FIELD NOTES / THE ROOF

A roof with
an upside.

A solar panel generates electricity. Your bill records the electricity imported from the grid and the electricity exported to it. Those are different numbers, and understanding the difference makes a solar quote easier to assess.

Three paths for every kilowatt-hour.

• Self-consumption: solar electricity used at home while it is produced. It reduces the electricity you need to import.
• Grid imports: electricity bought when your home needs more than the roof supplies.
• Exports: electricity sent to the grid. The export meter records this part, not every kWh your panels produce.

Alberta’s micro-generation framework allows eligible customers to receive credits for excess electricity. Billing and compensation terms should be confirmed with the retailer and distributor. Administration and tariff charges still appear on a solar home’s bill. Government of Alberta — Micro-generation ↗ and Alberta Utilities Commission — Micro-generation questions ↗.

What the lab models.

Annual generation = system DC capacity × entered annual yield
Period generation = annual generation × billing days ÷ 365
Self-consumption = lower of home load or generation × entered self-use percentage
Exports = generation − self-consumption
Grid imports = home load − self-consumption
Export credit = exports × entered credit rate

A real roof changes with orientation, shade, snow, system losses and seasons. An annual-average model does not reproduce a summer bill or show whether production overlaps with your use hour by hour. The self-use percentage is an assumption, capped at the modelled home load.

NRCan provides monthly and annual solar-resource estimates in kWh per installed kW of DC capacity for different orientations. Use a suitable location estimate or your installer’s design, and ask whether system losses are already included before applying any additional adjustment. Natural Resources Canada — Solar photovoltaic tools ↗.

Check the quote beyond the panels.

1. Ask for a roof-specific generation estimate and shading assessment.
2. Confirm your electrical service, meter and interconnection requirements with your distributor.
3. Ask how much output is expected to be used at home, exported and generated in each month.
4. Confirm your import rate, export-credit terms and how credits carry forward or are paid out.
5. Include installed cost, maintenance, financing and applicable program eligibility in a separate financial assessment.

The lab deducts export credits after its simplified tax calculation. Actual tax and credit treatment depend on your bill and agreement. It does not model batteries, seasonal solar tariffs, installation cost or investment payback. Rule 024’s current micro-generation requirements took effect April 1, 2026.

Planning funding too? Check current program status before assuming a rebate.