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Will a Breakthrough Solar Technology See the Light of Day?

77 points by codexjourneys 12y ago

jacquesm 12y ago
Anything requiring tracking is not going to be competitive with regular solar cells for simple mathematical reasons so I suspect this is not quite as breakthrough as the title makes it seem. In a nutshell: if you add the cost of lenses+tracking system you could buy more panels. That increased number of (passive) panels will be more reliable and will produce roughly about as much power as a non-tracking system would. The increased reliability is something very much valued in power generation, it also makes shading calculations and effects much less of a problem. Depending on how expensive the ground is and what other restrictions apply you're going to be be usually better off by installing a passive system. I've built a solar system with trackers, 2x8 panels, in the end I wished I'd gone for a stationary setup, the tracking was always troublesome (you need two axis tracking if you're going to utilize tracking to maximum effect, the lens system shown will definitely need two axis) and in the end produced only about 15 to 20% more power on these panels, and cost so much to set up and maintain that I could have bought another 8 panels and a rigid setup for the same money instead.
- bainsfather 12y ago
  One advantage of tracking systems is that they provide a more uniform power output over the day. You get higher power morning and evening. For off-grid systems this seems very useful. Also, there was a news story recently about the German grid having problems with load balancing - apparently they want to put panels on west and east facing roofs to try and get a more even load throughout the day. I guess that as panels get cheaper, it might be best to have static panels facing East, South, and West. Have we got to that stage yet, where this is cheaper than the moving parts? About your trackers - do you have any more info? Why did you go for 2-axis rather than 1 tilted axis? Were your problems due to inexperience/teething-troubles, or would you have the same issues if you were to do another system? I'd be interested to hear you experiences, thanks.
  - jacquesm 12y ago
    You still would not put panels facing East, South and West, you'd still install those facing South at the 12:00 position. 2 axis because the seasonal offset component got thrown in for free with the system I bought. It was quite thoroughly tested in the field before I bought two trackers, they work but the fact that you need a single post and the resulting forces on the foundation (in clay) caused a ton of issues (we were in a very windy area), the tracker mechanism had trouble with ice formation in winter (Rural Northern Ontario) and the repeated movement put extra strain on the wiring, especially at temperatures far below 0. As for variance, you're right that tracking systems provide more uniform power but most (if not all) solar farms are installed from a power produced / capital expense viewpoint, uniformity of output is currently not worth much.
    - bainsfather 12y ago
      Thanks for the info. Seems it was bought system, single titled axis, and the tilt could be changed manually for winter vs summer? Those large-area single-post setups do look unsuitable for windy regions. My static solar panels do follow a rough sine shape through the day. Clear sunny mornings or evenings I get very little power - 2 sin(0) is still zero [a], whilst generating surplus power at midday is not much use to me. I think [b] additional panels sited e.g. SE and SW might save me more money than additional panels facing south, as then supply would tend to match my demand better. [a] I still get the 10% or so from atmospherically scattered sunlight. [b] As you can see, I don't really know. e.g. how much extra atmospheric absorption is there near sunrise/sunset on average etc.
  - JetSpiegel 12y ago
    Why not create curved panels then? It's the best of both worlds. Not sure if it's feasible, technically.
    - netcan 12y ago
      I think you still have the same problem, just more uniformly distributed. Imagine a dome shaped panel. No matter what the orientation relative to the sun, the panels are equally facing it. But even still, any particular point in the dome has an orientation and it's only ideal while it's ideal. The point facing east is ideal for sunrise but is useless at sundown. You get as much uniformity as the sun and clouds give you, but you're equally wasting the same amount of panel face at any given time.
- Egregore 12y ago
  I have a manual positioning system for my solar panels, and I would say that difference between not positioned and correctly positioned panel is 2-3 times - in the morning and afternoons especially in winter time.
  - jacquesm 12y ago
    Yes, when the angle of incidence is bad that's true. But you have to average that over time to make a good comparison. Basically the power output of the panels drops off as the co-sine of the angle of incidence. So over a whole day you typically lose between 10 and 20%, take into account that in early morning and late afternoon 'twice the output' is not the same as twice the output around noon, and of course you are positioning your panels in such a way that they perform at their best when the lightpath through the atmosphere is the shortest (12:00).
    - netcan 12y ago
      What is the theoretical maximum efficiency that can be gained by an ideal tracking system relative to an ideal stationary one?
