Solar Irrigation System Calculator
Size a solar irrigation system for Canadian horticulture and field crops using NRCan PSH data, AAFC crop coefficients and CSA pump standards.
Solar Irrigation System Calculator
How to use this calculator
Enter eight values and the calculator returns daily water demand, hydraulic energy, electrical energy, the recommended PV array in watts-peak, the number of panels, pump operating power, and average flow during sun hours.
- Field area (hectares) — area actually irrigated. For tree-fruit blocks, this is the canopy area; for vegetable beds, the bed area; for potatoes, the in-row area.
- Crop ETc (mm/day) — peak-season values: Okanagan apples 5.0, southern Alberta potatoes 6.0, Manitoba field corn 5.5, BC blueberries 4.5, Ontario greenhouse 5.0–6.0. AAFC research centres and provincial agriculture ministries publish ET₀ and Kc tables.
- Irrigation efficiency (%) — 90% drip, 85% microsprinkler, 80% centre pivot, 75% solid-set sprinkler, 65% travelling gun. CSBE and CSA standards align with ASABE.
- Total dynamic head (m) — pumping water level plus pipe friction plus emitter pressure (drip 10–14 m, sprinkler 28–55 m).
- Peak sun hours/day — NRCan PV Performance Tool gives location-specific data. Typical Canadian PSH: Penticton 4.4, Lethbridge 4.6, Saskatoon 4.5, Winnipeg 4.3, Toronto 3.9, Halifax 3.7, Whitehorse 3.2.
- Pump wire-to-water efficiency (%) — 45% for a Lorentz PS2 or Grundfos SQFlex submersible without manufacturer pump curve; 50% for properly matched helical-rotor.
- System derate (%) — controller, wiring, soiling. 85% is the recommended default.
- Panel wattage (W) — 400 W is the 2026 Canadian residential standard; 540 W bifacial dominates field-scale ground-mount installations.
How solar irrigation works in Canada
A Canadian solar irrigation system has the same components as elsewhere: PV array, MPPT pump controller, DC pump, and the irrigation network. CSA C22.1 (Canadian Electrical Code) covers the DC side, with Section 64 specifically addressing renewable energy systems. Pumps are installed to CSA B214 plumbing code with provincial water well construction standards applying to borehole installations.
Most Canadian systems buffer with a polyethylene tank (5,000–25,000 L) at elevated head, with the pump filling the tank during daylight and gravity feed handling emitter pressure during the irrigation set. This decouples pump operation from irrigation scheduling and lets the system serve overnight or early-morning sets when ET is lowest.
Surface water abstractions need a provincial water licence in BC (Water Sustainability Act), Alberta (Water Act), Saskatchewan (Water Security Agency), Manitoba (Water Rights Act) and Ontario (Permit to Take Water for > 50,000 L/day). Solar pumping does not change the licensing requirement but is favourably treated under most provincial irrigation efficiency programs because it reduces fossil energy consumption.
The physics, derived first principles
Daily water demand:
V_L_day = ETc_mm × Area_m² / efficiency_fraction
V_m3_day = V_L_day / 1000ETc in mm/day times area in m² gives litres per day directly (1 mm × 1 m² = 1 L).
Hydraulic energy:
E_hydraulic_Wh = 1000 × 9.81 × V_m3 × H_m / 3600 ≈ V_m3 × H_m × 2.725Electrical input through pump and system losses:
E_electrical_Wh = E_hydraulic_Wh / (η_pump × η_system)
PV_Wp = E_electrical_Wh / PSHWorked example — one hectare apple orchard, Okanagan
- Area = 10,000 m², ETc = 5.0 mm/day, drip efficiency 90%
- V = 5.0 × 10,000 / 0.90 = 55,556 L/day = 55.56 m³
- TDH = 35 m (22 m pumping level + 4 m filtration + 9 m emitter pressure)
- E_hyd = 55.56 × 35 × 2.725 = 5,298 Wh/day
- Pump η 45%, system η 85%: E_elec = 5,298 / (0.45 × 0.85) = 13,852 Wh/day
- PSH 4.4: PV = 13,852 / 4.4 = 3,149 Wp → eight 400 W panels (3,200 Wp, 2% headroom)
AAFC planning guidance recommends 25–40% PV oversizing on the worst-month calculation. The worked block sized to summer average needs an additional 25% to handle pre-dawn pumping demand and panel degradation over 25 years, taking the install to about 4,000 Wp (ten 400 W panels).
