Solar Power Technologies

Solar energy, as everyone knows, is the energy derived from the sun. Solar energy has gained popularity in recent years and a lot of new methodologies and gadgets have been developed to harness it. The boom in the solar industry that is expected in the recent future, is driven by the high increase in oil prices and the search for cleaner, cheaper and a more reliable source of energy. But, the prevalence of solar energy has been there since the time the earth was formed or, as rightly said, since minutes after the big bang. Solar power is nothing but the heat, which in the form of radiation, reaches the earths’ surface. In a broader sense, solar energy is the heat energy exchange between any star and its planets.

At first, we need to understand the first law of thermodynamics, popularly known as ‘law of conservation of energy’. It states that, “Energy can neither be created nor destroyed, but, merely converted from one form to another or carried (transported) from one place to another”.  As a science enthusiast, ones understanding shall stretch far beyond this. When oil is burnt, chemical energy in the oil is converted to thermal energy as heat and when a ceiling fan spins, electrical energy is converted to mechanical energy. Considering both the cases, the energy before the energy conversion and after are the same. This means that the quantum of energy contained in the electricity is the same as that of the spinning fan. It also means that the energy of the universe during the big bang equals the energy it will have during dooms day.

 So, at what expense does this conversion occurs …???

 There is no physical/measurable sacrifice that happens. Sacrifice here means consumption. Something has to be consumed to produce another. Fuel is consumed to run a vehicle. Food is consumed to gain energy. But in the case of an energy transfer, there is no consumption but mere conservation. But this does happen in nature every day in front of us. How does this happen ??? and What is consumed ???

This thought gives rise to a another physical quantity named “Quality”. Energy has two forms, quantity and quality. Law of conservation of energy is a quantitative representation of energy balance and does not take quality into account. Quality is not measurable. It is only felt. Something analogous to smell, you know something smells, but you can’t quantify the amount of smell that travels along the air you breathe. With every energy conservation, there is reduction in quality of energy. Thus, quality plays a very major role in deciding the usability of the energy source.

On analyzing the formation of our fossil fuels, we know that, coal and petroleum are formed due to the prolonged action of high temperature and pressure on vegetable and animal matter buried under the earths’ crust. Now where does vegetation get its energy from ??? Due to photosynthesis, and photosynthesis occurs due to absorption of solar energy. So, we can clearly conclude that, fossil energy is basically solar energy after three conversion processes or after three quality reductions.

Apply the same to hydro power plants. Why does the dam get filled???- Due to flow of water. How does water flow???- Due to melting of ice, which is aided by the sun. How does ice get formed???- Due to snow fall. How does snow fall occur??? – a result of precipitation. Why does precipitation occur??? – Due to evaporation. And why does evaporation occur??? – Due to solar irradiation.

One should understand that addition of water to air does not make it heavier; rather, it makes it lighter. If you consider a particular volume of dry air and the same volume of moist air, the density of moist air will be lesser. This can be easily understood by the empirical deduction that when water evaporates from the oceans, it raises rather falling back into the oceans. Again, hydro energy is nothing but solar energy after three conversion processes. With this we know that solar power is superior to all other energy sources in the earth.

Is there any other source of energy superior to solar? YES – nuclear energy. The very reason why sun light is being produced is because of the nuclear fusion reaction that occurs in the core of the sun. And is there any other form of energy far superior than atomic energy? YES – antimatter. I will probably get back to this later. Let’s get back to where we were heading.

Thus proving that solar energy is the chief form of energy, due to its higher quality, it is wise to extract energy from that chief form. But unfortunately the technology to extract this chief form at a cheap rate does not exist. Time and need will surely create the technology in the future.

Now let us analyze some numbers. The average solar irradiation on the earth varies from 1600 – 2500 KWh/m² per year. This means that an average house  approx. 20m², receives around 35,000 KWh/year i.e 35,000 units of energy. The average Indian household requires 10,000 – 15,000  units of electricity a year. We now know that high quality energy is available to sustain an entire household for a full year. But it is not practically viable or this is too farfetched an idea in the early space age that we live in.

So what is the problem with the solar energy.?
When people can understand its potential, why aren’t we using it.?

Keep thinking … will get back soon on this.