Solar Payback in BC
Solar payback in BC: how to calculate your real payback period
Payback isn't one number you look up — it's a short chain of multiplications, and BC's cheap hydro plus the 2026 net-metering change bends every link of it. Here's the exact formula, step by step, with honest BC numbers so you can ballpark your own.
The payback formula at a glance
- 1. Production = size (kW) × regional yield (kWh/kW/yr) × orientation derate.
- 2. Split production into self-consumed (~40% without a battery) vs exported.
- 3. Value it: self-consumed at retail (~13.1¢), exported at the new ~10¢ rate.
- 4. Net cost = installed cost − rebates.
- 5. Payback = net cost ÷ annual bill offset.
Step 1 — Production: how many kWh your roof makes
Start with how much energy the array actually generates in a year:
Production = system size (kW) × regional yield (kWh per kW per year) × orientation derate.
BC yields vary by region (NRCan, south-facing at latitude tilt): the coast ~1,000 kWh/kW (Vancouver 1,007), the Southern Interior ~1,130 kWh/kW (Kelowna 1,132), and the north ~1,050 kWh/kW (Prince George 1,056). Orientation matters too — relative to a clean south-facing roof: south = 1.00, SE/SW ≈ 0.95, E/W ≈ 0.83, flat ≈ 0.90.
Example: a 6 kW system, on the coast, facing south: 6 × 1,000 × 1.00 = 6,000 kWh/yr.
Step 2 — Split it: self-consumed vs exported
This is the step most online calculators skip, and it's the one that matters most in BC. Solar generates midday; most homes use power in the evening. Without a battery, only about 40% of production is typically consumed on-site — the rest is exported to the grid.
Example: of 6,000 kWh, roughly 2,400 kWh is self-consumed and 3,600 kWh is exported.
Step 3 — Value each part
The two halves are worth different amounts, and that gap is the whole story:
- Self-consumed energy avoids buying power, so it's worth the full retail rate — about 13.1¢/kWh.
- Exported surplus, under the new BC Hydro RS 2289 rate (from July 1, 2026), earns only about 10¢/kWh — below retail.
Example: 2,400 × $0.131 + 3,600 × $0.10 ≈ $674/yr bill offset. Under the old 1:1 RS 1289 rate, every exported kWh was worth full retail, so the same system would have offset about $786/yr. That difference is exactly why the 2026 net-metering change lengthens payback — and why self-consumption is now the biggest lever you control.
Step 4 — Net cost: installed price minus rebates
Net cost = installed cost − rebates. As a rough BC ballpark, installed solar runs about $2.50–$3.00 per watt, so a 6 kW system is roughly $15,000–$18,000. Against that, BC Hydro rebates can take a meaningful bite: up to $5,000 for solar, up to $5,000 for a battery, and a $2,000 income supplement — landing many homes around $11,000–$14,000 net. Your stack depends on eligibility; see BC solar rebates 2026 for the catches.
Step 5 — Payback: net cost ÷ annual offset
Now divide:
Payback (years) = net cost ÷ annual bill offset.
Example: ~$12,000 ÷ ~$674 ≈ ~18 years (illustrative). That's the simple version — and it deliberately ignores two real effects that pull in opposite directions:
- Rate inflation — BC Hydro rates rise over time, so each offset kWh is worth more in future years. This shortens payback.
- Panel degradation — panels lose roughly 0.5%/yr of output, so production slowly drops. This lengthens payback.
For a quick ballpark these roughly offset; for a real decision you model both year by year — which is what the kit does.
The honest verdict
Because BC hydro is so cheap, payback here is often 10–15+ years — longer than the sunny-state numbers solar marketing quotes. A battery usually lengthens pure payback rather than shortening it, unless you're capturing Peak Saver value on top. And under RS 2289, self-consumption is the single biggest lever: the more of your own solar you use instead of exporting at 10¢, the faster the whole thing pays back. None of this means "don't" — it means run the real numbers before you sign. Is solar worth it in BC? walks through when the answer is yes.