Most commercial solar pages open with a payback figure. “Three to seven years.” “Under five years.” We are not going to do that, and the reason is the most useful thing on this page.
A commercial PG&E bill is not one number multiplied by kilowatt-hours. It is energy charges that move by time of day, plus demand charges based on your single highest fifteen-minute draw in the month, plus tariff-specific fixed costs. Two businesses on the same street, using the same annual kilowatt-hours, can have payback periods years apart because one of them spikes at 5pm and the other doesn’t.
So the honest version is: your payback comes out of your interval data, not out of an average. Here is what drives it, which businesses tend to do well, where the federal position actually stands as of 30 August 2026, and how the work gets done.
How fast does commercial solar pay back for a Bay Area business?
Four things set the answer.
1. Production. This one we can state, because it is our own verified planning figure: Contra Costa roofs produce about 1,500 kWh per kW per year. It is a good number for California and it barely varies between Concord, Martinez and Pittsburg. It is the least uncertain input in the model.
2. What you displace, not what you export. California’s Net Billing Tariff (NEM 3.0) took effect on 15 April 2023 and applies to non-residential customers of PG&E, SCE and SDG&E, not just homeowners. Exported power is credited at avoided cost — roughly a quarter of what it earned under NEM 2.0. So the value is in self-consumption: every kilowatt-hour you generate and use on site displaces a retail-priced kilowatt-hour you would otherwise buy.
This is where commercial beats residential structurally. A house is empty at noon and busy at 7pm — the worst possible match for a solar curve. A warehouse, a shop, a manufacturing floor or a cold-storage room is drawing hard at exactly the hours the array is producing. Load shape is the single biggest reason a business’s payback beats its owner’s house.
3. Demand charges. On most commercial tariffs, a meaningful slice of the bill is billed on peak demand, not consumption. Solar alone shaves demand only if your peak happens to fall in daylight. If your peak is a 6pm compressor start, solar barely touches it and storage becomes the lever. This is the item that most commercial proposals quietly ignore, and it is the item most likely to make a projected payback wrong.
4. Your tariff. PG&E’s commercial rate schedules differ substantially in how they split energy, demand and fixed charges, and businesses are frequently on the wrong one. Reviewing the tariff sometimes saves money before a single panel is ordered — see what PG&E rates look like in 2026.
How we actually model it. We pull twelve months of your interval data from PG&E, lay it against your current tariff, and model production hour by hour against that load. What comes out is a payback for your building. It is sometimes better than the industry’s stock answer and sometimes considerably worse, and we would rather tell you which before you spend anything.
Our public savings calculator is built for residential PG&E accounts — $24 base charge, 36¢/kWh, 1,500 kWh/kW/year. It will give a business owner a rough sense of the physics, but it does not model demand charges, so please don’t run a commercial decision through it.
Which business types see the strongest case — and which don’t?
Strongest, in our experience:
- Warehouses and light industrial. Large unobstructed roofs, daytime load, and often a large enough draw that demand management matters. The best structural fit there is.
- Grocery and convenience stores. Refrigeration runs continuously and pulls hardest in the heat — the same hours the array peaks. Concord, Pittsburg and Antioch get properly hot in summer, and that raises both the load and the value of covering it.
- Hotels and motels. Steady baseload from laundry, HVAC and hot water, and roof or carport area that is otherwise doing nothing.
- Gas stations and truck stops. Canopy structures are already engineered, lighting and refrigeration run long hours, and EV charging added later shifts the load profile in solar’s favour.
- Agricultural operations out toward Brentwood and Oakley — pumping and irrigation loads that are daytime by nature. We treat those separately under farm and agricultural solar.
- Manufacturing on a single day shift. Almost the ideal curve, provided demand charges are handled.
Weaker, and we will say so:
- Evening-peaking businesses — restaurants, bars, entertainment venues. Your load arrives as the sun leaves. Solar alone does comparatively little; the case, if there is one, runs through storage and needs to be built carefully.
- Small offices on a 9-to-5. Good match for the solar curve, but often too small a bill for the fixed costs of a commercial project to be worth it.
- Leased premises with a short remaining term. If you have four years left and no option to extend, you are financing an asset for a landlord.
- Buildings whose roof is near end of life. The roof comes first, always. Installing an array over a roof with a few years left in it means paying to remove and re-mount it later.
