So I got a little carried away and posted this on a slashdot article. Its prolly more appropriate here. This is essentially a brief overview of what I have been learning in my Energy & the Environment class. I would love to start a discussion here about energy technologies and their potential use in our future. So here goes.
The economic efficiency of using wind, solar, geothermal and hydro the main renewable energy sources is not a clear cut issue. It depends highly on your particular situation. With oil prices so cheap they are clearly not as good of an option in terms of price per unit of energy output as they were 6 months ago. However there is a lot to consider here.
Hydro is wonderful it has a large onetime ecosystem rearrangement including displacing people but after this point it provides cheap reliable energy when you need it and a reservoir is essentially one of the best batteries we have today. Unfortunately most of the possible large hydro projects have already been built in developed countries.
Wind power is highly dependent on your location. There are many places where it is already an economically competitive energy source and many were it is not or will never be. It does not produce reliable energy however so it must be paired with some energy storage method or a more reliable source.
There are many types of solar energy technologies but mostly I think we are focused on those aimed at producing electricity. If you took all of the solar energy landing on the united states and converted it to electricity at 100% efficiency there is enough energy to meet the entire energy needs of the US roughly 500 times over. Of course solar photovoltaic panels are not very efficient (10-20% in practical uses) and we want sun for other things like growing plants. People are building some large solar plants in places where land is cheap and more people are putting them on their roofs but it is an unreliable source of energy like wind and my understanding is that its usually not very economically practical yet.
There are not very many places where it makes sense to use geothermal energy to create electrical energy. However it can serve as a great heater and cooler in most places.
One of the biggest factors in what energy source is economically practical is government subsidies. There are many more renewable energy projects happening these days because of large government subsidies. Governments can think in the long run and this makes a lot of sense. But currently the largest subsidies go to nonrenewable fossil fuels. If for example all energies had to pay for their environmental impact (say co2 output) rather than being subsidized by public governments renewable energies would become much more economically practical.
One nonrenewable energy source that is relatively friendly environmentally is nuclear. I see this as one of the few technologies that we can switch too quickly that has the potential to meet our energy needs. It won't last for ever especially if we try to do everything with it but there is also a lot of room for research. If we ever figure out how to gain energy from fission to there is a huge potential for energy there.
Well thats the way I see it at least part of it.
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As I understand it, scalability is a major limiting factor for all these available "clean" technologies. The infrastructural costs required for nuclear, for one, to put even a dent in our otherwise fossil fuel based energy consumption are (as I understand it) astronomically large.
ReplyDeleteAfia, could you talk a little more about nuclear? I want to know about what, exactly, makes it environmentally friendly. Also, there is a tricky thing to developing nuclear power internationally, which is that America (rightly) gets nervous when hostile or unfriendly or secretive states say they intend to (or have) developed nuclear energy. Non-proliferation, something Obama is pretty big on, will make the spread of peaceful nuclear technology very complicated on a large scale.
ReplyDeleteWhat do you mean by that infrastructural costs?
ReplyDeleteNuclear tends to have very high upfront costs but these end up being from what I have heard between 75 and 90 percent of the total lifetime costs of operation (this would include decommission and storage of leftover radioactive bits). Besides building plants the only other infrastructure that we don't have mostly in place is what you do with the leftover new radioactive material. I would like to know more about what this entails but I have heard a number of comments recently saying this is not as big of a problem is it has been portrayed to be.
Having nuclear energy dose not mean you can build nuclear weapons. The canadian CANDU design uses natural uranium and thus never produces any materials that can be immediately used for nuclear weapons. To make nuclear weapons you need a much higher concentration of uranium 235 (99.3 of natural uranium is 238) in order to get a high enough proportion of uranium 235 you need to enrich it. This is a very expensive and tricky process and is what Iran has been working on that gets everybody jumpy. The CANDU reactors actually can use decomissioned warheads as fuel making it no longer weapons grade.
In terms of nuclear being environmentally friendly. It does not produce any green house gases. Right now this is the number one problem most people are focusing on. Nuclear has a safety record much much better than that of any fossil fuel. Part of this is because it takes few people to run nuclear plants and very little fuel. A truck a year can power a nuclear power plant. Mines are very dangerous and relatively very little uranium needs to be mined for the same amount of energy.
Again an area im trying to learn more about is what happens to a plant once you shut it down. This is especially big in Vermont right now because our nuclear reactor is trying to get a permit to keep running for awhile longer. It was not designed to run as long as it has and there is a strong citizen movement to have it shut down. Im very torn I think we need nuclear power to have any hope of repairing our environment in the next thousand years but I don't want a plant to run that is going to have an accident.
An encouraging tidbit is that the only major accidents that have ever happened at nuclear power plants think (chernobly and three mile island) occurred after the safeguards had been manually disabled.
Not sure I cleared anything up there. Mostly felt like rambling. If I get some time ill try to write something organized.