Clean Power

Published on February 26th, 2011 | by Michael Ricciardi


Solar ‘Energy Telescope’ Focuses on More Output, Less Cost

February 26th, 2011 by  

A University of Arizona engineering team led by Roger Angel has designed a new type of solar concentrator that uses half the area of solar (PV) cells used by other optical devices and delivers a light output/concentration that is over 1000 times more concentrated before it even hits the cells.

This comes as a result of a broader goal to make solar energy cost competitive with fossil fuels (target = 1$/W) without the “need for government subsidization.” *

Solar concentrators — optical systems of lenses, reflectors, and photo-voltaics — have been developed before, but for Angel and his team, their innovation was the result of rethinking the entire concentrator concept. This new “energy telescope” focuses incident light, via reflectors, through a ball lens, which then emerges 400 times more concentrated; a second series of funnels then triples this concentration (reaching concentration levels up to 1200 times the “geometric concentration”).

In the energy telescope, a large reflector and a ball lens at the focus concentrate sunlight uniformly on small photovoltaic cells. Here, the ball lens glows in concentrated sunlight during a test of power generation.

These funnels are crafted such that each receives the same amount of light, generating the same electrical output (current amplitude).

Cost savings also derive from the use of commercially available triple-junction solar cells (each junction captures a different wavelength of light) which have double the conversion efficiency of single-junction cells used in many arrays.

A series of these then devices are installed into an array consisting of eight dish reflectors (each with the new lens-funnel-cell design) as well as cooling and tracking components, all supported by a spaceframe structure (see image) constructed of  a “lightweight, high strength, low alloy steel in a mechanically efficient framework.”

Not surprisingly, Angel recently obtained an exclusive  license from UA for the technology and founded REhnu, LLC.

The new company will continue its development, deployment and testing of the new telescope in various configurations.

Researchers completed an end-to-end test in which a reflector with 4 rectangular segments powers a receiver with 8 triple junction cells. The receiver’s ball lens glows with concentrated sunlight in this first test, which yielded 500W of DC power. Images courtesy of REhnu LLC.

In a further boost to the new enterprise, REhnu LLC recently received a million-dollar grant from the Science Foundation of Arizona, a consortium of three Arizona-based CEO business organizations, whose goal is to “strengthen and diversify Arizona’s economy with strategic research and development investments. ” The foundation targets three economic sectors (bio-medicine, renewable energy, and IT/Comm.) that have “high-impact commercial potential.”

* It should be pointed out that despite private sector claims of not needing or using government subsidizing, such state subsidizing is fundamental to the R&D (and ‘in-kind” support) of much new tech. In this case, Angel’s device was developed while at the University of Arizona (a State supported school), which no doubt provided resources (human and other) and covered many costs associated with it’s initial design and testing (thus was the technology licensed by AU to the for-profit spin-off).

Quotes and some source material foe this post came from the article ‘Energy Telescope Aims for 1$ Watt’ by Nancy LaMontagne

Related Story: Solar Panel Film Increases Efficiency 300%, Cuts Costs in Half

Images: courtesy of REhnu LLC, via

Check out our new 93-page EV report.

Join us for an upcoming Cleantech Revolution Tour conference!

Tags: , , , , , , , , , , , , , , , , , , , , , , , , , , , , ,

About the Author

Michael Ricciardi is a well-published writer of science/nature/technology articles as well as essays, poetry and short fiction. Michael has interviewed dozen of scientists from many scientific fields, including Brain Greene, Paul Steinhardt, Arthur Shapiro, and Nobel Laureate Ilya Progogine (deceased). Michael was trained as a naturalist and taught ecology and natural science on Cape Cod, Mass. from 1986-1991. His first arts grant was for production of the environmental (video) documentary 'The Jones River - A Natural History', 1987-88 (Kingston, Mass.). Michael is an award winning, internationally screened video artist. Two of his more recent short videos; 'A Time of Water Bountiful' and 'My Name is HAM' (an "imagined memoir" about the first chimp in space), and several other short videos, can be viewed on his website ( He is also the author of the (Kindle) ebook: Artful Survival ~ Creative Options for Chaotic Times

Back to Top ↑