- Heavily shaded or structurally marginal roofs. A structural assessment can end the conversation, and it is better that it ends before the deposit than after.
Do commercial federal incentives still exist after 2025?
Yes — commercial is a different regime from residential, and it did not go away when the residential credit did.
The residential Section 25D credit expired on 31 December 2025. That is settled and it applies to homeowners buying a system for their own home. It does not govern a business investment. We covered the residential position separately.
Business projects fall under the Section 48E clean electricity investment credit. Under the federal legislation enacted on 4 July 2025, the timing rules for solar are:
- Projects that began construction on or before 4 July 2026 must be placed in service before the end of 2030.
- Projects that begin construction after 4 July 2026 must be placed in service before the end of 2027.
There are also foreign-entity restrictions that began applying in 2026 and that affect both who may claim the credit and where equipment may come from. Those rules are detailed and they matter for procurement.
Now the part where we stop. We are not tax advisors, and we will not tell you what rate you will receive. The 48E credit rate depends on prevailing wage and apprenticeship compliance, domestic content, and location-based adders — the analysis belongs to your CPA or tax counsel, and pricing it in a proposal without them is how businesses end up disappointed.
We also will not publish a depreciation schedule. Commercial solar is depreciable business property, but the classification and bonus depreciation rules for solar changed under recent federal legislation, and the sources available to us disagree with each other. Rather than pick the flattering one, we are telling you it is unresolved in our own reading and that your accountant should price it. If a competing proposal states a depreciation benefit as a certainty, ask which section of the code it comes from.
What we will do is give your accountant the project facts they need — equipment, cost basis, construction start, expected placed-in-service date — in a form they can work from.
Federal position above verified 30 August 2026 against published law-firm analyses of the 2025 legislation. Confirm with your own tax advisor before relying on it.
What does a 24/7 operation need that a 9-to-5 doesn’t?
A round-the-clock business — a hotel, a cold-storage facility, a 24-hour convenience store, a plant running two shifts — has a different problem from a business that closes at six.
Storage becomes a working tool, not just backup. A 9-to-5 operation consumes most of what it generates as it generates it. A 24/7 operation keeps drawing through the evening peak, when energy is dearest and solar is done. Storage shifts midday generation into those hours and, more valuably, shaves the demand peaks that a straight array cannot reach.
Sizing follows baseload, not roof area. The overnight floor of your load is the number that matters. Filling the roof and exporting the surplus at avoided cost is the expensive way to buy nothing.
Outage tolerance changes the specification. For a restaurant, a power cut is an evening lost. For a cold-storage facility it is inventory lost, and for a hotel it is a life-safety and guest-services problem. That drives which loads go on a backup panel and how the system is configured — and it is a design conversation, not a product choice.
Equipment cycles change the economics. Compressors, pumps and chillers starting at the wrong moment can set a monthly demand peak on their own. Sometimes the cheapest fix is a controls change, not a bigger system, and we will say so.
Who handles permitting, engineering and the roof work?
Plainly, so there is no confusion about what we are:
We design and project-manage. Licensed contractor partners carry out the physical installation. Navjot and Nam bring over a decade of California solar experience to the design, engineering and management side, and the trades are done by licensed people whose licences you can check.
On a commercial project, that means we handle:
- Electrical engineering and system design in-house, including single-line diagrams, structural loading and the interconnection package
- Permitting and regulatory compliance with the relevant authority — the City of Concord Building Division, another city’s building division, or Contra Costa County for unincorporated sites
- The PG&E interconnection application, which on commercial projects is usually the longest pole in the schedule and needs to be started early
- Tariff and interval-data analysis before design, so the system is built for your actual load
- Coordination of the licensed installation crews, and of the subcontracted roofing, framing and sheetrock work where a project needs it
- Inspection, commissioning and handover, including the documentation your accountant will want
One project manager, one point of contact, and a schedule you can hold us to.
—
Want a real number for your building?
Send us twelve months of PG&E bills, or authorise us to pull your interval data, and we will model it properly. If the payback doesn’t justify the project, we will tell you that — it is a shorter conversation and it costs you nothing.
Book a free consultation. No pressure, no obligation. More on how we work on commercial projects, and if you want to see the underlying physics for a small building, our savings calculator will give you a rough feel — just remember it does not model demand charges.
Rates, rules and federal deadlines verified 30 August 2026.