      - jacquesm 12y ago
        ~95% iirc assuming 'perfect' cells. There are some very impressive triple layer panels out there that do 44%+ right now, these are typically used in space applications. The balance between incident radiation and power produced is an interesting one, a 'perfect' solar panel would remain cold. Solar panels tend to produce less power as they warm up, so the better a solar panel gets at converting power the less it will get warmer! So there is a positive feedback mechanism at work here. Typical run-of-the-mill cells are 25% (single junction), and on cold clear winter days they can keep that up for quite a while. So that's 250 Watts per square meter of panel. I did some simulations to figure out the exact gain you could get from perfect seasonal and day tracking, it's about 28%, but no tracking system will ever reach that in practice. Typical reasons why you won't get to perfect: tracking systems tend to hunt the clouds if they are not clock based, otoh if they are clock based they tend to perform badly because they use energy to move when they're not producing energy themselves!
- wamatt 12y ago
  While your critique is certainly true of the first generation of trackers, I'm not sure if you're familiar with a company called Qbotix[1]? They're just one example where innovation in the space is producing cheaper and more reliable tracking. The basic idea is instead of having per panel tracking devices, rather, use a simple robot run around a fixed track and adjust the panels as needed. Then repeat again and again, throughout the day. If the robot malfunctions, swap it for the spare. [1] http://www.qbotix.com/ http://www.qbotix.com/
  - jacquesm 12y ago
    - wiring will have to deal with repeated bending (especially hard when it is far below 0) - you need more space otherwise the panels will shade each other - more components -> more cost - more components -> more can break (and will break) Swapping the robot for a spare is a very costly operation and can negate the power output by the panel whose robot malfunctioned over its entire lifetime after subtracting initial capital cost. And that's assuming that you will be able to obtain 'the spare' 10 years after you put the whole system into service.
    - pinkyand 12y ago
      Of course those are factors , but qbotix has raised investment, has managed to get some commitments for solar projects, and there's even a company using their system in the UK offering to finance projects on a long term electricity purchase basis, claiming it's much cheaper than current providers: http://castillium.co.uk/tracking-solar/tracking-250kw/ http://castillium.co.uk/tracking-solar/tracking-250kw/ So qbotix might have good solutions for the issues you mention. And that is of course without having concentrated solar power, which makes a qbotix a more attractive offer.
      - jacquesm 12y ago
        Raising investment is not typically a sign of technological excellence. It could be but it's certainly not a reliable indicator. Long term reliability of such systems can only be determined in the long term. So far the score does not look good for trackers.
- deleted 12y ago
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- imaginenore 12y ago
  > if you add the cost of lenses+tracking system you could buy more panels. That increased number of (passive) panels will be more reliable and will produce roughly about as much power as a non-tracking system would. How did you get to that conclusion? Arrays of plastic (and even glass) lenses are ridiculously cheap. So are the motors and parts for tracking. Panels, inverters and labor are still the expensive parts. http://greenzone.co/wp-content/uploads/2014/01/Soft-and-hard-costs-PV-residential.jpg http://greenzone.co/wp-content/uploads/2014/01/Soft-and-hard...
  - msandford 12y ago
    Further, these cells are DESIGNED to be concentrating. Meaning that if you have a 32sqft "solar panel" the cell material might only be a few dozen square inches; the concentration ratio is something like 1600:1. The plastic and glass are indeed cheap and the solar cell material is also cheap due to the very small quantity needed per panel.
    - jacquesm 12y ago
      Very high degrees of concentration tend to have negative effects on the longevity of the cell. So sure, you get a lot of power out of a smaller area (it will need good head dissipation but that's doable), but you may only get it for a shorter life-span. Solar is complex.
  - jacquesm 12y ago
    Motors and parts for tracking as well as the tracking base are definitely not ridiculously cheap. They have to be weather proof, have to operate unattended for a decade or more and have to operate in a very wide range of temperatures. A typical tracking system (besides lenses) adds significantly to the total system price compared to a non-tracking system. Dual axis tracking even more so.
- Retric 12y ago
  The cost benefit of tracking systems goes up as efficiency increases and goes down as panel costs go down. Currently, cheap low efficiency systems are the name of the game but a higher efficiency's tracking system might end up being valuable. The important thing to note is it's a global market and even a fairly niche system can have a huge market. For example plenty of places like Oil derricks are space limited and not generally grid connected. Portability can also be useful for remote locations.
  - jacquesm 12y ago
    That's true, if space is at a premium and servicing units is not a problem then trackers can have advantages.
