Solar Energy And The Optimistic Approach

So we have been talking about all the various problems of solar energy. And I am sorry to start it off with such a negative note but I did it because I wanted to end it on a positive note.
Yes , that’s right, solar energy holds a lot of potential And it “IS DEFINITELY” the future of our energy needs.

So why is everyone so optimistic on solar energy?
It’s simple. Because ever since life began on earth nature has always depended on solar energy for it’s continuous energy needs and evolution. Even the fossil fuels we use are indirect products of solar energy. The solar energy provided the animals and plants with energy as we know by photosynthesis and the food chain. These plants and animals died and their remains were buried under pressure and heat to form coal and petroleum as we know today.

So it’s obvious that solar energy should be our natural choice to be looking for. In fact Thomas Edison said that solar energy was the most natural as well as the most abundant source of energy available for us. Hence it is imperative that we try to find ways to harness it as much as possible.
So what’s the solution?
Simple!
Never give up!

That’s right scientists are striving today to make solar energy as much viable as possible and I have good news for you!!! Solar energy has made quantum leaps and it is proving to be a boon for many cities with abundant sunlight. Even during the night!

Here are some of the problems which are being tackled about solar energy.

Efficiency
The biggest drawback to efficiency is costs . Well scientists have been working on just those lines and they really have managed to increases efficiency and reduce costs as well. Yes they have developed new techniques and methods to greatly enhance consumer level use. It won’t be long before you will see everyone changing their power supplies just like how everyone is going digital from cable TV.

How?

1) Quantum dots
The solar PV cells are made even more tiny so that a greater surface area is exposed to the solar radiation resulting in good efficiencies.Nanotechnology holds huge promise in energy harnessing storage, as well as other industrial needs and the energy companies are no exception. And the best part is there has been steady progress in using quantum dot PV cells.
Quantum dot solar cells could offer a cheaper, more efficient alternative to conventional ...

2) Splitting the solar spectrum
Solar PV cells use only a part of the solar spectrum to produce usable energy. The remaining part is lost as heat. This heat can actually reduce the efficiency of the system. Now given how summers can be blazing hot in India especially. We wouldn’t want a power supply that runs on solar power and yet gets fried with excess heat.

Now this is where material scientists(the broader group under which falls the nanotechnology scientists) play their part in making the cells more heat resistant and usable under heat. A new technology uses a material such that it emits only those wavelengths which are harnessed by the cells to produce energy.

Some people have even used the simple fibre optics which was originally used in communications. But since it characterises no loss transmission it is also a pioneer in using correct frequencies.
optical fiber solar cell
3)Concentration cells
Concentration cells uses parabolic reflectors to focus the sunlight onto a small area of the PV cells which is found to increase efficiencies amazingly. Photoelectric emissions which requires greater frequency to produce electrons of good kinetic energy, while  photoelectricity requires greater intensity of sunlight to produce more electricity.

Hence we have a reduction in costs with materials used and we get more usable energy from the same amount of solar radiation. So it’s a pretty neat technique.

But what about the production of energy during the night and what about cloudy and rainy seasons?
Again I have good news as researchers have found more and more efficient ways to store solar energy during the night time as well. A new method that they have developed is using lots of reflectors to focus the radiation onto a tower. That tower contains a form of salt and the solar heat melts that salt to a molten state. This molten state dissipates heat very slowly and it is kept in as much thermal insulation as possible. During the night the heat from this molten salt is used to power up homes during the night!! In fact it can well last for 8 to 10 hours for commercial needs of a locality. Not bad for a salt based system!

As for the seasonal changes that’s where the limitations come in. But researchers are still working on high altitude solar panels and increased efficiency panels. In fact here again fibre optics plays an optimistic role in transferring energy from high altitudes. However it won’t be enough for commercial energy needs and this is where the other renewable sources come to play like hydel energy, wind energy.

In fact if you think about it carefully summer is the time when there is no wind or rain and solar panels would rule. But the other seasons are sufficiently more windy and rainy which means that wind and hydel power would be a boost. So the various renewable energy sources complement each other.

After reading about so many new revolutionary inventions and techniques the world doesn’t seem so bleak due to the global warming catastrophe anymore does it? However that does not give us reason to continue our wasteful ways. We must continue working on sustainable development so that our future generations continue to reap the benefits of nature and keep the human race moving forward.

Solar Energy

I am sure solar energy requires no introduction. Today India is being rocked by issues like the Nuclear proliferation treaty, coal scam etc. These are primarily because of the impending energy crisis that the world will come face to face with soon enough. And India is going to be one of the worst affected as it is one of the most densely populated countries. We recently got a glimpse of what might happen when fossil fuels get exhausted when there was a massive grid failure in the northern parts of the country. It was because of the fact that some of the states drew more than excess power that caused the generators to slow down thus disrupting the entire grid. It exposed the country’s dependence on fossil fuels only and the impending need to promote renewable energy sources. Sadly our policy makers are not too concerned with tapping alternative energy sources while all efforts to do so(nuclear power) is met with opposition for petty politics.
However there are plenty of other sources as well. While hydel power is a prospective source of energy in India it is consequential because it can damage fragile ecosystems and displace entire populations. Then naturally Solar energy seems to be the logical choice.
So what’s stopping them from adopting solar energy?
Two things:
a) Cost
b) Erratic supply
a) Cost
Yes like any other new product in the market costs determine how effectively it can be implemented. The biggest problem with solar energy is that it is very expensive. Yes it takes about 2000$ just to install solar Photovoltaic(PV) modules plus even in the well developed sunny states of the U.S. the cost of solar cells is about 0.11$ / kWh. Now that really is expensive if you compare it in the Indian currency.
b) Erratic supply
Yes it is true that India has a huge amount of solar radiation input being in the tropics and everything working out to be fine India should be having more than enough energy to compensate for the energy needs of the country. BUT we should also try to remember that India is a place where the monsoons cover the Indian skies with clouds for a considerable part of the year too. This does deter the energy supply and this would have been a cause of great distress among the millions as energy demands are high and an uninterrupted supply is necessary in many parts of the country. Plus supply during the night time would be a huge problem as there is no effective way to store energy obtained during the day.
But what exactly is  a photovoltaic cell?
A photovoltaic cell uses photons from the sun’s energy spectrum and converts it into kinetic energy of electrons.

It has an antireflective coating at the top to remove any sort to prevent loss of solar energy by reflection. As can be seen from the diagram, The photons strike the electrons at the junction of the p type and n type semiconductors to create a voltage difference. This voltage causes a current to flow in the closed circuit.
If solar energy needs no investment other than maintenance to continue then why should the initial high cost be a problem?
Well the problem comes from the fact that efficiency of solar PV cells is very small. Typical energy efficiencies are about 8 to 10% today. In fact all the major corporations of the world are working on increasing efficiencies as you read this article.

As you can see the technology used increases efficiency a lot. But what is not mentioned here is that the cost of increasingly complex technology is quite high. Efficiency determines the fate of new technology as solar pv cells are no exception.
But that does not mean that solar energy does not hold promise. For it has been calculated that the amount of solar radiation the earth receives at the sea level is more than enough to supply 8 times the energy requirements of the World’s population.

CBSE Published Question Paper and Answer Key of Proficielncy test 2012

Download Question Paper and Answer Key of Proficielncy test 2012 published by CBSE

Mathematics (Set-A)
Mathematics (Set-B)
Mathematics (Set-C)
Mathematics (Set-D)
Science (Set-A)
Science (Set-B)
Science (Set-C)
Science (Set-D)
Answer Key – Mathematics
Answer Key – Science

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