Solar Center Pivot Irrigation
Image source: Alberta Farmer Express
In Alberta, drought is becoming more and more common while electricity prices are only getting higher. This means special attention is needed regarding the efficiency of irrigation systems. There are a few government programs that can help with irrigation efficiency in Alberta including the Canadian Agricultural Partnership grant for Irrigation Efficiency (CAP-IE), the Farm Energy and Agri-Processing Program (FEAP) and Alberta’s On-Farm Solar Management Program from the Growing Forward 2 initiative.   There are a couple of government grants to utilize when upgrading or building new center pivot irrigation systems. CAP-IE provides one payment for each parcel of land (multiple parcels are possible) which can apply as:  
  • $15,000 of the eligible costs for an upgrade on the parcel from a gravity, side-wheel or high-pressure center pivot irrigation system to a new low-pressure center pivot (LPCP) system or a subsurface drip irrigation system.
  • 40% of the project cost up to $5000 for
    • equipment upgrades on the parcel; or
    • an upgrade on the parcel from an existing irrigation system to a surface drip irrigation system;
  Eligible equipment includes:  
  • new low-pressure centre pivot to replace a gravity, side-wheel or high-pressure centre pivot,
  • retrofit of a high-pressure centre pivot to a low-pressure centre pivot, including booster pumps, nozzle packages and pump modifications,
  • high-efficiency sprinkler nozzles and related equipment to upgrade an existing low-pressure centre pivot,
  • variable-rate irrigation equipment (controllers and software),
  • control panel upgrades, including base stations for telemetry,
  • surface or subsurface drip irrigation to replace gravity, side-wheel or high pressure centre pivot.
  FEAP meanwhile can provide 50% for retrofits of new fixed speed pumps with smaller HP motors or 50% for retrofits or new construction of variable speed drives (VFDs) for center pivot irrigation systems.   In addition to the energy-efficiency benefits, Alberta pivots can benefit from installing solar panels. Because of the way electrical rates are structured in Alberta, you almost always get less money for your solar energy if you sell it back to the grid, so it’s best to find applications where the electricity can be used directly. Center pivot irrigation combines extremely well with solar PV because the generation/usage patterns are practically identical. In Alberta, the two main irrigation wire service providers are Fortis and Atco. The irrigation rate structure for Atco has high distribution charges (58 ¢/kW/day) and low energy charges (1.1 ¢/kWh), while Fortis has low distribution charges (19 ¢/kW/day) and high energy charges (8.2 ¢/kWh).   In ATCO territory, almost your entire bill is determined by your capacity, thus installing a solar array with a control system to only irrigate when generating solar can greatly reduce your energy bill. The most critical time to line up is when your motors are starting up as this is when they consume the most electricity, so this is when they’ll set your peak.   With FORTIS, the better you line up your daily power consumption profile to the solar generation, the better rate you will get for your solar power. If you sell power to the grid, you will only get the rate that you buy your electricity at from your energy retailer (usually 6-7¢/kWh), but if you use the solar energy directly, you will be saving at a combined rate of around 14 ¢/kWh in the Fortis territory! At that rate, payback for a 150kW solar array can be in the neighbourhood of 6 years!   Check out our webpage on Alberta’s On Farm Solar Management Program from the Growing Forward 2 initiative for more information on the government grants that apply to solar irrigation systems.   Garnet Borch, E.I.T