What are renewable energy sources and why are they so important? We keep hearing these terms “renewable energy”, “renewable resources”, “renewable energy sources” all over the news and in political discussions world wide. But what is meant by these terms? Renewable energy sources are, absolutely and fundamentally, the types of motion we, or, rather, the earth, can replenish. Short of blowing up the earth, these energy sources would continue to exist, extracting energy from the ecosystem, and delivering it to us in easily usable forms.
This is quite different from the major sources of energy we use right now, namely fossil fuels. True, if we did use all of our fossil fuels, they would eventually one day be replenished. But it takes the earth tens of thousands of years, maybe longer, to filter the carbon out of the atmosphere and put it back under the soil. Because this process takes so long, we consider that fossil fuels are non-renewable. No one alive now will ever see these energy sources put back in the ground.
But we were talking about renewable energy sources. What types of these resources exist?
– nuclear energy
– hydroelectric energy
– wind energy
– geothermal energy
– biomass energy
– solar energy
to name just a few. Let’s examine these a little more, shall we.
Nuclear energy as a renewable resource is a bit of a misnomer as we really completely destroy matter to get usable energy. But nuclear energy is sometimes considered one of the renewables simply because we will probably never run out of nuclear material. Not only do we have a seemingly infinite supply of fissionable material, but each atom we use has an incredibly large amount of energy. Einstein was kind enough to actually tell us how much energy we would get. Hint: e = mc^2.
But, despite the incredible energy yields we get from splitting atoms, there are some not quite so kosher side effects. Namely radiation. It can kill you. No joke. We also have a major environmental danger in the form of a nuclear meltdown. Just ask the residents of Chernobyl how fun that was. Perhaps nuclear energy is amazing, but perhaps we can find another way too.
Hydroelectric energy is the creation of energy through water power. Normally what happens is a dam is built to capture the energy of water and then water flow is regulated and turns a turbine or turbines as it is released downstream. This is a renewable resource because, as long as it continues to rain, the river will continue to fill up and we will have water running downhill, hopefully, forever. Or at least until the earth becomes a barren desert wasteland.
Unfortunately, there is a little bit of a problem which is inherent in this type of dam. Most notably, when we build them, there is an unavoidable need to move the local dwellers of the affected area. Humans are forced to move, usually with no assistance provided in relocating. The local wildlife is also out of luck. The area is flooded and no thought is given to how this might possibly completely destroy the local ecosystem.
Wind energy rocks. Wind turbines have begun springing up in all kinds of places, but usually in the places that have wind. Really the only drawback to wind turbines is that the electricity they produce is very sporadic. Sometimes the wind blows, sometimes it doesn’t.
This is the action of taking energy from heat generated by the earth and converting it into energy we can use. This could theoretically be around as long as the core of the earth is molten.
This one is composed of wood, leaves, tobacco, grains, dung, farts, wool gloves. Basically any organic matter that can be burned. Another alternative is collecting gases that are given off by decomposing organic material. This one’s easy though. It’s renewable because life reproduces.
Solar energy is considered renewable because it is always shining. It is going to be a few million years before the sun burns out. Believe it or not, all the energy for every living organism originally came from the sun. The sun is actually the source for all energy that you find here on planet earth. However, the sun’s energy is directly converted to electricity through the use of solar cells. And for this reason, photovoltaic cells could easily lead us into an enlightened age.