What Is Solar Energy and How Do Solar Panels Work?

Energy runs the world, literally. What can be scarier to a fast-paced world than depleting energy sources? Well, perhaps, the fact that its energy sources are pushing the natural world over the edge as well!

Do you know what they say about going straight to the top when confronted with an issue? Well, when we choose solar energy, we are doing just that – skipping the intermediate reserves of finite energy that we call non-renewable, most of which, interestingly, are different forms of solar energy itself, and approaching the one at the top – the very source of all energy – the Sun itself for our energy needs.

Put simply, solar energy is the energy of the Sun. Did you know that the solar energy Earth receives in an hour is more than all the energy needs of humankind of an entire year? (National Renewable Energy Laboratory, US)

But, then, how do we harness solar energy to meet our needs of, say, electricity? The answer comes in the form of Solar Panels.

What are Solar Panels?

Yup, you guessed it right. The pictures of slant, rectangular slabs shining on rooftops you come across in websites and magazines next to descriptions of solar energy are those of solar panels. Think of solar panels as open surfaces that collect sunlight to transform its energy into electricity.

What is Solar Energy

A typical solar panel consists of

  • Solar cells – This is where the real action takes place, the ‘photovoltaic effect – the phenomenon of the conversion of sunlight into electrical energy. Solar cells are made of semiconductors called Silicon. Also, solar panels have an anti-reflective coating meant to discourage Silicon from bouncing off photons, i.e. particles of sunlight, before the photovoltaic effect takes place.
  • Glass casing and backing sheet – The fragile solar cells are held together between layers of a glass case and backing sheet, offering them protection, durability, and insulation.
  • Metal frame – A metallic frame, usually made of aluminium, is fitted around the panel such that it can be fixed onto a support structure.
  • Wiring – Think of these as the nerves of the entire system. The electric current that gets generated in the solar cells due to photovoltaic effect is transported via the various wiring that has been installed in the panel.

How do solar panels work?

The entire process of deriving energy from sunlight to power the electrical appliances takes place through four steps –

1.  Photovoltaic effect

That sunlight can ignite certain materials to give off electricity has been known to Science since the first half of the nineteenth century. But it was only in 1950 that Science arrived on the magical semiconductor called Silicon (yes, of the ‘Microelectronics’fame) as the ideal material upon which this phenomenon can be best exploited to harness solar energy.

The nitty-gritty Physics of a solar cell:

Are solar panels made of only the element Silicon? Not exactly. Since Silicon is a poor conductor of electricity, additional elements, namely Phosphorus and Boron, are added, rather ‘doped’, so that the resulting amalgamation produces an electrical field within the cell. The Silicon layer in which Phosphorus has been added acts as the ‘N-type’, while the one doped with Boron acts as the ‘P-type’. The ‘N-type’ layer has an excess of electrons, while the ‘P-type’ has a deficiency of the same. Right at the junction where they are combined, these get mixed forming a kind of barrier for further electrons to move from N-side to P-side. At the state of its equilibrium, an electric field is created in the cell due to the difference in electric charge on its two sides. This resulting electric field is crucial to the functioning of a solar cell, without which the electrons that get freed when exposed to sunlight would not have flowed in a certain direction. The existent electric field compels the electrons that are freed by absorption of sunlight to seek an external path, which we provide via wiring. As electrons from the P-side rush through the external path, i.e., wiring, towards the N-side, we have succeeded in creating an electric current -voila!

2.  Conversion of DC to AC

The nature of the electric current that gets generated due to the photovoltaic effect in a solar cell is unidirectional, i.e., it is a Direct Current (DC). Most electronic appliances we use in daily life are designed to work in AC (Alternating Current) though. This is where the role of an inverter comes into play. The inverter converts the Direct Current generated by solar panels into Alternating Current, at which point it is ready for use.   

Thus, if it is the solar panels that produce electricity, it is the solar inverter that makes it usable for our electrical appliances. 

3.  Distribution for home’s energy needs

The Alternating Current from the inverter is then ready to light up your homes, bring the cooling touch of air-conditioners and set all other electrical gadgets of yours in motion. There is a difference though, you can now be assured that the power you consume is in no way creating dents in the earth’s atmosphere by increasing the carbon emissions.

4.  Surplus supplied to the grid

The surplus power that your solar panel may produce is supplied to the grid, which can be distributed elsewhere via the conventional mode. You will receive credits for the same in your next month’s electricity bill!

Wait, why are we still using the grid?

Aren’t we getting rid of the grid altogether? Why is the conventional electrical grid still in the picture?

The thing is unless your home is in a remote location where the conventional electrical connection hasn’t yet been established, what you would be employing when you install Solar Panels from Minus CO2 is what they call the ‘on-grid’system. This means that your solar panels work in conjunction with the conventional electricity grid to provide for your electricity needs round the clock. This ensures that you suffer no issues that might factor in due to weather fluctuations, variations in sunlight due to day and night etc. Thus, when you install Minus Co2’s Solar Panels in your home or commercial building, up to 80% of its electricity needs would be supplied by the solar power, while the remaining 20% might be through the conventional electricity line. In addition, if your system generates more current than you consume, which it mostly will, the excess current is supplied back to the grid compensating for the times you may be deriving electricity from the grid, creating a win-win situation for everyone involved.

As is clear from the nuanced explanation of what really goes into the conversion of solar energy to electrical, the efficacy of the process would depend on the quality of the Solar Panels in place. When you say ‘Yes’ to Minus CO2, you are not just saying Yes to any solar panel but that of the finest the market does provide. You can be pretty assured that your Solar Panels is functioning at the very frontier Science has been able to reach in tapping into the amazing gift of solar energy.

So, less electricity bill, happier planet, efficient and cleaner power – what more do you need to say Yes to switching to Solar Power System from Minus CO2?