Solar Energy

Since prehistoric times, solar energy has been the most easily available and free source of energy. Every year, solar energy estimated to be equivalent to approximately 15,000 times the world’s annual commercial energy consumption reaches the planet. For 300 to 330 days per year, India receives solar energy in the range of 5 to 7 kWh/m2. This energy is enough to run a 20-megawatt solar power plant per square kilometer of land.  

The NTPC project would have nearly twice the capacity of Rajasthan’s Bhadla solar park, which is presently the country’s largest single-location solar power plant. By 2032, NTPC hopes to have built 60 GW (gigawatts) of renewable energy capacity.

“Longer-term benefits will come from the development of affordable, unlimited, and clean solar energy technologies,” the International Energy Agency declared in 2011. It would strengthen countries’ energy security by depending on an abundant, limitless, and mostly import-free supply. It boosts sustainability, decreases pollution, cut climate change mitigation costs, and keep fossil fuel prices lower than they would be otherwise. These benefits are widespread. As a result, the increased expenses of early deployment incentives should be viewed as learning expenditures that must be carefully spent and equitably shared “. Australia has the highest amount of solar power in the world, accounting for 9.9% of total electricity demand in 2020.

Solar thermal devices are utilized in residential and industrial solar water heaters, air warmers, solar cookers, and solar dryers.

I. Solar water heaters:

It comprises a thin, flat, rectangular box installed on the roof of a building or residence with a transparent cover towards the sun. Small tubes go through the box, carrying the fluid to be heated, which might be water or another fluid like an antifreeze solution. The tubes are connected to a heat-absorbing absorber plate, which is coated with specific coatings. Heat is generated in the collector and transferred to the fluid flowing through the tubes.

The most efficient, but also the most expensive, form of hot water solar collector is the evacuated tube collector. Glass or metal tubes with a vacuum are used in these collectors, allowing them to work in colder areas.

II. Solar cooker:

A solar cooker is a device that cooks using sun energy, reducing the need for fossil fuels, wood, and electricity to a considerable amount. However, it can only be used to augment cooking fuel, not to completely replace it. It is a basic cooking device that is suitable for home use throughout most of the year, with the exception of the monsoon season, overcast days, and the winter months. Solar cookers in a box: In India, the box solar cookers with a single reflecting mirror are the most common. These cookers have become quite popular in rural regions where women spend a significant amount of time gathering firewood.

III. Solar Photovoltaic (PV):

Using the photoelectric effect, a photovoltaic system transforms light into electrical direct current (DC). Solar PV has grown into a multibillion-dollar, fast-growing business that is continuing to increase its cost-effectiveness and, together with CSP, has the highest promise of any renewable technology. Lenses or mirrors, as well as tracking systems, are used in concentrated solar power (CSP) systems to focus a wide region of sunlight into a tiny beam. Concentrated solar power facilities were first produced commercially in the 1980s.

The technical name for solar electric is photovoltaic. Photo is short for “light,” while voltaic is short for “electric.” PV cells are typically constructed of silicon, a material that releases electrons spontaneously when exposed to light. The amount of electrons emitted by silicon cells is proportional to the amount of light shining on it. The silicon cell is encased in a metal grid that guides electrons along a route to produce an electric current. This current is directed into a wire that connects to a battery or a DC device. One cell typically produces 1.5 watts of electricity. Individual cells are linked to make a solar panel or module with a power output of 3 to 110 watts. Solar panels may be linked in series and parallel to form a solar array that can produce as much power as space allows. Modules are typically intended to provide 12 volts of power. The peak Watt production of PV modules is measured at solar noon on a clear day.

IV. Pumps for Solar Water:

The pump in a solar water pumping system is powered by a solar-powered motor rather than traditional energy taken from the utility grid. A solar array placed on a platform and a motor-pump set compatible with the photovoltaic array make up an SPV water pumping system. It transforms solar energy into electricity, which is then utilized to power the motor-pump system. Water is drawn from an open well, a bore well, a stream, a pond, or a canal via the pumping system.

Renewable energy sources, often known as non-conventional energy, are sources that are renewed by natural processes on a continual basis. Solar energy, wind energy, bio-energy (bio-fuels cultivated sustainably), hydro-power, and other sustainable energy sources are some examples.  

A renewable energy system transforms energy from the sun, wind, falling water, sea waves, geothermal heat, or biomass into heat or electricity that humans can utilize. The majority of renewable energy originates from the sun and wind, either directly or indirectly, and can never be depleted, which is why it is termed renewable.

However, traditional energy sources such as coal, oil, and natural gas provide the majority of the world’s energy. Non-renewable energy sources are the word used to describe these fuels. Despite the fact that the accessible amount of these fuels is enormous, they are finite and will, in theory, ‘run out’ at some point in the future.