The Future May be Under Our Feet
On The New York Times Editorial Page: 3 July 2005 you can read a piece with the title: Fusion Power, Elusive and Alluring. The first line states, "A standing joke among scientists is that fusion power - the holy grail of those seeking a boundless supply of energy to supplant fossil fuels - is always decades away." Actually I heard the joke in a slightly more optimistic form, where the last phrase stated “...is thirty years away at any given time.” For over fifty years now some of the best minds in science have worked on the problem. Every once in a while we even hear about “cold fusion” or“table top fusion”, the latter from sono-luminescent collapsing bubbles. But maybe we are putting our bets on the wrong horse.
An obvious source of fusion power is the Sun. Almost all our fuel sources can even be traced to that great fusion reactor in the sky. Space enthusiasts have proposed putting large solar electric arrays in orbit and beaming down the gathered power. As attractive as this may seem, there are enormous practical obstacles to the idea. Still in the long run it may be feasible.
Off course as we run out of hydrocarbon based fuels we are going to get pretty desperate. I’m thinking of the plight of the Easter Islanders as discussed in Jared Diamond’s book “Collapse.” If one believes in the Hubbert Peak argument this is going to happen soon. So are there any other possibilities that might give us the fuel we need before we are at each other’s throats?
One possibility, that seems very under-exploited to me, is geothermal energy. Heat pumps to supplement other forms of energy extraction in heating our homes and work places are gaining in popularity as hydrocarbon fuels become more expensive, but there’s not enough to keep up our industrial civilization going. Then there is Iceland, a place where the whole economy depends on the readily available geothermal energy supply. Great for the Icelanders but what about the rest of us? Actually even in the US and Europe there is a significant use of geothermal energy. This is discussed in the links given below.
An interesting aspect of oil and coal is that these fuel sources also have a geothermal origin of sorts. Rotting vegetation sank into the earth and was heated by our planets molten core to form our treasure trove of hydrocarbon fuel. Notice that the core supplies heat. We now know that radioactive sources maintain the core. Fantastic, we have a giant heat engine right under our feet, so why don’t we explore it more?
It may be right under our feet, but it’s not easy to get at, not at all. At first glance you might say that all we need do is drill into the core. Unfortunately we don’t have the technology to do this. The most that has been accomplished is one to two kilometers into the surface under the seabed. The lithosphere or shell covering the hot interior is up to one hundred kilometers deep. A long drill string is just that, in the sense that it’s like trying to make a hole in a layer of jello with a piece of string. Corrosion is also a major problem in the heat of the depths. Locating and utilizing deep wells has reached depths of up to 4 kilometers. The problem is finding them or having them where you want.
The only way geothermal energy is going to really pay off is by reaching lithosphere scale depths, and that calls for something new. Maybe we should put our brainpower and resources into doing this. It’s not as scientifically interesting as developing fusion power, and with luck we might solve the problem in thirty years! Why are we sinking huge sums of money into fusion research and practically nothing into utilizing this fuel source beneath our feet? Is the problem really more difficult than building a practical fusion reactor? Maybe it’s just not as interesting to our more creative scientists and engineers. But engineers do tend to follow the money, so a few billion spent on research here might be better than supporting a fusion reactor project in France. What are your thoughts on this?
To help your thinking here are a few links to look at. The last has a great summary of where we stand now with geothermal energy. It's illustrations show just how difficult it is to reach the really hot interior.
What is the Hubbert Peak?
On Deep Sea Drilling
Geothermal Energy Association
A nice brochure about Geothermal Energy
An obvious source of fusion power is the Sun. Almost all our fuel sources can even be traced to that great fusion reactor in the sky. Space enthusiasts have proposed putting large solar electric arrays in orbit and beaming down the gathered power. As attractive as this may seem, there are enormous practical obstacles to the idea. Still in the long run it may be feasible.
Off course as we run out of hydrocarbon based fuels we are going to get pretty desperate. I’m thinking of the plight of the Easter Islanders as discussed in Jared Diamond’s book “Collapse.” If one believes in the Hubbert Peak argument this is going to happen soon. So are there any other possibilities that might give us the fuel we need before we are at each other’s throats?
One possibility, that seems very under-exploited to me, is geothermal energy. Heat pumps to supplement other forms of energy extraction in heating our homes and work places are gaining in popularity as hydrocarbon fuels become more expensive, but there’s not enough to keep up our industrial civilization going. Then there is Iceland, a place where the whole economy depends on the readily available geothermal energy supply. Great for the Icelanders but what about the rest of us? Actually even in the US and Europe there is a significant use of geothermal energy. This is discussed in the links given below.
An interesting aspect of oil and coal is that these fuel sources also have a geothermal origin of sorts. Rotting vegetation sank into the earth and was heated by our planets molten core to form our treasure trove of hydrocarbon fuel. Notice that the core supplies heat. We now know that radioactive sources maintain the core. Fantastic, we have a giant heat engine right under our feet, so why don’t we explore it more?
It may be right under our feet, but it’s not easy to get at, not at all. At first glance you might say that all we need do is drill into the core. Unfortunately we don’t have the technology to do this. The most that has been accomplished is one to two kilometers into the surface under the seabed. The lithosphere or shell covering the hot interior is up to one hundred kilometers deep. A long drill string is just that, in the sense that it’s like trying to make a hole in a layer of jello with a piece of string. Corrosion is also a major problem in the heat of the depths. Locating and utilizing deep wells has reached depths of up to 4 kilometers. The problem is finding them or having them where you want.
The only way geothermal energy is going to really pay off is by reaching lithosphere scale depths, and that calls for something new. Maybe we should put our brainpower and resources into doing this. It’s not as scientifically interesting as developing fusion power, and with luck we might solve the problem in thirty years! Why are we sinking huge sums of money into fusion research and practically nothing into utilizing this fuel source beneath our feet? Is the problem really more difficult than building a practical fusion reactor? Maybe it’s just not as interesting to our more creative scientists and engineers. But engineers do tend to follow the money, so a few billion spent on research here might be better than supporting a fusion reactor project in France. What are your thoughts on this?
To help your thinking here are a few links to look at. The last has a great summary of where we stand now with geothermal energy. It's illustrations show just how difficult it is to reach the really hot interior.
What is the Hubbert Peak?
On Deep Sea Drilling
Geothermal Energy Association
A nice brochure about Geothermal Energy
posted by Marty Lesser at 20:24
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