Solar well pump: best kits, how to size them, and honest limits

By Alejandro · Updated October 29, 2026 · How we pick

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Short answer

A solar well pump runs a DC submersible pump directly from panels during the day and fills a storage tank, which supplies water at night and on cloudy days. For livestock tanks and cabins with water within about 150 feet, the RPS 200 kit is a complete, fairly priced starting point. For an off-grid home that wants AC or generator backup, the Grundfos SQFlex is the most flexible pump. Expect a few thousand gallons a day at best, not the flow of a grid-powered pump.

We compare solar pumps from maker and retailer specs; we haven't installed these in our own wells. How we pick.

Our picks

Best complete kit for livestock and cabins
RPS 200 Solar Well Pump Kit

A complete kit: pump, controller, panels and float sensors in one box, sized for filling a stock tank or cistern during the day. Skip it if your pumping level is deeper than about 150 feet or you want pressurized house water straight from the pump; it's built to fill a storage tank.
- Up to 5.1 GPM (no head); 3.1 GPM at 100 ft
- About 1,800 gal/day on a 6-hour sun day
- Two 100 W panels, 12V DC
- Helical rotor pump, brushless motor
- Low-water and tank-full sensors included
- 2-year warranty; lifetime rotor warranty
About $1,940kit with two panels, sale price at last check · checked October 2026 Check price at RPS Solar Pumps
Best for off-grid homes (solar plus AC backup)
Grundfos SQFlex Solar Submersible Pump (e.g. 5 SQF-80)

The best-known solar submersible. It accepts solar DC or a generator or grid AC, so you can back it up on cloudy weeks with an optional switch box. Skip it if you want one boxed kit with one price: panels, controller and mounts are bought separately, and totals add up fast.
- 5 SQF-80: 2–9 GPM, 15–130 ft of head
- Runs on 30–300 VDC or 90–240 VAC
- 75–300 W of panels for this model
- Dry-run, overload and overheat protection
- Deeper models to about 395 ft (11 SQF-2)
- 2-year warranty, 5-year extension offered
About $2,0955 SQF-80 pump only, retailer price · checked October 2026 Check price at The Solar Store
Best kit for deeper wells (to about 250 ft)
RPS 600 Solar Well Pump Kit

The same kit idea with three times the panel power, so it can push water from a deeper pumping level. Skip it if your well is shallow: the RPS 200 does the job for less, and six panels need room and a solid mount.
- 6.5 GPM (no head); 3.5 GPM at 250 ft
- About 1,260–2,340 gal/day on a 6-hour sun day
- Six 100 W panels
- Helical rotor pump, brushless motor
- Low-water and tank-full sensors included
- 2-year warranty; 30-day money-back
About $2,680kit with six panels, sale price at last check · checked October 2026 Check price at RPS Solar Pumps
Best low-flow pump for deep water
Shurflo 9300 Solar Water Pumping Kit

A small diaphragm pump that lifts a little water from a long way down. Run it all day into a tank and it adds up. Skip it if you need volume: at about 1.4 GPM from depth, it won't keep up with garden irrigation or a big herd.
- Up to 230 ft of head
- 1.36 GPM at maximum head
- 12–24 VDC
- Two 80 W panels, controller, top-of-pole mount
- Battery-ready with the LCB-G controller upgrade
About $1,780kit price at last check · checked October 2026 Check price at The Solar Store
Cheapest way to try it (light duty)
ECO-WORTHY 100W Solar Panel + 12V Submersible Pump Kit

A low-cost kit for light, seasonal jobs. Skip it if this is your household's water supply or a herd depends on it: flow is small, the maker's lift figure is the point where flow nearly stops, and long-term durability evidence is thin.
- 12V DC submersible pump
- Max lift 230 ft (70 m)
- Max flow 96 gal/hour (about 1.6 GPM)
- 100 W mono panel + 20A controller
- 1/2" barbed outlet
See today's priceAmazon prices change often Check price at Amazon

Quick comparison

Pump	Panels	Flow vs head (maker figures)	Price at last check
RPS 200 kit	2 x 100 W (included)	5.1 GPM at 0 ft; 3.1 GPM at 100 ft	About $1,940 kit
Grundfos SQFlex 5 SQF-80	75–300 W (not included)	2–9 GPM; 15–130 ft	About $2,095 pump only
RPS 600 kit	6 x 100 W (included)	6.5 GPM at 0 ft; 3.5 GPM at 250 ft	About $2,680 kit
Shurflo 9300 kit	2 x 80 W (included)	1.36 GPM at 230 ft	About $1,780 kit
ECO-WORTHY 100W kit	1 x 100 W (included)	Up to 1.6 GPM; lift to 230 ft	See Amazon

Prices change often, and RPS prices were sale prices. Flow figures are the makers' and assume full sun.

Who a solar well pump is for

Livestock watering in pastures far from power lines. This is the classic use: the pump fills a stock tank while the sun is up.
Off-grid homes and cabins that pump into a cistern or elevated tank, then use a small booster pump or gravity for pressure.
Backup water for a grid-powered home during outages, often as a second pump in the same well or a separate well.
Gardens and small irrigation where daytime-only pumping is fine.

It's a poor fit if you want a solar pump to replace a grid-powered 10 GPM pump and pressure tank in a typical house. Solar pumps move less water, only while the sun shines, and most aren't built to feed a pressure switch directly.

