India is the home of 1.33 billion people [1] with per capita electricity consumption of 1075 kWh [2]. The total electricity consumption is around 1.43 PWh (1.43 x 1015 Wh) per year.
The average solar irradiance in India is around 5.97 kWh/m2/day (5.97 kWh per square meter per day). This solar energy can be converted into usable electricity by using solar panels.
The most popular commercially available solar panels have the efficiency of around 15%. So, the output we can get from solar panel is around 0.89 kWh per square meter per day.
However, there are losses like impedance mismatch, soiling, shading, wiring, light induced degradation, inverter inefficiency, DC to AC size ratio etc, which is around 25%. This leads to the usable AC output of 0.67 kWh per square meter per day, i.e, 245 kWh per square meter per year.
Area Needed for Solar Panels: With the present technology we get 245 kWh of AC electricity per square meter per year from solar energy. To get the total annual electricity demand of 1.43 PWh, we need a total area of 5837 x 106 m2 (or 5837 Km2) i.e, a rectangle area of around 76 Km x 76 Km with 911 GW of solar power plant (1 MW solar plant produces around 1570 MWh of electricity annually). Total land area in India is around 3287263 Km2. So, the percentage of land area needed to meet all our electricity demand through solar energy is around 0.18%, as shown in the image (green coloured rectangle).
Area Needed for Storage System: In order to have 1 day autonomy, the total storage capacity should be around (1.43 PWh / 365) = 3.92 TWh. Considering the depth of discharge to be 50%, the needed storage capacity should be around 7.84 TWh. The typical dimension (l x w xh) of conventional 12V-150Ah battery is around 500 mm x 188 mm x 422 mm and weights around 65 Kg, i.e, a battery of capacity 1800 Wh requires space of 0.094 m2. Total area needed to store 7.84 TWh is around 409 x 106 m2 (or 409 Km2), i.e, a area of around 20 Km x 20 Km. So, the storage system needed for 1 day autonomy is around 0.01% of the total land area of India, as shown in the image (red coloured rectangle inside green rectangle, if you notice carefully !).
The total number of households in India is around 275 million. So a 3.5 kW rooftop solar system is good enough to meet all the electricity demand of India and it will take only 6 m x 6 m space on each roof !
Feel free to leave a comment below if you have any questions or suggestion.
Palash Khan
Co-founder & CEO, AlienSolar
He did his PhD in Physics from Saha Institute of Nuclear Physics, Kolkata and worked on LHC at CERN, Switzerland. After completing PhD he co-founded AlienSolar to promote solar energy with a vision to make it the main source of energy replacing the fossil fuels. Interested in renewable energy, automation and space technology !
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