Farm Fires Impact On Solar Generation In North India

It’s the beginning of winter, and yet again, almost as regularly as the South West monsoons leaving the country, we have the onset of air pollution, especially over North India. As AQI (Air Quality Index) levels rise, air purifiers are brought in, while others hope the measures taken by their local governments will help. For people in the solar sector, especially in North India, it also means a real drop in output from the solar plants in the region, especially in a broad area covering all of Delhi, and most of Punjab, Haryana, parts of Rajasthan and UP. Keep in mind that under normal circumstances, the moths of October and November should be one of the highest generating months on the solar calendar, thanks to clear skies, bright sunshine and cool weather, besides days that are not yet as short as they would be in December and January. Peak Air pollution has put paid to that.

The issue was highlighted by a small developer we spoke to, who highlighted how output in October on the solar plants with a cumulative capacity of 600 kW being managed by them has fallen to the levels seen in monsoon months, when cloud cover is the issue. That, in percentage terms, is a 20-30% drop on peak output, as seen in early summer and post February even in the region.

An IIT Delhi study released early this year, that pointed out India lost 29% of its utilisable global irradiance potential due to air pollution between 2002 and 2018. Interestingly, the impact was felt the most in the eastern grid, due to the year long situation in those parts of the country. For the North, the problem, that peaks between October to December each year, has a real economic cost for solar developers, even as society grapples with higher healthcare and other productivity issues.

A senior employee at a solar O&M firm we spoke to at REI 2022 reckons that close to 600 MW of actual solar capacity is impacted currently, and under normal circumstances, this 600 MW of solar panels would be generating over 2.5 million units of power each day. These drop to less than 1.8 million units per day, a loss of 6 to 7 lac units. At the most conservative levels, this is a cost of Rs 25- Rs 35 lacs per day during this period. While the person did not want to comment for what he called ‘back of the envelope’ calculations, he stressed that these numbers were conservative, in his view.

Smaller developers also concurred with the loss in output figure, right down to rooftop level installations. With most users having access to apps that tell them their generation figures on a daily basis or even in real time, the impact is certainly not lost on anyone, including the end customers. The big relief of course is that the large solar parks in Rajasthan are relatively unaffected, thanks to distance and wind direction at this time of the year.

The IIT study focused on soiling effect(dust) and the effect of gaseous pollutants on solar generation.

According to the team of Sagnik Dey, Dilip Ganguly, Somnath Baidya Roy and others from the Centre for Atmospheric Science in IIT Delhi, that conducted the study, successful implementation of the National Clean Air Programme, mitigation of household emissions and rural electrification would allow India to generate a surplus of 6-16 TWh in solar energy.

That simple premise, of getting more (energy) out of less (solar capacity) should appeal to all of us, in a country perennially starved of enough funding for issues that matter. It’s time the government counted the real cost of pollution and its impact on our energy security too. Thanks to pollution, right now, for all its promise of 300 days of sunshine, (North) India is losing an additional 60 days or more of optimum solar conditions to pollution. With almost 25 GW of capacity slated to come up in just the next 2-3 years in the region, that certainly takes the shine off solar potential for the region.

While the IIT study put a figure of $325 to $845 million in terms of additional benefits from clean air, it also claimed that for every 100 GW of solar capacity needed today, the same output could be delivered by 76 GW if air was as clean as our Clean Air Goals state for 2024.