How solar well pumps work

Panels feed a controller, which feeds a DC (or wide-input) submersible pump. Good controllers use maximum power point tracking (MPPT) to get the most from changing sunlight, start the pump gently, and shut it off when a float switch says the tank is full or a sensor says the well is low. Flow rises and falls with the sun, so a cloud cuts flow and evening stops it.

That's why the storage tank is part of the system, not an extra. You size the tank to carry you through nights and cloudy days, and size the pump and panels to refill it on an average day.

How to size a solar well pump

1. Daily water need

Start with gallons per day, not GPM. Count people, animals and garden use, then add a margin for hot weeks. Your local extension office can give livestock water needs for your climate and herd.

2. Total dynamic head

Add the pumping level in the well (static level plus drawdown), the rise from the wellhead to the top of the storage tank, and pipe friction. If you pump into a pressure system, add 2.31 feet of head for every psi. A 40 psi tank adds about 92 feet. Pumping into an unpressurized tank keeps head, and cost, down.

3. Sun hours

RPS quotes its daily output on a 6-hour solar pumping day. Winter days in northern states give less. Size for your worst month of real use: summer for irrigation, possibly winter for livestock.

4. Read the maker's chart

Each maker publishes flow at each head for a given panel wattage. Find your total head, read the GPM, then multiply by your sun hours and by 60. The RPS figures show the pattern: 200 W gives about 3.1 GPM at 100 ft, while 600 W gives about 3.5 GPM at 250 ft. More depth costs panels.

Example (RPS figures)	Head	GPM	Gallons on a 6-hour day
RPS 200 (200 W)	100 ft	3.1	About 1,100
RPS 200 (200 W)	Near 0 ft	5.1	About 1,800
RPS 600 (600 W)	250 ft	3.5	About 1,260
RPS 600 (600 W)	Near 0 ft	6.5	About 2,340

Gallon figures are GPM x 60 x 6 hours, matching RPS's stated ranges. Real days with morning and evening ramp-up deliver less than peak flow all day.

5. Storage

Plan on a storage tank holding at least a few days of use, so a cloudy stretch doesn't leave you dry. Batteries are an option on some systems (the Shurflo kit offers a battery-ready controller), but they add cost and upkeep. A tank of water is usually cheaper storage than a battery bank.

6. Well yield and pump fit

Low-yield wells pair well with solar: slow, all-day pumping gives the well time to recover. Check that the pump fits your well casing and that it has dry-run protection or a low-water sensor. The SQFlex and RPS kits include one.

Honest limits

Daylight only. No sun, little or no water, unless you add batteries or an AC backup like the SQFlex supports.
Low flow. Even good kits deliver a few GPM. Plan around a tank, not on-demand pressure.
Depth costs money. Doubling head means much more panel power for the same flow.
Panel siting. Panels need full sun and a sturdy mount. Shade from one tree branch cuts output.
Budget kits are a gamble. Inexpensive kits work for light, seasonal use. Long-term durability evidence is thin, and maker lift ratings are where flow nearly stops.

Water quality still matters

A solar pump changes how water gets out of the ground, not what's in it. Off-grid wells need the same yearly checks as any private well. Test for bacteria and nitrate every year; a certified lab kit covers both. Cisterns and storage tanks can grow bacteria if they're open to dust, insects or animals, so cover them and test the water at the tap, not only at the well. If a pasture well sits near manure, nitrate is the one to watch. Sand or grit in the tank is a sign to read our sediment guide before it wears the pump.

Mistakes to avoid

Sizing by GPM instead of gallons per day. A solar pump that runs six hours a day needs a different calculation than a grid pump.
Using well depth instead of pumping level plus rise. Head decides flow.
Skipping the float switch. Without one, the pump runs all day and overflows the tank.
Pumping into a pressure tank without planning for it. Pressure adds head and most solar kits are built to fill a tank, not run a pressure switch.
Ignoring winter. Short days and frozen lines can stop a system built only for summer.

Questions well owners ask

Can a solar pump run a whole house?

It can supply an off-grid house if it fills a storage tank and a small booster pump or gravity provides pressure. Running a typical house directly, like a grid pump with a pressure tank, is a poor fit for most solar kits.

How deep can a solar well pump go?

It depends on the model and panel power. The RPS 600 kit is rated 3.5 GPM at 250 ft, the Shurflo 9300 kit about 1.4 GPM at 230 ft, and some Grundfos SQFlex models reach about 395 ft. Deeper water means less flow for the same panels.

How many solar panels do I need for a well pump?

It depends on head and gallons per day. As examples, the RPS 200 kit uses two 100 W panels for water within about 150 ft, and the RPS 600 uses six for deeper wells. The maker's chart for your head is the real answer.

Do solar well pumps work on cloudy days?

At reduced flow, and not at all at night. That's why a storage tank sized for several days of use is part of the system. Some pumps, like the SQFlex, can switch to a generator or AC power.

Do solar well pumps need batteries?

Most don't. They pump directly from panels into a storage tank, which is usually cheaper storage than batteries. Some controllers support batteries if you need water at night.

How much does a solar well pump cost?

Complete kits in this guide run about $1,800 to $2,700. A Grundfos SQFlex pump alone is about $2,095 before panels and controls. RPS says its larger kits run $3,000 to $11,000.