Recently the coal companies has been complaining about Obama 'hating coal'. They advertise about the EPA shutting down plants - ignoring the fact that cheap natural gas price has meant gas powerplants have been replacing coal power plants (Source) I've talked about coal, in comparison to nuclear power before. But since that time, natural gas has gotten cheaper, so it is time to talk about it again.
But actually, I agree that Obama hates Coal - and this is a good thing. We don't support out-dated technologies - there are not many buggy whip companies still in business, nor are asbestos company thriving. Coal deserves to go the way of asbestos and the horse and buggy. Sure, we can still use it for certain, specialized projects. But no reasonable culture should burn it to generate massive amounts of electricity - at least not without much better technology to a) capture pollution and b) mine it safer.
Coal is the single worst power supply we use.
- It is the source of most of the CO2 - causing global warming. The main difference between coal and oil is that oil has hydrogen, while coal doesn't. So when you burn coal, you get almost pure carbon dioxide (plus some poisonous impurities). When you burn oil you get water and carbon dioxide. In effect, burning oil lets you burn some hydrogen into water, as well as carbon into carbon dioxide.
- Those poisonous impurities? Let's start with sulfur dioxide and nitrogen oxide, aka acid rain. It also includes mercury - which is why we can't eat all the fish we want. Oh and did I mention uranium and thorium? Coal is the main source of those pollutions. We are not talking about safe depleted versions, I am talking about the radioactive, deadly cancer causing stuff. Most of it settles in the ground close to where you burn the coal.
- Mining coal destroys the locality. Unlike oil and gas, we are not talking about a simple drill and pipe. We carve out mountains, dumping the non-coal into valleys. And we are not talking about harmless rocks, the refuse is contaminated with dangerous chemicals. Not just the mercury, uranium, thorium, but also the various toxic chemicals used in the mining process.
Anything over $115 is generally considered to expensive, given what people are willing to pay for power. It is 'experimental', as opposed to commercially viable, so the 'clean coal' technology is quite simply not cost effective.
The 'best' overall power source we have right now is probably wind. Zero pollution and you can use it in most places, though some places are much more efficient. In the right locations (on shore, 30+ feet above the ground so build a tower, in a windy area), it is cheaper than nuclear power (and sometimes coal), if not natural gas. It has no emissions, and only affects flying creatures (some bird kills). In good locations, it's price is around $96.8. In the worst locations - off shore, the transmission back to shore eats up a lot of the profit, making it the most expensive - around $330.6 using conventional technology - that may change. Most importantly, there are FAR more good locations for wind than any of the other sources. It doesn't need water, works at the north pole and the equator, doesn't need a volcano or people. It just plain works.
Next is hydroelectric. The cheapest non air polluting power we use at $89.9, but it screws with the environment a lot more than you would think and it is extremely limited by location. The geography has to be just right and it still blocks migrating fish (salmon in particular), turning land into lakes, and affecting water use. During drought situations, this can be particularly bad. You don't want to be in a situation where you have a choice of one of three: make electricity, kill the fish or restrict water usage.
Of the rest, most people consider natural gas to be the next best one. In the current market, with fracking providing a ton of natural gas, it is the cheapest power around. But that assumes you don't care about pollution. While it does pollute, it doesn't do all the really nasty stuff coal puts out. The only real problem I have with it is that the businessmen are refusing to divulge the chemicals they are pumping into the ground to get the gas out. They claim it is a business secret, but businesses are not allowed to keep secrets that might endanger our health. We should not have to trust that they are not using dangerous chemicals, they should divulge what they are using or stop using it. The high pollution plants can generate electricity at a low price of $65.5, but if we want to clean it up, it can cost as much as $105.3. Even at that price, 'clean gas' is viable technology, as opposed to 'clean coal'.
Next comes the popular nuclear. Zero carbon emissions and zero deadly accidents at a US nuclear power plants (far less than coal or oil which routinely kill their employees). It costs out at $112, the most expensive of the profitable energy production techniques. It does create relatively minute amounts of pollution (by weight), all of which gets stored on site, as opposed to being pumped into the air. But the pollution carries the nasty word 'radioactive' on it, scaring people. It also can be used to create several profitable and essential non-power related products, such as medical supplies and military weapons. The military uses is not just bombs, but fuel for small mobile power plants (aka submarines, air craft carriers) and depleted uranium is used as armor and bullets.
Among the commercially viable methods, the last one is geothermal. We use lava to heat water, to turn a steam generator. It needs a good source of lava. This is rare. But the process itself is fairly cheap - at $99.6, it is cheaper than coal. All we need is a few more volcanoes and boom, we got energy.
Note,you don't see oil here. Petroleum is too valuable for use in cars to be commercially burned for electricity now a days. Room temperature liquid fuels are just too convenient for small generators.
Finally the also-rans. Along with offshore wind plants, these are too expensive to be used commercially.
Biomass - the burning of corn, sugar, or garbage (including methane taken from a garbage dump). This costs $120.2. Just a bit too expensive to be commercially profitable - unless of course you get the garbage for free. If you own a large farm, factory or university sometimes you can burn your own waste and make your own power. Similarly, large cities can burn garbage to power their municipal buildings. But we can't burn all garbage and it isn't enough to give us all the power.
Solar photovoltaic (solar panels that directly convert light to heat) average at around $156.9. Not quiet as close to being profitable as biomass, but given it's ability to go super small scale, it is no surprise so many small scale devices use it. In fact, the smaller the scale, the better solar power works, at least compared to other technologies. Which of course pushes the research, so it may someday beat coal and natural gas.
Solar Thermal is the new kid on the block. Here you reflect light off mirrors, concentrate it down to heat water to turn the turbine. It is a bit too expensive at $251 to be commercially used yet. But the efficiencies it show may change that. There is a lot of research on ways to cut that down, the technology is not as mature as the other power generation methods. Unfortunately it also loses solar photovoltaic's best advantage- it can't be used small scale. It uses way too much land.
Finally, bringing up the rear is the newcomer on the block. Tidal has some potential - it has even less of an environmental effect than wind, but has fewer viable locations and is by far the most expensive one we use. I am talking $610 a MWh. But most of that is due to the lack of research and experimentation. Give it a few more years and it could be cheap enough to compete with coal.
(Note, most of this information came from Wikipedia.)