There is a vast energy empire run by a few monolithic companies. We blithely accept the argument fed to us that we will continue to find more sources of fossil fuel, especially oil, but also coal, gas, oil shale and tar pits. The fact is that we may not run out, but finding and tapping into new sources will eventually become more and more expensive, both mechanically/technologically and ecologically. In the meantime we become more and more reliant on these sources and they are thus also being depleted faster and faster. This is truly a headlong rush to disaster. As an extra unbonus we are releasing huge amounts of CO2 that the earth has stored over millennia. There is scientific debate over whether or not there is global warming. The naysaying should probably be viewed in much the same way as the denials, issued for decades by the scientists who were under the thumb of the cigarette companies, about the addictiveness and deadliness of cigarettes. This is clearly a case in which to question authority.

Nuclear energy, typically referring to fission of heavy elements (Uranium and Plutonium), is also a sad debacle in the history of our attempting to assuage our ever-increasing desire for juice. The plants cannot be kept completely safe forever, even in countries where there is a fairly open inspection process. Behind closed political/national doors, it is an immense loose cannon, as borne out by the accident at Chernobyl. And even for plants that can run safely in the free world, there remains the problem of disposing of waste that will still be unstable and unhealthy to be around for tens and hundreds of thousands of years. NIMBY (not in my back yard) was probably not invoked as strongly in any other issue.  Most spent fuel currently still resides at the sites of the nuclear power plants.

Renewable sources are what make sense for the long term. The alternatives are many, but the effectiveness is not uniform. Windmills do not do well in places where there is not a consistent wind. Solar energy is also problematic because the material to convert the light to electricity captures only a low percentage of the energy, and sunlight is very diffuse and thus requires a large area to gather any amount of energy on the order needed for a city or large industry. And we may well wish not to devote ever greater land to gathering energy.  Hydroelectric energy is clean, but the ecological cost of flooding a valley is high, and a large percentage of the valleys that are suitable for damming have been dam(n)ed already (so to speak).  Wave energy is quite abundant, but is also a very diffuse source and is also dependent on the weather.

Progress is being made on the nuclear fusion front. This source has negligible waste, and since it uses an isotope of water as its source, it is much cleaner and more plentiful than fission. The problem here is that it requires as yet unattained technology to contain superheated plasma at a high enough temperature for a long enough time at a high enough density to achieve fusion. Various laboratories around the world are making progressive inroads towards the goal, but at a painfully slow pace.

This should be a top priority for the world. As yet, it is only partially pursued. The sharing of information is stymied by nationalism. Countries want to have control over the technology and not be beholden to anyone else. And the countries that have nuclear fusion will be able to rest assured that their industry will not falter.  And scientific hubris is no help in this area, either.  It is understandably a highly coveted goal, but our need as a world far outweighs the desire of this or that lab to be the first to achieve sustainable fusion.

The other side of this coin is the above-mentioned energy empire. If plentiful, cheap energy suddenly comes on line, all the companies that have survived from the scarcity of fossil fuel become superfluous. It is not in their interest to see fusion become a reality. Builders of engines, drillers of oil, refiners of oil, distributors of oil, retailers of oil will instantly lose most of their value. It will not be an easy thing for the energy companies of the world to give up their mega-billion dollar revenue stream to this new energy.

Another pie-in-the-sky possibility (excuse the pun) is to develop the technology to gather the sun’s light in outer space. There would be no land constraint, at least probably not for thousands of years. The tough part of this, on several levels, is to find a way to transfer the energy from outer space to the earth’s surface. Sites would have to be far enough away from people to negate risk of frying anyone. And if there were such high energy transfer with such dangerous consequences, it would be a prime target for terrorists and belligerent nations. (Of course, if there were a peaceful, worldwide government...) In any case, if we expect to develop space as the next frontier to save earth from our increasing excesses, we will need this technology as the logical energy source for space stations.

Perhaps the most down to earth and truly abundant, concentrated source is the subterranean heat within the earth itself.  A mere 60 miles below the surface (much closer in some geologically active areas, a bit farther in others) the earth runs a piping hot 2200 degrees.  That would be a perfectly sufficient source of heat to power turbines for ages.  Waste heat could even be used to warm whole cities in the winter.  We have the technology to tunnel for miles under mountains.  Why not tap that capability going straight down?  The argument that if it could be done, it would already have been done is too lame to accept.  We are learning more and more daily.  We could certainly learn more about excavating and tunneling.  There are companies that have ceramics capable of being heated hot enough to melt rock.  They could be used to create super drills that would make a perfect seal for escorting water down and back up.  What are we waiting for?