Compact Solar Concentrators Ready For Installation in California
by Justin Thomas, Virginia on 02. 5.07

Practical Instruments, a manufacturer of concentrating solar panels, today announced partnerships with three Southern California-based installers of solar power systems: Energy Options, Permacity Corporation and Advanced Solar Electric. The three represent the first resellers and installers for the solar product called the Heliotube. A Heliotube consists of 10 small solar troughs that rotate to follow the sun. The troughs are integrated into a panel that is the same length and width as a traditional panel (60" x 42" x 6") and weighs 45 pounds. The company says Heliotubes have two main advantages over conventional panels: they can catch the sun for longer periods during the day, and they require less silicon in their construction. :: PR NewsWire
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I was super excited by this because I thought that slat arrays had hit the mainstream market. But then I realized that these things are not mirrors. It would be great to use those modules with mirrors instead of silicon solar cells! They are neat though still.
SLAT ARRAYS
Pity this only produces the same ammount of power as a traditional solar panel as well, if they had actually used higher grade solar cells with the concentrator and given a bit more power output it would be great.
Although this arrangement doesn't increase peak output it probably produces more through the course of the day (by following the sun and maximizing exposure) Also, because it uses less silicon it presumably (hopefully?) has less embodied energy.
There's not enough technical information on the website link or in the press release to determine what the product is or does.
There is no such thing as "watt equivalents". A watt is a defined term: volts times amps. The webpage products says this is 4.2 amps x 41 volts: 172 watts. The size is 65” x 44” = 19.7 sq.ft. Ordinary 13% efficiency PV at 12 watts per square foot is 238 watts from 19.7 sq.ft.
Heliotube = 172 watts
polycrystal PV = 238 watts
Here's a link to a panel, 175 watts, same as the Heliotube:
http://www.absak.com/pdf/pw_1650spec.pdf
Dimensions: 42" x 49" = 14.3 square feet. No moving parts to break down, no gaps to collect leaf litter, doesn't move.
There certainly could be a Watt equivalency, but it is better to compare annual output in a given climate and location. The problem with only comparing the peak output of the conventional flat panel is that this peak output only occurs with direct radiation at test condition levels. The advantage of tracking systems is that over the course of the day and season, they will produce more power for the same peak rating than their traditional fixed position cousins.
This mythcalculation is clearly demonstrated by Lion Kuntz's correct, but misleading math above.
Try integrating the output from these panels over an entire year and you will see the difference between peak Watt output ratings. That is how we should make the comparison between different technologies.