No glass cover over the PV cells. Maximises electrical cooling benefit and PV output. Thermal output suits pool heating, DHW pre-heat, or low-temp heat pump source. Fluid temp typically 25–40°C.
Glass cover traps heat for higher thermal output, suitable for direct DHW use. Reduces PV cooling benefit since heat is retained near the cells. Fluid temp typically 40–60°C.
Output Breakdown
PVT vs. Separate PV + Thermal Panels
| Metric | PVT (combined) | Separate PV + Thermal |
|---|
How to Use the PVT Collector Calculator
Unglazed PVT maximises electrical output and panel cooling, with lower-temperature heat suited to pool heating or DHW pre-heat. Glazed PVT delivers higher fluid temperatures for direct DHW use but with somewhat less electrical cooling benefit.
Choose the nearest Canadian city for irradiance data. Enter the usable south-facing roof area you have available - this is the constraint PVT is designed to make the most of.
PV cell efficiency drives electrical output. Thermal efficiency bonus is the additional heat harvested beyond the electrical conversion. Enter your electricity and backup thermal fuel rates for the financial comparison.
The comparison table shows what the same roof area would produce as a PVT system versus splitting the roof between a dedicated PV array and a dedicated solar thermal collector. This is the key decision input for limited-roof-area installations.
PVT Hybrid Collectors: When They Make Sense in Canada
Photovoltaic-thermal (PVT) collectors represent an elegant engineering solution to a real physical problem: standard PV panels get hot in the sun, and that heat reduces their electrical output. A PVT collector captures that waste heat with a fluid loop behind the cells, turning a liability into a second useful energy stream. The panel produces electricity from the front and usable heat from the back, simultaneously, from the same roof footprint.
The physics of PV temperature derating
Silicon PV cells lose approximately 0.4 to 0.5% of their rated power output for every degree Celsius above the 25°C standard test condition. On a sunny Canadian summer day with ambient temperatures around 30°C, an uncooled panel's cell temperature can climb to 55 to 65°C due to the combination of solar absorption and limited convective cooling, especially in still air or low-wind conditions. At 60°C, that's a 35°C rise above STC, translating to roughly 14 to 18% lost electrical output compared to the panel's rated capacity. A PVT collector's active fluid cooling can hold cell temperature 15 to 25°C lower, recovering a meaningful fraction of that loss - typically 6 to 12 percentage points of electrical output.
Roof area: the core trade-off
The central question for PVT is whether your roof area is the limiting constraint. If you have abundant south-facing roof space, splitting it between a dedicated PV array and a separate solar thermal collector usually wins on cost and simplicity - each technology operates independently, uses well-established components, and can be serviced or replaced without disturbing the other. PVT becomes attractive when roof area itself is scarce: dense urban infill lots, row houses with narrow south-facing roof sections, or commercial buildings where rooftop space competes with HVAC equipment, vents, and other systems. In these cases, extracting two energy streams from one limited footprint has real value even at a cost premium per unit area.
Unglazed vs. glazed: choosing the right PVT type
Unglazed PVT collectors have no glass cover over the PV cells, allowing maximum heat extraction and the strongest electrical cooling benefit, but the fluid temperature stays relatively low - typically 25 to 40°C. This makes unglazed PVT well-suited to pool heating (which needs only 25 to 30°C), domestic hot water pre-heating ahead of a conventional tank, or as a low-temperature source for a heat pump. Glazed PVT adds a glass cover that traps heat near the absorber, raising achievable fluid temperatures to 40 to 60°C - suitable for direct DHW delivery - but the retained heat also keeps the PV cells warmer, reducing some of the electrical cooling benefit. The solar-assisted heat pump calculator is worth exploring if you're considering unglazed PVT as a heat pump source, since this pairing is increasingly common in cold-climate applications.
Cost and economics of PVT in Canada
PVT collectors typically cost $1,200 to $1,800 per square metre installed in Canada, compared to roughly $400 to $550/m² for standard PV alone or $700 to $1,000/m² for dedicated solar thermal alone. On a pure cost-per-energy basis, PVT rarely beats separate systems when roof area isn't constrained - you're paying a premium for integration rather than getting genuinely cheaper energy. The case for PVT strengthens significantly when the alternative is forgoing one of the two energy streams entirely because there simply isn't enough roof area for two separate systems. This calculator's comparison table makes that trade-off explicit for your specific roof area and rates.
System integration considerations
A PVT installation requires both an electrical inverter connection (as with standard PV) and a hydronic plumbing connection (as with solar thermal), meaning the installation complexity combines both trades. Freeze protection for the thermal loop follows the same CSA B214 requirements as standard solar thermal - glycol closed-loop or drain-back systems are required for Canadian outdoor installations. Because PVT is a less common technology in Canada than standard PV or standard solar thermal, fewer installers have direct experience with it, which can affect both upfront cost and the ease of finding service support over the system's life.
Frequently Asked Questions
A PVT (photovoltaic-thermal) collector combines standard PV cells with a thermal absorber in a single panel. A fluid, usually water or glycol, circulates behind the PV cells and absorbs the waste heat the cells generate during electricity production. This serves two purposes: it harvests heat that would otherwise be wasted, and it cools the PV cells, which improves their electrical efficiency since PV output drops as cell temperature rises. The result is one panel producing both electricity and useful heat from the same roof area. Use this calculator to size a PVT system for your available roof space.
PVT collectors win on roof area efficiency, producing both electricity and heat from a single footprint, which matters most when roof space is limited. Separate PV and thermal panels typically win on cost-per-unit-of-energy and system simplicity, since each technology can be optimised independently and repaired or replaced without affecting the other. For most Canadian residential installations with adequate roof area, separate systems are more cost-effective. PVT becomes the better choice when roof area is the binding constraint, such as in dense urban infill housing or commercial buildings with limited usable roof space. The comparison table in this calculator shows both options side by side for your specific roof area.
Standard silicon PV panels lose roughly 0.4 to 0.5% of their rated output for every degree Celsius above the standard test condition of 25°C. On a hot summer day, an uncooled panel can reach 55 to 65°C, producing 12 to 20% less power than its rated capacity. A PVT collector with active fluid cooling can keep cell temperature 15 to 25°C lower than an uncooled panel, recovering 6 to 12% of that lost electrical output. This efficiency gain is in addition to the thermal energy harvested, which is the second energy stream the same collector produces.
Unglazed PVT collectors, which prioritize electrical output and panel cooling, typically deliver fluid temperatures of 25 to 40°C, suitable for pool heating, pre-heating domestic hot water, or low-temperature space heating with a heat pump. Glazed PVT collectors trade some electrical cooling benefit for higher thermal output, reaching 40 to 60°C, suitable for direct domestic hot water use. Neither type reaches the 80°C+ temperatures of a dedicated evacuated tube solar thermal collector, so PVT is best paired with a heat pump or used for pre-heating rather than as a standalone high-temperature heat source. The solar-assisted heat pump calculator explores this pairing further.
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