A Gippsland dairy irrigated 22 hectares on about 95% solar — using a dam instead of a big battery
Wilandra Farms in West Gippsland automated a block of fixed sprays against a modest solar array. The storage is water. The battery, where it exists on the wider farm, is not the hero of this story.
September 2026 · Clydebank / Airly, Vic22 ha, about 50 kW, almost no labour
Agriculture Victoria’s Energy Smart Farming note, published 14 February 2025, describes how Wilandra Farms — Clydebank / Airly area, West Gippsland — automated 22 ha of fixed-spray irrigation against a 50 kW solar array. The farm reports roughly 95% solar-powered irrigation for that area, lower bills, less grid draw, and zero labour to run the sprays once the automation is on.
The demo sat under Victoria’s Sustainable Irrigation Program with the West Gippsland Catchment Management Authority. Sandra Jefford’s line in the write-up is the useful one: the system has a “brain” matching irrigation to the energy that is actually there.
This piece is about that irrigated block. The farm’s wider energy work is larger — more solar, some batteries, wind, dairy hot-water shifted into daylight. Those are cousins. They are not this 22 hectare story.
The dam is the tank
Dam-as-battery means storing water uphill or in a tank or dam so you use solar when it shines, then irrigate later by gravity or a smaller pump. Wilandra’s version uses a storage dam with a level sensor. Water in the dam is the stored energy. You are not buying a shipping-container of cells to hold a week of pumping.
Pump while the sun is up
Bore or river into the dam on the solar hours. The level sensor decides when the dam is short.
A pump that can loaf
A variable-speed drive on the bore pump — about a 5–40 kW range — so weak morning sun still moves water.
Smaller sets
Fixed spray / pipe-and-riser sets in 4 / 8 / 12 groups, so the load fits the solar that is actually on the roof.
Pumps that loaf, sprays that fit
A variable-speed drive (sometimes VSD) is electronics that let a pump run slow or fast to match available solar instead of only full-blast. A stiff pump that only knows “on” waits for a fat slice of sun. A loafing pump starts early, sipping the east-facing hours.
Spray irrigators on a grid
Fixed spray / pipe and riser are irrigation methods — think spray irrigators or flood bays that sit in place, rather than a centre pivot rolling around the paddock. Smaller groups mean you can turn on a bite the array can feed.
Move the job to daylight
The farm’s wider energy page says the same thing in farm English: pump to the dam when the power is there, rather than pumping straight from a bore to a pivot the moment you want water. Storing water does the firming — making the solar usable later — so a big electrical battery stays optional.
95% for that block. Not whole-farm forever.
Treat the published result as about 95% solar for that irrigated block in the demo framing. It is not whole-farm zero-grid forever. Cloudy stretches still draw the grid, or a backup, the way any honest daytime-solar design does.
Mid-winter short days versus a summer irrigation peak is the real sizing argument. Size solar to the pump curve. Size the dam to the cloudy days you refuse to buy a battery for.
Duty cycle first, then hardware
Pumps and irrigators are the best off-grid (or near-off-grid) loads if you stop thinking “24/7 power” and start thinking “fill the dam while the sun’s up.” A house fridge does not get that choice. A spray set does.
On a mid-winter Gippsland day the array is thinner and the irrigation season is often quieter. On a summer peak you have more sun and more water to move. The design that wins is the one that lets the pump loaf in the morning, bite at noon, and rest when the dam is full — not the one that buys a battery large enough to pretend weather does not exist.
A Queensland cousin of the same idea sits on Ergon’s Solar Pump Program: a cashback when a daytime-only pump can abolish a fringe-of-grid connection. Different state, same physics. If the load can live in the sun, the wire is optional.
- Match the pump to the array, not the other way around.
- Break the irrigator into sets the solar can feed.
- Store water for the hours the array cannot cover.
- Keep the grid or a genset for the stretch you refuse to oversize.
Lots of solar, little battery
Mike’s third theme in this set of notes is daytime solar water pumping with minimal batteries. Wilandra is the clean public example. The 50 kW array on 22 ha is not a mine. It is a farm job with numbers you can read across to a bore, a tank, or a hillside dam.
Daylight first
If the job can wait for the sun, do not buy night-shaped hardware for a day-shaped task.
Water, not electrons
A dam, a tank, a header, a hill. Cheaper than a lithium stack for the same hours of pumping.
Grid or genset
Name the cloudy week. Write it on the drawing. Then stop arguing with the weather.
What we leaned on
Public figures in this piece come from the Agriculture Victoria / Energy Smart Farming write-up and the West Gippsland CMA technical report. The farm’s own energy page covers the wider plant; we kept the 22 ha / 50 kW demo in its own box.
- Agriculture Victoria / Energy Smart Farming, 14 February 2025 — automating fixed sprays
- West Gippsland CMA — Solar Fixed Sprays demo site technical report
- Wilandra Farms energy page (wider farm context)
- Ergon Solar Pump Program (Queensland cousin, daytime-only pumping)
A mine battery, a town battery, a dam
Bellevue Gold shows what long engines-off stretches look like when wind and solar keep topping a battery. Marlinja shows the community-scale version with the grid as the last resort. More notes live on Learn.
Size the pump to the sun, the dam to the cloud
We design plants for people who care what the load actually does in June and in January — homes, farms, and commercial loads. If you want a system sized that way, talk to The Off Grid Shop.
Prefer to talk it through? Call or text 0483 927 257 — Lismore HQ, local voices.