Spectrolab's Two Millionth Solar Cell (efficiencies of 39 percent)

[Larry Dighera]

The Boeing Company <http://www.boeing.com/news/releases/index.html>
Boeing's Spectrolab Produces Two Millionth Multi-Junction Solar Cell

ST. LOUIS, Oct. 24, 2006 -- Boeing [NYSE: BA] today announced that
Spectrolab, Inc., a wholly-owned subsidiary, has produced its two
millionth multi-junction, gallium-arsenide solar cell.

Spectrolab, the industry-leading solar cell producer, pioneered this
type of cell in 1983, perfecting the technology for production several
years later. Spectrolab's advancements gave satellite operators the
option of doubling satellite power and increasing potential revenue or
controlling costs by reducing spacecraft size without sacrificing
capability.

"We're very proud of Spectrolab's heritage in the space industry and
the integral role it has played in making space-based solar power what
it is today," said Howard Chambers, vice president and general
manager, Boeing Space and Intelligence Systems. "Spectrolab's on-orbit
products are creating more than 575 kilowatts of total power for
agencies like NASA and the National Oceanic and Atmospheric
Administration, and high performance commercial spacecraft for
customers such as DIRECTV and Thuraya."

Spectrolab also is the leading solar cell supplier for numerous
government and national security programs.

Spectrolab manufactured its two millionth multi-junction solar cell as
it celebrates its 50th anniversary. For the past five decades,
Spectrolab's technological advancements have driven space solar cell
efficiencies to more than 28 percent. Today, Spectrolab cells power 60
percent of all satellites orbiting the Earth as well as the
International Space Station.

Six of the seven programs currently operating on or in orbit around
Mars have Spectrolab-built solar cells and panels. The Mars Global
Surveyor, for example, has exceeded its mission life-span by about six
years and continues to function nominally. The Spectrolab-built solar
cells and panels on the rovers Spirit and Opportunity have both
operated well beyond their 90-day planned mission life, and have
conducted research operations for more than 33 months on the Red
Planet. In all, Spectrolab's products have powered more than 525
satellites and interplanetary missions over the past half-century

"I'd like to thank the U.S. Air Force and NASA for their visionary
support of Spectrolab and early adoption of the multi-junction solar
cell technology," said David Lillington, president of Spectrolab. "We
are laying the groundwork for the future. In 2007, we'll offer our
next-generation triple junction solar cell, which will be 30 percent
efficient. Long-term, we plan to achieve 40 percent efficiency space
solar cells through further advancements in our multi-junction
technology."

Spectrolab also is a leader in multi-junction solar cells for use in
terrestrial solar concentrators, which hold record-breaking
efficiencies of 39 percent. Spectrolab is working with several
domestic and international solar concentrator manufacturers on clean,
renewable solar energy solutions. Currently, the company's solar cells
are delivering power to a 1-kilowatt solar concentrator test system in
the Arizona desert, which has functioned optimally for more than two
years. Spectrolab's terrestrial concentrator cells also are generating
power in a 33-kilowatt full-scale concentrator system in the
Australian desert.

A unit of The Boeing Company, Boeing Integrated Defense Systems
<http://www.boeing.com/ids/index.html> is one of the world's largest
space and defense businesses. Headquartered in St. Louis, Boeing
Integrated Defense Systems is a $30.8 billion business. It provides
network-centric system solutions to its global military, government,
and commercial customers. It is a leading provider of intelligence,
surveillance and reconnaissance systems; the world's largest military
aircraft manufacturer; the world's largest satellite manufacturer; a
foremost developer of advanced concepts and technologies; a leading
provider of space-based communications; the primary systems integrator
for U.S. missile defense; NASA's largest contractor; and a global
leader in sustainment solutions and launch services.

 

[Martine Riddle]

Like Kopin, its too bad they only supply NASA and DOD.

So this is meaningless to the average Joe.

Cheers

 

[SJC]

The Boeing Company <http://www.boeing.com/news/releases/index.html>
Boeing's Spectrolab Produces Two Millionth Multi-Junction Solar Cell

ST. LOUIS, Oct. 24, 2006 -- Boeing [NYSE: BA] today announced that
Spectrolab, Inc., a wholly-owned subsidiary, has produced its two
millionth multi-junction, gallium-arsenide solar cell.

Spectrolab, the industry-leading solar cell producer, pioneered this
type of cell in 1983, perfecting the technology for production several
years later. Spectrolab's advancements gave satellite operators the
option of doubling satellite power and increasing potential revenue or
controlling costs by reducing spacecraft size without sacrificing
capability.

