The Ministry of New and Renewable Energy (MNRE) has issued a letter recommending efficient utilization of water for cleaning utility-scale solar projects.

The ministry has said that project developers are currently using too much water for cleaning solar modules, and they should try and minimize wastage.

The ministry has also recommended the use of robotic cleaning technology, which uses less water for cleaning solar projects. Water is scarce in most regions where solar projects have been developed in India. Currently, developers have to seek permissions from local authorities to get access to groundwater and canals. Given the fact that the projects are in remote locations, it is also difficult for developers to arrange water from other sources to maintain their projects.

A source at the MNRE commented on the development stating, “This is an advisory to state nodal agencies and project developers to focus on judicious use of water. We expect that with large solar capacities coming up, a lot of water will be required for cleaning and maintaining the projects. Hence we are encouraging developers to look at technologies available to mitigate wastage of water.”

Last year, Mercom reported on the news of Ecoppia, a robotics company that provides photovoltaic solar panel cleaning, signing an agreement with SB Energy to install two thousand robots across its five project sites at the Bhadla Solar Park (Phase III & IV) in Rajasthan.

Nalin Kumar Sharma, Vice President, marketing, Ecoppia said “In the renewable ecosystem, there cannot be an unsustainable use of water, therefore we welcome this advisory from the MNRE. A World Bank report has stated that most Indian states are witnessing stress in terms of water availability. Using water from cleaning solar panels is not the most optimal use of the resource. Robotic cleaning technology can be used 365 days a year, specially in difficult conditions such as dust storms which can result in drop in efficiency rates by almost 30%. Robotic cleaning can also reduce dependance on manual labour which reduces insurance costs as well”.

The Bhadla project is in a water-deficient region and often faces massive dust storms. This increases the panel soiling that results in reduced energy output. Hence, the water-free cleaning technology of Ecoppia’s system was expected not only to solve the water problem but also maintain the energy output.

The waterless cleaning process uses microfiber, which delicately cleans the solar modules and removes dust particles.

MNRE has also suggested the developers consider anti-soiling coating technology on panels, hydrophobic and nano-technology based self-cleaning modules.

Coal is still the biggest culprit when it comes to water usage to produce energy. Mercom reported on India’s water woes last year, and an NTPC official told Mercom back then that “A 1,000 MW coal-powered thermal project will require between 6,500 to 8,000-kiloliters of water per day. It comes down to almost 6.5-8 kl/MW/day. This is almost eight times the water required for solar projects.”

Image credit: Ecoppia