  - alexthornton 12y ago
    In the game of solar PV, niche markets are not going to drive the kind of demand that manufacturers like this would need to reduce manufacturing costs. PV manufacturers must scale to very large numbers (hundreds of MW per year) to be competitive.
    - deleted 12y ago
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- DennisP 12y ago
  Unless they're being completely fraudulent about it, their estimate of cost per kWh would have to include whatever tracking system they require.
- jerf 12y ago
  "Anything requiring tracking is not going to be competitive with regular solar cells for simple mathematical reasons so I suspect this is not quite as breakthrough as the title makes it seem." I see one thing which even 5 hours after your post no one has observed, which is that while your argument may make sense for two otherwise-equal non-concentrating solar panels, for a concentrating solar panel based on small cells you don't have a non-tracking option to compare against. If your concentrator isn't tracking, then the vast majority of the time it's concentrating on not-the-solar-cell, which isn't useful. You'll never be able to mount this on your roof flush with your shingles. If they can make small, 40-50% efficient cells, then the tracking setup may very well beat a conventional lucky-to-be-20% efficient setup regardless of how it tracks. The additional money the setup is making over a conventional cell (literally) buys you some maintenance options that are harder to justify for a solar cell that starts out more expensive than natural gas. I've got my own questions about their claimed efficiency, but the good news is that solar efficiency is pretty easy to directly measure, so I can just sit back and wait for their customers to work out what's going on. If they're right, they're right.
  - jacquesm 12y ago
    No, that does not make any difference. You're tracking the same area, it's based on incident light, not on the resulting surface area of the detector. See the image with the article, it's a giant square leaf doing 2 axis tracking. So the concentrator and the cells are on the same substrate. I did try exactly what you are suggesting (to separate the tracked panels and the concentrator) but then you run into a totally different set of problems.
    - jerf 12y ago
      I'm not sure you got my point. There is no non-tracking concentrated high-quality solar cell option to compare against. You can only compare "tracking conventional" to "non-tracking conventional" to "tracking concentrating high-quality", and if they really get higher conversion ratios the latter can't be collapsed into the former without loss.
      - 12y ago
- hobbes78 12y ago
  You can't build passive systems out of concentrated cells... It only works when the lens is aligned with the sun, so you'd get power a couple of minutes per day...
  - jacquesm 12y ago
    Yes, that's the obvious downside of concentrators. Which has been discussed to boredom in the tech literature. You can basically do any one of the following: - passive, non concentrated - ordinary panels but tracking the sun in either 1 or 2 axis - trough (sp?) concentrators to a cylindrical collector, tracking in one axis (no significant gain from tracking the other axis) - parabolic concentrators to a collector moving with the parabola, tracking in two axis - parabolic concentrators to a stationary collector (I built a prototype like this) tracking in two axis The latter can come in two variations, one where the collector is placed on a post or one where it is placed close to the ground. These require different degrees of complexity and freedom of movement for the trackers. So yes, any kind of concentrator will be associated with some kind of tracking.
Shivetya 12y ago
If the technology is so break through I am pretty sure it would be snatched up. While many technologies sound break through they are only such until someone with expertise gets in there and starts to pull back the layers. There of course is that one glaring issue of, if an inferior tech is many times cheaper your break through will have to be many times more significant.
lordnacho 12y ago
Even if this particular entity doesn't make it, the people involved will have learned things that will be useful for future firms. It's not just financial capital that needs to be efficiently allocated.
pankajdoharey 12y ago
Damn! You China.
crdoconnor 12y ago
>With fields of over 1,000 of these devices, utilities would produce electricity at less than 5 cents per kilowatt-hour. That is even cheaper than today’s least expensive option: a new natural gas plant. Ummm... https://www.greentechmedia.com/articles/read/xcel-energy-buys-utility-scale-solar-for-less-than-natural-gas https://www.greentechmedia.com/articles/read/xcel-energy-buy... Natural Gas is ALSO in the midst of an unsustainable boom built with insane levels of debt: http://www.bloomberg.com/news/2014-04-30/shale-drillers-feast-on-junk-debt-to-say-on-treadmill.html http://www.bloomberg.com/news/2014-04-30/shale-drillers-feas... Anybody who thinks natural gas is going to stay cheap forever, or even for more than a couple of years is kidding themselves. It's an awful long term investment even if you don't account for the environmental damage.
chrisBob 12y ago
