Geothermal as base load
Australia’s left-leaning New Matilda yesterday published a piece asking, Is Geothermal The Baseload Alternative? It reminds me that I want to get around to publishing my own calculations of price per megawatt for various energy sources in both Australia and the US. Geothermal could be crucial to the energy mix over the next few years but there are too many figures floating around out there. So more on that soon.
The author, David Hollier, provides a neat summary of how geothermal works:
To harvest geothermal energy, you need to drill four to five kilometres below the surface, where the rock temperatures are 200 degrees or more, hot enough for the liquid they heat to drive turbines. The first challenge is to get wells down into this layer to check that the rocks are hot enough. If they are, you can pump water into the rock at a pressure high enough to fracture the rock, and to allow the water to move through the fractures, forming a reservoir. Then other wells are drilled, and the hot water is pumped back up to surface where it drives the turbines.
Once the system is up and running, this hot water can be constantly recycled. There are no other inputs into the process. Unlike wind and solar, it does not rely on specific weather conditions. And apart from the wells, there is no “mine” as such: minimal demands are made of the land. Geothermal is a renewable energy source that taps the ceaseless heat production at the earth’s core as it radiates towards the surface.
He raises an issue that I’ve mentioned a few times recently here:
So if all this is true, why have we heard so little about geothermal? If it’s a solution to the clean energy crisis, why hasn’t industry development been accelerated before now? Is it a victim of coal industry resistance — or a PR failure? Or might it have something to do with the fact that there are now more lobbyists than credible climate change scientists doing the rounds in Canberra?
Too bloody right. As Al Gore has noted many times, the lack of political will is the chief obstacle to action on global warming:
A couple of minor points. First, geothermal is not totally GHG-neutral. There are some emissions, primarily associated with the construction of the plant. Also, I take issue with David’s point here: “Solar and wind. Wind, tidal and solar. We all know that these can’t yet deliver baseload.” This is not true and I’ve written about it before.
I agree with Hollier on geothermal. He’s also right when he says: “Solar and wind. Wind, tidal and solar. We all know that these can’t yet deliver baseload.”
In order to power all of NSW’s industry, you would have to cover the entire state in solar panels and wind turbines. This would literally mean clearing vegetation and wiping out farmland in order to build the required infrastructure. It is simply not an option.
Intermittency is also not that simple a concept to overcome and wind is an especially inefficient source. It is not simply a matter of “if it’s not blowing here, it’s blowing over there”; the problems are far more complex and must take into account economics, physical difficulty in transmitting electricity from remote locations (like the northeast tip of Tasmania) and a variety of other factors.
And by the way, Al Gore is a phoney. He talks the BS about coastlines disappearing under water at any minute, but buys beach front properties and drives there in his petrol-guzzling SUV. Then he burns tonnes of fossil fuels by jetting all over the world to peddle his lies and exaggerations.
redhot
12 Nov 09 at 9:11 pm