Solar Battery ROI Calculator (Canada)

How the calculator works

The solar battery ROI calculator works out the four numbers a Canadian household needs to decide on storage: annual savings uplift, net battery cost after provincial rebates, simple payback in years, and 10-year net present value at a 5% real discount rate.

Plug in nine inputs and the tool returns the investment case. The engine mirrors our solar self-consumption calculator but reframes the output for the purchase question rather than the operational ratio.

1. PV system size (kW DC) — your existing or planned array. NRCan microFIT/net-metering data places the residential median at 7 kW DC.
2. Peak sun hours/day — annual average from CanmetENERGY irradiance atlas. Calgary 4.2, Toronto 3.8, Ottawa 3.9, Vancouver 3.2, Montreal 3.8, Halifax 3.7, Winnipeg 4.1.
3. Annual usage (kWh) — pull 12 months from your utility portal. Statistics Canada 2024 average household: ON 9,000, BC 11,000 (electric heat common), QC 18,000 (electric heat), AB 7,500, NS 10,500.
4. Retail rate (C$/kWh) — your blended import rate. Hydro Ontario 17c (off-peak 10.2c, mid 12.2c, on-peak 17.0c TOU), BC Hydro Step 1 11.3c / Step 2 14.1c, Hydro-Québec 7.8c, Manitoba Hydro 10.3c.
5. Net-metering credit (C$/kWh) — what your utility credits for exports. Default 10c reflects the BC Hydro 9.99c “Renewable Energy Customer” rate; 1:1 retail provinces should set this equal to retail.
6. Battery capacity (kWh) — usable storage.
7. Battery installed cost (C$) — turnkey including CSA-compliant interconnect, electrical permit, and ESA/Technical Safety BC inspection.
8. Provincial rebate (%) — 0 for most provinces in 2026; up to 30% for BC Hydro Renewable Energy Customer participants on qualifying batteries.
9. Daytime overlap (%) — your unaided self-consumption percentage. Default 30%; raise to 40% if you run electric vehicle charging or heat-pump operation through midday.

How the math works

annual_kWh_produced  = system_kW × peak_sun_hours × 365 × 0.77
no_battery_self      = min(annual_use, annual_prod × overlap_pct/100)
battery_capture      = battery_kWh × 365 × 0.92 × 0.85
with_battery_self    = min(annual_use, no_battery_self + battery_capture, annual_prod)
bill_no_batt         = max(0, imports × retail − exports × credit)
bill_w_batt          = max(0, imports × retail − exports × credit)
annual_uplift        = bill_no_batt − bill_w_batt
net_battery_cost     = battery_cost × (1 − rebate_pct/100)
simple_payback_yr    = net_battery_cost / annual_uplift
10yr_NPV             = Σ uplift_t/(1+0.05)^t − net_battery_cost

The 0.77 IEC 61724-1:2017 performance ratio is appropriate for southern Canada; expect 0.80–0.83 in interior BC and AB where cooler ambient temperatures partly offset shorter daylight hours in winter. The 0.92 × 0.85 = 0.782 effective battery utilisation matches NRCan CanmetENERGY field-test data for residential LFP duty in conditioned space.

Worked example: 7 kW PV in Toronto, Ontario TOU + 10 kWh battery

• 7 kW × 3.8 PSH × 365 × 0.77 = 7,479 kWh/yr generated
• Annual usage 9,000 kWh, baseline overlap 30%
• Ontario TOU: 17c on-peak, 12.2c mid-peak, 10.2c off-peak. Blended retail used as input: 13c. Net-metering 1:1 retail credit.
• No battery: self = min(9000, 7479×0.30) = 2,244 kWh
  • Imports 6,756 × 13c = C$878 · Exports 5,235 × 13c = C$680 credit
  • Bill = max(0, C$878 − C$680) = C$198 · Savings C$972/yr
• With 10 kWh battery: capture = 2,854 kWh, self = 5,098 kWh
  • Imports 3,902 × 13c = C$507 · Exports 2,381 × 13c = C$310 credit
  • Bill = max(0, C$507 − C$310) = C$197 · Savings C$973/yr
• Battery uplift: C$1/yr — payback infinite

This is the structural Ontario problem: 1:1 retail crediting wipes out the bill case. The Ontario Energy Board’s annual netting under net metering 6.0 means even TOU households see no benefit from time-shifted consumption — they’re crediting the meter, not the meter at retail-time-of-export.

