(This is Part 7 of a series. Go back to Part 6.)
As we've seen, energy is one of the most fundamental threads of the world's interconnected fabric. Solving humanity's energy challenge is, of course, intimately related to solving its climate and ecological ones. It is also intimately related to various geopolitical tensions across the globe—whether in a "cold" or "hot" phase. In addition, the price of energy profoundly affects the world's financial and economic systems.
So, though we've discussed the energy challenge elsewhere, let's here take one more look at what might be the most elegant and satisfactory solutions to humanity's energy challenge:
What is that challenge? It has two parts: The first part is that humanity is running out of cheap fossil fuels. Note that the last sentence doesn't say that humanity is running out of fossil fuels. It is indeed, but that's something that's going to happen down the road. What's happening right now is that humanity is running out of cheap fossil fuels, and that is already having a deep effect on global financial, ecological, diplomatic and military areas.
The second part of humanity's energy challenge is the effect that our extraction, processing and consumption of energy is having on the planet's biosphere—the thin planetary crust where all life takes place.
We've discussed elsewhere the crucial concept of EROI—energy return on investment. It measures how much energy we're getting back versus the amount of energy that has to be invested to get the energy.
For instance, in the early years of the Petroleum Age humanity had suddenly discovered an energy elixir, because the EROI of oil was over 100. We were going after the low-hanging fruit—the oil that was the cheapest and easiest-to-obtain. Our energy return on energy invested was fabulous, and humanity threw an energy party that has lasted for over a century.
But now, of course, we must sooner or later make the transition away from fossil fuels and towards more sustainable sources of energy, both because we have to live on this planet that we're despoiling and because our EROI on fossil fuels is steadily falling.
As we extract oil and other fossil fuels from increasingly difficult and harsh environments, the EROI on global oil is estimated to have fallen from 100 to about 18. We're still obtaining about 18 units of energy for every 1 unit of energy invested to get it, but the ratio is falling with every passing year. This being so, regardless of when we "run out" the writing is on the wall for fossil fuels. What will replace them?
Before looking at the alternatives to fossil fuels, though, we should deal with the largest and oldest fossil fuel: coal. Humanity has enough coal to power its energy needs for centuries—what's the problem? Of course, the problem with coal is that it releases twice as much carbon dioxide as oil for an equivalent amount of energy.
Yet in general, coal has become the fuel of choice in new electric generating plants around the globe. China alone installed an estimated 80 megawatts of new coal-fired plants last year alone, which is more than all the power generated in Great Britain.
All these new coal-fired power plants are going to create an absolute tsunami out of the global warming situation unless some way can be found to sequester the CO2 produced by coal and then bury it deep in the earth. Such a process has not yet been commercially demonstrated, but is considered technologically feasible.
The giant Texas energy utility TXU, after its takeover by "green" equity funds, has now announced that it will build two experimental coal-fired generating plants designed to capture and sequester carbon dioxide. American Electric Power has also announced a similar demonstration plant. All of this is good news and hopefully the beginnings of a trend.
Yet even if this expensive "sequestration" strategy were to become globally prevalent—itself a tall order—I don't think that coal can be a significant part of a long-term solution to humanity's energy challenge. The primary reason, perhaps, is that the amount of sequestration we're talking about is enormous.
For example, as the analysts John Deutch and Ernest Moniz point out, a standard 1000 MW plant would have to sequester, during its 50-year lifetime, over a billion barrels of highly-pressurized gas—and many hundreds of such plants would be needed to even begin making a real difference in the CO2 reaching the atmosphere. So we're talking about sequestering trilions of barrels of highly-pressurized gas. Hmm.
Well, instead of burning something toxic and then trying to deal with the enormous waste-disposal problems thereby created, it would seem to make more sense, long-term, to focus on those ways of producing energy that are inherently clean, sustainable and renewable. I do feel confident that clean and renewable energy generation will eventually prevail almost completely in human society, for the simple reason that otherwise life on earth may become unsustainable.
Though we've discussed renewable energy elsewhere, let's now look at it from a somewhat different perspective—the long-term efficacy of each of the various forms of alternative energy in solving humanity's energy challenge:
(This is the end of Part 7. Go to Part 8.)
—jim sloman, 3.20.07
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