Have any companies explored fixed, or movable mirrors as a simple way to maximize the light on the panels? Since mirrors are much lower cost than the panels I am surprised that no one faces the PV system away from the sun, and then points 3 mirrors at each panel. In places that aren't space constrained this seems like a much more efficient approach. We have a heliostat for a piece of artwork [1] that keeps the sun hitting the same spot with only slight variations in angle over the year, and it only requires a single motor and gear train. I am aware that the solar furnace type systems all use mirrors, but I haven't seen any PV systems that use this approach. [1] http://www.janetsaadcook.com/BU/BU-1.htm#BUarc http://www.janetsaadcook.com/BU/BU-1.htm#BUarc
- jacquesm 12y ago
  We built a prototype to do just that: http://pics.camarades.com/v/jacques/renewables/concentrator/ http://pics.camarades.com/v/jacques/renewables/concentrator/
yessql 12y ago
Yeah, this "breakthrough" has the potential to one day to produce electricity at a cost that conventional PV already delivers. http://www.greentechmedia.com/articles/read/Austin-Energy-Switches-From-SunEdison-to-Recurrent-For-5-Cent-Solar http://www.greentechmedia.com/articles/read/Austin-Energy-Sw... I would never bet on CSP.
alexthornton 12y ago
I am curious how they generated their cost estimate. Hardware costs have already come down so significantly in the past few years, non-hardware costs (aka soft costs in the solar industry) now represent around 2/3 of the total installed costs. Soft costs include installation and maintenance, which precise tracker systems would increase over the traditional fixed PV array. Hardware cost reductions are probably not hitting the low hanging fruit of solar power costs. http://www.nrel.gov/news/press/2013/5306.html http://www.nrel.gov/news/press/2013/5306.html Another factor to consider with concentrated solar is that it is more likely to be affected by soiling (ie, dust, bird poop and other particulate) issues than traditional PV. This would mean even more cleaning and maintenance adding more to the soft costs. Soiling is a fairly common problem in areas with lots of sun and little rain. http://www1.eere.energy.gov/solar/pdfs/pvmrw2011_19_cpv_winter.pdf http://www1.eere.energy.gov/solar/pdfs/pvmrw2011_19_cpv_wint...
- zackmorris 12y ago
  This is true, I was going to post a similar comment. So one thing to consider is that the way we incorporate solar and other alternatives into our society and economy is incorrect. We should be adding it to all new construction, as it would not significantly increase costs like retrofits do. Also simple design decisions like giving a building the proper orientation with the sun, choosing deeper crawlspaces, using white roofs, using dual pane windows, choosing swamp coolers or ground loop heat pumps over air conditioning, and going with ductless/non-centralized climate control can eliminate the majority of utility costs. Amortized, these initial costs appear as savings because the payback is only a couple of years today. The only truly expensive components (windows and heat pumps) would be readily affordable with subsidies, because the government is in it for the long haul. Homes are being built in Germany that are completely off the grid. They only have small wall units in each room for emergency heating, but are otherwise insulated well enough that the home is room temperature year-round. In fact, to get to the point of all this, alternative energy and wisdom in construction is already significantly cheaper in the long term than the status quo. But incentives and building code regulation is being blocked at every turn by the fossil fuel industry, and by libertarians who unwittingly support it by taking the short view on spending and ignoring amortization or return on investment, offsetting the opportunity cost of inaction onto the public and environment. There is an argument for freedom here (that we should be able to build however we want), and I sympathize with that as a resident of the red state of Idaho, but there is no economic one. We passed that point about 10 years ago when wind and solar installs started going up exponentially around the world, but we chose to have a military presence in oil-rich countries instead.
transfire 12y ago
So those 250% tariffs on Chinese solar panels have really worked out for us, right!? The whole energy sector is so frack'd. Oil cartels periodically drop prices precipitously to drive competition out of the market. They pay off Federal politicians to create 250% tariffs, and State politicians to outlaw the the sale of electric cars direct to customers and make it illegal to use your solar cells during power outages. Oh, the irony of "free market" Republicans passing all these things. Our clueless president dumps billions into an obvious boondoggle designed to undermine the solar market, while real breakthroughs wither on the vine.
- wyager 12y ago
  > the irony of "free market" Republicans > Our clueless president While I agree with the sentiment, it is important to emphasize that protectionist policy and bribery is not limited to any one political party.
Johnythree 12y ago
There is another factor with Tracking: You size your array to cope with poor conditions, not best conditions. Worst conditions are when it's overcast, and not surprisingly the best alignment then is pointing straight up. So there is a argument that pointing straight up, actually gives more power when it's needed (which would make trackers redundant). I have two sets of panels: One is mounted at the approved angle, while the other is flat on the roof. The flat ones actually seem to do better in the winter. I guess it depends very much on the seasons at your location.

