Solar Water Purification Technologies and Photovoltaics: Is Integration Possible

Currently 708 million people lack access to a safe water supply, most of them in rural areas. Unsafe water and poor sanitation cause 80% of all diseases in the developing world. Development of simple, cost-effective and socially acceptable domestic water purification units is a challenge that requires the application of scientific knowledge from various disciplines. Solar disinfection is one of the most appropriate point-of-use water treatment methods in remote regions with restricted or unavailable access to electrical power and/or chemical supplies. They use the bactericidal effect of UV radiation or convert the solar energy into heat for thermal pasteurization or distillation. But their widespread is limited by the lack of low-cost sensors to detect when the water is clean, i.e. if the treated water has received enough radiation and/or if it has reached the pasteurization temperature. Additionally, for the case of natural UV photocatalytic reactors, the use of only a small fraction of the solar spectrum (5%) limits the system efficiency and increases the cost.Photovoltaic solar cells can be used to measure irradiance (from their current) and temperature (from their voltage), and can also be integrated into hybrid systems to increase their total efficiency (photovoltaic-thermal, photovoltaic-photocatalytic). This article explores the potential of the integration of solar photovoltaic in solar water treatment processes.