"We're very proud of Spectrolab's heritage in the space industry and
the integral role it has played in making space-based solar power what
it is today," said Howard Chambers, vice president and general
manager, Boeing Space and Intelligence Systems. "Spectrolab's on-orbit
products are creating more than 575 kilowatts of total power for
agencies like NASA and the National Oceanic and Atmospheric
Administration, and high performance commercial spacecraft for
customers such as DIRECTV and Thuraya."

Spectrolab also is the leading solar cell supplier for numerous
government and national security programs.

Spectrolab manufactured its two millionth multi-junction solar cell as
it celebrates its 50th anniversary. For the past five decades,
Spectrolab's technological advancements have driven space solar cell
efficiencies to more than 28 percent. Today, Spectrolab cells power 60
percent of all satellites orbiting the Earth as well as the
International Space Station.

Six of the seven programs currently operating on or in orbit around
Mars have Spectrolab-built solar cells and panels. The Mars Global
Surveyor, for example, has exceeded its mission life-span by about six
years and continues to function nominally. The Spectrolab-built solar
cells and panels on the rovers Spirit and Opportunity have both
operated well beyond their 90-day planned mission life, and have
conducted research operations for more than 33 months on the Red
Planet. In all, Spectrolab's products have powered more than 525
satellites and interplanetary missions over the past half-century

"I'd like to thank the U.S. Air Force and NASA for their visionary
support of Spectrolab and early adoption of the multi-junction solar
cell technology," said David Lillington, president of Spectrolab. "We
are laying the groundwork for the future. In 2007, we'll offer our
next-generation triple junction solar cell, which will be 30 percent
efficient. Long-term, we plan to achieve 40 percent efficiency space
solar cells through further advancements in our multi-junction
technology."

Spectrolab also is a leader in multi-junction solar cells for use in
terrestrial solar concentrators, which hold record-breaking
efficiencies of 39 percent. Spectrolab is working with several
domestic and international solar concentrator manufacturers on clean,
renewable solar energy solutions. Currently, the company's solar cells
are delivering power to a 1-kilowatt solar concentrator test system in
the Arizona desert, which has functioned optimally for more than two
years. Spectrolab's terrestrial concentrator cells also are generating
power in a 33-kilowatt full-scale concentrator system in the
Australian desert.

A unit of The Boeing Company, Boeing Integrated Defense Systems
<http://www.boeing.com/ids/index.html> is one of the world's largest
space and defense businesses. Headquartered in St. Louis, Boeing
Integrated Defense Systems is a $30.8 billion business. It provides
network-centric system solutions to its global military, government,
and commercial customers. It is a leading provider of intelligence,
surveillance and reconnaissance systems; the world's largest military
aircraft manufacturer; the world's largest satellite manufacturer; a
foremost developer of advanced concepts and technologies; a leading
provider of space-based communications; the primary systems integrator
for U.S. missile defense; NASA's largest contractor; and a global
leader in sustainment solutions and launch services.

39% efficient - great.
$800/watt - not.

I see no proof that it costs $800 per watt. A 1000 sun concentrator
may cost no more than $5 per watt with the chip, reflector/lense and tracker.

 

[SJC]

1,000 sun concentrator??? I kind of doubt that anyone has ever made a
PV cell that would survive that much concentrated solar flux. Such a
thing would almost certainly need a sophisticated cooling system.

You can do thermodynamics at that level of concentration, but now we're
talking about moving parts and very hot fluids/gasses. Reliability
becomes problematic.

If you look at the datasheet, it is specified at 1000 suns. The efficiency is
peak at around 500 suns, but you can run them up there. They measure
1 centimeter x 1 centimeter, so a little over 1 square foot provides almost 1000 suns.
http://spectrolab.com/prd/terres/cell-main.htm

 

[sylvan butler]

If you look at the datasheet, it is specified at 1000 suns. The efficiency is
peak at around 500 suns, but you can run them up there. They measure
1 centimeter x 1 centimeter, so a little over 1 square foot provides almost 1000 suns.
http://spectrolab.com/prd/terres/cell-main.htm

Yes, if you could cool them. You do realize, don't you, that 1000 suns,
with under 40% becoming electricity, means 60% is either heat or
reflected. 600 suns of 'waste' means roughly 600,000 watts of waste per
square meter or 60 watts of waste per square centimeter. Imagine how
hot and how bright is the 60w filament inside of a light bulb. The
range of possiblity is that either they never ran the cell at 1000 suns,
or they ran it for only a very short time, or else they have a massive
cooling system.

sdb

 

[Me]

Sure they have, just search the NREL data base for
examples.


