Benny
Member
Oh dear - just when solarcube disappears another one starts up.
http://www.indiegogo.com/projects/rawlemon-solar-devices
Looks very pretty with the big glass sphere but a load of gobbledigook on the site.
Eveb works at night !
Concentrates diffuse radiation !
"can reach up to 70% yield surplus" - whatever that means.
But they've raised $69,000.
Where's Keef ?
axess
Member
Hi Benny,
This device is mentioned in an article in the New Scientist- "moon units" (1February2014Page41) which claims to capture the sun reflected off the moon-
"A 500mm sphere...can track the moon, concentrate its thin stream of reflected photons up to 20000 times onto a standard solar cell, and produce enough electricity to operate an LED, says Rawlemon's Andre Broessel."
Also works in daylight apparently.
Bushwalker
Member
The prices they want for their PV equivalent sizes (!m and 1.8m diameters) are eye watering.
The units may be highly efficient at concentrating the solar energy received onto a small cell, but the physics are that we have 1000w per square metre available. Even if these were 100% efficient, and standard cells are 17% efficient, then one 1m2 rawlemon device is equivalent to about 4-5 standard panels which would be way cheaper to install.
I'm sceptical this is better than the suncube even if it becomes available and is well made. The economics don't stack up.
Looking at the indiegogo contributions, most of the supporters seem to want the toy version.
BW
johnmath
Member
Benny said:
Oh dear - just when solarcube disappears another one starts up.Looks very pretty with the big glass sphere but a load of gobbledigook on the site.
Eveb works at night !
Concentrates diffuse radiation !
"can reach up to 70% yield surplus" - whatever that means.
But they've raised $69,000.
Where's Keef ?
Spherical concentrators have been used for 160 years for recording the hours of sunlight. http://en.wikipedia.org/wiki/Campbell–Stokes_recorder
Assuming the tracking system works reliably and lasts, it's a neat curiosity. How this device suddenly reverses it's optical properties in diffuse light is a mystery (hint: it won't). That - and a whole lot of other "have my cake and eat it too" gobbledygook on the website - seems to indicate that double counting must have been in the math curriculum of the "inventor". It's a shame he isn't a scientist and doesn't realise that enthusiasm isn't protection against foolishness.
A word of warning: a 1.8 meter ball of water weighs over three tons. It also seems to have a concentration factor of 100 times. I don't know how long a few square centimetres of silicon is going to withstand 2,500 watts of energy on it. It might be better as a solar powered tracking pizza cooker.
Morbo
Member
axess said:
"A 500mm sphere...can track the moon, concentrate its thin stream of reflected photons up to 20000 times onto a standard solar cell, and produce enough electricity to operate an LED, says Rawlemon's Andre Broessel."
Also works in daylight apparently.
thats 3V * 0.01A, to operate 1 LED. I am afraid its easier just to do the full moon do its work. For free.
Johnnojack
Member
"I am afraid its easier just to do the full moon do its work. For free."
Yes.
I have an 8" reflecting telescope (200mm v 500mm)> If I focus it on the moon the light coming from the eyepiece can be used to read a book. Much brighter than a single LED
