Solar Billing Basics for Idaho Homeowners

A solar proposal is only as good as its assumptions about your utility bill. Before comparing quotes, it helps to understand how solar energy actually gets counted.

Energy you use vs. energy you send back

When your panels are producing, your home uses that power first. If the panels make more than the house needs at that moment, the extra flows back to the grid. When the panels aren't producing enough, like at night, you pull power from the grid as usual.

Those two directions are often valued differently. Energy you use directly offsets power you would have bought at your retail rate. Energy you export is credited under your utility's rules for customer-owned generation, and that credit may be lower than the retail rate.

Why the export rate matters

If exports are credited below retail, a system sized to use more of its own production can make more financial sense than one sized to export a lot. That's why two proposals with the same panel count can show very different savings.

Idaho utilities set these rules in tariffs approved by the Idaho Public Utilities Commission, and they can change. Check your utility's current program for on-site generation, or ask your installer to show which rate schedule their numbers use.

Other things on your bill

• Fixed monthly charges usually stay the same with or without solar.
• Seasonal rates can make summer and winter savings look very different.
• Credits carried forward may have limits or expiration rules.

Questions to ask before you sign

• Which utility rate schedule and export credit did you use?
• What share of production do you expect my home to use directly?
• What utility rate increase, if any, is built into the savings estimate?
• Does the estimate include any tax incentives, and are they still available? (The federal residential clean energy credit is not available for expenditures made after December 31, 2025.)
• Will my roof need replacement before the panels reach the end of their life?

A good proposal shows its assumptions so you can check them. If the numbers only work with big rate increases or incentives that no longer apply, that's worth knowing before you commit.