Discussions of the best and worst energy sources often devolve into opinionated and dogmatic “religious” wars, full of speculation and low on scientific rigor. But this may not continue for much longer. According to a December 2008 press release, Stanford University environmental engineering professor Mark Z. Jacobson completed the “first quantitative, scientific evaluation of the proposed, major,energy-related solutions by assessing not only their potential for delivering energy for electricity and vehicles, but also their impacts on global warming, human health, energy security, water supply, space requirements, wildlife, water pollution, reliability and sustainability.”
In the study, Jacobson reveals what he found to be the 8 best-to-worst electric power sources. Here they are, in illustrated detail!
The Four Best
(Images via TreeHugger, 4HCirriculum)
The best source of electric power, according to Jacobson’s study, is wind. As the diagram above helpfully illustrates, wind is converted to usable electricity by way of a blade-driven turbine with an internal generator. While wind currently only provides 1.5% of worldwide power, it is becoming more and more widely used, doubling in the 3 years between 2005 and 2008. According to Jacobson, a nationwide roll out of wind would result in a “better than 99% reduction” in carbon and air pollution emissions.”
Concentrated solar power (CSP)
(Image via Sustainable Design Update, RobertDowney.com)
Second to wind in Jacobson’s study was concentrated solar power, or CSP. Shown above, CSP systems utilize vast arrays of lenses and mirrors in order to focus a lot of sunlight into a small beam, which is then used as the heat source for power plants. Unlike some of the other power sources covered here, CSP is not new. Primitive forms of it date back to around 700 B.C. when the Chinese first used mirrors to ignite their firewood.
Clocking in at third in Jacobson’s study of the best and worst electric power sources is geothermal. The task of a geothermal power pant is using heat stored in the Earth to heat water that is in turn used to power steam turbines. As one might imagine, this is somewhat difficult. The rewards, however, seem to be worth it. According to EcoFriend, geothermal power generation represents “a completely safe, clean, and a virtually inexhaustible process and can fill the world’s annual needs 250,000 times over with nearly zero impact on the climate or the environment.”
The “last of the best” in Jacobson’s study was tidal power. Tidal power is based on the idea that the change in water levels between high and low tides can be forceful enough (in coastal areas) to power turbines. Since water is roughly 1,000 times more dense than air, lots of energy can be squeezed from even low-velocity tides. Tides also have the advantage of being more predictable than solar or wind power, which are only reliable insofar as the sun is shining or the wind is blowing.
The Four “Not So Best”
Solar photovoltaic (PV)
(Images via EIA, Ardenham Energy)
Photovoltatic solar panels are what most people associate with solar power. They are simply panels that use semiconductors to convert the sun’s rays directly into electricity. While these are certainly useful (and sales have risen from about 15,000 in 1998 to 886,000 in 2007), there are limitations, namely that they can only suck up electricity when the sun is shining.
(Images via Sweden, Piston Heads)
The sixth best electric power source according to Professor Jacobson is wave power. It’s main strong point? According to Sweden’s national website, “while solar power is available for about 1,000 hours a year and wind power for about 2,200 hours a year, wave power is available for up to 4,000 hours a year.”
(Image via K2M Energy)
The 7th best electric power source was hydroelectric, which currently provides about 19% of total world electricity. Despite this, hydroelectric comes with some significant disadvantages, such as how much space is required to build and operate a hydroelectric dam, possible dangers to nearby animal habitats, and disruption of aquatic ecosystems.
(Images via Hello World Bea, Guardian)
The “worst” electric power source in the study was nuclear power. While nuclear has proven effective across the world (namely by powering 75% of France), the main risk is safety. As meltdowns like the one at Chernobyl have demonstrated, the risk of accidents in nuclear fission looms large, holding the potential to wipe out entire populations depending upon the severity of the meltdown.
Again: the entirety of Professor Mark Z. Jacobson’s detailed study on the 8 best and worst electric power sources can be read here.