Short answerOne acre at one inch of water a week needs about 3,880 gallons a day, roughly 11 gpm over 6 sun hours: beyond small DC pumps, but well within an AC pump on a solar pump inverter. A quarter acre at 1.5 inches a week needs about 1,450 gallons a day and about 120 W of panels at 40 ft of head.
Affiliate links on this page. We may earn a commission if you buy through them, at no extra cost to you. That doesn't change what we recommend. How we make money.
Key takeaways
- One acre at an inch a week is about 3,880 gallons a day.
- Small DC pumps suit gardens and fractions of an acre.
- An acre and up usually means an AC pump on a solar pump inverter.
By area
| Area | Sq ft | Gal/day at 1 in/week | Gal/day at 1.5 in/week | gpm over 6 sun hours (1.5 in) | Panel W at 40 ft TDH | Panel W at 80 ft TDH |
|---|---|---|---|---|---|---|
| 1/4 acre | 10,890 | 970 | 1,455 | 4.0 | 120 | 240 |
| 1/2 acre | 21,780 | 1,940 | 2,909 | 8.1 | 240 | 470 |
| 1 acre | 43,560 | 3,879 | 5,819 | 16.2 | 470 | 930 |
| 2 acres | 87,120 | 7,759 | 11,638 | 32.3 | 930 | 1,860 |
| 5 acres | 217,800 | 19,397 | 29,095 | 80.8 | 2,320 | 4,640 |
What the numbers mean
An inch of water over an acre is about 27,150 gallons. Crops in peak summer often need 1 to 2 inches a week from rain and irrigation combined; your county extension office can give a local figure for your crop and soil. Drip delivers water to the root zone with little evaporation, so a drip system usually needs less than these area figures, while sprinklers need more.
Flow is the daily gallons spread over 6 summer sun hours. Pumping into a tank and irrigating from it lets the pump run all day at its own pace and the drip run at the pressure it wants. See drip irrigation off a solar pump.
Choosing the system by size
| Area | Usual design |
|---|---|
| Up to about 1/4 acre | One small DC pump to a raised tank, gravity drip |
| 1/4 to 1 acre | Larger DC pump or two pumps, a big tank, zones watered in turn |
| 1 acre and up | AC pump on a solar pump inverter, or a pond with a high-flow surface pump |
VEVOR 12V DC 120W submersible deep well pump
Low-volume wells: a cabin, a garden or a few head of stock. The deepest submersion rating of the three.
- Voltage
- 12V DC (12 to 14.8V)
- Rated power
- 120 W
- Max flow (zero head)
- 3.2 gpm
- Max head (zero flow)
- 230 ft
- Max submersion
- 98.4 ft
- Outlet
- 1/2 in
- In the box
- Pump only: no panel, controller or pipe
VEVOR 24V DC 277W submersible deep well pump
Stock water and small irrigation where the water level is within about 100 ft.
- Voltage
- 24 to 42V DC (36V rated)
- Rated power
- 277 W
- Max flow (zero head)
- 9.25 gpm
- Rated point
- 5.28 gpm at 84 ft
- Max head (zero flow)
- 272 ft
- Max submersion
- 65.6 ft
- Outlet / cable
- 1 in / 33 ft
- In the box
- Pump only
VEVOR 48V DC 369W submersible deep well pump
Deeper lifts at modest flow. Wants two 36V-class panels in series to reach its voltage.
- Voltage
- 48 to 82V DC (72V rated)
- Rated power
- 369 W
- Max flow (zero head)
- 8.4 gpm
- Rated point
- 1.77 gpm at 167 ft
- Max head (zero flow)
- 273 ft
- Max submersion
- 65.6 ft
- Outlet / cable
- 1 in / 33 ft
- In the box
- Pump only
We have not tested these products; specifications are the merchant's own. Affiliate disclosure.
Questions
- Can a solar pump irrigate an acre?
- Yes, but not usually with a small DC pump. An acre at one inch a week needs about 3,880 gallons a day, roughly 11 gpm over 6 sun hours. A solar pump inverter driving an AC pump, or several DC pumps into storage, can supply it.
The calculator opens with an irrigation setup; change the area, lift and pipe.