THE MODEL / OPEN ASSUMPTIONS

Good numbers.
Clear assumptions.

The Home Energy Lab is a browser-based scenario calculator for Alberta residential electricity. It explains the relationship between your inputs; it does not read a meter, verify a bill, assess a roof or recommend an electricity contract.

The starting home.

With no upgrades selected, the starting scenario calculates to $175.10 for 30 days. The fixed delivery and other fees are entered per period; they are not automatically prorated when billing days change. Administration is charged per day.

How the bill is calculated.

Efficiency reduction = baseline kWh × sum of selected illustrative reductions
EV kWh = monthly km × wall kWh/100 km ÷ 100 × days ÷ (365 ÷ 12)
Home load = max(0, baseline kWh − efficiency reduction + EV kWh)
Solar generation = DC kW × annual yield × days ÷ 365
Self-consumed solar = min(home load, solar generation × self-use fraction)
Exported solar = solar generation − self-consumed solar
Grid imports = home load − self-consumed solar

Energy = grid imports × energy rate ÷ 100
Administration = daily administration × days
Delivery = fixed delivery + grid imports × variable delivery rate ÷ 100
Subtotal = energy + administration + delivery + other fees
Estimated tax = subtotal × tax percentage ÷ 100
Export credit = exported solar × export credit rate ÷ 100
Estimated total = subtotal + estimated tax − export credit

Rates entered in cents are divided by 100. Unrounded values are used internally; displayed dollar values are rounded to cents. A negative total is a scenario credit, not a guaranteed payout.

Tax is calculated on the subtotal before deducting the export credit. This is a simplified presentation, not tax advice or a reproduction of every retailer’s tax treatment. Fixed fees and riders may be more complex than the lab’s fixed-plus-variable model. Compare your actual bill and retailer’s rules.

The switches are experiments.

Selected reductions are added, up to 14% with all four switches on, and applied to baseline electricity before adding EV charging. They are deliberately illustrative; they are not measured appliance savings, engineering predictions or reductions guaranteed for your home. “Smarter climate” is not a heat-pump model. The lab does not model natural gas, heating-system efficiency or heat-pump operating cost.

Averages are not seasons.

Solar output is distributed evenly over 365 days. EV energy uses an average month of 365 ÷ 12 days. Actual driving, solar production, weather and demand vary. The model’s solar self-use percentage cannot establish real-time overlap between generation and consumption. It excludes batteries, time-varying tariffs, demand charges, capital cost, financing, maintenance and investment payback.

The rate check.

Supplier difference before tax =
  grid imports × (current rate − comparison rate) ÷ 100
  + billing days × (current daily admin − comparison daily admin)

This comparison holds imported kWh and days constant. It omits delivery, other fees, taxes, incentives and contract conditions. A lower supplier cost does not imply the same percentage reduction in your whole bill.

Reference rates checked September 29, 2026: ENMAX Calgary RoLR 12.06¢/kWh plus $0.4134/day; ENMAX Easymax 2-year fixed example 7.89¢/kWh plus approximately $0.36/day. Verify current availability and terms. The RoLR reference period ends December 31, 2026. Annualizing today’s inputs would be a scenario, not a forecast beyond that expiry.

Your next decision.

Bring the Passport to a retailer or qualified professional. Confirm current tariffs, roof design, electrical capacity and applicable permits before changing equipment or signing an agreement. Report a calculation or source concern so the lab can improve.