Not that sophisticated. Air cooled heat sinks can
be used. Pumped water cooling works better and you
get to keep the heat.

Duane

My thoughts exactly, why not liquid cool the back side of the
Cells, and put the BTU's into a thermal storage. You get heat,
and power from the same basic energy source and impove the
efficency of the total system, significantly. Looks like
a "Win - Win" to "Me"

Me I like efficent systems......

 

[SJC]

Yes, if you could cool them. You do realize, don't you, that 1000 suns,
with under 40% becoming electricity, means 60% is either heat or
reflected. 600 suns of 'waste' means roughly 600,000 watts of waste per

whoa...where are you getting 600,000 watts per square meter?
we receive 1000 watts per square meter here on earth.
there is about 100 watts per square foot so 60 watts of heat to get rid of.
just heat sink the die to a good heat sink, it is not going to melt.

 

[Larry Dighera]

Like Kopin, its too bad they only supply NASA and DOD.

So this is meaningless to the average Joe.

Cheers

Thanks for the warm greeting, Martine.

Have you seen this:

http://www.boeing.com/news/releases/2006/q3/060828a_nr.html
ST. LOUIS, Aug. 28, 2006 -- The Boeing Company [NYSE: BA] has signed a
contract to provide 600,000 solar concentrator cells to SolFocus,
Inc., a California-based renewable energy company that is developing
renewable terrestrial energy alternatives.

"Companies on the cutting edge of the renewable energy revolution come
to us because we are the world's leading manufacturer of solar cells,"
said Charles Toups, vice president of engineering for Boeing Space and
Intelligence Systems. "Our Spectrolab subsidiary has leveraged its
expertise in space photovoltaic products to create solar cells with
record-breaking efficiencies for Earth-based applications."

Under the 12-month contract from SolFocus, Inc. of Palo Alto, Calif.,
Spectrolab will build and deliver 600,000 solar concentrator cells
that will be used to convert the sun's rays into affordable
electricity for homes and businesses. The cells produced for SolFocus
will be capable of generating more than 10 megawatts of electricity,
or enough to power about 4,000 U.S. homes. With the average solar cell
efficiency above 35 percent at concentration, Spectrolab's
concentrator photovoltaic cells generate electricity at a rate that
can be more economical than electricity generated from conventional,
flat panel photovoltaic systems.

"Our mission is to deliver reliable solar-generated electricity at
wholesale energy prices, and Spectrolab's multi-junction concentrator
solar cells are key to making that possible," said Gary D. Conley, CEO
of SolFocus. "Spectrolab's cells will be integrated into our upcoming
solar concentrator field test program and then into the first phase of
active deployments."

A significant advantage of concentrator systems is that fewer solar
cells are required to achieve a specific power output, thus replacing
large areas of semiconductor materials with relatively inexpensive
optics that provide optical concentration. The slightly higher cost of
multi-junction cells is offset by the use of fewer cells. Due to the
higher efficiency of multi-junction cells used in the concentrator
modules, only a small fraction of the cell area is required to
generate the same power output compared to crystalline silicon or
thin-film, flat-plate modules.
=====================================================================

http://www.boeing.com/news/releases/2006/q3/060815b_nr.html

ST. LOUIS, Aug. 15, 2006 -- The Boeing Company [NYSE: BA] today
announced it has signed a multi-million dollar contract to supply
concentrator photovoltaic (CPV) cell assemblies to an Australian
company that produces renewable solar energy.

Under the contract with Solar Systems Pty. Ltd. of Hawthorn, Victoria,
Boeing will deliver 500,000 concentrator solar cell assemblies for use
at power stations that generate renewable energy for small, remote
Australian communities. Spectrolab, Inc. of Sylmar, Calif., a
wholly-owned Boeing subsidiary, will manufacture the cells. Deliveries
will begin later this year.

The solar cell assemblies will be capable of generating more than 11
megawatts of electricity -- enough to power 3,500 average-sized homes.
"For the past 50 years, Spectrolab has been a leader in space-based
solar cells," said Dr. David Lillington, president of Spectrolab, the
world's leading producer of space and terrestrial concentrating solar
cells. "We have leveraged our expertise in space photovoltaic products
and created terrestrial concentrating solar cells with record-breaking
efficiencies averaging above 35 percent. We are now partnering with
the best of industry and making great strides in reducing the cost of
solar energy to homes and businesses worldwide."

This contract with Solar Systems continues an earlier relationship
between the two companies. In April, Spectrolab and Solar Systems
brought the world's first full-scale ultra high efficiency 35-kilowatt
solar generator online in Australia. The system created a new
benchmark for solar concentrator systems both in system efficiency and
cost, and showed great promise for the future of renewable energy.

