Vega Solar Pumps

A Vega solar pump runs straight from solar panels, with no batteries and no grid connection, through an MPPT controller that gets the most water out of the available sunlight. The range covers 3-inch DC borehole pumps from 210 W to 1.2 kW, 4-inch DC motors, solar inverters that run standard AC pumps up to 22 kW, a DC pressure booster and a DC pool pump. This guide shows what each system can deliver, how to size the panels and what it costs.

How a Vega solar pump system works

The panels produce DC power that rises and falls with the sun. The controller tracks the maximum power point (MPPT) of the panels and drives a brushless permanent-magnet motor at whatever speed the sun allows. The pump fills a storage tank during the day; the tank, not a battery, is your storage. Because the motor speeds up and slows down with the light, there is no hard start and no need for a separate control box.

Solar pumps deliver water by the day, not by the hour. Flow varies from zero at dawn to the full rated flow in strong sun. Size the system on litres per day at your head and store the water in a tank large enough for two or three days.

3-inch DC solar borehole pumps: 3HR and 3HRI

Both ranges are complete pump-and-controller kits for 3-inch and larger boreholes, with a brushless DC motor, MPPT controller, intelligent water-shortage protection and tank and well probe inputs. The 3HR is built in 304 stainless steel; the 3HRI in 201 stainless steel at a lower price, and is not recommended for brackish water. Maximum submersion depth is 50 m.

Head figures are from the performance table at full sun. Prices include the DC controller.

Controller voltage limits

Wire the panels so their combined open-circuit voltage stays below the controller limit on the coldest morning, when Voc is highest.

Sizing a solar borehole pump

1. Daily water need. Add up household, garden and livestock use in litres per day.
2. Total head. Pumping water level + height to the tank inlet + pipe friction.
3. Sun hours. South Africa averages about 5 to 6 peak sun hours a day, less in winter. Design on winter sun if you need water all year.
4. Pick the pump. Find the model whose flow at your head, multiplied by the sun hours, covers the daily need.
5. Size the panels. As a rule of thumb, install about 1.3 times the pump power in panels, wired within the controller voltage limit.

Worked example

A cottage and garden need 4 000 litres a day. The pumping water level is 55 m and the tank sits 5 m above the borehole with about 3 m of pipe friction: total head is about 63 m. The 3HR500-120 delivers roughly 1 000 l/h at 80 m, so at 63 m it gives well over 1 000 l/h in full sun. With 5 sun hours that is over 5 000 litres a day. Panels: about 1.3 × 500 W = 650 W, wired for a Voc below 96 V.

4-inch DC borehole motors

For higher flows than the 3-inch pumps, Vega makes 4-inch brushless DC motors that drive a standard 4-inch pump end, so any Vega 4SD pump end of the right kW can go solar.

The low-voltage motors (48, 72 and 110 V DC) come with their own controller, rated 17 A with maximum panel Voc of 96, 144 and 200 V. The brushless DC motors run at 110 to 300 V and 12 A, so the same power comes with less current and thinner cable on a deep hole. Both have a maximum submersion depth of 70 m.

Solar inverters for AC pumps

The TGP accepts solar and AC power together, topping up from the grid or a generator when the sun is weak. The EBH-3 lets an existing 380V borehole or irrigation pump run from a large solar array, which is often cheaper than a grid connection on a remote farm.

Solar booster and pool pumps

The SQB250 is a peripheral-vane pump with a brushless motor, dry-run protection and a 1-inch outlet. It runs during daylight straight from the panels, or around the clock from a regulator and 12V deep-cycle batteries, and can switch automatically with a pressure switch. The combo kit adds the controller, regulator and connector. The TSP500 circulates pool water through the filter by day from solar panels, for water up to 60 °C.

Spares and accessories

Installation notes

• Face the panels north, tilted at about your latitude, with no shade between 9:00 and 15:00.
• Fit the well probe so the pump stops before the borehole runs dry, and the tank probe to stop when the tank is full.
• Hang the pump on a safety rope and keep it at least 3 m below the pumping water level.
• Keep the controller in the shade; the DC motor controllers are rated for a maximum ambient of 35 °C.
• Check the Voc of your panel string against the controller limit before connecting.

Price guide

Prices include VAT and are correct at the time of writing. Solar panels are not included.

Frequently asked questions

Related guides

• Solar Pump Guide — all brands
• Vega Borehole Pumps
• Vega Borehole Motors
• Vega Variable Speed Drives
• Vega Pumps
• Vega Solar Pumps — shop the category