Farm solar lives or dies on when you actually pump.
Farms are among the best and the worst commercial solar sites, and which one you are depends almost entirely on load shape. energy.gov.au describes farms as major energy users, with pumps, tractors, cool storage, harvesting and livestock facilities all drawing heavily — and notes that for cotton growers, electricity and diesel can account for up to 50% of total input costs. A dairy with twice-daily load is a very different proposition from an irrigator whose entire consumption falls in four months.
Reviewed by the Mission Green commercial team · Updated August 2026
Farms are major
energy users.
And the money is concentrated in a few specific things.
energy.gov.au puts it plainly: "Farms are major users of energy. Pumps, tractors, cool storage, harvesting, maintaining crops and livestock facilities all require large amounts of energy." It notes that while wages, exchange rates and commodity prices are set externally, direct action on energy is something a farmer can control.
The scale can be substantial. For cotton growers, energy.gov.au states electricity and diesel account for up to 50% of a grower's total input costs. When an input runs at that share, its shape matters as much as its size.
It identifies four levers: improving practices and systems, changing or modifying equipment, switching to alternative and less expensive energy sources, and purchasing energy more strategically. Solar sits inside the third, but the fourth is where a lot of avoidable cost hides — and it costs nothing to look at.
The question
nobody asks first.
Two farms, the same system, completely different outcomes.
Dairy, cool storage
Twice-daily milking or continuous refrigeration gives a load that recurs all year. This is the best match for solar and the easiest case to model honestly.
Irrigation pumping
A load concentrated into a few months. The system generates all year and displaces expensive consumption only in season, which lengthens payback and makes the annual average misleading.
Harvest and processing
Short, intense periods of very high load. These drive demand charges disproportionately, and a demand peak set at harvest can bill for the rest of the year.
An annual generation figure hides all of this. Two farms with identical arrays can have very different results purely because one consumes across twelve months and the other across four.
Ask for the model to be shown month by month against your own consumption, not as an annual total. If a proposal cannot do that, it has not engaged with the thing that actually determines whether farm solar works.
A harvest peak
can bill all year.
This is where seasonal operations get caught.
On tariffs with an annual demand component, the charge is set by the highest measured interval over the preceding twelve months. SA Power Networks' published structures charge demand on the "highest 30 minute demand interval during the last 12 months".
For a seasonal operation that is a specific hazard. Everything running at once during harvest, or several pumps starting together at the beginning of an irrigation season, can set a demand figure that is then billed every day for the following year — including the many months when the farm is drawing very little.
Staggering pump starts costs nothing and directly attacks this. It is routinely the highest-return intervention available on a farm, and nobody sells it because there is nothing to sell.
Farm-specific things
worth knowing.
The constraints that do not show up on suburban rooftops.
Shed roofs are not all equal. Orientation is often set by prevailing wind and vehicle access rather than by solar, and older machinery sheds may need structural assessment before carrying an array.
Three-phase and distance matter. Pumping loads are frequently three-phase and frequently a long way from the main switchboard. Cable runs and voltage drop are real costs on a farm in a way they are not in a suburb.
Ground mount is a genuine option. Unlike most commercial sites, farms often have space. Ground-mounted arrays can be oriented properly, sited near the load rather than near the house, and cleaned and maintained safely from the ground.
Certificate thresholds apply as they do anywhere. Small-scale eligibility requires 100 kW or less and under 250 MWh a year, and a well-oriented rural array is exactly the sort that can pass the capacity test and fail the output test.
So what should
your farm actually do?
Short version.
Get twelve months of interval data before anything else. The seasonal shape is the whole design question and there is no substitute for the actual record.
Fix your starts before you buy generation. Sequencing pumps and staggering start-ups attacks the demand charge directly, costs nothing, and does not depreciate.
Size to in-season consumption, and be honest about the off-season. A system that carries a farm through irrigation and exports for eight months is a different investment from one that runs a dairy year-round.
Consider ground mount where you have the room. Better orientation, easier maintenance, and no argument about shed structure.
Look at how you buy energy as well as how you make it. energy.gov.au lists purchasing energy more strategically alongside equipment changes for a reason — on a farm with a large seasonal load, the tariff you are on can be worth as much as the array.
Farm solar:
your questions, answered.
It depends far more on when you use power than on what the system costs. A dairy or a cool store with continuous load is an excellent match. An irrigation operation whose consumption falls into a few months generates all year and displaces expensive electricity only in season, which changes the payback substantially. Ask for the model month by month against your own consumption rather than as an annual total.
It varies by enterprise, and it can be very large. energy.gov.au states that for cotton growers electricity and diesel account for up to 50% of a grower's total input costs. It describes farms generally as major users of energy, with pumps, tractors, cool storage, harvesting and livestock facilities all drawing heavily.
Frequently because the bill contains a demand charge that solar does not address. On tariffs with an annual demand component the charge is set by the highest measured interval in the preceding twelve months, so a single harvest peak or a simultaneous pump start can set a daily charge billed for the following year regardless of how much solar you generate.
Ground mount is a genuine option on a farm in a way it is not on most commercial sites, because you usually have the space. It allows proper orientation, siting near the load rather than near the buildings, and safe maintenance from ground level. Shed roofs are often oriented for wind and vehicle access rather than for sun, and older sheds may need structural assessment first.
On a demand tariff, yes, and it is usually the highest-return change available because it costs nothing. If two or three motors start within the same half-hour interval, that combined draw can set your demand charge. Sequencing them spreads the load across intervals and lowers the measured peak permanently.
No. The same small-scale thresholds apply: 100 kW or less and under 250 MWh of annual output, with Clean Energy Council listed products meeting the relevant standards. A well-oriented rural array is exactly the kind that can satisfy the capacity test and still exceed the output test, so check both.
Where these figures come from.
Sector context from energy.gov.au. We do not publish farm system prices — the variable that decides an agricultural project is the shape of your year, not the cost per watt.