High pollution levels may hit India’s solar ambitions, say industry experts
NEW DELHI: High pollution levels could play spoilsport for India’s solar power generation plans, industry experts fear. For instance, in the national capital region (NCR), high pollution levels have hit the efficiency of solar roof top projects to the extent of 10%, they say.
India plans to set up 100 gigawatt (GW) of solar capacity by 2022, of which 40,000 megawatt (MW) is to come from solar roof top projects.
“...probably 90% of our projects are in the metros, the top eight cities of India ... They are usually either in centre of city or in industrial areas. And we have already seen, particularly in NCR, that whenever we set up a project we do a generation forecast based on 25 years of meteorological data. We have already seen in NCR that the plant underperforms—radiation is consistently lower than what historical average suggests,” said Andrew Hines, co-founder of CleanMax Solar, an on-site rooftop solar power developer.
Delhi is among the most polluted cities of the world. The World Health Organisation ranked Delhi as the most polluted city in the world in 2014. However, in 2016, the city was ranked at number 11.
Experts says the phenomenon of pollution interfering with efficiency in generating solar power, known as dimming effect, is well known.
Dimming effect is a phenomenon wherein the amount of solar radiation reaching the earth’s surface decreases due to the presence of pollutants or particulate matter in air that absorb solar radiation and reflect it back into space.
“Dimming effect is well established and because of that the solar panels are bound to receive less solar radiation and that ultimately results in those panels generating less energy. If we can eliminate such particles from atmosphere, the efficiency will definitely improve,” said Sumit Sharma, a fellow at The Energy and Resources Institute, a Delhibased think tank.
India receives solar radiation of 5-7 kWh per sq. m for 300-330 days in a year.
“This means that something is going on. There is no explanation other than the pollution. Certainly if you have look at pollution today or in the last few years versus last 25 years that’s the biggest factor. It’s already driving generation numbers down in cities. Rural areas pollution may not be as much of a factor although pollution doesn’t stay contained. So if it is in NCR it will be there in neighbouring States,” added Hines.
The annual mean of particulate matter (PM) under 2.5 micrograms found in every cubic metre of air or PM 2.5 in the data released in 2014 for Delhi was at 153 ug/m3. It declined to 122 ug/m3 in 2016.
“In the urban and industrial areas, we clearly see more particulate matter that impacts the generation capacity of solar panels due to soiling. What it means for us is frequent cleaning and possibly longer term impact on the module health,” said Sanjeev Aggarwal, MD & CEO of Amplus Energy Solutions Pvt. Ltd, which sets up solar rooftop projects.