Made in IBM Labs: Collaboration Aims to Harness the Energy of 2,000 Suns

   Made in IBM Labs: Collaboration Aims to Harness the Energy of 2,000 Suns

- High Concentration PhotoVoltaic Thermal system able to convert 80 percent of
the collected solar energy

- System can deliver electricity, potable water and cool air in remote

- Design based on a low-cost, large dish-like concentrator and micro-channel
cooled high performance photovoltaic chips suitable for mass-production

PR Newswire

ZURICH, April 22, 2013

ZURICH, April 22, 2013 /PRNewswire/ -- Today on Earth Day, scientists have
announced a collaboration to develop an affordable photovoltaic system capable
of concentrating solar radiation 2,000 times and converting 80 percent of the
incoming radiation into useful energy. The system can also provide desalinated
water and cool air in sunny, remote locations where they are often in short



(Logo: )

A three-year, $2.4 million (2.25 million CHF) grant from the Swiss Commission
for Technology and Innovation has been awarded to scientists at IBM Research
(NYSE: IBM); Airlight Energy, a supplier of solar power technology; ETH Zurich
(Professorship of Renewable Energy Carriers) and Interstate University of
Applied Sciences Buchs NTB (Institute for Micro- and Nanotechnology MNT) to
research and develop an economical High Concentration PhotoVoltaic Thermal
(HCPVT) system.

Based on a study by the European Solar Thermal Electricity Association and
Greenpeace International, technically, it would only take two percent of the
solar energy from the Sahara Desert to supply the world's electricity needs*.
Unfortunately, current solar technologies on the market today are too
expensive and slow to produce, require rare Earth minerals and lack the
efficiency to make such massive installations practical.

The prototype HCPVT system uses a large parabolic dish, made from a multitude
of mirror facets, which are attached to a sun tracking system. The tracking
system positions the dish at the best angle to capture the sun's rays, which
then reflect off the mirrors onto several microchannel-liquid cooled receivers
with triple junction photovoltaic chips -- each 1x1 centimeter chip can
convert 200-250 watts, on average, over a typical eight hour day in a sunny

The entire receiver combines hundreds of chips and provides 25 kilowatts of
electrical power. The photovoltaic chips are mounted on micro-structured
layers that pipe liquid coolants within a few tens of micrometers off the chip
to absorb the heat and draw it away 10 times more effective than with passive
air cooling.

The coolant maintains the chips almost at the same temperature for a solar
concentration of 2,000 times and can keep them at safe temperatures up to a
solar concentration of 5,000 times.

The direct cooling solution with very small pumping power is inspired by the
hierarchical branched blood supply system of the human body and has been
already tested by IBM scientists in high performance computers, including
Aquasar. An initial demonstrator of the multi-chip receiver was developed in a
previous collaboration between IBM and the Egypt Nanotechnology Research

"We plan to use triple-junction photovoltaic cells on a micro-channel cooled
module which can directly convert more than 30 percent of collected solar
radiation into electrical energy and allow for the efficient recovery of an
additional 50 percent waste heat," said Bruno Michel, manager, advanced
thermal packaging at IBM Research. "We believe that we can achieve this with a
very practical design that is made of lightweight and high strength concrete,
which is used in bridges, and primary optics composed of inexpensive pneumatic
mirrors -- it's frugal innovation, but builds on decades of experience in

"The design of the system is elegantly simple," said Andrea Pedretti, chief
technology officer at Airlight Energy. "We replace expensive steel and glass
with low cost concrete and simple pressurized metalized foils. The small
high-tech components, in particular the microchannel coolers and the molds,
can be manufactured in Switzerland with the remaining construction and
assembly done in the region of the installation. This leads to a win-win
situation where the system is cost competitive and jobs are created in both

The solar concentrating optics will be developed by ETH Zurich. "Advanced
ray-tracing numerical techniques will be applied to optimize the design of the
optical configuration and reach uniform solar fluxes exceeding 2,000 suns at
the surface of the photovoltaic cell," said Aldo Steinfeld, Professor at ETH

With such a high concentration and a radically low cost design scientists
believe they can achieve a cost per aperture area below $250 per square meter,
which is three times lower than comparable systems. The levelized cost of
energy will be less than 10 cents per kilowatt hour (KWh). For comparison,
feed in tariffs for electrical energy in Germany are currently still larger
than 25 cents per KWh and production cost at coal power stations are around
5-10 cents per KWh.

