Here is an idea about the limestone system for transporting energy from the desert I blogged before.
That proposal wants to calcinate limestone in the desert, making a lot of quicklime. Then transport that quicklime to your destination country as you would transport coal, and get the energy back there.
One point I did not notice when discussing this earlier is actually very simple. Instead of using the quicklime as fuel, one could obviously use it in the cement industry as well.
The cement industry is responsible for about 5% of global CO2 emissions (Wikipedia). For every ton of cement produced there are 900 kg of CO2 emitted. At 3.3 billion tons of cement produced in 2010, there is a substantial amount of CO2 emissions in play here. About 40% of that come from the energy used to make quicklime.
That of course means that for every ton of quicklime from the desert displacing one made by a coal fired kiln there are 360 kg of CO2 saved.
A legal requirement to make all cement with solar kilns in the deserts would save CO2 emissions in the gigaton range.
And it would provide an excellent source of CO2 (which is generated in the chemical reaction from limestone to quicklime) which can then be used to make synthetic fuels. Alternatively, one could dispose of that CO2 safely in some enhanced olivine weathering process.
As a more general point, the original idea is to transport quicklime as an energy carrier. That can be expanded to transporting useful materials of all kinds that require much energy to make, and do so because these materials are useful on their own, even when one is not interested in getting the energy invested in making them back.
I recall that the aluminum industry has always placed their smelters where there are large sources of cheap electricity (Wikipedia). So if the desert projects really take off, making aluminum right in the desert would be an excellent way to effectively use that energy. It sure beats sending it a couple of thousand kilometers over some power line and using it at the destination to smelter aluminum.
[...] and troughs, that will be local consumption of the energy, but not necessary of the products. I mentioned before that making aluminum or quicklime in the desert is one way to transport the energy without power [...]
[...] I have been looking for alternatives before, and I have come up with some, like transporting quicklime or making [...]
I love this idea! It would be ideal for a desert location near limestone deposits, on a rail line or highway but not anywhere near electrical transmission lines. There are some issues – cement kilns run continuously and usually have a long start time – but that might not be true of an electric kiln. Also, cement kilns are not water-intensive whereas aluminum smelters are. Well, technically, its the bauxite processing to alumina step that is water intensive but thats usually done at the same location as the smelting because they are both energy intensive.
[...] wouldn’t know what “olivine” is anyway. I have mentioned olivine briefly in two posts in 2011 on this blog, but I think it should get some more [...]