Agriculture: seasonal loads, year-round charges

The load profile

Agricultural electrical demand is defined by two things: very large individual motor and heating loads, and a season that concentrates them into a short window.

Irrigation is the dominant case in much of the country. A center pivot or deep well pump motor is measured in tens or hundreds of horsepower, and one 100 hp pump is roughly 75 kW of connected load. Farms commonly run several. When multiple pumps start within the same interval, the peak is enormous, and it is set by an event that lasts minutes.

Grain drying is seasonal and brutal. Electric drying systems and the fans that serve them run continuously during harvest, at full output, for weeks. The rest of the year they are dark.

Livestock operations have a different shape. Ventilation fans in poultry and swine barns are weather-driven and scale up together in hot weather. Dairy operations run milk cooling compressors, vacuum pumps and water heating on a milking schedule that repeats two or three times daily.

Controlled environment agriculture, including greenhouses and indoor cultivation, is its own category: lighting on timed cycles, HVAC and dehumidification sized aggressively, and a load profile where the lighting schedule creates a step change several times a day.

Load factors vary widely. Seasonal operations often come in under 25 percent, which is excellent. Indoor cultivation runs higher because the lights are on a fixed schedule, but the step changes are large and controllable.

Why it is a good candidate

The seasonality is the whole argument, and it works against the farmer in a specific way that demand control addresses directly.

Many agricultural tariffs carry a ratchet clause: the utility bills the greater of this month's peak or a percentage of the highest peak set in the previous eleven months. A single interval during harvest or during the hottest week of irrigation season can set a floor that gets billed through winter, when the farm is using almost nothing. The farm pays for capacity it has not touched in six months.

That makes each individual peak event disproportionately expensive, and it makes preventing peaks disproportionately valuable. Some tariffs also include a provision allowing a ratchet to be reset when the customer demonstrates that demand-reduction equipment has been installed. That clause is worth reading for specifically. It is not universal, but where it exists it changes the economics substantially.

The loads themselves are also well suited. Pumps can be started in sequence rather than simultaneously with no change in the volume of water delivered over a day. Grain drying can be staged. Ventilation banks can be rotated. Dairy water heating and milk cooling both have thermal storage.

Which loads get controlled

Irrigation pump motors, primarily through start sequencing. The point is not to run pumps less, it is to keep two large motors from starting inside the same demand interval.

Grain drying elements and fans, broken into blocks rather than controlled as one large load, so the dryer runs at partial output continuously instead of cycling between full and off.

Ventilation fan banks, rotated so total airflow stays adequate while total draw stays flat.

Electric water heating for dairy sanitation and general farm use.

Milk cooling compressors, with careful attention to product temperature limits.

In greenhouse and indoor operations, HVAC, dehumidification and supplemental heating, plus lighting circuits where the operator's protocol allows staged startup.

What does not get controlled: anything tied to animal welfare or product safety without explicit limits. Ventilation in a poultry barn in July has a hard floor below which you do not go, and that floor is set with the operator and documented before installation.

What the buying process looks like

Interval data covering a full 12 months is essential here, more than in any other vertical, because a summer-only sample misses the harvest peak and a winter sample misses irrigation entirely.

Tariff analysis with the ratchet clause as the first thing we look for. If there is a ratchet, we model its effect over a full year rather than a single month, because the annual number is very different from the monthly one. We also check for any provision covering ratchet reset with installed demand-reduction equipment.

Site inspection covering pump locations and distances, service configuration, panel locations, and whether the loads are close enough together for practical control. Farms are physically spread out, and control has to reach equipment that may be a long way from the main service. Power line carrier has a working range of roughly 2,000 wire feet, which covers many sites and not all of them.

Then an equipment list and a quote built for that specific operation.

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