It’s not like we’re going to run out of sunlight…
Here’s an interesting map I saw on an environmental blog the other day that I can’t stop thinking about :
“Solar power systems installed in the areas defined by the dark disks could provide a little more than the world’s current total primary energy demand (assuming a conversion efficiency of 8%). That is, all energy currently consumed, including heat, electricity, fossil fuels, etc., would be produced in the form of electricity by solar cells.”
On the surface, this seems like one of those fun little activist infographics that makes it seem as if we’re one giant leap away from solving all of our troubles. Obviously this approach would have problems since these tiny dots are still hundreds of square miles in size, but considering the advancements in solar technology over the last few years and the fact that the area represented by these dots could be dispersed on roofs and other wasted space, I wonder how well an investment in solar energy would pay off. Would the costs (monetary and energy-wise) required to replace our energy needs with solar panels be worth it? Is the technology efficient enough yet to justify this sort of investment? What do you guys think?
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Apart from nuclear, tidal and geothermal, all our energy ultimately comes from the Sun. Wind power comes from heating of parts of the atmosphere. Fossil fuels are the result of millions of years of photosynthesis.
There are three methods of converting light to energy, that I know of. One is use of silicon’s photoelectric effect. I understand the development of cells that use polycrystaline silicon has reduced the cost of these in recent years. They’re still costly in terms of energy and I’d imagine nasty chemical byproducts of their manufacture: these can probably be contained, but that takes more energy and equipment– that’s one of the reasons unregulated Chinese, etc manufacturing can produce goods more cheaply, though I think poor labour rights has more to do with it.
The second is by direct heating, e.g. concentrating the sun’s rays using mirrors to heat concrete tanks. (I’ve seen experimental setups to do this, with automated mirrors to track the sun. This seems more practical than solar cells to me, but I don’t know how well it works, or even if it’s being developed any more.) There are lots of variations on this, e.g. black tanks containing water on the roof.
The third is via photosynthesis. This has a lot of potential, I think, but the use of synthesised chemical treatments — fertilizers, pesticides, etc– which are often petrochemical or mineral-based, i.e. extracted or mined, negate carbon savings. So to actually be carbon neutral, I think it’d have to be produced organically.
Lots on this at Wikipedia, including the graphic: http://en.wikipedia.org/wiki/Solar_energy#Types_of_technologies
Comment by me — April 12, 2007 @ 7:07 am
Umm, wouldn’t there be MAJOR transmission costs involved? Sunny places are not always the places where there are large power needs/population centers. Except for Florida, I guess.
Comment by Dan — April 12, 2007 @ 1:41 pm
While an interesting idea, I think it will be a looooong while before we are all getting our power from a solar landscape in Arizona.
What would be more helpful would be tax credits to convert those countless hot water heaters across the US into solar. If you could start to reduce the amount of energy we use in just heating water…
The other side of the coin is a consolidation of technology. I looked into solar hot water heaters and found most of the information very confusing. It would be immensely helpful if there were more ‘off the shelf’ systems out there. I know I personally would save many $$ over the long haul…
Comment by Dave — April 12, 2007 @ 2:11 pm
The transmission issue is the most difficult technical issue to deal with. Current transmission technology, which I am no expert on, is inefficient, losing a lot of electricity over longer distances. Typically, research into more efficient transmission is underfunded by an order of magnitude.
Other difficulties with this approach have already been mentioned. Solar cells are not very efficient, they are energy-intensive to make and tend to wear out within a decade or so (again, I’m no expert, and I’m not gonna do research for a blog comment - this is just what I remember about these issues). They also tend to produce a great deal of haserdous waste during production.
Comment by Joe — April 12, 2007 @ 2:27 pm
yes, it’s time. Whatever the efficiency is or isn’t, it cant be any worse than coal and nukes. Let’s do it already!. A new deal for sustainability. Why not offer a full tax credit to any home or business that install solar panels? There are so many ways we could move this forward. Yes, it’s time it’s time
Comment by danny b — April 16, 2007 @ 5:45 pm
In the long run, those little dots should be up in geosynchronous orbit. Of course they’d have to beam the power down with microwaves, but having 24/7 sunshine at twice the intensity of that at the surface will make up for transmission losses. Plus, the receiving antennae can be right next to the cities that need the power.
Some of the dots could be at the Sun-Earth L2 point, where they are always looking at the night side of Earth.
Unfortunately, it only works economically when we have Space Elevators to get those thousands of tons of equipment up there relatively cheaply. So it won’t be soon. While we’re stuck on Earth, the Supergrid could help solve those long-distance transmission problems.
Comment by Bob Munck — April 16, 2007 @ 8:06 pm
This is off topic, but, being a huge Democrat and a huge supporter of ACORN and other equal economic opportunity organizations, why in the world are we Democrats not taking the FairTax and running with it?
I’ve had several fellow party members tell me that it is regressive and preys on the poor. Unfortunately, I believe they are misinformed. In actuality, the FairTax reimburses all U.S. citizens up to the poverty line and it brings more jobs to American soil! What gives?
Are’nt we the party of social justice? Don’t we condemn the other side for protecting the interests of U.S. social elites too often? This is a chance for American’s to finally shed a regressive tax structure. I employ anyone reading to research what I have said, see it for yourself, and then put pressure on our leaders to make a change for the better!
http://www.fairtax.org
DW
dw2777@uab.edu
Comment by DavidW — April 22, 2007 @ 8:01 pm