What Sits on Top of the Per-Watt Base
Base solar sales commission runs per watt of the installed system, and VA Horizon has covered those bands, and where the money funding them comes from, in a separate guide on setter and closer economics. A flat per-watt rate rewards closing a deal. It does not, on its own, reward closing a bigger deal, attaching a battery, or maintaining volume month over month, which is the gap SPIFFs and bonus layers exist to fill.
The Flat Per-Kilowatt Bonus
One documented structure pays a flat bonus of $200 per kilowatt sold, stacked on top of whatever base per-watt commission the rep already earns (Everstage). On a 12-kilowatt system, close to VA Horizon’s own average system-size reference point, that adds $2,400 in bonus on top of the base commission already covered elsewhere. It is the simplest SPIFF structure to administer, no tiers, no thresholds, a fixed add-on per unit sold.
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Book a Solar CallThe Battery-Attach Bonus: Where the Incentive Money Concentrates in 2026
Solar sales comp plans commonly layer a dedicated battery-attach bonus reaching up to $1,000 additional per installation when a battery is sold alongside the panel system (Everstage). That incentive lines up with where the market is moving: national solar-plus-storage attach rate hit 45% in Q1 2026, up from 38% a year earlier (SurgePV). A sales org paying a flat per-watt rate with no battery-specific incentive is asking reps to sell into the fastest-growing segment of the market without paying anything extra for doing it.
Tiered Volume Bonuses: Rewarding the Sixth Deal More Than the First
A different mechanic scales the commission rate itself with monthly volume instead of adding a flat bonus per unit. One documented structure pays 4% commission on each of a rep’s first five deals in a month, then steps up to 6% on the sixth deal and every one after it (Everstage). The effect is different from a flat bonus: it rewards sustained monthly output specifically, since a rep who closes four deals every month never reaches the higher tier, while a rep who closes seven earns a meaningfully richer rate on the back half of their month.
Where SPIFFs Pay Out, and the Clawback Problem
Commission, and by extension any SPIFF or bonus layered on top of it, is commonly split across milestones in solar, roughly 30% at contract signing and 70% at installation or Permission to Operate, with clawback clauses letting the company recover paid commission if a deal cancels or gets refunded within a specified window (Everstage). A SPIFF layered on top of base commission needs to specify explicitly which milestone it pays against, and whether it is subject to that same clawback. A per-kilowatt or battery-attach bonus paid in full at signing, with no clawback language, is a different financial exposure for the company than one paid at install and covered by the same cancellation window as the base commission.
| SPIFF Type | Typical Structure | What It Rewards |
|---|---|---|
| Flat per-kilowatt bonus | Around $200 per kilowatt sold, stacked on base commission | Deal size, not sustained volume |
| Battery-attach bonus | Up to $1,000 additional per installation with a battery sold | Attaching storage to the sale |
| Tiered volume bonus | 4% on the first five deals in a month, 6% on the sixth and beyond | Sustained monthly output |
Structures documented by Everstage as examples in active use, not an exhaustive or universal list. A sales org should confirm milestone timing and clawback terms for any SPIFF layered on top of base commission.
What this means for you
- A flat per-kilowatt bonus, cited around $200 per kilowatt, is the simplest SPIFF to administer and rewards deal size on top of base commission.
- A battery-attach bonus of up to $1,000 per installation lines up directly with where the market is moving. National storage attach rate hit 45% in Q1 2026.
- A tiered volume bonus, for example 4% on the first five deals and 6% after, rewards sustained monthly output in a way a flat bonus cannot. Either way, specify the payout milestone and clawback terms explicitly.
Sources
The external data in this guide draws on the sources below. Figures described in the text as estimates or industry triangulations are directional and are not attributed to a single dataset.