Rooftop PV panels generate electricity that runs a conventional split-system or central AC. Simple, reliable, and works with any existing AC unit. Best economics for residential and light commercial in Canada.
Solar thermal collectors drive an absorption chiller to produce chilled water. No electricity required for cooling. COP 0.6–1.4 depending on chiller type. Economical at 50 kW+ cooling capacity with solar thermal already installed.
System Summary
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How to Use the Solar Cooling Calculator
PV-powered AC is the right choice for most Canadian homes and small commercial buildings. It uses rooftop solar to generate electricity for a conventional AC unit. Solar thermal absorption cooling suits larger buildings where chiller capital costs can be spread over bigger loads.
Choose the nearest Canadian city for location-specific irradiance and summer design temperature data. Enter your annual cooling electricity use from utility bills, or use the cooling load calculator to estimate it from your building size.
For PV-powered AC, enter your panel wattage and performance ratio. For absorption, choose the chiller COP and collector type. Set the fraction of your annual cooling load you want solar to cover.
Your electricity rate and installed cost determine the payback period. PV-powered AC installed costs run $2.50 to $3.50 per watt for a standalone PV system paired with existing AC. Absorption systems vary widely by chiller capacity.
Solar Cooling for Canadian Buildings
Solar cooling takes advantage of a natural alignment: cooling demand peaks in summer when solar irradiance is at its annual maximum. This seasonal coincidence makes solar cooling fundamentally more efficient than solar space heating, where peak demand and peak solar resource are six months out of phase. A properly sized solar cooling system in Toronto or Calgary can offset the majority of summer cooling electricity at exactly the time when the provincial grid is under peak demand stress.
PV-powered AC: the practical Canadian choice
For residential and small commercial buildings, the most cost-effective solar cooling approach is to pair a rooftop PV array with a high-efficiency air conditioner or heat pump. The PV array generates electricity that runs the AC directly during the day, and exports surplus power to the grid under net metering when the AC isn't running at full capacity. This approach uses standard, well-understood technology. It requires no special plumbing, no heat transfer fluid, and no chiller — just panels, an inverter, and your existing or new AC equipment. The solar PV HVAC calculator sizes a PV array against your full heating and cooling load if you want to combine both on one system.
Solar thermal absorption cooling: when it makes sense
Absorption chillers use heat — rather than electricity — to drive a refrigeration cycle using a lithium bromide or ammonia-water working pair. A single-effect absorption chiller needs driving heat at 80 to 100°C, achievable from evacuated tube or high-quality flat-plate collectors. The thermal COP of 0.6 to 0.8 looks low compared to an electric chiller's COP of 3 to 5, but the driving energy is essentially free solar heat. The economics work when you already have solar thermal collectors installed for space heating or DHW, and the chiller capital cost can be justified by a large cooling load. In Canada, this typically means buildings with 50 kW or more of cooling capacity, such as hotels, hospitals, or large office buildings. The solar thermal calculator sizes the collector array for the driving heat.
The solar cooling fraction and monthly variation
Summer solar resource peaks in June and July, exactly when cooling loads are highest in most Canadian cities. This alignment means a solar cooling system achieves its highest monthly offset in June through August. In shoulder months like May and September, cooling loads are low and even a small PV array can cover them entirely. The monthly breakdown in this calculator shows how solar offset varies across the cooling season so you can see when the system is working hardest.
Summer design temperatures and peak AC sizing
The summer design temperature for HVAC equipment sizing in Canadian cities ranges from 28°C in Vancouver to 33°C in Toronto and 30°C in Calgary at the 2.5% design condition. These peaks drive the equipment sizing, but annual energy consumption is what determines PV array size. A system sized for 100% of annual cooling energy will still need grid power on the hottest days when loads exceed average, unless the array is significantly oversized. For equipment sizing (rather than energy modelling), use the cooling load calculator and confirm peak demand with a mechanical engineer.
Frequently Asked Questions
Solar cooling uses solar energy to drive a cooling process instead of grid electricity. The two main approaches are PV-powered cooling, where rooftop solar panels generate electricity to run a conventional air conditioner, and solar thermal cooling, where heat from solar collectors drives an absorption chiller that produces chilled water. PV-powered cooling is more common in Canada because absorption chillers require high driving temperatures and are typically economical only in larger commercial buildings. Both approaches reduce the net electricity demand for cooling and take advantage of the natural coincidence of peak solar production and peak cooling load in summer.
A single-effect absorption chiller driven by solar thermal heat at 80 to 100°C has a COP of approximately 0.6 to 0.8. A double-effect absorption chiller driven at 130 to 160°C achieves COP 1.0 to 1.4. This is lower than a conventional electric chiller's COP of 3 to 5, but the driving energy is free solar heat. When comparing solar thermal cooling to PV-powered cooling, account for the full system: solar thermal cooling uses no electricity for cooling but needs expensive chiller hardware, while PV cooling uses simpler hardware but requires panels sized for the electrical load. Use the solar thermal calculator to size the collector array for the driving heat.
PV-powered cooling is absolutely viable in Canada and is the most practical solar cooling approach for residential and light commercial buildings. The solar resource in summer aligns well with cooling demand, particularly in Calgary, Toronto, and the Prairie provinces. Solar thermal absorption cooling is viable for larger commercial buildings with cooling loads above 50 kW, where the absorption chiller capital cost is justified. In smaller buildings, PV-powered cooling offers better economics. The net metering calculator shows how surplus summer PV production earns credits against your winter heating bills.
A typical 5 kW residential air conditioner running 6 hours per day would consume 30 kWh per day at peak load. With 4 peak sun hours per day in Toronto in July, a 10 kW PV array would produce about 31 kWh per day at a performance ratio of 0.78, fully covering the AC load on an average day. In practice, you size to the annual cooling load. This calculator sizes the PV array to your annual cooling energy and your chosen offset fraction. For a combined heating-and-cooling PV system, use the solar PV HVAC calculator.
Related HVAC Tools
Get your annual cooling energy input
Size PV for heating and cooling combined
Size collectors for absorption cooling
Model surplus PV credits by province
Reduce cooling load at the source
Full financial model with incentives