If you are new to Solar Energy concepts and interested to know everything about it from scratch, you are at the right place. We have the basic concepts explained, the current solar statistics, benefits of solar energy in a well-defined manner.
As per Wikipedia definition “Solar energy is radiant light and heat from the Sun harnessed using a range of ever-evolving technologies such as solar heating, photovoltaics, solar thermal energy, solar architecture and artificial photosynthesis”. It is an important source of renewable energy and its technologies are broadly characterized as either passive solar or active solar depending on the way they capture and distribute solar energy or convert it into solar power.
Renewable energy is generally defined as energy that comes from resources which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat. Renewable energy replaces conventional fuels in four distinct areas: electricity generation, air and water heating/cooling, motor fuels, and rural (off-grid) energy services.
Sunlight can be visualized in two forms – heat and light. Hence, solar energy can be divided into two main components – Solar Light Energy and Solar Heat Energy.
Solar Light Energy – Here the main objective is to convert the energy contained in sunlight to electricity in the form of photons. This sector is known as Solar Photovoltaic (Solar PV)
Solar Heat Energy – Here, the objective is to use the heat energy in sunlight directly to generate electricity. This sector is generally referred as Solar Thermal.
The total solar energy absorbed by Earth’s atmosphere, oceans and land masses is approximately 3,850,000 exajoules (EJ) per year. In 2002, this was more energy in one hour than the world used in one year.
By photosynthesis green plants convert solar energy into chemically stored energy, which produces food, wood and the biomass from which fossil fuels are derived.
Solar power is the conversion of sunlight into electricity, either directly using photovoltaics (PV), or indirectly using concentrated solar power (CSP). Concentrated solar power systems use lenses or mirrors and tracking systems to focus a large area of sunlight into a small beam. Photovoltaics convert light into an electric current using the photovoltaic effect.
Wikipedia defines “The photovoltaic effect is the creation of voltage or electric current in a material upon exposure to light and is a physical and chemical phenomenon.
The standard and obvious photovoltaic effect is directly related to the photoelectric effect, though they are different processes. When the sunlight or any other light is incident upon a material surface, the electrons present in the valence band absorb energy and, being excited, jump to the conduction band and become free. The chemical bonds of the material are vital for the process to work, as crystallized atoms are ionized and create a chemical electric imbalance, driving the electrons. These highly excited, non-thermal electrons diffuse, and some reach a junction where they are accelerated into a different material by a built-in potential (Galvani potential). This generates an electromotive force, and thus some of the light energy is converted into electric energy.”
With about 300 clear, sunny days in a year, India’s theoretically calculated solar energy incidence on its land area alone, is about 5,000 trillion kilowatt-hours (kWh) per year (or 5 EWh/yr). The solar energy available in a year exceeds the possible energy output of all fossil fuel energy reserves in India. India is ranked number one in terms of solar electricity production per watt installed, with an insolation of 1,700 to 1,900 kilowatt hours per kilowatt peak (kWh/KWp).
On 16 May 2011, India’s first 5 MW of installed capacity solar power project was registered under the Clean Development Mechanism. The project is in Sivagangai Village, Sivaganga district, Tamil Nadu. In January 2015, the Indian government significantly expanded its solar plans, targeting US$100 billion of investment and 100 GW of solar capacity by 2022.
As of 31 August 2015, the installed grid connected solar power capacity is 4,229.36 MW, and India expects to install an additional 10,000 MW by 2017, and a total of 100,000 MW by 2022.
Water heating, Cooling, Ventilation, Cooking etc at a small scale level. At a large scale level, solar energy is mainly used to generate electricity.