Photovoltaic solar power, such as the panels installed on a home's roof, uses no water at all to generate electricity. The only water usage occurs when the panels themselves need to be washed to improve their efficiency.
A photovoltaic cell alone cannot produce enough usable electricity for more than a small electronic gadget. Solar cells are wired together and installed on top of a substrate like metal or glass to create solar panels, which are installed in groups to form a solar power system to produce the energy for a home.
A photovoltaic cell is the most critical part of a solar panel that allows it to convert sunlight into electricity. The two main types of solar cells are monocrystalline and polycrystalline. The "photovoltaic effect" refers to the conversion of solar energy to electrical energy.
Akbarzadeh and Wadowski designed a hybrid PV/T solar system and found that cooling the solar photovoltaic panel with water increases the solar cells output power by almost 50%.
The water-based cooling system was found to increase the solar cells performance higher than the air based cooling system. Dubey and Tiwari designed an integrated combined system of a photovoltaic (PV) panel with a thermal (T) solar water heater. The hybrid PV/T solar system has been designed and tested in outdoor condition of New Delhi.
There's an infographic that claims solar power uses no water at all to generate power. However, the claim is not entirely correct. The passage goes on to explain that the water usage of solar power is minimal compared to other sources like coal and nuclear power.