This assumes that the solar panels are 20% efficient at converting sunlight to usable electricity, which seems reasonably conservative. The best quality panels which you can buy today are about 15-20% efficient, and there are also reports of technologies in development which might push this up much further into the 30-40% range.
"According to the United Nations 170,000 square kilometers of forest is destroyed each year. If we constructed solar farms at the same rate, we would be finished in 3 years."
"The Saharan Desert is 9,064,958 square kilometers, or 18 times the total required area to fuel the world."So even using a conservative estimate, which is likely to be exceeded as the technology is refined, it looks as if a future powered substantially by the sun is eminently doable provided that there is sufficient political motivation. Even if the idea of land based solar farms proves to be unpopular it would still be possible to build floating solar factories on the seas, with the added advantage that you can concentrate them around the equator to maximise efficiency and also use them to produce hydrogen by electrolysis at the same time.
Constructing solar farms in desertified areas of the world would make the most sense, since this land is usually neither of commercial nor wildlife interest. Large areas covered by solar panels would also mean that the energy which normally heats the ground is blocked, so the surrounding region and its atmosphere may be cooled, perhaps to the extent that former desert becomes suitable for farming again.
5 comments:
I don't think solar panels cool the environment. Basically, they are black bodies, and so turn incident radiation into local heat efficiently. Desert surface reflects a lot of the sunlight straight back again.
The main way they might help is if they are water-cooled. In which case they would contribute to cloud formation - and clouds can reflect back sunlight into space.
You may be right about deserts reflecting much of the light, but in principle the better solar panels are transforming up to 20% of the light energy into electricity and this energy would otherwise be partly responsible for heating the environment.
If a significant area of desert were covered with solar panels there would be a non-trivial temperature differential between the upper surface and the area below in shadow. With some ingenuity the thermoelectric effect could be exploited to extract any remaining energy - although this would increase installation costs.
ISWYM - though note what eventually happens to that electricity: it does work and creates heat - and probably somewhere not that far away.
Solar power seems like a bit of an environmental disaster to me. I suppose it would be OK if you could stick the collectors in orbit.
Anyway, it seems to me that fusion power is highly likely to sort out our energy needs for most of the forseeable future.
In the long run, yes, fusion is the way to go. But fusion power has been "coming soon" for decades and although I'm following some of the amateur attempts it doesn't look as if fusion is going to be a viable energy source in the near term (unless someone makes an unexpected breakthrough).
Space based solar would be possible, but to make it economically viable we need cheap access to space with vehicles capable of lifting millions of tonnes of equipment out of the atmosphere. I think there's much more engineering work to be done before it's a realistic prospect, but the new moves towards space tourism provide an incremental path towards that goal.
Once there are very large space based solar factories maintaining them also becomes an issue, and I expect this will have to be done robotically to be cost efficient. Every time a comet or a few micrometerorites pass by, that could cause damage.
So in the near term building solar farms in desertified areas which noone cares about that much might be the best way forward.
Post a Comment