We put one tubewell on solar. Here's the honest math.

A solar tubewell can reduce diesel use, but the payback depends on your farm. Here is what to include when comparing installation and running costs.

The appeal of a solar tubewell is easy to understand when you pay a diesel bill through the irrigation season. Sunlight can supply energy for daytime pumping. Whether the investment pays back quickly depends on the well, the pump and how much you actually use it.

Our earlier farm note recorded a diesel bill of roughly ₨60,000 a month during the irrigation season. Treat that as a historical figure from one installation, not a current fuel quote or a monthly saving every farm can expect. A useful comparison needs a full year of pumping records, including months when demand is lower.

Compare complete installation quotes

Ask an installer to quote for the complete system: panels, mounting structure, a compatible pump or motor, the drive or controller, wiring, protection and installation. Water depth and the volume you need affect the design. A price for panels alone will not tell you the solar tubewell cost of a working installation.

Work out the payback

To estimate simple payback, divide the installed cost by expected annual savings after maintenance and backup fuel. For illustration, a system costing ₨1,200,000 that saves ₨300,000 a year after those costs has a four-year simple payback. These are example numbers, not our invoice or a supplier quote. Financing and later equipment replacements need a separate allowance.

Solar pumping also changes the working day. Output varies with sunlight, and some farms need storage or another power source when demand does not match it. Cleaning, inspections, servicing and eventual component replacement still cost money after installation.

Count the water as well as the savings

Lower energy costs are a reason to measure water use carefully. A pump that costs less to run can still draw too much groundwater. Our renewable-energy target is a longer-term aim; each new installation needs a sensible water plan and a budget that works on its own.