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This article makes the prototypical solar energy mistake: thinking efficiency matters. It doesn't (unless you're working on satellites). There is no shortage of

by bdcs 13y ago

This article makes the prototypical solar energy mistake: thinking efficiency matters. It doesn't (unless you're working on satellites). There is no shortage of rooftop space. There is a shortage of dollars. The only thing that matters with solar is cost (in dollars) per installed watt (in watts). Efficiency plays a part in that; a more efficient cell for the same price is much better! But, a slightly more efficient cell for something much more expensive is not an advance at all. This finding is technically neat, but I don't see how it is a breakthrough by any means. Admittedly, I only read TFA.

just2n 13y ago
The breakthrough isn't necessarily in efficiency (the title is misleading), but rather that it is done using low quality silicon which I would suspect means the costs would come down drastically compared to current top-performing cells. There's no mention of expected costs nor comparison with a correlation between current panel efficiency and cost to show that it would have a large impact on the market, so we can't really know. The article is definitely more hype than substance.
capisce 13y ago
"Australian scientists have found a way of hugely increasing the efficiency of solar panels while substantially reducing their cost." Did you ignore the part of TFA that was about cost reduction?
- jussij 13y ago
  Not only that but this: Silicon wafers account for more than half the cost of making a solar cell. "By using lower-quality silicon, you can drastically reduce that cost," he said.
  - oyvindeh 13y ago
    Also, it would require less materials to make them, and they would produce less garbage when they are to be thrown away. And (I guess) they will require less energy to produce. Although there is no shortage of rooftop space, you could still fit them into places where there currently isn't so much space. Perhaps, at some point, we could put them on top of electric cars, making them less dependent on charging sockets.
    - yial 13y ago
      Like the Fisker? http://en.wikipedia.org/wiki/Fisker_Karma http://en.wikipedia.org/wiki/Fisker_Karma
dredmorbius 13y ago
Agreed. Tom Murphy makes that point in his blog: "Don't be a PV Efficiency Snob": http://physics.ucsd.edu/do-the-math/2011/09/dont-be-a-pv-efficiency-snob/ http://physics.ucsd.edu/do-the-math/2011/09/dont-be-a-pv-eff... There's plenty of solar capacity on the planet to meet not only present electric generation demand, but the growth require for substituting much present fossil-fuel usage with electricity. Probably even bringing up per-capita energy allotments to a reasonable fraction of Western levels (1.5 - 2.5 kWh/day would make a huge difference for most people's lives). The real challenges are cost -- building out solar capacity would require 8-9 doublings of existing capacity, at least. Financing this (or ramming through the construction regardless) is going to be the biggest challenge. Storage though is the other bogeyman. There's very little pumped storage available. Grid batteries, likely emphasizing cost over size, weight, or efficiency, as there simply isn't enough of many common battery materials to meet requirements, thermal storage. Maybe hydrogen production, maybe electrically-powered synfuel production, flywheels. There are a few reactor options, mostly still not commercially proven, which may help bridge the gap: TerraPower, LFTR, and other breeder designs. Relying strictly on conventional uranium fission reactors would burn through known reserves in a few decades -- 30-80 years.
- belorn 13y ago
  Two common methods to store excess electricity from wind/solar is with hydroelectricity, and district heating. It would be really interesting to see numbers on the maximum amount of excess power that could be stored if those two techniques was universal utilized for this purpose.
  - dredmorbius 13y ago
    Pumped storage is very limited in suitable sites and total capacity. It also has impacts on the local environment and safety (large bodies of water with large daily fluctuations and keeping people and property out of water intakes). Direct thermal storage addresses some needs but not actually providing grid-level storage. Thermal electric storage does seem based on reading and some back-of-the-envelope calculations to be one option that scales reasonably well. It can be based on cheap, abundant substrates, and fits well with existing technology for converting between electricity and heat (or for CSP where heat is banked during the day). Tom Murphy's "Nation Sized Battery" presents some good numbers. If you want to extend his coverage to other techologies, you're going to want their storage density (by volume or kg), round-trip efficiency, and materials cost and availability. The key to me is that you need massively abundant, massively cheap materials. http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/ http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...
danmaz74 13y ago
Have you actually read the article? It says that the breakthrough is in achieving pretty high efficiency with low quality - and thus low price - silicon. It doesn't claim to have found the best-of-breed efficiency.
kokey 13y ago
They do mention that it allows for using cheaper silicon, but doesn't actually quantify it e.g. a potential x.xx% cost reduction. I'm not sure if this is because it's based on PR from Suntech, who obviously doesn't want to indicate how far prices can come down by.

