lists, while referrals and supplier-driven partnerships are typically the least expensive. At the same time, pricing structure can add another variable, since quotes most often diverge because of overhead and profit margins. Some solar companies run lean operations with 12% to 15% margins, while others build in 25% to 35%.

However, this variation gives installers the most room to make strategic decisions. Acquisition costs remain volatile and channel-dependent, and the solar businesses best positioned to manage that volatility are the ones actively pulling every available lever to keep costs down.

In response to the market shifts, many installers are shifting to a "customer lifetime value" model that includes batteries, electric-vehicle (EV) chargers, roofing services, monitoring, and maintenance. The goal is for customer lifetime value to drive future referrals, upsells, and repeat purchases that generate revenue at a much lower incremental cost than chasing a brand-new cold lead. Diversifying services and offerings is a smart move, but it can often involve reallocating resources toward opening new business units or purchasing new equipment and away from marketing and customer relations departments.

Turning Every Rooftop PV System Into a Marketing Asset

A finished project is a visible, ongoing advertisement in the neighborhood. A single completed residential installation can generate tens of thousands of dollars in potential business from surrounding homes through referrals and word of mouth. But simply posting a picture or video of a successful project to an installer's existing network of followers won't always translate into new customers, for one main reason: those followers are typically already satisfied customers, not prospective ones.

That's the gap Trinasolar's new Installer Incentive Program, run in partnership with BayWa r.e., is designed to close. The program rewards installers by amplifying rooftop project success across Trina's hundreds of thousands of followers, or through geo-fenced posts targeted at an installer's specific market, putting finished projects in front of homeowners who haven't bought yet rather than ones who already have.

Installers looking to succeed in 2026 and beyond must treat every rooftop as an ongoing customer relationship and as a referral asset in a market where paid acquisition alone is no longer enough.

Protecting the Long-term Value of a Successful Residential Solar Install

A successful rooftop solar installation can serve as a powerful marketing tool, but a problematic one can ruin reputations and make new customer acquisition more costly, or even outright impossible. Incentives and rewards will only go so far without a durable PV module backed by an industry-leading manufacturer's warranty.

Trinasolar's dual-glass 445W Vertex S+, a dedicated rooftop PV module using n-type TOPCon advanced cell technology, packs more power per roof, exceeds IEC thresholds for enhanced protection, and carries a 30-year power warranty and 25-year product warranty. That durability ensures customer peace of mind and the installer's long-term reputation in the very neighborhoods they're counting on for referrals.

A homeowner might not calculate these advantages directly into their buying decision, but the benefits show up indirectly, in faster turnarounds, more consistent pricing, and fewer costly delays. Over time, that operational reliability becomes a genuine competitive edge that less-connected competitors can't easily replicate.

Interested in joining Trinasolar’s new Installer Incentive Program? Check out the full program terms, tier thresholds, benefit details, and connect with a member of Trina’s local residential team, or contact your BayWa r.e. Account representative.

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Residential Solar Market Still Absorbing the Loss of 25

Solar Demand Pull-Forward Masked the Real Trend

What Do Residential Solar Customer Acquisitions Actually Cost Installers

Turning Every Rooftop PV System Into a Marketing Asset

Protecting the Long-term Value of a Successful Residential Solar Install

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