77 points by codexjourneys 12y ago

Anything requiring tracking is not going to be competitive with regular solar cells for simple mathematical reasons so I suspect this is not quite as breakthrough as the title makes it seem. In a nutshell: if you add the cost of lenses+tracking system you could buy more panels. That increased number of (passive) panels will be more reliable and will produce roughly about as much power as a non-tracking system would. The increased reliability is something very much valued in power generation, it also makes shading calculations and effects much less of a problem. Depending on how expensive the ground is and what other restrictions apply you're going to be be usually better off by installing a passive system. I've built a solar system with trackers, 2x8 panels, in the end I wished I'd gone for a stationary setup, the tracking was always troublesome (you need two axis tracking if you're going to utilize tracking to maximum effect, the lens system shown will definitely need two axis) and in the end produced only about 15 to 20% more power on these panels, and cost so much to set up and maintain that I could have bought another 8 panels and a rigid setup for the same money instead.

bainsfather 12y ago
One advantage of tracking systems is that they provide a more uniform power output over the day. You get higher power morning and evening. For off-grid systems this seems very useful. Also, there was a news story recently about the German grid having problems with load balancing - apparently they want to put panels on west and east facing roofs to try and get a more even load throughout the day. I guess that as panels get cheaper, it might be best to have static panels facing East, South, and West. Have we got to that stage yet, where this is cheaper than the moving parts? About your trackers - do you have any more info? Why did you go for 2-axis rather than 1 tilted axis? Were your problems due to inexperience/teething-troubles, or would you have the same issues if you were to do another system? I'd be interested to hear you experiences, thanks.
- jacquesm 12y ago
  You still would not put panels facing East, South and West, you'd still install those facing South at the 12:00 position. 2 axis because the seasonal offset component got thrown in for free with the system I bought. It was quite thoroughly tested in the field before I bought two trackers, they work but the fact that you need a single post and the resulting forces on the foundation (in clay) caused a ton of issues (we were in a very windy area), the tracker mechanism had trouble with ice formation in winter (Rural Northern Ontario) and the repeated movement put extra strain on the wiring, especially at temperatures far below 0. As for variance, you're right that tracking systems provide more uniform power but most (if not all) solar farms are installed from a power produced / capital expense viewpoint, uniformity of output is currently not worth much.
  - bainsfather 12y ago
    Thanks for the info. Seems it was bought system, single titled axis, and the tilt could be changed manually for winter vs summer? Those large-area single-post setups do look unsuitable for windy regions. My static solar panels do follow a rough sine shape through the day. Clear sunny mornings or evenings I get very little power - 2 sin(0) is still zero [a], whilst generating surplus power at midday is not much use to me. I think [b] additional panels sited e.g. SE and SW might save me more money than additional panels facing south, as then supply would tend to match my demand better. [a] I still get the 10% or so from atmospherically scattered sunlight. [b] As you can see, I don't really know. e.g. how much extra atmospheric absorption is there near sunrise/sunset on average etc.
- JetSpiegel 12y ago
  Why not create curved panels then? It's the best of both worlds. Not sure if it's feasible, technically.
  - netcan 12y ago
    I think you still have the same problem, just more uniformly distributed. Imagine a dome shaped panel. No matter what the orientation relative to the sun, the panels are equally facing it. But even still, any particular point in the dome has an orientation and it's only ideal while it's ideal. The point facing east is ideal for sunrise but is useless at sundown. You get as much uniformity as the sun and clouds give you, but you're equally wasting the same amount of panel face at any given time.
Egregore 12y ago
I have a manual positioning system for my solar panels, and I would say that difference between not positioned and correctly positioned panel is 2-3 times - in the morning and afternoons especially in winter time.
- jacquesm 12y ago
  Yes, when the angle of incidence is bad that's true. But you have to average that over time to make a good comparison. Basically the power output of the panels drops off as the co-sine of the angle of incidence. So over a whole day you typically lose between 10 and 20%, take into account that in early morning and late afternoon 'twice the output' is not the same as twice the output around noon, and of course you are positioning your panels in such a way that they perform at their best when the lightpath through the atmosphere is the shortest (12:00).
  - netcan 12y ago
    What is the theoretical maximum efficiency that can be gained by an ideal tracking system relative to an ideal stationary one?
    - jacquesm 12y ago
      ~95% iirc assuming 'perfect' cells. There are some very impressive triple layer panels out there that do 44%+ right now, these are typically used in space applications. The balance between incident radiation and power produced is an interesting one, a 'perfect' solar panel would remain cold. Solar panels tend to produce less power as they warm up, so the better a solar panel gets at converting power the less it will get warmer! So there is a positive feedback mechanism at work here. Typical run-of-the-mill cells are 25% (single junction), and on cold clear winter days they can keep that up for quite a while. So that's 250 Watts per square meter of panel. I did some simulations to figure out the exact gain you could get from perfect seasonal and day tracking, it's about 28%, but no tracking system will ever reach that in practice. Typical reasons why you won't get to perfect: tracking systems tend to hunt the clouds if they are not clock based, otoh if they are clock based they tend to perform badly because they use energy to move when they're not producing energy themselves!
wamatt 12y ago
While your critique is certainly true of the first generation of trackers, I'm not sure if you're familiar with a company called Qbotix[1]? They're just one example where innovation in the space is producing cheaper and more reliable tracking. The basic idea is instead of having per panel tracking devices, rather, use a simple robot run around a fixed track and adjust the panels as needed. Then repeat again and again, throughout the day. If the robot malfunctions, swap it for the spare. [1] http://www.qbotix.com/ http://www.qbotix.com/
- jacquesm 12y ago
