Solar Payback Calculator for Alberta
Estimate your solar investment payback period and return on investment. Works with Solar Club rates and low/high season electricity pricing across Alberta.
Solar Payback and ROI Calculator
Enter your solar system cost, low and high season production (kWh), electricity rates (¢/kWh), and optional D&T service area for variable delivery savings on self-consumed solar. This Alberta solar payback calculator estimates your payback period, average ROI per year, and lifetime return. Use solar rates from your retailer or bill optimization analysis for accurate inputs.
Solar System & Production
Distribution & Transmission (D&T)
Your Results
Cumulative Savings Over Time
Bars show cumulative savings. Dashed line = system cost (payback when bars exceed it). Blue line = cumulative ROI ($) on right axis—your net return over time.
Loan Amortization
| Year | Interest | Principal | Total payment | Ending balance |
|---|
How These Values Are Calculated
For those who like to deep dive and nerd out about numbers, we've provided a summary of all value calculations below. All results assume a 25-year system lifetime and apply your annual electricity price increase to both low and high rates each year. If you set a financing interest rate, an annual loan payment is subtracted from electricity savings. Amounts are in Canadian dollars.
Annual electricity savings (each year)
For year n (starting at year 1), rates are escalated from your inputs:
- Low rate ($/kWh) = (Low rate ¢/kWh ÷ 100) × (1 + annual increase)n−1
- High rate ($/kWh) = (High rate ¢/kWh ÷ 100) × (1 + annual increase)n−1
Seasonal value (benefit of solar at each season’s rate):
(Low season production × Low rate) + (High season production × High rate)
Gross annual savings = seasonal value + variable D&T savings (if applicable)
If financing is enabled, net annual savings = gross annual savings − annual financing payment (see below).
Distribution & transmission (D&T)
Regulated delivery charges depend on your wires owner (not your energy retailer). ENMAX is a retailer in Calgary; delivery is typically billed through ATCO Electric Ltd. The calculator uses one combined variable ¢/kWh per area (transmission + distribution energy charges). Fixed $/day charges are listed for reference but are not included in savings.
Preset variable & fixed rates used in this calculator
| Service area | Variable D&T | Fixed D&T | Basis (approximate) |
|---|
Formulas (each year n)
- Variable D&T rate ($/kWh) = (Preset or custom ¢/kWh ÷ 100) × (1 + annual electricity increase)n−1
- Self-consumed kWh = (Low season production + High season production) × (Self-consumed % ÷ 100)
- Variable D&T savings (added to gross annual savings) = Self-consumed kWh × Variable D&T rate ($/kWh)
D&T savings = Self-consumed kWh × (Variable D&T ¢/kWh ÷ 100) × (1 + annual increase)n−1
Worked example: ENMAX / ATCO Electric (Calgary) — year 1
Using the preset 5.50 ¢/kWh variable rate, default production (4,500 + 7,000 = 11,500 kWh), and 30% self-consumed:
- Self-consumed kWh = 11,500 × 0.30 = 3,450 kWh
- Variable D&T rate = 5.50 ÷ 100 = $0.055 /kWh
- D&T savings = 3,450 × $0.055 = $189.75 /year (included in payback & ROI)
Compare your bill’s delivery lines to the custom rate option if your actual variable ¢/kWh differs. Official tariffs change with AUC approvals; these presets are planning estimates, not a bill replica.
Financing cost (optional)
When Financing Interest Rate is greater than 0%, the calculator assumes the full system cost is borrowed and repaid with equal annual payments over 25 years (standard amortization). The same payment is subtracted every year from gross electricity savings.
- Annual rate = Financing interest rate ÷ 100 (e.g. 6% → 0.06)
- Annual financing payment — if rate is 0%: System cost ÷ 25. Otherwise: System cost × [r × (1+r)25] ÷ [(1+r)25 − 1] where r is the annual rate
- Net annual savings = Gross annual savings − Annual financing payment
Net annual savings = Gross annual savings − Annual financing payment
Payback, ROI, and the chart use net annual savings when financing is on (gross electricity savings minus the loan payment). Payback is when cumulative net savings equal your system cost—the same target as the red dashed line on the chart. At 0% financing, loan payments are not applied and results match a cash purchase.
When financing is enabled, an amortization schedule appears below the chart with yearly interest, principal, total payment, and ending loan balance.
Payback period
Cash purchase (0% financing): Cumulative gross electricity savings are totaled until they equal your system cost.
Financed system: Cumulative net savings (gross savings minus equal annual loan payments) are totaled until they equal your system cost.
If payback falls partway through a year, the calculator interpolates within that year (e.g. 8.4 years means full recovery during year 9). If net savings never reach system cost within 25 years, payback is shown as —.
ROI over lifetime
Dollar amount shown in Your Results and on the blue chart line at year 25 (cumulative ROI):
(Sum of 25 annual savings) − System cost
Financing: annual savings are net of loan payments before subtracting system cost.
Average ROI per year
Lifetime net profit (cash or financed, as above) expressed as a percentage of system cost, spread evenly across 25 years:
(Lifetime ROI % ÷ 25) where Lifetime ROI % = (Net profit ÷ System cost) × 100
Cumulative savings chart
- Green bars — running total of net annual savings (hover a bar for gross savings, financing payment, and components)
- Red dashed line — your system cost (cash payback when bars cross above it)
- Blue line — cumulative ROI in dollars (cumulative savings minus system cost; matches ROI over Lifetime)
By using this calculator, you acknowledge results are estimates only and subject to assumptions. See Terms of Use.
Sign Up for the Solar Club™ through SHARED VALUE ENERGY
Get the best solar rates and lowest monthly admin fee and bring down the cost of your utility bill with solar.