Soiling

A group of scientists in Bangladesh has developed a model to determine the optimal cleaning schedule for a PV installation at any location in the globe, requiring only the average insolation and soiling rate for a given site to make the calculation. The study also draws new conclusions regarding the influence of sandstorms and rain on soiling, and aims to be among the first studies to paint a global picture of soiling trends by region.

Dutch materials company DSM has sold its resins and functional materials businesses, which encompass its anti-reflective and anti-soiling solar glass coating products. That will mean a focus on module backsheets in DSM’s Advanced Solar business unit.

Scientists in Spain have tested various properties of anti-reflective and anti-soiling coatings for PV module glass, aiming to develop a material that offers the best balance of desired material properties at the lowest cost. Over a year of testing, the best coatings were shown to boost module output by around 2%, and the group also made several observations that could influence future developments of coatings for PV module front glass.

Scientists in the United States and India are investigating the impacts of soiling on PV installations in the Indian state of Gujarat. The group, which found that soiling losses for the state could add up to $12 million per year, is looking for low-cost ways to monitor and reduce the impacts of soiling on modules in the field.

U.S.-owned business intelligence firm Wood Mackenzie has attempted to evaluate the market opportunities offered by the repowering of solar projects around the world which feature inverters which are 10 years old – as well as those which will expire ahead of time.

Researchers in China have sought to understand how soiling exacerbated by anti-reflective coatings might inhibit solar panel output. In terms of effectiveness against soiling, the scientists found hollow-silica-nanoparticle coatings did better than solid silica alternatives.

A U.K. study has identified 13 soiling agents with differing effects on light transmittance. Researchers found some dust particles were able to degrade photovoltaic performance by as much as 98%.

Scientists in the U.K. have developed a system which makes panels vibrate to provide cleaning. The academics have conceded, however, they are yet to calculate the ‘sweet spot’ of mechanical stress to be applied.

Researchers in Tunisia have proposed a method of determining the characteristic I-V profile of a partially shaded PV module, and to extrapolate it into a string profile.

The developer of the material, US-based specialist Pellucere, says its innovation can raise PV energy yield 3.5-4.2%.