Three roofs, one
process, three very
different answers.
A rooftop solar feasibility engagement across an industrial recycling portfolio, delivered under BOMA Enspire. The same six-step process ran on the largest roof and on the smallest — and the smallest building turned out to have the best economics on the portfolio.
Daytime load,
daytime
generation.
The client is an industrial recycling operator with a small portfolio of GTA facilities. All three buildings run daytime operating hours — 177 Mills runs 7am to 5pm, Monday to Friday — which is the core rationale for behind-the-meter solar at each site. The building consumes the power roughly when the array produces it, so almost none of the generation has to find its value through export.
Baseline energy use intensity across the portfolio ran around 0.90–0.94 GJ/m² against a sector median near 0.72 GJ/m². Solar was assessed as one route among several, not as a foregone conclusion.
177 Mills Road
Single-storey manufacturing and warehousing, 101,626 ft². The largest roof and the largest project.
228 Midwest Road
Active recycling operation on a footprint of roughly 14,000 ft². 1960s to 1970s industrial stock.
250 Midwest Road
A similarly scaled recycling facility next door — and, as it turned out, the best project of the three.
177 Mills Road,
Ajax.
611 kWdc / 499 kWac across the warehouse and manufacturing roof: 1,488 Canadian Solar HiKu6 modules on ten Sungrow SG250HX inverters, modelled at 414,292 kWh in year one.
| Scenario | Year-1 energy | Simple payback | IRR |
|---|---|---|---|
| PV only, no incentive | 414,292 kWh | 23 yrs | 1% |
| PV only, Save on Energy | 414,292 kWh | 14 yrs | 6% |
| PV only, incentive + 30% tax credit | 414,292 kWh | 6 yrs | — |
| PV + battery, no incentive | 419,483 kWh | 33 yrs | −2% |
| PV + battery, Save on Energy | 419,483 kWh | 24 yrs | 1% |
| PV + battery, incentive + tax credit | 419,483 kWh | 12 yrs | — |
GHG reduction 14 tCO2e/yr. Optional battery scenario modelled at 515 kW / 4.8 MWh.
228 and 250
Midwest Road,
Scarborough.
Two much smaller projects on adjacent recycling facilities, at 89 kWdc and 59 kWdc. Same modelling, same incentive analysis, an order of magnitude less capital.
| Building & scenario | Year-1 energy | Simple payback | IRR |
|---|---|---|---|
| 228 Midwest — no incentive | 107,211 kWh | 17 yrs | 4% |
| 228 Midwest — Save on Energy | 107,211 kWh | 11 yrs | 8% |
| 228 Midwest — incentive + tax credit | 107,211 kWh | 5 yrs | — |
| 250 Midwest — no incentive | 79,790 kWh | 15 yrs | 5% |
| 250 Midwest — Save on Energy | 79,790 kWh | 9 yrs | 10% |
| 250 Midwest — incentive + tax credit | 79,790 kWh | 5 yrs | 21% |
250 Midwest is the standout on this portfolio. It is the smallest system at 59 kWdc, and it posts the fastest payback and the highest IRR — 21% — once the Save on Energy incentive is stacked with the 30% tax credit. Project economics on rooftop solar depend at least as much on incentive eligibility and cost basis as they do on system size.
An owner ranking three roofs by area would have put this one last.
Why no
battery.
At every one of the three buildings, adding storage roughly doubles installed cost while adding only a few percent more annual energy. Batteries shift power in time; they do not generate more of it, and round-trip losses reduce the usable total. No dedicated storage incentive currently applies in this case.
Storage remains a real option where demand charges are high, export capacity is constrained, or outage resilience has a value of its own. On these three roofs, today, it is not a financial one — and the modelling is on the page above so the client can see why rather than take our word for it.
The sun, and
the wiring.
Monthly solar resource at each location, and the sequence a behind-the-meter array connects through. Neither is exotic — but getting the second one wrong is how a feasibility number turns into a construction change order.
Six steps,
identical at
every scale.
The same underlying process we run on an energy audit. Only the tools change with the application: SAM and PVsyst here, where an audit would use RETScreen and eQUEST. The smallest project got the same treatment as the largest, which is the only reason we found out it was the better project.
More on
this work.
All figures modelled in SAM and cross-validated in PVsyst. Tax-credit scenarios apply the 30% capital-cost credit to the post-rebate cost basis; eligibility varies by site and by owner and should be confirmed with a tax advisor. This was a feasibility engagement — the figures are modelled projections at study stage, not measured results from a built system. Array placements are modelled by Quwa over third-party aerial site imagery. Capital costs, annual savings and net present values are commercially confidential to the client and are not published.
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.