VIDEO
http://www.youtube.com/watch?v=P_uv5htt8mo | VIDEO
http://www.youtube.com/watch?v=pXyJrFKwjrc | VIDEO
http://www.cctv.com/program/bizchina/20070824/107528.shtml |
http://www.geek.com/solar-technology-breakthrough-sees-about-4500-watts-per-square-foot/ |
Israel sees breakthrough in solar energy
Source: CCTV.com
VIDEO http://www.youtube.com/watch?v=P_uv5htt8mo
|
Israeli Solar Project | 4500-watts-per-square-foot
Prof. David Faiman
Director, The Ben-Gurion National Solar Energy Center
Chairman, Department of Solar Energy and Environmental
Physics
Department of Solar Energy and Environmental Physics
Concentrator Photovoltaics | http://www.bgu.ac.il/solar/index.html
|
September 2007
Dear Friend of the Environment,
Please forgive this rather impersonal response to your recent e-mail. My problem is that owing to a flood of unexpected publicity, I find myself incapable of answering each inquiry on a one-for-one basis. I shall therefore summarize where our development stands, and what may reasonably be expected for the near future.
First, there are no miracles:
The amount of energy received from the Sun is fixed by our distance from that star.
Therefore, if you heard (correctly) that we have produced
1,500 times more power from a 4” x 4” piece of semiconductor
than from a conventional silicon solar cell, you should
not think
that roof-top solar panels will now be able to produce
that much more power.
They won’t and they can’t.
Instead, we use a reflecting parabolic dish
to collect a large amount of solar energy and concentrate
it onto a small solar cell module.
The point is that, this way, we need use only a small
amount of expensive semiconductor material
(1000 times less than normal) for electricity generation,
but a correspondingly large amount of low-cost (glass)
material for collecting the light.
By separating out the light collection function
from the light-conversion function of a solar cell,
the economic prospects look excellent.
However, there are a number of catches that you should
be aware of
before you get too excited.
Firstly, this kind of technology only produces significant
amounts of energy
in regions that are traditionally considered to be
“sunny”: deserts being ideal.
So to my friends in northern Europe,
my advice would be to stick to wind and perhaps wave
power.
Secondly, if you live in a crowded city,
the chances are that your dish will be shaded by other
buildings for large parts of the day.
So for you too, the economics would not be so great.
What we have in mind would be domestic systems for
use
on farms, rural homes, industrial estates, the roofs
of shopping centers: i.e.
places with un-obscured access to sunshine for most
of the day.
And of course huge utility-scale plants out in the
desert.
To this end, Ben-Gurion University, my employer, has
entered into partnership with
a commercial entity
which hopes, quite soon, to be able to demonstrate
and market systems
based on our scientific achievements.
For the time-being,
for reasons that I am sure you will appreciate, no
further information is available.
Thank you for your interest,
Yours sincerely,
David Faiman
Professor of Physics, Ben-Gurion University.
08-24-2007 14:57
Israeli scientists say they have discovered a way to
mass produce solar energy
efficiently enough to compete with oil and other conventional
fuels.
Scientists say that by using two separate devices --
one to collect and intensify the
sunlight, and one to convert the rays into electricity
-- they can produce the same
amount of electricity as a conventional power plant,
for the same price. Ordinary
solar panels BOTH collect and convert sunlight into
electricity.
But the key to harnessing the sun's power efficiently
is replacing them with solar
panels that ONLY convert. Solar energy has traditionally
been dismissed as
inefficient and expensive. But proponents promote
it as a limitless and
environmental-friendly energy source -- to replace
coal, oil and nuclear power.
A solar energy system built on 12 square kilometers
in the Negev desert region of
southern Israel would produce 1,000 megawatts of electricity.
That would supply
about 10 percent of the country's general electricity
need.
by RickGeek posted on August 22, 2007 2:48 pm
In a land abundant with sunlight (along with religious
and political struggles), a
remarkable new solar technology is being tested. While
no specific details about how
the process works were given, it is easy to compute
the potential based on what has
been observed.
Using something like a large brick and focusing large
mirrors onto its very small
surface area, scientists have been able to get roughly
10,000 times more energy from
a single panel than with conventional solar technology.
The scientist in the video
held the brick-like device in his hand, being about
1/3rd square feet in size and about
1/2 inches thick. The solar panel arrays behind him
were several square feet each. He
said his brick generates about 1500 watts continuously
while in use while the much
larger panels behind him generate only one watt per
individual component (there
looks to be about 100 components per panel). He computed
that a 12 km area in
Israel’s Negev desert would provide enough electricity
to serve one million people. It
would be a much less expensive form of energy, one
capable of providing 1,000
Megawatts at production costs which are far below
traditional production methods.
That power generation figure would account for 10%
of Israel’s current power
generation, nearly all of which is produced by coal.
Large mirrors are used in this production method. They
do not need to be of
extremely high quality and are much less costly to
manufacture than traditional solar
cells. They are oriented by computers designed to
keep the sun’s light focused on
the brick throughout the rotation of the Earth, also
accounting for seasonal axis
tilting. Producing about 4,500 watts per square foot
of material (rough figures derived
from video observations only), the bricks require
approximately 1,500 square feet of
sunlight focused onto its tiny footprint. The end
result is a power-source which
operates any time the sun is shining which, in the
Negev, is almost all of the time.
Several other traditional advancements have been seen
in the solar technologies.
We’ve seen new doping techniques which are expected
to increase solar efficiency
to 61% by the year 2020. Plastic solar technologies
have recently seen a similar type
of doping breakthrough allowing them to exceed the
5% efficiency barrier. Plastic
solar panels with efficiencies around 14% are expected
within two years. Plastic
solar panels, while being much less efficient, are
significantly cheaper to
manufacture and, provided the square footage is available,
can be much cheaper to
employ per watt. Current high-end (expensive) solar
technologies hid the mid-40%
efficiency ranges, and the more mainstream are just
under 30%.