Millions of American farms, ranches and homesteads sit next to water they rarely use: a farm pond, a creek along the back field, an irrigation ditch, a stock tank or a dugout. The problem is usually not the water. It is getting it uphill and across a field to the crops, often hundreds of feet from the nearest power pole.
A solar surface pump solves that. It sits on dry ground beside the water, pulls water up through a short suction hose, and pushes it out to drip lines, sprinklers, a greenhouse or a storage tank, powered by a few panels. There is no fuel to haul, no generator to start and no monthly power bill.
This post covers how solar surface pumps work, when to choose one over a submersible, where they work best on US farms and gardens, how to set one up, and the water rules to check before you start pumping.
How a solar surface pump system works
A solar surface pump system has only a few parts, and the pump itself never goes in the water:
Solar array → Pump controller → Surface pump (fed by a floating intake) → Filter → Drip lines or tank
Solar panels feed a controller that runs the pump at whatever speed the sunlight allows. The pump sits on the bank and draws water through a suction hose from a floating intake fitted with a strainer and foot valve. It then pushes the water through a filter to drip lines, sprinklers, a greenhouse or a storage tank. Surface pumps are strongest at pushing water: they can move it a long way and up a hill, as long as the suction side stays short.
Surface pump or submersible?
The deciding question is how far below the pump the water sits. A surface pump works by suction, and atmospheric pressure can only push water up so far. In practice, keep the pump within about 20 feet of the water surface, and closer is better, especially at higher elevations where thinner air reduces suction.
| Solar surface / transfer pump | Solar submersible pump | |
|---|---|---|
| Where it sits | On dry ground beside the water | Underwater, in a well, cistern or pond |
| Best water source | Ponds, creeks, ditches, dugouts, tanks, cisterns | Drilled wells and deep boreholes |
| Vertical lift from source | Limited by suction (keep within about 20 ft) | Hundreds of feet |
| Strength | High flow, pushing water long distances and uphill | Lifting water from depth |
| Service access | Easy; everything is above ground | Pump must be pulled from the well |
| Main setup task | Priming and keeping the suction line airtight | Lowering the pump and wiring down the well |
If your water is in a drilled well, choose a submersible. If it is in a pond, stream, ditch or tank you can stand beside, a surface pump is usually simpler, cheaper and easier to service. Some farms use both: a submersible fills a tank, and a surface pump boosts water from the tank out to the field.
Where solar surface pumps pay off
Vegetable farms and high tunnels
A farm pond paired with a solar pump and a raised cistern can supply drip irrigation for vegetables and high tunnels. In one USDA SARE-funded project in the North Central region, a grower trenched a line 110 feet up a hillside from the pond to a cistern; after installation, all of the farm's irrigation came from the pond, with only a small booster pump still on grid power (SARE project FNC05-557).
Orchards and field crops
In Wisconsin, The Little Farmer orchard planned a large pond with solar-powered pumps and aerators to protect its apples and pumpkins from drought, with USDA and state grant support (UW Extension). At larger scale, a Kansas farm is using a 22-acre pond and a pump mounted on a pontoon to feed solar-powered subsurface drip irrigation for corn (Farm Talk).
Pastures and livestock
A Tennessee rancher used a solar submersible to lift spring water into a 1,000-gallon tank, then a solar surface pump to pressurize a pipeline feeding 21 quick-connect water points for rotational grazing. NRCS reimbursed 75% of the cost.
Market gardens, homesteads and greenhouses
Small growers with a creek, pond or rain cistern can run drip tape, soaker hoses or micro-sprinklers straight from a small solar transfer pump. Brushless DC pumps are quiet enough to run next to a greenhouse or house.
Why solar: extension specialists note that remote pumping is worth considering once the grid is more than about half a mile away, since line extensions can cost $10,000 to $50,000 or more per mile (NCAT ATTRA).
Setting one up: practical tips
- Measure your total head. Add the suction lift (pump above the water surface), the rise from the pump to the highest point of delivery, and friction loss in the pipe. Drip systems also need about 10 to 30 psi at the emitters, and every 1 psi equals about 2.3 feet of head.
- Keep the suction side short and tight. Mount the pump as close to the water and as low as practical. Use rigid or reinforced suction hose at least as wide as the pump inlet, and seal every joint, since one small air leak can stop a surface pump from priming.