by bdcs 13y ago

just2n 13y ago

The breakthrough isn't necessarily in efficiency (the title is misleading), but rather that it is done using low quality silicon which I would suspect means the costs would come down drastically compared to current top-performing cells. There's no mention of expected costs nor comparison with a correlation between current panel efficiency and cost to show that it would have a large impact on the market, so we can't really know. The article is definitely more hype than substance.

capisce 13y ago

"Australian scientists have found a way of hugely increasing the efficiency of solar panels while substantially reducing their cost." Did you ignore the part of TFA that was about cost reduction?

jussij 13y ago
Not only that but this: Silicon wafers account for more than half the cost of making a solar cell. "By using lower-quality silicon, you can drastically reduce that cost," he said.
- oyvindeh 13y ago
  Also, it would require less materials to make them, and they would produce less garbage when they are to be thrown away. And (I guess) they will require less energy to produce. Although there is no shortage of rooftop space, you could still fit them into places where there currently isn't so much space. Perhaps, at some point, we could put them on top of electric cars, making them less dependent on charging sockets.
  - yial 13y ago
    Like the Fisker? http://en.wikipedia.org/wiki/Fisker_Karma http://en.wikipedia.org/wiki/Fisker_Karma

dredmorbius 13y ago

Agreed. Tom Murphy makes that point in his blog: "Don't be a PV Efficiency Snob": http://physics.ucsd.edu/do-the-math/2011/09/dont-be-a-pv-efficiency-snob/ http://physics.ucsd.edu/do-the-math/2011/09/dont-be-a-pv-eff... There's plenty of solar capacity on the planet to meet not only present electric generation demand, but the growth require for substituting much present fossil-fuel usage with electricity. Probably even bringing up per-capita energy allotments to a reasonable fraction of Western levels (1.5 - 2.5 kWh/day would make a huge difference for most people's lives). The real challenges are cost -- building out solar capacity would require 8-9 doublings of existing capacity, at least. Financing this (or ramming through the construction regardless) is going to be the biggest challenge. Storage though is the other bogeyman. There's very little pumped storage available. Grid batteries, likely emphasizing cost over size, weight, or efficiency, as there simply isn't enough of many common battery materials to meet requirements, thermal storage. Maybe hydrogen production, maybe electrically-powered synfuel production, flywheels. There are a few reactor options, mostly still not commercially proven, which may help bridge the gap: TerraPower, LFTR, and other breeder designs. Relying strictly on conventional uranium fission reactors would burn through known reserves in a few decades -- 30-80 years.

belorn 13y ago
Two common methods to store excess electricity from wind/solar is with hydroelectricity, and district heating. It would be really interesting to see numbers on the maximum amount of excess power that could be stored if those two techniques was universal utilized for this purpose.
- dredmorbius 13y ago
  Pumped storage is very limited in suitable sites and total capacity. It also has impacts on the local environment and safety (large bodies of water with large daily fluctuations and keeping people and property out of water intakes). Direct thermal storage addresses some needs but not actually providing grid-level storage. Thermal electric storage does seem based on reading and some back-of-the-envelope calculations to be one option that scales reasonably well. It can be based on cheap, abundant substrates, and fits well with existing technology for converting between electricity and heat (or for CSP where heat is banked during the day). Tom Murphy's "Nation Sized Battery" presents some good numbers. If you want to extend his coverage to other techologies, you're going to want their storage density (by volume or kg), round-trip efficiency, and materials cost and availability. The key to me is that you need massively abundant, massively cheap materials. http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-battery/ http://physics.ucsd.edu/do-the-math/2011/08/nation-sized-bat...

danmaz74 13y ago

Have you actually read the article? It says that the breakthrough is in achieving pretty high efficiency with low quality - and thus low price - silicon. It doesn't claim to have found the best-of-breed efficiency.

kokey 13y ago

They do mention that it allows for using cheaper silicon, but doesn't actually quantify it e.g. a potential x.xx% cost reduction. I'm not sure if this is because it's based on PR from Suntech, who obviously doesn't want to indicate how far prices can come down by.