  - wiring will have to deal with repeated bending (especially hard when it is far below 0) - you need more space otherwise the panels will shade each other - more components -> more cost - more components -> more can break (and will break) Swapping the robot for a spare is a very costly operation and can negate the power output by the panel whose robot malfunctioned over its entire lifetime after subtracting initial capital cost. And that's assuming that you will be able to obtain 'the spare' 10 years after you put the whole system into service.
  - pinkyand 12y ago
    Of course those are factors , but qbotix has raised investment, has managed to get some commitments for solar projects, and there's even a company using their system in the UK offering to finance projects on a long term electricity purchase basis, claiming it's much cheaper than current providers: http://castillium.co.uk/tracking-solar/tracking-250kw/ http://castillium.co.uk/tracking-solar/tracking-250kw/ So qbotix might have good solutions for the issues you mention. And that is of course without having concentrated solar power, which makes a qbotix a more attractive offer.
    - jacquesm 12y ago
      Raising investment is not typically a sign of technological excellence. It could be but it's certainly not a reliable indicator. Long term reliability of such systems can only be determined in the long term. So far the score does not look good for trackers.
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imaginenore 12y ago
> if you add the cost of lenses+tracking system you could buy more panels. That increased number of (passive) panels will be more reliable and will produce roughly about as much power as a non-tracking system would. How did you get to that conclusion? Arrays of plastic (and even glass) lenses are ridiculously cheap. So are the motors and parts for tracking. Panels, inverters and labor are still the expensive parts. http://greenzone.co/wp-content/uploads/2014/01/Soft-and-hard-costs-PV-residential.jpg http://greenzone.co/wp-content/uploads/2014/01/Soft-and-hard...
- msandford 12y ago
  Further, these cells are DESIGNED to be concentrating. Meaning that if you have a 32sqft "solar panel" the cell material might only be a few dozen square inches; the concentration ratio is something like 1600:1. The plastic and glass are indeed cheap and the solar cell material is also cheap due to the very small quantity needed per panel.
  - jacquesm 12y ago
    Very high degrees of concentration tend to have negative effects on the longevity of the cell. So sure, you get a lot of power out of a smaller area (it will need good head dissipation but that's doable), but you may only get it for a shorter life-span. Solar is complex.
- jacquesm 12y ago
  Motors and parts for tracking as well as the tracking base are definitely not ridiculously cheap. They have to be weather proof, have to operate unattended for a decade or more and have to operate in a very wide range of temperatures. A typical tracking system (besides lenses) adds significantly to the total system price compared to a non-tracking system. Dual axis tracking even more so.
Retric 12y ago
The cost benefit of tracking systems goes up as efficiency increases and goes down as panel costs go down. Currently, cheap low efficiency systems are the name of the game but a higher efficiency's tracking system might end up being valuable. The important thing to note is it's a global market and even a fairly niche system can have a huge market. For example plenty of places like Oil derricks are space limited and not generally grid connected. Portability can also be useful for remote locations.
- jacquesm 12y ago
  That's true, if space is at a premium and servicing units is not a problem then trackers can have advantages.
- alexthornton 12y ago
  In the game of solar PV, niche markets are not going to drive the kind of demand that manufacturers like this would need to reduce manufacturing costs. PV manufacturers must scale to very large numbers (hundreds of MW per year) to be competitive.
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DennisP 12y ago
Unless they're being completely fraudulent about it, their estimate of cost per kWh would have to include whatever tracking system they require.
jerf 12y ago
"Anything requiring tracking is not going to be competitive with regular solar cells for simple mathematical reasons so I suspect this is not quite as breakthrough as the title makes it seem." I see one thing which even 5 hours after your post no one has observed, which is that while your argument may make sense for two otherwise-equal non-concentrating solar panels, for a concentrating solar panel based on small cells you don't have a non-tracking option to compare against. If your concentrator isn't tracking, then the vast majority of the time it's concentrating on not-the-solar-cell, which isn't useful. You'll never be able to mount this on your roof flush with your shingles. If they can make small, 40-50% efficient cells, then the tracking setup may very well beat a conventional lucky-to-be-20% efficient setup regardless of how it tracks. The additional money the setup is making over a conventional cell (literally) buys you some maintenance options that are harder to justify for a solar cell that starts out more expensive than natural gas. I've got my own questions about their claimed efficiency, but the good news is that solar efficiency is pretty easy to directly measure, so I can just sit back and wait for their customers to work out what's going on. If they're right, they're right.
- jacquesm 12y ago
  No, that does not make any difference. You're tracking the same area, it's based on incident light, not on the resulting surface area of the detector. See the image with the article, it's a giant square leaf doing 2 axis tracking. So the concentrator and the cells are on the same substrate. I did try exactly what you are suggesting (to separate the tracked panels and the concentrator) but then you run into a totally different set of problems.
  - jerf 12y ago
    I'm not sure you got my point. There is no non-tracking concentrated high-quality solar cell option to compare against. You can only compare "tracking conventional" to "non-tracking conventional" to "tracking concentrating high-quality", and if they really get higher conversion ratios the latter can't be collapsed into the former without loss.
    - 12y ago
hobbes78 12y ago
You can't build passive systems out of concentrated cells... It only works when the lens is aligned with the sun, so you'd get power a couple of minutes per day...
- jacquesm 12y ago
  Yes, that's the obvious downside of concentrators. Which has been discussed to boredom in the tech literature. You can basically do any one of the following: - passive, non concentrated - ordinary panels but tracking the sun in either 1 or 2 axis - trough (sp?) concentrators to a cylindrical collector, tracking in one axis (no significant gain from tracking the other axis) - parabolic concentrators to a collector moving with the parabola, tracking in two axis - parabolic concentrators to a stationary collector (I built a prototype like this) tracking in two axis The latter can come in two variations, one where the collector is placed on a post or one where it is placed close to the ground. These require different degrees of complexity and freedom of movement for the trackers. So yes, any kind of concentrator will be associated with some kind of tracking.

