Is Rooftop Solar a Good Buy for You?

What decides whether solar is worth it?

Three inputs do most of the work: what you pay per kilowatt-hour, how much the roof will produce, and what the system costs installed. Higher rates make every kilowatt-hour your panels generate more valuable. Strong sun and a good roof raise output. Lower installed cost shortens the wait.

Everything else is a modifier. How exported power is credited, whether incentives exist, how you finance it, and how long you will own the house all move the answer. Province matters because electricity rates and net-metering rules differ widely. Start with the costs in how much solar panels cost in Canada and then run the numbers for your bill.

A worked example with stated assumptions

Assume a 7 kW system costing $21,000, producing 8,500 kWh a year, with power valued at 15 cents per kWh. Annual value is about $1,275. Simple payback is 21,000 divided by 1,275, roughly 16 years. Raise the power value to 22 cents and it falls to about 11 years. Drop output to 7,000 kWh because of shade and it stretches past 20.

These are illustrations, not quotes. The sensitivity is the point: a small change in the rate or the shade moves the result by years. The payback period guide shows how to build a version with your own bill and how to include rate changes.

A second check is useful: ask what the money would earn elsewhere. Paying off a high-interest debt, or insulating an attic, may return more per dollar than panels do, and with less risk. Solar tends to be the better pick when those cheaper options are already done and the roof is good. That sequence, envelope first and generation second, is why energy advisers often begin with an audit, and the same order of work shaped the low-energy homes at Okotoks. Panels then cover a smaller, cleaner load.

Who should think twice?

A few situations tilt against solar. A roof near the end of its life should be replaced first, since removing and refitting panels costs money. Heavy shade from mature trees or a taller neighbour can cut output sharply; see the best direction for solar panels. A move planned within a few years may not recover the investment unless the market values the system, and the evidence on that is covered in whether solar raises home value.

Renters, and condo owners without roof rights, usually cannot install at all. A household that uses very little power may be better served by efficiency work and a heat pump first.

Does cold weather or snow ruin the economics?

Less than people expect. Cold air helps panels run efficiently, and bright winter days with snow on the ground can give a decent boost. The real winter problem is short days. Output in December is a fraction of June output, and yearly averages already include that. The detail is in whether solar panels work in winter.

Southern Alberta and Saskatchewan combine strong sun with cold air and tend to model well. Dense cloud regions model lower. A designer's production estimate for your address beats any national rule of thumb.

Is electricity the only worthwhile solar investment?

Not always. In a cold country, a lot of household energy is heat. The Okotoks neighbourhood described on the how it works page used solar collectors and seasonal ground storage to meet most of its space heating, reaching 97 percent solar share by 2012. That project was a research community with its own economics and was later wound down, so it is no template for a single house. Still, it shows why heating, not just power, belongs in the value question. If your furnace is the largest bill, a heat pump may beat panels as a first step.

Quick answers