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Sketch of the problem:
1. Solar energy is good but storage is a problem.
2. There are ways to store the electricity generated, such as batteries, air pressure systems, molten sands (and other thermal techniques). They all have their drawbacks. (Smart grids would go some way in solving this problem
- but let's not take this into account for the sake of the argument)
3. Most of these storage techniques require raw materials that have to be brought from and to the site (case of batteries), or specific sites (case of pressure systems, in e.g. seabeds or 'caves').
4. In rural areas of the developing world, solar would be great as a decentralised energy component. But storage issues there are even more complicated (because funds are lacking).
The idea:
-use excess electricity to run a machine that turns air into nitrogenous fertilizer.
-this can be done by an electric arc discharge, which lets nitrogen react with oxygen to form nitric oxide.
-capture this stuff in water
-use the nitrogen-rich water as a fertilizer (this technology has been described in some patents)
This combination would effectively 'store' solar electricity and generate a product that is much needed in rural areas of the developing world, where agricultural production is dismally low.
This way, we can use real distributed solar energy and at the same time solve the huge problem which is the lack of nitrogenous fertilizer in developing regions.
Urea
http://en.wikipedia.org/wiki/Urea
This is the stuff to make. Nitrogen dense, nonexplosive, soluble. [bungston, Jul 02 2010]
[link]
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I have my doubts about the efficiency of the electric arc discharge, and besides, this doesn't provide a method of re-converting your stored energy back into electric current. |
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For distributed, low-cost conversion of solar energy into nitrogenous fertilizer, I have one word for you: |
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Could be used to electrocute cats, or alternatively just drop the cats into the nitric acid. |
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But can the fertilizer then be used to power my
laptop? |
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If captured in water, the technology to store large quantities of water is also somewhat tricky and it also requires large quantities of water, which may be scarce in the arid locales optimal for large scale solar. |
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But I like the principle. Everywhere there is sun there is air and there is nitrogen. Solid bioavailable nitrogen could be made stable, especially in a dry area, then shipped out by truck or rail. |
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Here is a question for you, django: in the third world (for example west africa), is agricultural production low for lack of nitrogenous fertilizer? I am sure other factors enter in. |
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//use excess electricity// any way of going straight from solar, bypassing the "produce electricity" step ? |
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Interestingly I'm working on a project that does the opposite: uses solar energy to extract electricity from manure! |
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//Here is a question for you, django: in the third world (for example west africa), is agricultural production low for lack of nitrogenous fertilizer? I am sure other factors enter in.// |
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Of course, many other factors would play a role. But given Africa's notorious soil crisis, inputs of nitrogen alone have shown +/-200% crop increases in recent national nitrogen programs in both Malawi and Ghana. |
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I'm sorry... +/- 200% increase? so they either made twice as much or they somehow lost what they made? I think you're using that symbol wrong. |
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My main concern here is that the sun is shining during peak energy consumption. I've never heard of solar power production going OVER consumption.
Furthermore, the increased complexity of having a COMBO powerplant/fertilizer factory would probably only be insignificantly less than building a specialized one of each... |
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//I'm sorry... +/- 200% increase? so they either made twice as much or they somehow lost what they made? I think you're using that symbol wrong.// |
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Not at all, in fact, 200% yield increases are very common in African agriculture, when subsistence farmers who use no soil inputs, suddenly use basic fertilisers. This is well known and corroborated by countless studies. 200% would just be a (conservative) average. |
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In my own experiment in Cameroon, we obtained an average yield increase of 243% - on 75 test plots - for maize, solely due to NPK and urea applications. There were plots that got a more than 800% boost. Not exceptional at all in these oxisols and ultisols (which are the dominant soils throughout Sub-Saharan Africa). |
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//My main concern here is that the sun is shining during peak energy consumption. I've never heard of solar power production going OVER consumption. Furthermore, the increased complexity of having a COMBO powerplant/fertilizer factory would probably only be insignificantly less than building a specialized one of each...// |
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I agree, it might be better to just use solar power, stored in batteries, to produce fertilizer on demand. In several very remote regions - with no supply chain for imported fertilizers - I can even imagine this to be profitable. |
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Let's not forget that the notorious Norsk Hydro fertilizer plant (which ran on electric arcs obtained from hydropower), competed with Haber-Bosch fertilizers will into the 1920s. Once natural gas goes above $12 per cubic meter or so, the arc process is probably competitive. |
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[django] - I think you've missed the point - the contention was not with the "200", rather it was with the "+/-" |
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Oh, now I see. Sure. In my language (Dutch) we use that symbol to express "more or less". Which symbol do you use in English? Is it something like a tilde "~"? |
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//In my language (Dutch) we use that symbol to express "more or less". Which symbol do you use in English? Is it something like a tilde "~"?// |
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Yes - a tilde would be fine.
I think using +/- to mean "approximate" should be a dubious practice in any language, since mathematical notation is supposed to be universal. |
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pashute, that's easy -- use the manure as fertilizer for solar-grown algae, and then make electricity from the algae. |
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django, the English language is very context sensitive... "+/- 200%" means "somewhere between -200% and +200%", whereas "200% +/-" would mean "somewhere between slightly more than 200% and slightly less than 200%" |
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