Shivetya 12y ago

If the technology is so break through I am pretty sure it would be snatched up. While many technologies sound break through they are only such until someone with expertise gets in there and starts to pull back the layers. There of course is that one glaring issue of, if an inferior tech is many times cheaper your break through will have to be many times more significant.

lordnacho 12y ago

Even if this particular entity doesn't make it, the people involved will have learned things that will be useful for future firms. It's not just financial capital that needs to be efficiently allocated.

pankajdoharey 12y ago

Damn! You China.

crdoconnor 12y ago

>With fields of over 1,000 of these devices, utilities would produce electricity at less than 5 cents per kilowatt-hour. That is even cheaper than today’s least expensive option: a new natural gas plant. Ummm... https://www.greentechmedia.com/articles/read/xcel-energy-buys-utility-scale-solar-for-less-than-natural-gas https://www.greentechmedia.com/articles/read/xcel-energy-buy... Natural Gas is ALSO in the midst of an unsustainable boom built with insane levels of debt: http://www.bloomberg.com/news/2014-04-30/shale-drillers-feast-on-junk-debt-to-say-on-treadmill.html http://www.bloomberg.com/news/2014-04-30/shale-drillers-feas... Anybody who thinks natural gas is going to stay cheap forever, or even for more than a couple of years is kidding themselves. It's an awful long term investment even if you don't account for the environmental damage.

