Off-grid, RV & cabin
Enter your herd size, daily water need per head, and well depth. Get the solar panel wattage needed to pump enough water for your animals.
How it works
Step 1
Different livestock types have very different daily water requirements per head.
Step 2
How deep the well runs and how far water has to climb to reach the trough both add directly to the pump's real energy cost.
Step 3
Herd size and pumping depth combine into a single wattage figure, sized for daily watering, not a rough guess.
For 30 head of cattle at 15 gallons a day each, pumped from 150 feet of well depth plus 20 feet of additional lift to a storage tank, roughly 120 watts of solar covers the daily pumping energy at 6 peak sun hours. This is a comparatively modest panel size, since most of a pump's energy demand comes from the small daily volume needed relative to a household's continuous power draw. Pair this with the annual maintenance cost estimator to see the full picture before you commit.
Cattle typically need around 10 to 20 gallons a day depending on size and weather, sheep and goats need roughly 1 to 3 gallons, and horses commonly need 8 to 12 gallons. Hot weather and lactating animals push these figures toward the higher end of each range, so plan for summer peak demand rather than a mild-weather average if your climate sees meaningful seasonal swings. The EPA's guide to protecting a private well publishes the current rules, so confirm the details there before you file anything.
Total head, the well depth plus any additional lift to a storage tank, directly multiplies the energy needed to move each gallon of water. Pumping the same volume of water from twice the depth roughly doubles the energy required, making head depth one of the biggest factors in system size, often larger in effect than herd size itself for deep wells. The real comparison is against a grid connection. The levelized cost of energy calculator in our Savings & Payback section can help you weigh the system cost against what the grid would charge.
A storage tank lets the pump run only during peak sun hours while gravity-feeding water to the trough throughout the day and night, avoiding the need to size the pump and panel for constant demand regardless of sunlight. Without storage, a system would need battery backup or a much larger panel to guarantee water availability around the clock, which is rarely the most practical or cost-effective approach for livestock watering. USDA NRCS's conservation practice guidance covers watering system design in more depth if you're planning infrastructure beyond just the pump. Panels are only half an off-grid system. The battery storage size calculator in our Battery & Storage section sizes the battery bank your daily load needs to get through cloudy stretches.
If you're also irrigating pasture or crops from the same or a nearby well, check the solar for irrigation pump calculator for that separate load, and compare against remote property off-grid cost if you're weighing a full off-grid buildout for the property. For the electrical side of running a pump motor, the inverter sizing for well pump startup in our inverters and equipment tools covers the surge current a pump draws when it kicks on, and the annual maintenance cost estimator in our maintenance and lifespan tools helps budget for keeping the well itself in good condition, something EPA's guide to protecting a private well also covers well.
Questions
For 30 head of cattle at 15 gallons a day each, pumped from 150 feet of well depth plus 20 feet of additional lift to a storage tank, roughly 120 watts of solar covers the daily pumping energy at 6 peak sun hours.
Cattle typically need around 10 to 20 gallons a day depending on size and weather, sheep and goats need roughly 1 to 3 gallons, and horses commonly need 8 to 12 gallons. Hot weather and lactating animals push these figures toward the higher end of each range.
Total head, the well depth plus any additional lift to a storage tank, directly multiplies the energy needed to move each gallon. Pumping the same volume of water from twice the depth roughly doubles the energy required, making head depth one of the biggest factors in system size.
Yes, in almost every case. A storage tank lets the pump run only during peak sun hours while gravity-feeding water to the trough throughout the day, avoiding the need to size the pump and panel for constant demand regardless of sunlight.
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