Water Desalination and Cool Air

Current concentration photovoltaic systems only collect electrical energy and
dissipate the thermal energy to the atmosphere. With the HCPVT packaging
approach scientists can both eliminate the overheating problems of solar chips
while also repurposing the energy for thermal water desalination and
adsorption cooling.

To capture the medium grade heat IBM scientists and engineers are utilizing an
advanced technology they developed for water-cooled high performance
computers, including Aquasar and SuperMUC. With both computers water is used
to absorb heat from the processor chips, which is then used to provide space
heating for the facilities.

"Microtechnology as known from computer chip manufacturing is crucial to
enable such an efficient thermal transfer from the photovoltaic chip over to
the cooling liquid," said Andre Bernard, head of the MNT Institute at NTB
Buchs. "And by using innovative ways to fabricate these heat transfer devices
we aim at a cost-efficient production."

In the HCPVT system, instead of heating a building, the 90 degree Celsius
water will be used to heat salty water that then passes through a porous
membrane distillation system where it is vaporized and desalinated. Such a
system could provide 30-40 liters of drinkable water per square meter of
receiver area per day, while still generating electricity with a more than 25
percent yield or two kilowatt hours per day -- a little less than half the
amount of water the average person needs per day according to the United
Nations**, but a large installation could provide enough water for a town.

Remarkably, the HCPVT system can also provide air conditioning by means of a
thermal driven adsorption chiller. An adsorption chiller is a device that
converts heat into cooling via a thermal cycle applied to an absorber made
from silica gel, for example. Adsorption chillers, with water as working
fluid, can replace compression chillers, which stress electrical grids in hot
climates and contain working fluids that are harmful to the ozone layer.

Scientists envision the HCPVT system providing sustainable energy and potable
water to locations around the world including southern Europe, Africa, Arabic
peninsula, the southwestern part of the United States, South America, and
Australia. Remote tourism locations are also an interesting market,
particularly resorts on small islands, such as the Maldives, Seychelles and
Mauritius,since conventional systems require separate units, with consequent
loss in efficiency and increased cost.

A prototypeof the HCPVT systemis currently being tested at IBM Research -
Zurich.Additional prototypes will be builtin Biasca and Rueschlikon,
Switzerland as part of the collaboration.

*Concentrating Solar Power: Outlook 2009 published by Greenpeace
International, SolarPACES and European Solar Thermal Electricity Association


AIRLIGHT ENERGY is a private Swiss company based in Biasca that supplies
proprietary technology for large-scale production of electricity using solar
power and for energy storage. AIRLIGHT ENERGY has developed an innovative and
complete solution for the markets of Concentrated Solar Power (CSP). For
further information visit

About IBM Research
For more information visit

About ETH Zurich
ETH Zurich is one of the leading international universities for technology and
the natural sciences. It is well-known for its excellent education,
ground-breaking fundamental research and for putting its new findings directly
into practice. Founded in 1855, ETH Zurich today has some 18,000 students from
over 100 different countries, 3,800 of whom are doctoral students. It offers
researchers an inspiring working environment and its students a comprehensive
education. 21 Nobel Laureates have studied, taught or conducted research at
ETH Zurich, underlining the excellent reputation of the institute.

To learn more about ETH Zurich visit:

About Interstate University of Applied Sciences Buchs NTB
For more information visit


European Contact:
Christopher P. Sciacca
IBM Research
Phone: 41-44 724 84 43

US Contact:
Jenny Hunter


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