Lesedi Solar Care Business Plan — Technology, Method & the Water Constraint

Conventional wet cleaning consumes roughly 0.6 to 1.2 litres per square metre per cycle. On a 75 MW plant that is in the order of 400,000 to 800,000 litres…

Technology, Method & the Water Constraint

Jump to section

8.1 The water constraint

Conventional wet cleaning consumes roughly 0.6 to 1.2 litres per square metre per cycle. On a 75 MW plant that is in the order of 400,000 to 800,000 litres per full cycle, an untenable draw in districts where municipalities and farmers already compete for supply, and increasingly one that host communities will not accept. Water is therefore not an operational detail; it is the constraint around which the entire service model is designed.

Figure 13. Water use per MW per cleaning cycle.

Metric	Conventional wet cleaning	Lesedi blended programme
Water per MW per cycle	~5,300 litres	~520 litres
Annual water on a 75 MW plant (6 cycles)	~2.39 million litres	~234,000 litres
Reduction	—	~90%

8.2 Method hierarchy

Method	Water use	Deployment	Application
Dry robotic brushing	Zero	Track-mounted, semi-autonomous	Primary method on utility rows in arid sites; overnight operation
Semi-automated dry brush	Zero	Tractor or vehicle-mounted rotating brush	Large arrays with suitable row geometry
Low-volume deionised rinse	~0.08 l/m²	Backpack and lance systems	Periodic residue removal; bird soiling; post-harvest films
Manual detail cleaning	~0.15 l/m²	Trained crews with soft-brush kit	Rooftop C&I, constrained geometry, warranty-sensitive modules

The blended programme meets module warranty requirements on brush pressure, water quality and technique, a point that matters commercially, because an owner whose cleaning contractor voids a module warranty has destroyed far more value than the cleaning recovered. Deionised water is produced at depot level and transported in bowsers, eliminating dependence on site potable supply.

StrengthWater discipline converts a regulatory constraint into a competitive moat

This is the most defensible element of Lesedi’s positioning. The highest-irradiance districts, where solar assets cluster and where soiling is most severe, are also the most water-stressed. As municipalities tighten restrictions, operators dependent on conventional wet cleaning will progressively lose access to exactly the sites worth the most. A near-waterless method is therefore not a differentiator competitors can match with a brochure; it requires capital equipment, method development and depot-level deionised water production. Regulatory tightening, a threat to most operators, is competitively advantageous to Lesedi, a genuinely unusual risk profile.