MIT Solar Towers Beat Solar Panels By Up To 20x

An anonymous reader writes "A team of MIT researchers has come up with a very different approach to solar collectors: building cubes and towers that extend solar cells upward in three-dimensional configurations. The results from the structures they've tested show power output ranging from double to more than 20 times that of fixed flat panels with the same base area (abstract, full pre-print). The biggest boosts in power were seen in the situations where improvements are most needed: in locations far from the equator, in winter months and on cloudier days."

Comments

Picture...

[Anonymous Coward]

Picture available here. It's a solar pancake!

Re:Picture...

[Firethorn]

That's an interesting article, but I found the link about using an ion cannon to make cells 1/10th as thick at 1/2 the cost of cheap chinese cells to be potentially more revolutionary.

At this point we're not especially limited on space for solar installs. Our problem is that our collection systems aren't cheap enough.

Re:Picture...

[uigrad_2000]

The Ion cannon article was featured on Slashdot two weeks ago.

I think a better way to state it, would be to say that efficiency per square foot of ground used is not important, unless the cost of the cells come down.

Now that there is word of a new manufacturing process to reduce cost, two weeks later, we find an article about how to arrange low-cost cells.

Re:Picture...

[pla]

At this point we're not especially limited on space for solar installs. Our problem is that our collection systems aren't cheap enough.

This. These 3d shapes give a better yield for a given footprint, but actually cost more.

Hey, If you can make individual flat panels cheaply enough, I'll pave half an acre with them for all I care about the "footprint". That said, I really don't understand why no major company has come up with mass produced smaller panels in a roofing-shingle form factor, but, entirely different topic.

Now, the part of this that does appeal to me involves the improved yield at high latitudes - But does that mean improved only against the footprint, or against the surface area? If the former, hey, cool, I live just far enough North that solar won't realistically pay back the investment given the present dominant efficiencies and prices; If the latter, then to repeat myself, just make 'em cheaper, I'll provide the space.

Re:Picture...

[fast turtle]

Did you RTFA? I happened to do so having caught it a couple of days ago. The interesting element to this design is the early/late (dawn/dusk) power generation as the current method doesn't get enough solar incidence to generate anything until 3 hours after sunrise/3 hours before sunset. That's 6 hours of production that's being missed, which is why this design reaches 15-20x the generated power of conventional flat panels.

Re:Picture...

[icebike]

Yeah, I read dud RTFA. It said:

While the cost of a given amount of energy generated by such 3-D modules exceeds that of ordinary flat panels, the expense is partially balanced by a much higher energy output for a given footprint, as well as much more uniform power output over the course of a day, over the seasons of the year, and in the face of blockage from clouds or shadows.

This suggests to me that there is no ROI on this method, or at least none that could not be more cheaply matched by simply tilting existing solar arrays.

I don't discount the possibility that we are seeing another poorly written TFA, and that there is an eventual ROI. But the implication is that the generation of power early and power late in the day may never actually pay for the structures and maintenance needed to collect it, leaving you with zero net gain over a tilted array in northern latitudes.

paper link

[Trepidity]

As seems depressingly common in science journalism, they vaguely mentioned the existence of a paper, but don't actually give the title or (dare we hope) a hyperlink to the paper. At least they did mention the name of the journal it was published in.

In any case, the paper is "Solar energy generation in three dimensions." If you're at a university with a subscription the official version (not open-access) is here. There is also an open-access preprint version at the arXiv.

Re:Costs more

[chudnall]

The time is ripe for such an innovation, Grossman adds, because solar cells have become less expensive than accompanying support structures, wiring and installation. As the cost of the cells themselves continues to decline more quickly than these other costs, they say, the advantages of 3-D systems will grow accordingly.

“Even 10 years ago, this idea wouldn’t have been economically justified because the modules cost so much,” Grossman says. But now, he adds, “the cost for silicon cells is a fraction of the total cost, a trend that will continue downward in the near future.” Currently, up to 65 percent of the cost of photovoltaic (PV) energy is associated with installation, permission for use of land and other components besides the cells themselves.

Re:Prior art...

[mutube]

According to this Wired article the 7th graders work has been 'debunked' (or rather disproven) due to not actually testing power output but rather the 'open voltage on the circuit'. Unfortunately both the links in the Wired article point to Google webcache results that have expired so it's not possible to verify.

Re:Prior art...

[Endo13]

Apologies. Reread the GP post and realized the above links don't really deal with what he was getting at.

Here's one that's a bit more helpful, but still doesn't have all the details. It appears all the sites and cached pages are gone.
http://www.treehugger.com/clean-technology/blog-debunks-13-year-olds-solar-power-breakthrough.html