Solar Thermal & Hot Water Calculator
Free two-minute sizing + payback estimator for Canadian solar water heating projects. Dairy, hotel, laundromat, MURB, or residential — pick your building type, current fuel, and daily hot-water draw. We size the array, apply the federal 30% Clean Tech ITC where eligible, and model payback against your specific backup fuel.
Estimate your solar thermal project
Solar thermal panels displace the fuel that heats your water — natural gas, propane, electric, oil, or heat-pump. Pick your building type, daily hot-water draw, and current fuel; the tool estimates system size, annual fuel savings, and payback.
Fill in your building details on the left and hit Estimate My Solar Thermal Project.
Common questions
How does this calculator differ from the residential and commercial solar calculators?
Solar thermal is fundamentally different from PV. This calculator estimates fuel-displacement savings (natural gas / propane / electric / oil / heat-pump) rather than electricity generation + net-metering export. The inputs, math, and outputs are tuned for hot-water and space-heating projects, not electricity generation.
Do I need to know my daily hot water usage?
No — leave the litres field blank and the calculator will use a typical value for your building type (e.g. dairy 3,500 L/day, hotel 6,500 L/day, laundromat 5,500 L/day). If you know your exact draw, enter it for a more precise estimate.
Why does payback vary so much by backup fuel?
Solar thermal displaces the fuel currently heating your water. Oil ($0.16/kWh_thermal) and propane ($0.12/kWh_thermal) are the most expensive to displace, so payback is fastest. Natural gas ($0.05/kWh_thermal) is the cheapest, so payback runs longer. Heat pumps are already efficient (COP 3+), so solar thermal against a heat pump has the slowest payback.
Does the federal 30% Clean Tech ITC apply to solar thermal?
Yes — most active solar heating equipment qualifies under CRA Class 43.1, which is a qualifying class for the 30% refundable ITC. Available only to incorporated Canadian corporations (not sole-proprietor homeowners). Confirm equipment eligibility with your accountant.
What happens after I submit the form?
Your project is routed to a Canadian installer with solar thermal experience for your segment (dairy, hotel, MURB, etc.) within one business day. No obligation. Installers pay us a small referral fee only if they win the project.
Is solar thermal always the best choice, or should I look at PVT or heat pump too?
Depends on your load. Big constant hot-water draw with high fuel prices (dairy, hotel, laundromat) — solar thermal usually wins. Roof area is tight AND you have both electricity and hot water load — PVT hybrid may beat separate systems. Cold climate + heat pump water heater already installed — pairing them is often more cost-effective than adding solar thermal on top.
Want the deep-dive first?
The full guide covers case studies (Miller's Dairy Creemore, Drake Landing seasonal storage, Travelodge Saskatoon, One Old Mill condos), payback ranges by segment, and honest discussion of where solar thermal doesn't pay back.
Read the Pillar Guide