The Sun (our Sun), the only known celestial body in entire universe which is nurturing life and not only nurturing it but also help to sustain it. Our Sun is the reason behind our existence without it the life couldn’t exist in the first place. What are we witnessing now, water, plants, animals, oxygen, land everything is here because of the Sun. Why is that? Because our planet has gone through many events at the right place and at right time, thanks to the Sun. Everything on Earth is because of the Sun, literally everything. Since last 4.54 billion years (give or take few million years) it is helping our planet to develop in many ways and now at this enduring time (on the verge of Sixth Extinction event), it helped us to create a new alternative that has the ability to save entire Planet and that alternative is Solar Energy.
Now, why to harness the Sun?
The answer is pretty straightforward, the Earth intercepts a lot of Solar Energy and by that, I mean really a lot of energy. Okay let us look at the magic number, and the number is 173 thousand Terawatts (that is 15 zeroes past 173). That’s about 10,000 times more power than planet’s population uses. So, is it possible that one day the world could be completely reliant on Solar power?
In order to answer this question, we need to first look at how Solar PV (Photovoltaic) panels covert Solar energy into electricity.
Solar panels are made of small Solar cells and the most common material used to make them is Silicon, a semiconductor that is the second most abundant element on Earth. In a Solar cell, crystalline Silicon is sandwiched between conductive layers. Each Silicon atom is connected to its neighbours by four strong bonds, which keep electron in place so no current can flow. A Silicon Solar cell uses two different layers of Silicon. An N-type Silicon has extra electrons and P-type electrons have extra spaces for electrons, called holes. And where the two types of Silicon meets electrons can wander across the P-N junction, living a positive charge on one side and creating a negative charge on the other.
When light (photons) strikes the PV panel with enough energy it can knock an electron from its bond, leaving a hole at N-side. Then negatively charged electron and location of the positively charged hole are now free to move around. But because of the electrical field at P-N junction, they will only go one way. The electron is drawn to the N-side while the hole is drawn to the P-side. The mobile electrons are used to power electrical equipment with the help of conducting metal plates from there they flow through an external circuit doing electrical work before returning to the conductive aluminium sheet. Each Silicon layer generates around a half Volts but you can put them in series to generate more electrical energy. 12 PV cells are enough to charge a cell phone, but to power an entire home we need a lot of such Solar cells. Electrons are the only moving things in an entire Solar cell and they go back where they come from. There’s nothing to get worn out or used up so Solar cells can last for decades.
Now let us look at how electricity is converted. The energy which is generated by PV panels is of DC type but most of the electrical gadgets at home are powered by AC. That is where the inverter comes into the picture, an Inverter is a device which is used to convert DC into AC, which is then supplied to electrical equipment. And the excess electricity generated is either stored in the battery for backup purposes or sent to a grid where it can be used by other customers.
So what is stopping us from being completely reliant on Solar Power? I will explain it on the next blog. Thank you for your time!
Switch to renewables! Go green! Go electric!
External Link: https://www.originenergy.com.au/for-home/solar/why-solar.html
– Pankaj R. Gode.
Illuminating The Dark Fields 