Renewable energy has been a subject of extensive research as well as debate but it is still something that many of us don’t know much about. Electricity is something that, much like water and other necessities, we often take for granted. We all know that electricity must be generated – perhaps by a large dam, the burning of fossil fuel, or even by nuclear fission – but we should never forget that the energy sources with which we produce electricity must be renewable if we are to continue enjoying its benefits on such a large scale.
One thing we do know is that there is a limit to the fossil fuels that are available, not to mention most countries don’t have their own supply so must rely on imports to quell their enormous demands. And availability isn’t the only problem fossil fuels face. The burning of fossil fuels produce large amounts of greenhouse gases which in turn contribute to the pollution of our environment as well as the greenhouse effect. Recent earthquakes and subsequent fuel shortages have served as a reminder of how unprepared we are in the absence of oil.
Although nuclear power is extremely efficient in terms of cost and capacity factor – typically around 90% as opposed to say, hydroelectricity at 44% – there are several obvious drawbacks. Images of Chernobyl and Fukushima Daiichi immediately come to mind. Current nuclear reactors use what’s called nuclear fission to split atoms and thereby generate energy. But this method triggers a “chain reaction” of atom-splitting which although conducive to generating lots of energy, is also harder to control. Naturally, there are many safeguards to prevent the nuclear fission from getting out of control.
But if or when this chain reaction gets out of hand, you have what happened at Chernobyl – a nuclear meltdown. Granted, there are safeguards that should have been implemented there but weren’t such as the 1 meter thick concrete and steel-reinforced wall that contributed to the disaster, but as was demonstrated by the recent earthquake and tsunami in Tohoku, Japan, some things are just out of our control. This is when we ask ourselves if nuclear energy efficiency is worth the drawbacks of a possible nuclear meltdown – even after all known safety measures are taken.
There are advances in science being made regarding what’s called nuclear fusion, which is considerably safer and is the reverse process of nuclear fission – the fusing together of atoms as opposed to splitting them apart. Due to their not being a “chain reaction” during this process, it is considered much safer as the process can be ended at any time. In any case, we don’t have this technology yet, and until we do – and even then – I believe we must continue researching and discovering ways to harness other forms of renewable energy.
This is perhaps a case of “you either love it or hate it”. There are two main reasons that make this form of energy unpopular: Noise and aesthetics. If you’ve ever lived near a windmill you’d know that they can make a rather annoying noise. As far as looks go, some people like them and feel they add a sense of calm and serenity to the landscape, whereas others don’t share the same opinion. Another factor is that wind and its speed is not constant and therefore does not have a high capacity factor – only about 30%.
There are two forms of solar power conversion – photovoltaic(PV) and concentrated solar power(CSP). Photovoltaic solar panel systems are what you often see on rooftops and are the more commercial form of capturing solar power. Concentrated solar power on the other hand is the method of directing a larger area of sunlight into a focused beam and is usually only used for larger-scale energy production. Photovoltaics utilize a phenomenon called the photoelectric effect, which simply put, is the emission of electrons due to absorbed electromagnetic radiation.
As with wind power, solar power is greatly influenced by such things as geographic location, weather, and time of day and year. It’s hard to give an accurate capacity factor(CF) for solar energy without a location, but as reference, a rather sunny, arid climate like Arizona’s may have a CF of 19%. Obviously, if you’re living near one of the poles, solar energy won’t be one of your choice forms of power, whereas, if you’re living near the equator, it very well may be. The determining factor will be what the most abundant forms of potential energy are in a given location.
The concept of using water to generate energy has been around since the first uses of water wheels, mills, and dams. Besides the well-known hydropower systems of dams and reservoirs, there are other various kinds of hydropower such as the harnessing of the oceans’ tides, currents as well as temperature differences and converting them into usable energy. But of all these methods, perhaps the most well-known and popular is what’s often called “conventional hydropower” – aptly named – which is the system of damming large amounts of water and converting its potential energy into kinetic energy.
But although most hydroelectric power comes from such dams, there are some drawbacks – environmental and otherwise. Dams can be used to not only generate electricity, but to also regulate water flow, for use in irrigation as well as to prevent flooding during heavy rains. But this is true only for the people – granted, the majority perhaps – directly benefiting from these perks, while those who live far downstream may suffer from insufficient water. Another problem is with fish swimming upstream to spawn – a rather insurmountable hurdle no matter how determined they may be. (Fish ladders help but often are not enough.)
Constructing dams are also extremely expensive undertakings! As an example, the Three Gorges Dam in China will cost an estimated $22.5 billion making it one of the most expensive projects in the world. Dams also potentially cause unnatural erosion of neighboring land as well as the blocking of silt from being deposited downstream, causing other geologic concerns. So as you can see, dams are great with their clean electricity generation, but they carry with them their fair share of woes and drawbacks.
I believe we must remain on the journey to not only discover clean, renewable energy, but to also discover the means to extract it with the efficiency and volume that we as a race require it. One thing is for sure, and that is that we all must learn to sacrifice and try new things in order to make steps toward the future. Our present reliance on nuclear and oil-based energy is at such an extreme that it will be impossible to institute change on the level that we need without many feeling the lack.
But at the same time I don’t think we can afford to wait until we have “that perfect energy source” that is clean, renewable, affordable, safe, AND lucrative for power companies, as if we do, we may very well be waiting a long, long time. I say we should all do what we can when we can, to reduce our own carbon footprint and stop waiting for some brilliant/magical form of energy to be discovered that solves all our problems! I don’t mean we need to all become treehuggers and start picketing in our spare time, but we CAN do what we can and this is our responsibility!