Generation, sized
to the incentive.
A rooftop array is an engineering problem and a programme problem at the same time, and the second one usually decides the first. Size a system to the roof and you forfeit the rebate. Size it to the rebate ceiling and the same roof pays back in half the time. We model both, in PVsyst and SAM, before anyone commits to a capital number.
Feasibility
through design.
We are not an installer and we do not sell panels, which means the study can conclude that a roof is not worth it. That happens, and it is a useful answer to have paid for rather than discovered later.
Rooftop and carport feasibility
Usable roof area against structure, obstructions and setbacks; array geometry, tilt and azimuth; yield modelled hour by hour in PVsyst and cross-checked in SAM.
Incentive and tax structuring
Which programmes the system qualifies for, what the sizing rules actually cap, and how the rebate and the tax credit interact on the same capital cost.
Interconnection and utility coordination
Load displacement sizing against the facility's own peak, single-line development, and the conversation with the local distribution company before the design is fixed.
Storage and peak shaving
Battery sizing where it earns its place — against demand charges, Global Adjustment exposure or a demand response commitment, modelled as its own case rather than assumed.
Why a 1.1 MW-DC array
is sized for a
1 MW-AC rebate.
IESO Save on Energy pays $860 per kW-AC on commercial solar, and the cap applies to AC nameplate — inverter output — not to DC panel capacity. A 1.1× DC:AC ratio puts the array right at the eligible ceiling. Going larger forfeits the rebate on the incremental capacity and leaves only the tax credit, so the marginal panel earns considerably less than the ones below it.
This is the sort of thing that is obvious once stated and expensive to discover after a system is quoted. It is also why a roof's physical capacity is rarely the right design target.
- Micro-generation, ≤10 kW-DC — $1,000 per kW-DC
- Small and medium, >10 kW-AC to 1 MW-AC — $860 per kW-AC, paid upfront
- Above 1 MW-AC — still eligible, but the incentive is capped at 1 MW-AC and at 50% of total eligible project cost
- Sizing rule — load displacement only: system size cannot exceed the facility's maximum load
Programme rates and rules as at the 2026 season. Confirm current terms with the IESO before relying on them; the funding explorer tracks the live figures alongside 109 other routes.
1 MW-AC on a
regional mall.
Vaughan Mills, managed by JLL: a 1,547,019 ft² enclosed retail centre consuming 26.3 GWh a year. A feasibility study completed in April 2026 sized a 1.1 MW-DC rooftop array specifically to the Save on Energy ceiling so the IESO rebate and the 30% federal Clean Technology ITC could both be claimed.
How the incentives halve the capital cost
| Line item | What it is | Share of gross capital cost |
|---|---|---|
| Gross CAPEX | 1.1 MW-DC rooftop PV, fully installed | 100% |
| − Save on Energy Retrofit | IESO upfront commercial rebate at $860/kW-AC, capped at 1 MW-AC | −26% |
| − Clean Technology ITC | Federal refundable tax credit, 30% on the post-rebate cost basis | −21% |
| Net CAPEX | What the owner actually funds | 50% |
The array is 2,445 modules at 450 Wp on fixed racking at 10° tilt and 0° azimuth, 5,401 m² of collector, simulated at 1,369 MWh a year in PVsyst 7.2.4 for a 14.2% capacity factor. That covers about 5% of the facility's annual load and avoids 46.6 tCO2 a year on the Ontario grid factor — using between 10 and 20% of the available roof, with no impact on leasable floor area and no land take. The site's 6,993 kW summer peak comfortably accommodates the array under the load-displacement rule.
A feasibility study, not a delivered installation. Figures are modelled projections at study stage and depend on programme terms, final pricing and interconnection outcome. Capital costs, the facility's utility spend and net present values are commercially confidential to the client and are not published — the percentages above carry the point without them. The $860/kW-AC and $1,000/kW-DC figures are published IESO programme rates.
Cold storage,
two sites,
six megawatts.
Two Lineage cold storage facilities carrying 360,521 ft² of roof between them. Modelled at 5° tilt across two roof-utilisation cases, because on an industrial roof the constraint is almost never the sun — it is mechanical equipment, access routes and the structural capacity of the deck.
| Case | Roof used | DC capacity | P50 generation | P90 | P99 |
|---|---|---|---|---|---|
| 83% roof utilisation | 300,434 ft² | 5,994 kW | 7,599 MWh | 7,076 MWh | 6,650 MWh |
| 70% roof utilisation, conservative | 252,365 ft² | 5,037 kW | 6,386 MWh | 5,946 MWh | 5,588 MWh |
P90 and P99 are the exceedance cases — the generation the array beats in nine years out of ten, and in ninety-nine out of a hundred. Probability coefficients from PVsyst: 0.93 and 0.88 against P50. A P50 number is what a developer quotes; a P90 number is what a lender sizes debt against. Publishing only the first is how a project ends up underperforming a business case that was never wrong, only optimistic.
Six steps,
same as the
audits.
The underlying process does not change between an energy audit and a solar study — site and data gathering, baseline, scenario modelling, comparison, financial synthesis, verified recommendation. Only the tools change: SAM, PVsyst and OpenSolar here where an audit would use RETScreen and eQUEST.
Common questions.
A refundable federal tax credit on capital invested in new clean-technology property in Canada — 30% for property in service between 28 March 2023 and 31 December 2033, dropping to 15% in 2034. Refundable means the benefit arrives even with no tax payable. The full 30% requires electing to meet prevailing-wage and apprenticeship labour requirements; without that election it is 20%. Taxable Canadian corporations and REIT mutual fund trusts can claim it; sole proprietors cannot. Confirm treatment with your own tax advisor — we model it, we do not opine on it.
Yes, and that stacking is usually what makes a commercial rooftop project work. The ITC applies to the post-rebate cost basis, not the gross, so the order matters to the arithmetic. What you cannot do is claim two ITCs on the same equipment — the Clean Tech ITC and the Carbon Capture ITC are mutually exclusive per property, though a project with different equipment types can claim across components. It does stack with accelerated capital cost allowance under Classes 43.1 and 43.2.
It depends almost entirely on the electricity price the building pays and on whether the incentives can be stacked, not on irradiance. A 14% capacity factor is unremarkable; a project that halves its capital cost and displaces power at commercial retail rates is not. On the industrial recycling portfolio we studied, simple payback ran fourteen years with the Save on Energy incentive alone and as little as six once the tax credit was stacked on top. Same roof, same sun.
No. We do the feasibility, the design, the incentive structuring and the EPC decision support, then run the procurement and oversee delivery through our project management practice. Not selling the hardware is what lets the study say no.
Studies we have run.
PROMPT: three-building solar study
611 kWdc on one roof and 59 to 89 kWdc on two more, modelled in SAM and PVsyst against the Save on Energy incentive and the 30% tax credit.
Maurice Coulter Co-operative
A 56 kW rooftop array on 3,800 ft² of unused roof, designed as one of ten measures in a $2.0M CMHC-funded deep retrofit.
What pays for this
109 funding routes across ten provinces and 40 administrators, with the eligibility rule and the deadline stated for each.
Thirty minutes, with the engineer who would run the work.
No cost and no obligation. Bring twelve months of utility bills if you have them — that alone is usually enough to say whether a building has a capital problem or a controls problem.