"The breakthrough demonstrated by this fully operating, full-scale
system shows the potential for CPV to dramatically change the
economics of solar power. We expect this to be the first commercial
phase of a very large and valuable relationship," said Solar Systems
Managing Director Dave Holland. "Our partnership with Spectrolab
represents a new level of cooperation toward the common goal of
meeting the community's power needs with clean, green electricity."

Solar Systems' concentrators resemble a satellite dish with curved
reflecting mirrors shaped to concentrate sunlight onto the solar
cells. A sun-tracking mechanism allows electricity to be produced from
morning to late afternoon. Small, remote communities are using a
number of concentrator dishes in "solar farms" for energy during the
day and switching to diesel generators at night.

A significant advantage of concentrator systems is that fewer solar
cells are required to achieve a specific power output. Large areas of
semiconductor materials now can be replaced with lower cost
concentration devices. The higher cost of ultra high efficiency
multi-junction cells is offset by the need for fewer cells. Because
multi-junction cells are so efficient, only a fraction of the cell
area is required to generate the same power as crystalline silicon or
thin-film flat-plate designs.
===============================================================

 

[sylvan butler]

This is easier than cooling the CPU in your PC. The solar cell can run
hotter than the typical CPU chip, and that 60W is less heat than most

It can run hotter, but the hotter they get the less efficient they are.
Under 1000 suns, your margin for increasing loss is not very big.

desktop PC CPUs put out. The one sq-cm is even similar to the size of
a typical CPU chip.

If you assume only one cell is going to be present. To cool a 1sqcm CPU
chip you usually end up using a heat spreader of some kind to conduct
the heat out (e.g. a copper plate or core in the heat sink), and a
rather large finned heat loss area with forced air.

Now what if you want a lot of those cells together to make up a complete
panel with a usable output voltage? Look at the heat sink on a dual
core or quad core CPU. Now imagine 36 x 60watt light bulbs all
together.

Take a look at this unit doing exactly this:
http://www.greenandgoldenergy.com.au/

They seem to be using 30W of dissipation/cell as their working number.

''While 500 suns sound massive it is really only a heat load
of about 30 watts per solar cell. ''

That's an interesting gadget. Hard to find tech specs though. But they
do say they use the 1sqcm cells, and they use 500 sun concentration. So
the 30W is exactly half of what I predicted for 1000 sun concentration.
Makes perfect sense.

''We also mount the solar cells on a massive heat spreader which
transfers the heat into the SunCube. Solar Appliance's aluminium heat
radiator. This heat radiator is larger than the solar collection area,
is always in the shade and cooled by passing winds much more easily than
flat panels.''

They even run about the same calculation I did (and did account for some
reflectance losses: ''As an example 500 cm^2 of Fresnel lens will
connect 50 watts of power at 1,000 W/ m^2 or 0.1W / cm^2. The Fresnel
lens will loose / reflect about 8% or 4 watts leaving 46 watts beaming
to the cell which then converts say 40% to electricity. That leaves 46 *
0.6 = 27.6 watts to be spread and dissipated by the passive heat
management system.''

I'd say my original statement is right on the money, wouldn't you?

It will be interesting to see if the SunCube becomes a commercially
viable and successfull product.

sdb

 

[sylvan butler]

whoa...where are you getting 600,000 watts per square meter?

When you multiply 1000 watts per square meter, by 1000 suns, and extract
40% as electricity, the remaining 600,000 watts is waste. Just like I
said. It's about 4th or 5th grade math, not exactly rocket science.

sdb

 

[SJC]

sylvan butler wrote:
...

Where people get confused with your statement is where you start with
1000W and wind up with 600,000W as waste heat.

Typically, concentrator systems use small PV cells and large optics.
If we start with such a system measuring one square meter and the cell
itself is operating at 1000 suns (1000x concentration) then the cell(s)
would be 1/1000th of a square meter. The entire one square meter system
would receive some 1000 watts from sunlight and the cell(s) convert 40%
of that to electricity (400W) and the remainder (600W) would wind up
in some other form, typically heat.

Anthony

I understand math well. But when you have your head where the
sun does not shine, it is hard to hear what you are saying.

 

[sylvan butler]

dissipating 60 watts from a concentrating PV system is problem then
theater marquees and server racks should be burning up left and right.

marquees: 20% as light, and plenty of free air
server racks: expensive active cooling system

Of course, that's an entirely different question than whether the heat
can be dissipated effectively from a properly designed concentrating PV

Yup.

sdb