Renewable Souces of Energy

Renewable sources of energy
A way to stop the problem of Global Warming is to get rid of the greatest source of CO2 emissions. The biggest source of Carbon Dioxide emissions are power stations that burn fossil fuels.

So if the coal power stations are replaced by the renewable sources of energy it will reduce the concentration of CO2 but also get rid of the coal mining and transportation, which have huge environmental impacts such as deforestation, water and air pollution and also CO2 emissions from transport. Most wide spread types of renewable energy are hydro electric energy, solar energy and wind energy. However hydro electric power requires blocking the river with huge dams to provide sufficient amounts of energy. Therefore it causes problems downstream, as it interrupts in the natural processes of the river. Having studied the dams and their effects, I would eliminate them from my choice of possible solutions of renewable energy as though it doesn’t emit CO2 it harms the environment in other ways.
Solar energy
Solar energy I relatively new area of energy production, which was developing in very fast pace over the last few decades. There are different solar panels on the market. They should be compared by cost effectiveness to see which one is the best, to know what the total output of energy they have is and how many panels would it require to get rid of the fossil fuels for good. Using the British site “http://www.comparemysolar.co.uk” It is possible to extract data for different producers of solar panels for comparison.

For four different producers of solar panels the effectiveness of one panel was compared to its productivity. Effectiveness was calculated by dividing its energy output by cost of setting up one panel.
On the scatter graph data for different producers was marked in different colours to make it clearer to see if there is any correlation. It seems as for each of the producers there is a different correlation: For GD solar and electrical the effectiveness of panels increases as their productivity increases however for EvoEnergy it seems to be pretty much the same. Drawing a trend line showed that there is a slight positive correlation that can be summarized by saying that the more energy one panel produces the more cost effective it is, even though it can cost more than the smaller one. However to prove that there is a positive correlation it is possible to use Spearman’s rank.
To start with I state that there s a significant correlation between the productivity and effectiveness of solar panels. Now in the table below all the values are ranked from highest to lowest and then the difference between the ranks and difference squared are calculated to be used in the formula: 1-6d2n3-n. n | Energy Rank | Effectiveness Rank | Difference in ranks | | kWh | rank | Kwh/₤ | rank | d | d2 | 1 | 4330 | 16 | 0.28 | 16 | 0 | 0 | 2 | 5620 | 13 | 0.35 | 13 | 0 | 0 | 3 | 7340 | 10 | 0.40 | 11 | 1 | 1 | 4 | 21750 | 1 | 0.45 | 10 | 9 | 81 | 5 | 5500 | 15 | 0.55 | 5 | 10 | 100 | 6 | 6500 | 11 | 0.62 | 2.5 | 8.5 | 72.25 | 7 | 8520 | 8 | 0.59 | 4 | 4 | 16 | 8 | 16200 | 3 | 0.62 | 2.5 | 0.5 | 0.25 | 9 | 6030 | 12 | 0.46 | 9 | 3 | 9 | 10 | 10090 | 7 | 0.49 | 6.5 | 0.5 | 0.25 | 11 | 12110 | 5 | 0.49 | 6.5 | 1.5 | 2.25 | 12 | 20450 | 2 | 0.47 | 8 | 6 | 36 | 13 | 5520 | 14 | 0.30 | 15 | 1 | 1 | 14 | 7950 | 9 | 0.34 | 14 | 5 | 25 | 15 | 11140 | 6 | 0.36 | 12 | 6 | 36 | 16 | 15240 | 4 | 0.63 | 1 | 3 | 9 |

Now the sum of squares of differences can be calculated: d2 = 389. Then
1-6d2n3-n = 1-6*389163-16 = 1-23344096-16 = 1 – 0.572 = 0.428
Now to be significant value should be more than 0.564, so using the spearman’s rank, the weak or no correlation was determined. It means that this pattern could be caused by the chance.
However from the scatter graph, it is clear which the most efficient solar panel is. It produces 9535 kWh of energy and costs ₤ 15540 per year. It will be used to compare with the most effective wind turbine.
Wind turbines
Wind energy is providing about 3% of energy worldwide, however the possibilities are huge wind turbines can be placed off shore, in deserts, in the mountains, where they don’t affect people and animals almost at all. However there is a question of what I better smaller or bigger turbines?
Having gathered some data about wind turbines cost and production I will compare tiny turbines, medium ones and huge ones much like the solar panels were compared.

The effectiveness of the wind turbine is its productivity divided by its cost. And as the exponential trendline increases, it means that the cost effectiveness increases.
When compare the efficiency of the smallest turbine with the biggest:
2.5/10000 = 0.00025 the cost efficiency of the small personal turbine.
2500/3300000 = 0.000758 The cost efficiency of the huge industrial scale power turbine
It is clear that efficiency of the big turbine is 3 times the efficiency of the small one. So the summary is that the bigger the turbine is the more effective it is, then there is another question: why not build an enormous wind turbine, for example the size of “Empire State Building” . The problem with huge turbines is that they are either unstable and have a risk of falling down, or they are too heavy for wind too turn them.
So the best performance possible has the 2500 kw turbine, which will be used for comparison.
Comparing wind turbines and solar panels
Best found solar panel produces 9535 kWh per year has dimensions of 65m2 and costs ₤15240.
Best found wind turbine has power of 2500 kW is 100 m high and costs 3.3 million pounds.
To compare them it is nessasary to convert their power generation to identical units. It is easier to convert kW to kWh per year. There are 365*24 hours in a year so 1 kW is 8640 kWh per year. That means that wind turbine generates 21600000 kWh per year.
When this amount is divided by that produced by the energy produced by one solar panel, the result is the number of solar panels that generate the same amount of energy as one wind turbine:
21600000/9535 = 2265 panels, this amount of solar panels costs 2265*15240 = ₤34523754 which is 10 times the cost of one wind turbine. Moreover this amount of solar panels would cover 138185 m2 = 13.8 hectares of land, when wind turbine would require about 100 m2 of land for its base.
To sum up, wind turbines are much more cost efficient and space efficient then solar panels, so they are much better to invest to stop global warming.

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[ 1 ]. The 102- story skyscraper in Manhattan, New York.