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SolarCube™ to slash residential solar to below-grid energy price
Award-winning, innovative solar technology focuses sun's energy onto
photovoltaic cells for increased efficiency. Product release slated for March.
by Sterling
D. Allan
Pure Energy Systems News
Copyright © 2006
Roof-mounted SunBall™,
uses the same technology that is employed in the SunCube™ system, which
is slated to become available for sale in March. |
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Greg Watson, right, receives the "People's Choice" award from
ABC TV for his solar invention. |
ADELAID, AUSTRALIA -- Green and Gold Energy of Adelaide announced Tuesday
that its award-winning solar technology will be commercially available for
Australian customers in March through the company website.
The cost-effective solar design by inventor and CEO, Greg Watson, is said to
track and capture the suns energy far more efficiently than traditional
stationary photovoltaic panel designs.
"My invention creates electricity cheaper than you can buy it [from the
grid]", claimed Greg Watson in a feature ABC News interview. (Ref.)
His invention won the "People's Choice" award for New Inventors in
2005 on ABC TV's Inventor's Choice program. (Ref.)
Their announcement pertains to the 6 mega-Watt-hour (MWh) annual output SunCube™
system comprised of twenty units, each rated at 150 Wp and 300
kWh annually, as well as a 3 kilowatt AS4777 grid connect inverter. (Ref.)
To give you a rough idea, six MegaWatt-hours computes to 685 Watts continuous
output; and is dependent -- plus or minus -- on the sun exposure in the
region. Combined with a battery storage system, this is enough power to
supply the minimal electrical needs of a typical home. The US and EU-approved
grid connect inverter enables the home to be a "hybrid", run either on
grid or solar power -- but most importantly, enabling the grid meter to run
backwards, for possible net income from the grid for energy generation.
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Solar Efficiency and $ / kWh Savings
The SunBall™, which has undergone extensive prototype testing, puts out
330Watts per square meter of lens surface. While this solar-to-electricity
conversion in the vicinity of 33 percent efficiency is remarkable, what is more
important to Watson is the bottom line cost of the energy production in terms of
cents per kilowatt-hour. Solar conversion efficiency is indeed part of the
equation, but materials innovations and system design are even more important.
"Too many academics are chasing ultimate efficiency, which I suppose is ok
for writing papers and going to conferences, but what turns meters backward is
kWh. The reason you and others will buy SunCube™ systems is that they can
generate electricity on your roof at less $ / kWh than what you pay your
electricity supplier."
Another company that is taking a similar approach, but for utility-scale
applications is International Automated Systems, which uses lenses to focus the
sun's rays to run heated water through a proprietary bladeless turbine. They,
too, expect to be able to produce electricity at below-grid prices. (Ref.)
Priced at AU$11,590 ex tax / US$8,693 ex tax fully installed (not including
shipping), Green and Gold Energy calculates that the 6 MWh SunCube™ system
delivers rooftop electricity for AU$0.077 / US$0.058 per kWh without rebates,
which is better than what most residential customers can get from the grid.
Installation is via licensed electricians is included in the price. (See company
explanation
of calculation and assumptions made.)
"Once your investment is paid off, the rest is free," notes Watson.
The SunCube™ has been especially designed for international shipping in a flat
pack. "Assembly is a simple do-it-yourself task requiring about 30 minutes
of time and common hand tools", according to the company site. (Ref.)
The SunCubes in the systems will be shipped as fully assembled units.
Fresnel lenses focus the sun's energy on a few photovoltaic cells,
reducing the number of PV cells needed. |
Inside the SunCube™ |
How the SunBall™ Works
While the company has many photos and videos and descriptions of the SunBall™,
they are withholding detailed information on the SunCube™ until they are
closer to release of the product. It is based on the same technology.
Fresnel lenses on the flat surface of the half sphere of the SunBall™ focus
the sun's rays on several high-efficiency photovoltaic cells inside the
ball. This focusing of the sun's rays means much fewer solar cells are
required. Here is where most of the cost-savings are realized. Judging the
location of the sun from the angle of sunlight striking the cells, a
microprocessor instructs the tracking motor to adjust the position of the ball,
following the sun as it crosses the sky. The back side of the ball, always in
the shade, dissipates the heat.
Durability of SunCube™
Most of the functions, such as the heat controls, mounting structure, bearing
surface, environmental seal, and wind loading reduction, are encapsulated within
the hemisphere shape rather than sitting external to the panels, resulting in
additional savings in maintenance.
The SunCube has been designed to withstand 120 kph winds. If severe winds and/or
debris are expected, the SunCubes can be easily removed from the roof. They also
have an emergency stow mode, with the lens facing the deck. At 120 kph the
SunCube will add about 5% of peak loading on the rafter / truss.
There is a stress sensor in the base which if a preset limit is exceeded will
cause the SunCube to rotate so the smaller side profile is facing into the wind.
