The Solar Sunflower
arstechnica.com
The Solar Sunflower
1–10 of 47 posts
Re: The Solar Sunflower
#2Another step towards _Ringworld_!
Re: The Solar Sunflower
#3I take exception to the use of the word 'invention' here because that most likely implies that patents are at stake. Tech such as this has been tried on-and-off by various parties since the 80's, with many variations on geometry, working fluid, actuation and tracking.
Parabolic segments are a pretty expensive way to do this because it requires moving the collector around. Much simpler and easier to have a stationary reflector harness and actuate the individual mirrors instead, then you can keep the collector on the ground where it is much easier to tie it into something that makes use of the collected energy.
Re: The Solar Sunflower
#4I take exception to the use of the word 'invention' here because that most likely implies that patents are at stake. Tech such as this has been tried on-and-off by various parties since the 80's, with many variations on geometry, working fluid, actuation and tracking. Parabolic segments are a pretty expensive way to do this because it requires moving the collector around. Much simpler and easier to have a stationary…
Agreed. The simpler solutions are cheaper and easier to maintain. There are just too many points of failure on a system such as this.
Re: The Solar Sunflower
#5I take exception to the use of the word 'invention' here because that most likely implies that patents are at stake. Tech such as this has been tried on-and-off by various parties since the 80's, with many variations on geometry, working fluid, actuation and tracking. Parabolic segments are a pretty expensive way to do this because it requires moving the collector around. Much simpler and easier to have a stationary…
Especially if such reflector units could be mass produced and designed such that their mooring+maintenance requirements are absolutely minimal.
Re: The Solar Sunflower
#6I take exception to the use of the word 'invention' here because that most likely implies that patents are at stake. Tech such as this has been tried on-and-off by various parties since the 80's, with many variations on geometry, working fluid, actuation and tracking. Parabolic segments are a pretty expensive way to do this because it requires moving the collector around. Much simpler and easier to have a stationary…
Especially if such reflector units could be mass produced and designed such that their mooring+maintenance requirements are absolutely minimal.
I built a (crappy) prototype to test this and it worked remarkably well:
http://pics.camarades.com/v/jacques/renewables/concentrator/
Re: The Solar Sunflower
#7While reading the article, I was wondering why combined PV/water heating conventional panels aren't taking off on rooftop installations. Looks like something that would make a lot of sense.
Re: The Solar Sunflower
#8Earlier quoted context omitted.
Especially if such reflector units could be mass produced and designed such that their mooring+maintenance requirements are absolutely minimal.
I built a (crappy) prototype to test this and it worked remarkably well: http://pics.camarades.com/v/jacques/renewables/concentrator/
That is pretty cool, it looks remarkably similar to something one of the Google Energy projects was doing. I tried something a bit different which was to make an actual parabola but to build a mirror reflected the Sun into the same point all the time. (basically you take advantage of the fact that the position of the Sun in the sky for all time/seasons can be calculated for a particular latitude, and then build a reflector where it has a surface for each calculated point.) It works ok, and as a bonus you have something you can put in your lawn which is always annoying your neighbor :-)
The real magic in the sunflower though is that its a dual cycle system harvesting both thermal and electric energy from the system. A lot of "off grid" solar installs will have both PV and Thermal panels as burning electricity to create hot water is really wasteful.
Re: The Solar Sunflower
#9I take exception to the use of the word 'invention' here because that most likely implies that patents are at stake. Tech such as this has been tried on-and-off by various parties since the 80's, with many variations on geometry, working fluid, actuation and tracking. Parabolic segments are a pretty expensive way to do this because it requires moving the collector around. Much simpler and easier to have a stationary…
Agreed. I saw a demonstration of a unit very similar to the one in the article, that had vacuum-focused thin film reflectors and a sodium-cooled sterling engine. That was in 1997.
Re: The Solar Sunflower
#10While reading the article, I was wondering why combined PV/water heating conventional panels aren't taking off on rooftop installations. Looks like something that would make a lot of sense.
It's a good question. The panels are available, for example these: http://www.solimpeks.com/pv-t-hybrid-solar-collectors/
My guess is they're not as popular because the overall installation complexity is much higher: you have to run the piping, and I'm not even sure exactly what you do with the hot water that comes out. There won't be room for it in your existing hot water heater, so you'll need a second tank, and where do you put it? How big does it need to be? And what happens when it fills up? Are the panels cooled only with fresh cold water, or do you reuse the water in the second tank once it's full? And if the latter, what happens when that water gets too hot to use? I guess you'd start letting some of it evaporate -- that'll be the fastest way to get rid of the excess heat, but may be undesirable in a water-poor area; and once you start evaporating water, you have to worry about scale formation.
Probably somebody knows the answers to all these questions, but they're not obvious to me. For new construction, they're probably not that hard to solve, but for a retrofit on an existing house -- which is the vast majority of where the panels are going -- the complexity seems prohibitive.
Somebody please correct me if I'm mistaken!