Alternative Energy Will Save Us
The Common Misconceptions About Peak Oil
A continuing series
So far we have talked about the following subjects, where energy comes from, OPEC, Deepwater production, tar sands, and oil shale. In this post we are going to explore the fascinating world of ALTERNATIVE ENERGY.
I am not really sure what alternative energy is, but for the sake of this article, we will define it as any type of energy source that is not a major commercial source of energy in the US. I guess we could define it by what it is not. Alternative energy is not conventional crude oil, conventional natural gas, coal, nuclear, and large-scale hydroelectric power. It is oil shale and tar sands, but as stated above, those subjects have been treated in separate posts on this blog.
For alternative energy sources they can be divided into renewable energy (e.g. solar, wind, biomass, tidal, other hydro etc.) or non-renewable (methane hydrates for example, also geothermal which kind of falls between renewable and non-renewable).
The greenies favorite white horse is renewable energy. To many people, this is going to save the planet. Now why isn’t this possible?
We kind of have to look at these energy sources one at a time and evaluate what they are capable of. Let’s look at wind energy first.
Wind is a reasonably good source of power to turn a turbine to make electricity. In some parts of the world (e.g. Denmark) wind power is a major contributor to the electrical generation capacity. However, it has some downsides. 1) It can never be counted on to provide a large percentage of the power generation requirements for a large country. Here are some reasons why:
Wind is a diffuse and fickle energy source. It is there when you don’t need it and it is not there when you do. Although in some places it is almost constant in terms of it always blowing somewhat, most of those places are in the middle of oceans, in Antarctica, in the Texas Panhandle or other God-forsaken places far from urban centers. Electricity from wind requires an inordinately large foot print (e.g. 300 sq mi to replace one conventional power plant), and it requires a hell of a lot of concrete, steel, wire, and electrical infrastructure to put it all together. At best it could replace 20% of the generating capacity needed for a large community, although many people think that is a stretch. Even then, it only cuts down on the UTILIZATION of conventional power plants but not the need for them. Power must be provided at 100% of the peak demand load. If the wind is not blowing, a wind turbine is useless. Consequently, 100% of conventional, always-on, generation capacity must be maintained for the times that wind in unavailable. To read about the pros and cons of wind energy here is a good source.
I guess my conclusion about wind is that it is a nice niche energy source, and it should be fully researched and exploited, but I don’t ever see it becoming a major part (>5%) of the world’s energy mix.
OK, what about solar? Solar energy is divided up into categories like passive vs active and direct vs indirect. But what we are talking about here is the use of solar energy as a major transportable energy source, not how to use passive solar energy to decrease your heating bill in New Mexico. So that means active, direct solar power generation.
Solar power generation has many of the same drawbacks as wind power does. It is not there when you need it and there when you don’t need it. Just like with the wind, the availability of the sun is highly variable from location to location and from season to season. Not only that but even at the sunniest spot on earth, the sun doesn’t shine 12 hours of every day (on average). So now we are talking about the need for energy storage as well as power generation.
Also there is a significant downside in cost and footprint: “While the price of photovoltaic cells has been slowly dropping, solar-generated electricity is still four times more expensive than nuclear (and more than five times the cost of coal). Maybe someday we'll all live in houses with photovoltaic roof tiles, but in the real world, a run-of-the-mill 1,000-megawatt photovoltaic plant will require about 60 square miles of panes alone. In other words, the largest industrial structure ever built”
Enough rain on your parade yet, or shall we look at some others. Biomass is one that is bandied about. How does it stack up?
Of course biomass is the oldest energy source on the planet. In its simplest form, biomass is just wood or dried animal dung to be used for burning. In a more general sense, however, basically all organic waste that can be turned into heating fuel (i.e. burn it) or into transportation fuel through various chemical engineering processes (gasification and Fisher-Tropsch etc.). Also, ethanol can and is made directly from different types of biomass. Ethanol is clean (relatively speaking), but growing the amount of cellulose required to shift US electricity production to biomass would require farming an area the size of 10 Iowas, not to mention what additionally will be needed to replace the 10,000,000 barrels of oil we burn in our motor vehicles every day (US only).
I guess if we used every arable spot of land in the US for growing biomass to make fuel we could come close to meeting our energy needs, but we would starve to death.
What about geothermal energy. Like energy from the Sun, energy from inside the earth is everywhere. But for the most part it is diffuse, low-grade energy source. Only in a few places on the earth is there a sufficiently high near-surface heat gradient to utilize geothermal energy to do things like generate large-scale electrical power (Indonesia, New Zealand, the Phillipines). Basically if you have active volcanoes nearby, geothermal is an energy source available to you. However, it is important to realize that geothermal is not completely renewable.
Most geothermal power generation schemes are like any other heat-based schemes (nuclear, coal, natural gas). The heat is used to create steam which is in turn used to rotate turbines and generate electricity. For geothermal this is done by extracting naturally-super-heated groundwater, flashing it to steam, running it through a turbine, then pumping the used-up steam/water back into the ground. The net effect of this process is to cool the reservoir of geothermal energy to the point where, eventually, there is not enough heat in the system to effectively provide power. At such a time, the resource must be abandoned. For the Kamojang Geothermal Field, Java, Indonesia, the typical life of a power-generation unit is about 35 years.
So where does that leave us. The reasons why the above are considered “alternative” energy sources rather than “primary” energy sources is that they are not as efficient at providing widespread energy at affordable prices. The reason why oil, coal, and natural gas are the preferred energy sources world wide are because:
1. They are dense in terms of their energy content
2. They are widely available and have been available in large quantities
3. They are transportable
4. They are useful in their raw or easily refined states to be used as heating fuel, transportation fuel, or generate electricity
5. They are cost effective
So far, none of the above alternative energy sources we have looked at even comes close to achieving these 5 things.
Does that mean we should ignore them? Hell no. We should be working with utmost urgency to try to improve on and utilize all of the alternative sources of energy we can come up with. However, from what we know now, alternative energy my deflect some of the blow from Peak Oil, but not much.
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