Basically it rotates so the lens assembly faces the deck. This also increases
survival from wind blown debris. This automatic emergency stow also works via an
in-built hail impact detector which will also rotate the SunCube so it faces the
deck. Additionally night stow uses this position to reduce lens accumulation of
junk falling from the sky.
SunBall™ Characteristics:
(for comparison, since specific information is not yet
released for the SunCube™)
- The rounded back and base can be colored to match roof color.
- Easily installed by one man (licensed) on all domestic and commercial roof
types.
- No need to be installed on street-facing roof (if north facing, and
depending on slope of roof).
- Significantly lower cost per Wp than flat panels.
- Attractive shape.
- Higher annual kWh output than flat panels.
- Hemispherical shape significantly reduces wind loading by about 50%
compared to flat panels that do not hug the roof.
Domestic Rooftop:
(for comparison, since specific information is not yet
released for the SunCube™)
- Each rooftop SunBall™ weighs approx 20kg per 330Watt output for each 1m
squared SunBall™.
- Takes 20 solar cells.
- Collection surface measures 1m square, with diameter 1.13m
- Height would be 1/2m off the roof
- Bearings of rotating axis are 100mm off roof
- If one solar cell is damaged, can just change one cell, rather than whole
unit.
- If lens is damaged, can just change one lens, rather than whole unit.
- Would need 4 SunBalls™, to generate approx 50% of electricity usage in a
domestic home.
About Green and Gold Energy
Watson's company, Green & Gold Energy was founded to to deliver
cost-effective, grid-competitive solar electric power. Their stated goal
is to reduce the delivered cost of rooftop-generated photovoltaic electrical
output to below that available from the grid. (Ref.)
Green and Gold Energy, will manufacture and distribute the SunBall™ and
SunCube™ rooftop solar PV tracking concentrators. The company is
soliciting for a US manufacturing partner. (Ref .)
The company is working on a new website that will surface when the online
ordering facility is launched late February, early March 2006.
Watson will be joining the New Energy Congress on February 7, following an
approval vote presently under way. (Ref.)
# # #
ACKNOWLEDGEMENTS
SOURCES
CONTACT:
Greg Watson <email >
Green and Gold Energy
Adelaide, South Australia
+61 408 843 089
Footnote
Wp refers to the Watt peak name plate rating for flat plates. There
are two Wp test conditions STC and PTC which are quite different.
1) STC = 1,000 W / m2 solar insulation, AIM 1.5 solar spectrum and
cell temp controlled / maintained at 25 deg C. This gives the highest
panel reading but is very artificial as the operational cell
temperature is much higher.
2) PTC = 1,000 W / m2 solar insulation, AIM 1.5 solar spectrum,
ambient air temp at 20 deg C, wind at 1 m / sec and elevation at 10 m
above the ground
PTC came after STC as an attempt to provide something closer to real
world data. The STC test was dreamed up by the flat panel suppliers so
they could claim big number.
Another test is NOCT (Normal Operating Cell Temperature) which is
tested as follows:
NOCT = Cell temperature at 800 W / m2 solar insulation, AIM 1.5 solar
spectrum, air temp 20 deg C and wind at 1 m / sec.
A typical flat panel has a NOCT of 47 deg C. I suspect the flat panel
suppliers used 800 W / m2 so as to NOT scare off flat panel purchasers
with a real NOCT at 40 deg C and 1,000 W / m2 of about 85 deg C. I
would add that at 85 deg C and a cell output temperature derating of
0.55% / deg C a flat panel will loose about 30% of the STC rated
output.
The Spectrolab cells I use in the SunBall loose only 0.04% / deg C
cell temp rise so they are virtually unaffected by temp rise. During a
40 deg C hot summer afternoon the SunCube will loose only about 1 - 2%
of rated output where flat panels are down 30% or more. This is one of
the effects which give the SunCube such a high annual kWh output.
There is a lot more about the SunCube design than just the use of high
efficiency cells.
-- Greg Watson (Feb. 1, 2006) |
Related
 IAUS
to Push Solar to Within Competitive Range of Grid Power - Thermal
solar panels coming into production in September will produce electricity at
3-5 cents per kilowatt-hour. Highly-efficient bladeless turbine has wide
range of waste-heat-harnessing applications. Methanol production
technique will draw CO2 out of the environment, reversing global warming. (PESN;
August 2, 2005)
 Solar
Panel Light concentrator - Concentrating Photovoltaic Glazing, by Stellaris
Corporation, concentrates light onto narrow strips of thin film
photovoltaic (PV) material by means of small (6mm high) lenses, reducing the
amount of PV material required in manufacturing the module by 67%. (Renewable
Energy Access; Oct. 14, 2005)
See also
Page created by Sterling
D. Allan Jan. 31, 2006
Last updated December 22, 2014
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