Today’s modern world depends more and more on electricity. We consume much fuel, heating and electricity, but everything has its price. Let’s have a look at what our normal power is composed of, what conventional energy does to our planet and how “green energy” can look like.
Conventional Energy
The term conventional by itself means common or traditional. In regards to energy we address sources that have been in use for a long time. Common sources of energy are fossil fuels like petroleum, natural gas and coal. The problem we face with fossil fuels are on the one hand the limited quantity of available resources and on the other hand the environmental pollution. Oil and natural gas are products of dead organisms like plankton and seaweed. When these organisms die in deep waters, where no oxygen is reaching the ground, they decompose. Over time they mixed with mud and were buried by many layers of sediments. The more layers on top the higher the pressure and heat became. Chemical processes turned what’s left into hydrocarbons, which moved towards the surface. Short hydrocarbon molecules are found as gas, whereby the longer molecules form liquids. This process takes several hundred millions of years and explains why today’s fossil fuels are limited.
The process of winning energy from coal, gas and oil are all very similar. In a simplified schema, coal is put into a boiler and burned. The heat causes water to evaporate which as a results brings the turbine into rotation. The mechanical energy in the turbine is transformed into electrical power with the help of a generator. As you may noticed, almost all power pants are located near water. Now we know why.
Fig.1 Power plant construction Credits
The products of combustion are eliminated into the air where they are causing the environmental pollution. Let us break down how fossil fuels are burned.
The chemical process is again the same: hydrocarbon reacts with oxygen to carbon dioxide and water.
Carbon dioxide and water sound harmless so far, this might be correct in terms of toxicity, but it damages us in the long term (keyword: greenhouse effect). The greenhouse effect is heating our environment slowly but steadily. The reason lies within our atmosphere. While sun rays can pass through clouds and gases, thermal radiation can’t.
Global warming gases like carbon dioxide, methane, ozone, water vapour etc. absorb the thermal radiations and causes the earth to heat.
It goes even further as smog is polluting the air. Small particles are wasting fresh air, there are even cities where people wear masks in order to not inhale the smog.
The following pie chart shows that 85.5% of our energy is from fossil fuels and only 10.1% by renewable energy sources. A common misconception is that most of our electricity is won from nuclear fission. Only a tiny portion of 4.43% makes the amount of nuclear fission.
Nuclear power plants do not emit any green house gasses and therefore don’t play a role in heating our environment. However, gaining energy though nuclear fission requires enriched uranium. While the actual waste of fossil fuel power plants are only carbon dioxide and few other particles, nuclear power plants produce radioactive waste. There is a problem with disposing the waste since it needs a safe storage. Another issue with nuclear plants are incidents where the plant is damaged and radioactive material leaking (Fukushima/Chernobyl).
Fig.2 World energy consumption 2015 Credits:
Renewable Energy Sources
Now we will investigate different sources of renewable energy as well as their benefits and disadvantages. The main advantage of “green” energy is that it’s practically indefinitely available. Wherever the sun shines, air streams or water flows we can win energy. The following are leading examples of these sustainable sources.
Solar power
Fig.3 Solar panels. Credits:
Solar panels are used to absorb sun rays and convert them into energy. The principle behind this is called photovoltaic. Through the photovoltaic effect photons generate electricity. There is no byproduct or waste and solar panels can be used anywhere where enough sun is shining. Depending on the efficiency of the panels which is up to 21% for commercial use, only 7 square meters of panels are needed to win one kilowatt.
In areas of less sun, solar panels are ineffective and too expensive. A typical solar installation costs around 25.000 Euro.
Wind wheels
Fig.4 Wind turbines. Credits:
One of the most efficient ways to win sustainable energy is the use of wind. The rotor blades are moved by the wind and rotate. This mechanical energy is converted with a generator into electrical energy. The principle is the same as with the power plants, just we have no environmental waste products. The space it takes is less than any other method requires. Though it might not deliver enough energy to supply a whole city, it is very useful. The problem so far is that these wind turbines only can be used where wind is. Often at the coast and mountains.
There are many more ways to win electricity from renewable sources. Besides solar and wind energy, there is geothermal energy, hydroelectric plants and bio plants.
One of the reasons why we still use conventional energy is that renewable energy is too expensive yet. Fossil fuels are cheaper and more commonly used. Conventional energy sources are more reliable at the moment as wind and sun are depending on the weather.
With less sun and wind there will be less power. Nevertheless the benefits are obviously. Clean power and sustainable energy for the next generations. Cities or even country are independent from big companies and the price fluctuation of oil and gas doesn’t have an impact any more.
Germany obtains 29% of its total energy from renewable sources at the moment and its getting more and more.
Fig.5 Energy consumption in Germany. Credits:
What is the best solution?
In fact people can discuss and find pro or contra arguments for both sides. As for me I am of the opinion that we slowly have to replace the conventional with the renewable energy sources. Our planet is suffering from the industrialization and can’t recover. Weather phenomena like storms or tsunamis world wide are getting more intense and worse. One day we will have consumed all fossil fuels and if we don’t have alternatives up to then, humanity will have to face serious issues. Lucky scientists around the globe and working on new technologies. One of the most promising approach is the use of nuclear fusion.
Nuclear fusion is the process where two atoms fuse to one. This is happening for instance in the sun where hydrogen is fused to helium. Sun is basically nothing more then hydrogen and helium.
Fig.6 Hydrogen fusions to helium. Credits:
What do you think? Do we need more renewable and sustainable energy or should we continue the way we did? While our needs require more electricity our resources become less. How long will this calculation work?
Thank your for reading on my blog. I hope you enjoyed the article and if you have questions feel free to leave a comment.
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