Worked example: 7 kW PV in Vancouver, BC Hydro REC + 10 kWh battery

• 7 kW × 3.2 PSH × 365 × 0.77 = 6,300 kWh/yr generated
• Annual usage 11,000 kWh, retail 14c (Step 2), REC export credit 9.99c
• No battery: self = 1,890 kWh; imports 9,110 × 14c = C$1,275; exports 4,410 × 10c = C$441
  • Bill = C$834; savings C$706/yr
• With 10 kWh battery: self = 4,744 kWh; imports 6,256 × 14c = C$876; exports 1,556 × 10c = C$156
  • Bill = C$720; savings C$820/yr
• Battery uplift: C$114/yr · Net cost C$11,500 − C$5,000 BC Hydro = C$6,500
• Simple payback 57 yr — well past warranty; battery economically irrational on bill arithmetic alone.

The BC Hydro spread (14c retail vs 10c credit) is wider than Ontario but still too narrow to deliver meaningful uplift. The case for batteries in BC rests almost entirely on outage resilience (Atlantic storms, summer wildfire grid de-energisation, ice-storm outages) rather than bill savings.

Worked example: 7 kW PV in Halifax, Nova Scotia + 10 kWh battery

• 7 kW × 3.7 PSH × 365 × 0.77 = 7,282 kWh/yr generated
• Annual usage 10,500 kWh, retail 18c, NS Power net-billing credit 8c (post-2023 reform)
• No battery: self = 2,185 kWh; imports 8,315 × 18c = C$1,497; exports 5,097 × 8c = C$408
  • Bill = C$1,089; savings C$801/yr
• With 10 kWh battery: self = 5,039 kWh; imports 5,461 × 18c = C$983; exports 2,243 × 8c = C$179
  • Bill = C$804; savings C$1,086/yr
• Battery uplift: C$285/yr · Net cost C$13,500 (no current NS rebate)
• Simple payback 47 yr — improved but still well outside warranty

Nova Scotia’s 2023 net-billing reform created the widest retail/credit spread in Canada, but the absolute uplift is still capped by the modest 7,282 kWh annual production at Halifax irradiance. The case has improved but doesn’t yet pencil without a return of the SolarHomes Battery Pilot.

Where Canadian battery ROI works

For 2026, only three corridors deliver inside-warranty payback:

1. BC Hydro REC participants stacking the C$5,000 rebate with a 10 kWh+ battery and self-installation of complementary load-shifting (heat-pump scheduling, EV midday charging).
2. Northern Ontario or rural Atlantic homes with unreliable grid power, where backup-power resilience value (avoided spoilage, avoided generator fuel, insurance premium reductions) is monetisable.
3. Off-grid cottages and remote properties where the battery is replacing diesel or propane backup. The off-grid solar system calculator handles this sizing more directly.

When to wait

The Canadian battery market is on the cusp of structural change. Three triggers will improve the maths:

1. Federal Section 25D analogue — the federal NDP-Liberal supply agreement repeatedly raised a Canadian residential clean energy credit; if enacted at 25–30% it would shave 2–4 years off every Canadian battery payback.
2. Ontario net-metering reform — IESO’s “Net Billing” consultation (concluded December 2025) may reduce Ontario’s 1:1 retail credit. If it does, the Ontario case flips overnight.
3. Hydro-Québec exports — Quebec is exploring battery aggregation programs to firm wind exports to the US Northeast. Residential VPP enrolment with revenue share would deliver direct uplift.

Until at least one of those lands, the right play for most Canadian households is PV without battery plus utility-rate optimisation. Model the no-battery case in our solar net metering savings calculator and the underlying generation in our solar panel output calculator.

Sources

• Natural Resources Canada, CanmetENERGY residential PV deployment data and irradiance atlas 1991–2020.
• Statistics Canada, “Households and the Environment: Energy Use” Table 25-10-0021-01 (2024 update).
• Hydro-Québec, BC Hydro, Hydro One, Manitoba Hydro, NS Power — published 2026 residential tariff schedules.
• Canadian Solar Industries Association, “Canadian Solar PV Market Outlook 2026.”
• HomeStars and Solar Industry Magazine 2026 installer quote aggregator data.
• BC Hydro, “Renewable Energy Customer Program Terms and Conditions” 2026 edition.

For deeper provincial comparisons, also see our cost of solar panels calculator.