Module prices reached record lows this year while grid electricity and delivered diesel went the other direction. Every few years we redo the standard pumping economics for our customers; this year the arithmetic moved again, in solar's favour.
Where the money now sits
The array is no longer the dominant line item. In current project costs, the pump, structure, inverter and installation together outweigh the modules. That matters because it changes what further module price drops can achieve: the next savings have to come from engineering and installation efficiency, not from glass.
Payback by site type
- Off-grid versus diesel: the strongest case in the industry. Payback in a handful of seasons is common; in high-fuel-cost regions it is closer to one or two.
- Grid-supplemented farms: solar takes the daytime pumping and the grid becomes backup. Payback depends on the tariff, but at current European electricity prices it is well inside a decade.
- Replacement of existing diesel: comparing against a sunk-cost engine is the weakest case, and still usually wins on a ten-year view.
The number to watch is still the source
System economics are decided less by panel prices than by water depth and daily volume. The first question in any quote is still not "what does solar cost?" but "what does your water cost to move?" The technology side of the equation has never been cheaper; the physics of the well remains the physics of the well.