- Fit a foot valve and strainer. A check (foot) valve at the end of the intake keeps the line full of water between pumping cycles, and a strainer keeps out leaves, snails and fish.
- Float the intake. In a pond or creek, hang the intake from a float about 1 to 2 feet below the surface. That avoids sucking up bottom silt and draws the cleanest, warmest water.
- Filter before drip. Surface water carries algae and sediment. A screen or disc filter ahead of the drip lines prevents clogged emitters.
- Use a tank for flexibility. Pumping into a raised tank lets you irrigate on your own schedule, by gravity or with a small booster, and smooths out cloudy spells.
- Automate with a float switch. Most solar pump controllers accept a float switch, so the pump stops when the tank is full and restarts when the level drops.
- Protect it for winter. In freezing climates, drain the pump, suction line and above-ground pipe before the first hard freeze, or pull the pump indoors. The panels need no winterizing.
Check the water rules before you pump
Having water on or next to your land does not always mean you can pump it. US water law varies a lot by state.
- Western states generally follow prior appropriation ("first in time, first in right"). Pumping from a creek or river for irrigation usually needs a water right or permit from the state water agency, and junior users can be cut off in dry years.
- Eastern states mostly follow riparian rights, which let landowners next to a stream make reasonable use of it, though many states now require registration or permits above certain withdrawal volumes.
- Ponds fed only by rain on your own land are usually the simplest case, but a pond on a stream, or one fed by a spring, may fall under the same rules as the stream.
- Fish screens are required on many stream intakes, especially in the Pacific Northwest and California where salmon and steelhead are present. Idaho law, for example, bars taking water from a stream without a suitable screen to keep fish out (Idaho Department of Water Resources), and Washington irrigators have been barred from pumping until their intake extensions had approved screens (Northwest News Network).
Before you buy, call your state water resources agency and your local NRCS or conservation district office. NRCS can also help with cost-share for qualifying irrigation and pumping projects.
Recommended RockSolar solar transfer pump kits
Each kit below pairs a DC brushless surface transfer pump and controller with 445 W bifacial solar panels. They run automatically from sunrise to sunset, accept a float or pressure switch for tank filling, and include dry-run protection. Maximum flow and maximum head are separate ratings: a pump delivers its top flow at low head and less as the head rises.
| Kit | Max flow | Max head | Solar panels | From | Best for |
|---|---|---|---|---|---|
| 0.4 HP 20–40 V Transfer Pump Kit | 8.8 GPM | 98 ft | 1 × 445 W | $649.99 | Gardens, small ponds, filling a cistern |
| 1.07 HP 40–90 V Transfer Pump Kit | 9.6 GPM | 203 ft | 2 × 445 W | $1,299.99 | Pushing water uphill or far to a tank, greenhouses |
| 1.07 HP 65–110 V Transfer Pump Kit | 24.2 GPM | 98 ft | 3 × 445 W | $1,459.99 | Drip or sprinkler zones on market gardens and orchards |
| 3.75 HP 60–450 V Transfer Pump Kit | 268 GPM | 82 ft | 10 × 445 W | $3,499.99 | Field crops, large ponds and high-volume transfer |
For grazing operations, the Solar Transfer Pump System for Cattle Ranchers adds a 24 V 100 Ah LiFePO4 battery and float switch for day-and-night pumping, and can move water up to 5,000 feet, delivering about 6,000 to 10,000 gallons a day depending on sun and head.
Prices were current at the time of writing; check the product pages for current pricing and availability.
The bottom line
If you have a pond, creek, ditch or dugout within reach, a solar surface pump is one of the simplest ways to put it to work. It sits on dry ground, is easy to service, moves high volumes over long distances, and runs on sunshine with no fuel or power bill. Keep the suction side short and airtight, filter before drip, store water in a tank for flexibility, and confirm your water rights before you start.
Ready to size a system? Note how far the pump will sit above the water, how far and how high the water must travel, and how many gallons a day you need, then talk to a solar pumping specialist about the right kit.
Sources
- Sustainable Solar Irrigation System, SARE project FNC05-557
- The Little Farmer Invests Big in Solar, UW Extension
- Sunshine Systems: Kansas solar pond irrigation, Farm Talk
- Solar-Powered Livestock Watering Systems, NCAT ATTRA
- Solar Water Pumping, University of Nebraska CropWatch
- Fish screen requirement order, Idaho Department of Water Resources
- Irrigators struggle to secure fish screens, Northwest News Network