The newness of mainstream consumer solar power poses a challenge. If you want to buy a car, for instance, there are plenty of people who’ve done it and can tell you how the process works. Putting solar panels on your roof costs as much as a car, but the number of experienced buyers is far, far smaller. The number of customers who have owned a solar system through its full lifecycle is even more limited.

1. Do you have a roof that can support solar panels?

This is pretty key. If your roof is covered in shade most of the day throughout the year, it might not have a favourable enough “solar window” to justify the costs of panels. That’s something you’ll want to assess before you move forward.

If you do have a suitably sunlit rooftop to work with, one of the experts says, make sure it’s in good shape structurally. Solar installations these days can come with warranties for 20 or 25 years. If your roof will need a renovation a few years down the road, it’ll be easier to take care of that before the panels go up. That way, you won’t have to pay in extra time and money to disconnect your panels during the roof renovation and put them up again afterwards.

2. Have you done everything you can to improve efficiency?

The amount of solar energy you need to produce depends on how much you use, so it makes sense to trim your usage as much as possible before paying for all those panels.

3. Which kind of solar should you use?

The two dominant solar technologies to pick from are photovoltaic, which uses arrays of cells to turn sunlight into electricity, and thermal, which uses sunlight to heat water or air for use inside. If your home uses a lot of energy for heating, or you live somewhere where heating fuel is expensive relative to electricity, a solar thermal investment could break even sooner.

4. Is your installer trustworthy?

This applies any time you hire someone to come into your home, but solar combines the logistics of a home improvement project with the risks of electrical work. Credentials and references are especially important. “You wouldn’t hire an electrician who had never done electrical work to come into your house and change things around,” says Kelly Larson, an electrical contractor in California with 20 years of experience doing solar installations.

This is harder to predict, but, ideally, you want a company like Calpro Solar that will stick around for the lifetime of your installation. Since solar cells don’t have moving pieces, they tend to need very little maintenance. Still, in the event that anything does stop working during the warranty period, Calpros Solar will be around to fix it.