Impact of Dust for Solar PV in Indian Scenario: Experimental Analysis

Introduction

With the increase in population and thrive for smart city, the self-sustainable energy demand globally has stipulated over 500 million tera-joules/year (reported by International Energy Agency, 2015). India has bagged third position after China and USA in energy consumption. This reveals that the energy consumption in the nation is on a significant rise and as predicted, will grow the fastest among the major economies by 2040 (as illustrated in Figure 1) (“Physical Progress (Achievements)”. About 67% of the country’s electricity is procured from conventional sources such as fossil fuels, mostly coal. Moreover, India accounts for 11% of global coal consumption making it world’s second largest coal consumer ((“Achieving 2022 target four years ahed of schedule”), “India hits 20 GW solar capacity milestone”, 2018). This demonstrates the massive dependence on non-renewable energy sources such as coal, which is culpable of CO2 emissions. The coal based power plants contribute about 35% to the total all-India CO2 effusions (“India hits 20 GW solar capacity milestone”, 2018).

To meet the extensive energy demand and to move towards cognitive cities, there has been a remarkable transition from non-renewable to sustainable energy resources. Amongst the several renewables such as wind, hydro, solar is the most boosted sector with the annual potential of 1,575-49,837 exa-joules (“India hits 20 GW solar capacity milestone”, 2018). However, it is good to know that India is steadily switching to renewables, their share in India's installed capacity being 40%. Moreover, 18% of India’s energy production is reliant on renewable sources (Pal Chandra, 2018). Earlier, solar energy used to be expensive, but now the solar and wind tariffs are declining. Since 2010, there has been a noteworthy decline in tariffs for solar energy owing to reduction in cost of PV modules, increase in scale of projects etc. In 2017, solar tariff dropped to historic low of Rs.2.44/kWh from Rs15/kWh in 2010 (Economic Times, 2017).

Figure 1.

World energy outlook 2017, IEA

By 2027, it is estimated that the renewable energy capacity would become 275 GW (“Economic Times”). Over a few years, renewable energy could become as affordable as conventional sources. Knowing the fact, that clean power is now cheaper, would widen its use throughout the country, in particular for the 24 crore Indians still without electricity. The total available solar energy in one hour, if harnessed completely, could meet the global energy needs for a year. Being a tropical country, India receives tremendous amount of sunlight throughout the year (illustrated in Fig.2 (a)), 300 days of sunlight contributing to 5000 trillion kWh (“Economic Times” and Bhushan, 2018). Solar Photovoltaics Cells (PVC) provides a means of harnessing sunlight and converting it into usable electricity and is expected to yield maximum outputs. Although solar PV technology is approaching maturity from its first to fourth generation, it cannot be denied that solar panels have quite low reported efficiency. Due to perpetual outdoor exposure, many environmental factors hinder panel’s capability to yield ideal outputs. One of such imperative factor influencing panel performance is dust. With the passage of time, solar panels develop a thin layer of dust on their surface. Sources like pollution, vehicular movement, rising temperatures, changing weather patterns, nature and many others result in dust generation. Large parts of North India as reported are turned into Dust Bowl owing to depleting groundwater, unsustainable agriculture and deforestation (Nattakarn, 2017). Fig.2 (b) illustrates dust storm in north region on May 14, 2018.