Canadian irrigation efficiency by method
| Method | Distribution efficiency | Pressure required |
|---|---|---|
| Subsurface drip | 88–95% | 10–14 m |
| Surface drip | 85–92% | 10–14 m |
| Microsprinkler | 80–88% | 14–21 m |
| Centre pivot | 80–90% | 30–55 m |
| Solid-set sprinkler | 75–85% | 28–55 m |
| Travelling gun | 65–75% | 45–70 m |
| Furrow | 50–70% | 5–15 m |
For solar pumping, drip is the right answer for most horticultural and high-value vegetable crops. Field corn, potatoes and forage in southern Alberta still operate centre pivots, where solar pumping competes against diesel or grid pumping at irrigation-tariff rates.
NRCan and AAFC field study results
NRCan’s CanmetENERGY and AAFC research centres have tracked roughly 200 solar pumping installations on irrigated horticultural and field-crop holdings across Canada from 2018 to 2024:
- Median installed cost: CA$8,500/ha for new-build drip; CA$5,500/ha for retrofitting solar to existing pump infrastructure.
- Median payback period vs. diesel: 5.2 years for tree fruit (high pump utilisation), 6.8 years for field crops.
- Ten-year retention: 89% of installations still in original operation.
- Most common failure mode: pump controller at 12–14 years, not pump or panels.
- Winter freezing of surface installations is the main maintenance issue in Saskatchewan, Manitoba and Ontario; submersible pumps avoid this entirely.
Canadian incentives and rebates
- Agricultural Clean Technology Program — federal program (AAFC) covering 50% of project cost up to CA$2M for clean-tech adoption including solar pumping.
- Canadian Agricultural Partnership — federal-provincial cost-share program with parallel solar pumping eligibility in each province.
- BC CleanBC Industrial Program — rebates for solar pumping in agricultural and First Nations community applications.
- Alberta Solar Programs — Alberta Agricultural Carbon Offset Program and Solar Rebate occasionally applied to qualifying solar pumping projects.
- Ontario Greenhouse Energy Profitability Program — has cost-shared solar pumping in protected cropping.
- Federal Capital Cost Allowance Class 43.1/43.2 — accelerated depreciation (50%/100%) for renewable energy equipment including solar pumping.
Common Canadian-specific mistakes
- Sizing to ET₀ instead of ETc. Forgetting the crop coefficient under-sizes by 15–25% for actively growing potato or corn crops in southern Alberta and Manitoba.
- Ignoring winter shutdown. Surface pumps and exposed mainlines must be drained before first freeze in all provinces except coastal BC. Submersible pumps stay in the well year-round.
- Using static water level. Bore draw-down in Prairie aquifers averages 5–15 m under typical irrigation pumping. Use the pumping water level from the well construction report.
- Designing to annual-average PSH. Annual-average PSH overstates April and September capacity by 30–40% for most Canadian sites. Match the design PSH to the irrigation season, which is essentially May–September for most crops.
- Forgetting filtration head. A media filter for solar drip adds 6–10 m of TDH; surface-water filtration for stream or pond sources adds another 4–8 m.
Sources
- NRCan PV Performance Tool / RETScreen — Canadian PSH and renewable energy planning
- Agriculture and Agri-Food Canada — ET₀ and Kc data from federal research centres
- Canadian Society for Bioengineering — irrigation standards — CSBE technical references
- BC Ministry of Agriculture irrigation guides — provincial crop coefficient tables
- FAO Irrigation and Drainage Paper 56 — reference ET methodology
- Lorentz PS2 sizing manual — solar pump curves and efficiency defaults
- CSA Group — CSA C22.1 Canadian Electrical Code — DC system electrical standards