Solar tube well installation in Peshawar and KP

How a solar tube well works

The panels feed a solar pump drive, which turns their DC output into the supply the motor needs and adjusts the pump speed to the sunlight available. In the morning the pump starts slowly, runs at full speed through the middle of the day, and slows again in the evening.

There is no battery. Storing water is far cheaper than storing electricity, so the usual design pumps during daylight into the field or a tank and draws from the tank afterwards.

Because the drive starts the motor gently, it avoids the heavy starting surge that strains a pump on a generator or a weak supply.

How we size one

Three facts decide the system: the depth the water is lifted from, the volume you need each day, and the motor. Deeper water or more water means a bigger motor, and a bigger motor means more panels.

The array is sized larger than the motor's rating, so the pump still delivers useful water on a hazy morning or a short winter day rather than only at noon in June.

We take these measurements at the well rather than guessing from the motor plate. A system sized only from the motor's rating can fall short in winter, exactly when it is hardest to notice until the crop shows it.

Using the pump you already have

If your existing motor is in good condition and suits the depth, a solar drive can often run it, which saves the cost of a new pump. We check the motor and the bore at the survey and tell you plainly if it is not worth keeping.

Where the old motor is worn out or wrongly sized for the water level, replacing it at the same time is usually cheaper than paying for extra panels to drive an inefficient pump.

Solar against diesel

A diesel tube well costs money every hour it runs: fuel, oil, servicing, and the trip to fetch the diesel. A solar one costs most of its money on the day it is installed and very little afterwards.

Diesel can pump at night and on cloudy days; solar pumps only in daylight. For most irrigation that is not a real limit, because the field or a tank takes the water during the day. If you need water at a particular hour of the night, tell us at the survey and we will design around it.

Upkeep is simple: rinse the panels with plain water every few weeks in the dusty months, keep the structure tight, and keep the drive dry and shaded.