Solar Energy in Glenforest

Gryphons Need Some Sun!

Our Energy Sources

The world revolves around energy - everything needs it! Energy can be harnessed through many ways - in Canada as of 2009-2010, coal and crude oil make up of more than 50% of our primary energy production. However, these sources are known to pollute the environment, and are not renewable. This means that once they run out, they run out! Renewable Energy is something that comes naturally and is sustainable, so it won't run out any time soon. Because of how fast fossil fuels are running out, and its in environmental impact, renewable energy sources are now constantly being sought after.
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What is solar energy?

Solar energy is an extremely viable option for a renewable energy source, the sun produces an enormous amount of energy. Over 1000 watts of per square yard hits earth's surface everyday. According to a 2011 projection by the International Energy Agency, solar power generators may produce most of the world’s electricity within 50 years. Doing so will reduce the environmental impact we have, as it is common knowledge that non-renewable energy sources emit harmful pollutants into the atmosphere. Solar energy is essentially harnessing energy from the sun to use, and its quickly becoming more and more popular!


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How it Works

Solar cells, or Photovoltaic cells convert sunlight directly to electricity. Most of these cells are made of semiconductors, such as silicon. Basically, when sunlight hits the semiconductors, some energy is absorbed. The energy absorbed knocks the electrons loose, allowing them to flow, thus creating electricity. Below is a simple picture showing the basic process.


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Environmental Impact

Emissions
The burning of fossil fuels is the number one source of carbon dioxide emissions, a harmful greenhouse gas. Solar power is regarded as an "emissions-free" form of energy. However, the building, installation, maintenance, etc are bound to have some sort of environmental impact. Even so, solar panels generally pay for themselves after a decade or so, both money wise and environmentally wise (the cost of the energy produced will eventually outweigh the cost of producing and installing, and the environmental impact of installing solar panels are much less than other traditional energy sources such as coal, etc)

Surrounding ecosystems
One of the main concerns of building large scale solar energy farms is the impact it would have on the ecosystems surrounding it. There is still debate on whether the benefits of the solar farm outweigh the possible disruption in the surrounding ecosystems. However, this is not a great concern for our case - using solar energy in Glenforest, as we are not doing anything of this big scale.


Efficiency

It was mentioned before that over 1000 watts of per square yard hits the earth's surface everyday. However, today's solar panels are not able to capture all of that energy. Some of the best solar panels are only able to harness around 20%. This is because solar cells today are only sensitive to small portion of the sun's whole light spectrum.

As we know, visible light is only a small part of the electromagnetic spectrum. Electromagnetic radiation from the sun is made up of a large range of different wavelengths, and thus different energy levels. Because the light that hits the solar cells have a wide range of energies, some photons will not be strong enough to move the electrons. Other photons will be too strong, and the extra energy is lost.

The fact that a semiconductor like silicon is used should be considered as well. Because it is not nearly as good as a metal is for transporting current (it's internal resistance is fairly high), more energy is lost. This, coupled with the problem mentioned above is why most solar panels are only able to harness 20%.

However, remember that times are quickly changing and technology is developing faster than ever. There is no doubt that the efficiency of solar panels will only increase. In fact, an article was published very recently (May 9th, 2013), stating that a team at the California Institute of Technology are working on a solar cell that is designed to absorb a larger portion of the the sun's rays, changing the current 20% efficiency to 50%, more than double!
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The graph above shows the development of general efficiency growth in solar panels. The blue and green lines show the most commonly used solar panels today. The purple lines show the efficiencies of much more advanced and costly panels, generally used for space.


Applications to Glenforest

On average, a solar panel nowadays will produce 10 watts per sq-foot, and will be able to provide output for about 5 hours a day (slightly more in summer, slightly less in winter), averaging about 1800 hours a year.

10 watts x 1800 hours = 18 000 Wh = 18 kWh per square foot

Glenforest is approximately 100 000 square feet. Assuming we cover 75% of the roof with solar panels, we would have 75 000 square feet of solar panels.

75 000 x 18kWh = 1 350 000 kWh per year generated by Glenforest

An average building uses 17kWh annually per square foot. This means Glenforest uses:

17 kWh x 100 000= 1 700 000 kWh annually.

Dividing the amount of energy produced by the amount of energy used will give us a percentage of how much of our energy is generated by the solar panels.

1 350 000 / 1 700 000 = 0.794 = 79.4 %

In summary, if Glenforest were to cover install solar panels covering roughly 3/4 of its roof, approximately 80% of its energy consumed would be generated from the solar panels! However, the cost of installation and production would be huge, it would be much different from installing solar panels on a house simply due to the sheer amount. Although the solar panels would pay for themselves in roughly a decade, this would be impossible if there wasn't a program or funding set up from the government.