Development of a Hydrophobic, Anti-soiling coating for PV Module Cover Glass

Soiling of photovoltaic modules is a serious problem that significantly reduces power output. The requirements for a hydrophobic anti-soiling coating are discussed and the development of a transparent hydrophobic coating with good durability is described. The performance of the coating has been assessed using optical transmittance, water contact angle and roll-off angle measurements. The durability of the coating is a key issue and the coating has been subjected to laboratory environmental stresses as described in IEC test standards for PV modules. These tests include UV exposure and damp heat exposure up to 1000 hours. Outdoor testing is now underway to confirm these results.