The fastest way to end up with a solar system that doesn’t quite work the way you wanted is to size it from a sales pitch instead of from your actual electricity usage. The pitch usually starts with the size of your roof and ends with the biggest system that fits. The right starting point is the back of your utility bill.
Step one: read your actual usage
Your power company will give you a year of monthly kWh consumption if you ask. That’s the number that matters. Twelve months covers winter heat, summer AC, and the in-between months that aren’t either. Average it out, and you have a baseline.
Step two: think about what’s changing
- Adding an EV? Add roughly 3,000–4,000 kWh per year per car.
- Switching to a heat pump? Your winter usage goes up significantly — budget for it.
- Cutting the natural-gas appliances? Plan to absorb that load on the electric side.
Step three: size to that, not the roof
Once you know your real annual kWh need, you size the array to produce that amount given your location’s sun hours. In northern Utah, a 1 kW system produces roughly 1,400–1,600 kWh per year. Divide your need by that, and you have a kW target. Then check if your roof — orientation, shade, and area — can actually support it.
A word on batteries
Batteries are a different decision than panels. They’re great for outage backup and for shifting usage across time-of-use rate windows. They’re not usually a great financial play on their own — the math depends heavily on your utility’s net-metering policy.
If you’d like an honest size-and-scope conversation, we’ll start with your bill, not your roof.