chrisBob 12y ago

Have any companies explored fixed, or movable mirrors as a simple way to maximize the light on the panels? Since mirrors are much lower cost than the panels I am surprised that no one faces the PV system away from the sun, and then points 3 mirrors at each panel. In places that aren't space constrained this seems like a much more efficient approach. We have a heliostat for a piece of artwork [1] that keeps the sun hitting the same spot with only slight variations in angle over the year, and it only requires a single motor and gear train. I am aware that the solar furnace type systems all use mirrors, but I haven't seen any PV systems that use this approach. [1] http://www.janetsaadcook.com/BU/BU-1.htm#BUarc http://www.janetsaadcook.com/BU/BU-1.htm#BUarc

jacquesm 12y ago
We built a prototype to do just that: http://pics.camarades.com/v/jacques/renewables/concentrator/ http://pics.camarades.com/v/jacques/renewables/concentrator/

yessql 12y ago

Yeah, this "breakthrough" has the potential to one day to produce electricity at a cost that conventional PV already delivers. http://www.greentechmedia.com/articles/read/Austin-Energy-Switches-From-SunEdison-to-Recurrent-For-5-Cent-Solar http://www.greentechmedia.com/articles/read/Austin-Energy-Sw... I would never bet on CSP.

alexthornton 12y ago

I am curious how they generated their cost estimate. Hardware costs have already come down so significantly in the past few years, non-hardware costs (aka soft costs in the solar industry) now represent around 2/3 of the total installed costs. Soft costs include installation and maintenance, which precise tracker systems would increase over the traditional fixed PV array. Hardware cost reductions are probably not hitting the low hanging fruit of solar power costs. http://www.nrel.gov/news/press/2013/5306.html http://www.nrel.gov/news/press/2013/5306.html Another factor to consider with concentrated solar is that it is more likely to be affected by soiling (ie, dust, bird poop and other particulate) issues than traditional PV. This would mean even more cleaning and maintenance adding more to the soft costs. Soiling is a fairly common problem in areas with lots of sun and little rain. http://www1.eere.energy.gov/solar/pdfs/pvmrw2011_19_cpv_winter.pdf http://www1.eere.energy.gov/solar/pdfs/pvmrw2011_19_cpv_wint...

zackmorris 12y ago
This is true, I was going to post a similar comment. So one thing to consider is that the way we incorporate solar and other alternatives into our society and economy is incorrect. We should be adding it to all new construction, as it would not significantly increase costs like retrofits do. Also simple design decisions like giving a building the proper orientation with the sun, choosing deeper crawlspaces, using white roofs, using dual pane windows, choosing swamp coolers or ground loop heat pumps over air conditioning, and going with ductless/non-centralized climate control can eliminate the majority of utility costs. Amortized, these initial costs appear as savings because the payback is only a couple of years today. The only truly expensive components (windows and heat pumps) would be readily affordable with subsidies, because the government is in it for the long haul. Homes are being built in Germany that are completely off the grid. They only have small wall units in each room for emergency heating, but are otherwise insulated well enough that the home is room temperature year-round. In fact, to get to the point of all this, alternative energy and wisdom in construction is already significantly cheaper in the long term than the status quo. But incentives and building code regulation is being blocked at every turn by the fossil fuel industry, and by libertarians who unwittingly support it by taking the short view on spending and ignoring amortization or return on investment, offsetting the opportunity cost of inaction onto the public and environment. There is an argument for freedom here (that we should be able to build however we want), and I sympathize with that as a resident of the red state of Idaho, but there is no economic one. We passed that point about 10 years ago when wind and solar installs started going up exponentially around the world, but we chose to have a military presence in oil-rich countries instead.

transfire 12y ago

So those 250% tariffs on Chinese solar panels have really worked out for us, right!? The whole energy sector is so frack'd. Oil cartels periodically drop prices precipitously to drive competition out of the market. They pay off Federal politicians to create 250% tariffs, and State politicians to outlaw the the sale of electric cars direct to customers and make it illegal to use your solar cells during power outages. Oh, the irony of "free market" Republicans passing all these things. Our clueless president dumps billions into an obvious boondoggle designed to undermine the solar market, while real breakthroughs wither on the vine.

wyager 12y ago
> the irony of "free market" Republicans > Our clueless president While I agree with the sentiment, it is important to emphasize that protectionist policy and bribery is not limited to any one political party.

Johnythree 12y ago

There is another factor with Tracking: You size your array to cope with poor conditions, not best conditions. Worst conditions are when it's overcast, and not surprisingly the best alignment then is pointing straight up. So there is a argument that pointing straight up, actually gives more power when it's needed (which would make trackers redundant). I have two sets of panels: One is mounted at the approved angle, while the other is flat on the roof. The flat ones actually seem to do better in the winter. I guess it depends very much on the seasons at your location.