India has decided to fight air pollution by setting an ambitious 100 GW target for solar energy until 2030. However, the changes, in the weather and high pollution, witnessed so far in the country make such developments very difficult concerning solar power generation in the future, according to a study ‘Future photovoltaic potential in India: navigating the interplay between air pollution control and climate change mitigation’ published in in Environmental Research Letters.
To evaluate the situation, research has been conducted to assess the solar photovoltaic potential across the Indian power grid under two scenarios: moderate climate action with intermediate air pollution and weak climate action with strong air pollution control. The results indicate that the nationally averaged photovoltaic potential is projected to decrease compared to the 1985–2014 baseline, primarily due to reduced solar radiation, increased temperatures, changing weather patterns, and high pollution levels. These factors are expected to reduce the efficiency of solar photovoltaics (SPV) in the future.
Researchers at the Centre for Atmospheric Sciences at IIT Delhi have investigated the impacts of climate and air pollution on integrated solar photovoltaic (SPV) incidence data gleaned from global climate models under CMIP6, the sixth phase of the Coupled Model Intercomparison Project. They have packed CMIP6 as one of the first models projected under several emission scenarios in defining future climates’ impacts.
Since the study uses data from 1985 to 2014 for predicting the changes from 2041 to 2050, it shows a 3.3% decline in SPV efficiency by mid-century, which translates into an annual average loss of about 600 to 840 gigawatt-hours (GWh) of energy generated, keeping current solar power production levels in mind.
SPV power generation at the location depends on the installed PV capacity and the PV potential, which has implications on solar radiation, changing ambient temperature, surface winds, and humidity. Since local conditions significantly affect SPV performance, the study explores two potential future scenarios.
In the first scenario, moderate efforts are made to reduce air pollution and address climate change, while the second scenario involves strong air pollution controls but limited climate change mitigation. The findings show a greater decline in SPV performance under the first scenario compared to the second, emphasizing the critical role of air pollution control in sustaining solar power efficiency.
Future change in PV potential
Direct effects of climate change on PV productivity in India are shown through enhanced projected changes in PV potential between the baseline period (1985-2014) and the mid-century (2041-2050). This analysis was done under two different scenarios: SSP245, which includes an intermediate control for air pollution and a climate mitigation measure; and SSP585, which is under strong air pollution control but weak climate action. The 30-year average annual PV energy potential indicates that the maximum potentials are in northern (0.24), southern (0.23), and western (0.22) power grids: while the lowest potential is in eastern (0.2) and north-eastern (0.18) grids.However, by mid-century, both SSP scenarios predict a general decline in PV potential against the baseline with averages of national decline of -3.3% under SSP245 and -2.3% under SSP585. The decline is expected to be more pronounced under SSP245 than SSP585, due to differing levels of air pollution mitigation and climate actions in each scenario.
In SSP245, the eastern power grid, particularly the eastern Indo Gangetic Plain (IGP) is expected to experience the highest decline (-5.1%), followed by the northern (-3.4%), north-eastern (-3%), and southern (-2.3%) grids. In contrast, under SSP585, the western grid is projected to have the largest drop (-2.7%), followed by the northern (-2.4%), eastern (-2.2%), and lowest over north-eastern (-1.1%) grids. Usage of PV up to 18% in few projected areas from the northeastern power grid and southwestern coastal zones from the southern power grid (Kerala).
A research detail has been brought out by the Centre for Atmospheric Sciences – IIT Delhi that talks about the combined effects of climate change and air pollution on solar photovoltaic (SPV) performance between developing radiation data from the global climate models under phasism-6 of the Coupled Model Intercomparison Project (CMIP6). CMIP6 is foremost in modeling future climate impacts under various emission scenarios.
It predicts an SPV efficiency decline of 3.3% by mid-century, based on the baseline data from 1985-2014, against changes predicted for 2041-2050. This would amount to an annual loss of 600-840 gigawatt hours (GWh) of electricity generation when translated in terms of present solar power generation.
There is the installed PV capacity of a site and PV potential that indicates as a dependent variable, solar radiation, ambient temperature, surface winds, and humidity indicating it. Since local conditions significantly affect SPV performance, the study explores two potential future scenarios.
In the first scenario, moderate efforts are made to reduce air pollution and address climate change, while the second scenario involves strong air pollution controls but limited climate change mitigation. The findings show a greater decline in SPV performance under the first scenario compared to the second, emphasizing the critical role of air pollution control in sustaining solar power efficiency.
Geographic Variation in Solar Energy Potential
The study evaluates solar energy potential using two key metrics: the total number of solar-rich days per year and the number of consecutive solar-rich days, analyzing their impact on power grids across five zones—northern, eastern, western, northeastern, and southern.
India experiences around 215 solar-rich days annually, defined as days with incoming solar radiation exceeding 208 watts per square meter, essential for photovoltaic (PV) generation. The southern, western, and northern grids receive the most solar-rich days, while the eastern and northeastern grids receive fewer. Weak air pollution controls could reduce these days by up to 15 per year, whereas moderate measures might limit the reduction to about eight days.
The second metric, consecutive solar-rich days, tracks uninterrupted solar radiation. India averages 165 such days annually, with the northern region leading and the northeastern grids trailing. Under weak pollution controls, these consecutive days could decrease by up to 20 days, compared to 15 days with moderate controls. Increased aerosols, associated with high pollution levels, are the primary cause of reduced solar radiation.
The study projects a decline in solar-rich days, with the most significant reductions in highly irradiated regions like the northwest and western grids. This poses challenges for the northern, western, and southern grids, where most of the country’s solar parks are located, in maintaining SPV performance amid climate change.
Regional impacts will depend on future air pollution control and climate action. For example, the northeastern grid may see an increase in solar-rich days under strong air pollution mitigation and weak climate action scenarios, attributed to reduced cloud cover in the region. Despite traditionally having fewer solar-rich days, this could enhance solar energy potential in the eastern and northeastern grids.
A declining trend in solar radiation is projected over most of India during 2041-2050, irrespective of the dominant meteorological factor.
The study shows that under a scenario with moderate efforts to control both air pollution and climate change, the eastern power grid, particularly the eastern Indo-Gangetic Plain, will experience the steepest decline in solar energy potential (-5.1%), followed by the northern (-3.4%), northeastern (-3%), and southern (-2.3%) grids.
In a second scenario, with strong air pollution control and weak climate action, the largest reduction is for the western grid (-2.7%), followed by the northern (-2.4%), eastern (-2.2%), and northeastern (-1.1%) grids, the latter of which experiences the least effect.
Experts say the findings underline the rising difficulties of working towards a sustainable future in the face of the dual threats posed by climate change and air pollution.