New solar powerfor
new Amonix CPV system in New Mexico is packing a big solar power punch,
delivering 5 MW to local utility El Paso Electric under a 25-year Power
If, as a child, you used a magnifying glass to burn wood or light a
cotton string on fire, then you've played around with the basic theory
behind Amonix Inc.'s concentrated photovoltaic systems.
The Amonix systems are much more high tech, however, and rely on a
Fresnel lens to concentrate the sunlight on cells comprising three
different materials. This allows them to capture more energy from the
same light wavelengths compared with traditional PV systems, says Carla
Pihowich, Amonix vice-president.
By mounting the panels on dual-axis trackers, Amonix systems have a
smaller footprint than traditional PV systems but with greater
electricity output, she says.
"CPV (concentrated photovoltaic) is not only competitive today but will
widen the gap and be even more competitive than alternative PV
technologies going forward by 2020," Pihowich says.
The Seal Beach, California-based company boasts the largest CPV project
to date in North America, located in Hatch, a town in south-central New
Mexico famous for its chili peppers.
Altogether, Amonix is responsible for 52 of 62 MW of CPV production
globally, she says.
The 5 MW Hatch project, which was fully commissioned in June 2011, is
owned and operated by NextEra Energy Resources LLC, a subsidiary of
NextEra Energy Inc. based in Juno Beach, Florida. The firm sells the
electricity—enough for about 1,300 residences—to El
Paso Electric under a 25-year Power Purchase Agreement.
The Hatch project was constructed on 39 acres in the Hatch Industrial
Park, about seven miles west of the village of Hatch. The village
funded the project through the sale of Hatch Industrial Revenue Bonds.
NextEra Energy Resources leased the ground for 99 years from the
Although the company obtains the bulk of its renewable energy from wind
generation, Steve Stengel, a spokesman for NextEra Energy Resources,
says the firm is "technology neutral."
"The Amonix concentrated photovoltaic (CPV) solar power systems are a
good fit for our site in Hatch, N.M., because their technology performs
very well in high-sun, low-humidity climates," Stengel said. "They have
a high energy density and are designed to operate in utility-scale
The Hatch project involves 84 60 kW Amonix systems that were
manufactured at its new state-of-the-art production plant in North Las
The North Las Vegas location was no accident, either, Pihowich says.
Amonix chose it so production would be strategically located near its
target market of the desert Southwest.
Each 22-meter-by-15-meter system is about the size of an IMAX movie
screen and consists of 7,560 high-efficiency multijunction gallium
indium PV cells.
The multi-junction cells achieve much higher production rates by using
different materials than the traditional silicon cell. They also
combine multiple semiconductors within a single package.
Multiple layers of cell material are deposited onto a gallium
substrate. Each layer is designed to optimize conversion of specific
wavelengths of sunlight.
The subcells are connected serially, so what light the first material
doesn't use is passed along to the second.
The cells are also covered with a Fresnel lens that concentrates the
amount of sun hitting the cells by up to 500 times.
This enables them to produce a significant increase in voltage, while
losing less energy to heat. As a result, they provide the solar
industry's highest efficiencies, Pihowich says.
The cells can exceed 39 percent in volume production in the field
compared with 12 percent for thin film PV and 22 percent for
high-efficiency silicon-based PV cells, she says.
These multi-junction cells have proven their ruggedness in space,
having been used on the Mars Rover and Spacelab, to name a few
projects, Pihowich says.
Secondary optics are added to create individual modules, which are then
integrated into MegaModules.
the Amonix Inc. MegaModules are erected on pedestals, the systems have
minimal impact on the environment. When stowed horizontally during
windy periods, each MegaModule
sits nearly 28 feet off the ground.
Seven MegaModules are joined together to create each Amonix CPV system.
The factory-fabricated subsystems are designed for easy installation
and field adjustability, she says.
In conjunction with its Mega-Modules, Amonix uses a proprietary
computer-controlled dual-axis tracking system that follows the sun
throughout the sky, much like a sunflower, Pihowich says.
CPV performs best in areas that are sunny and have a high
DNI—or direct normal irradiance—a measure of the
solar resource available to concentrating solar collectors that track
the sun throughout the day.
In addition, CPV solar farms themselves take up much less space per
kilowatt generated than conventional PV solar farms.
"We use land more efficiently than other technologies, producing about
1 MW on 4 acres," Pihowich says.
Because the MegaModules are erected on pedestals, the systems have
minimal impact on the environment, she says. When stowed horizontally
during windy periods, each MegaModule sits nearly 28 feet off the
As a result, the land below can be used for other purposes, such as
CPV also is well-suited to deserts because it doesn't require any water
for power production. "That's very important where water is very
precious," Pihowich says. "And there's water scarcity in our target
market." The only water that's used is to wash the modules about three
to four times per year.
Blattner Energy, based in Avon, Minnesota, was selected as the
engineering, procurement and construction, or EPC, contractor for the
Hatch project because of the firm's long-standing relationship with
NextEra and its experience installing large-scale wind farms.
Before starting a project, Blattner applies its own version of the LEAN
process to determine the most efficient steps to follow. The Hatch
project was no exception, says Aaron Pyfferoen, Hatch project manager
"Before construction, we determined the best way, right crew size, and
most efficient way to build this out," he says.
Finding experienced laborers in the rather remote Hatch area wasn't a
problem because Blattner Energy's sister firm, D.H. Blattner&
Sons, has historically been involved in railroad work.
They were able to draw from the pool of laborers who work on the Sunset
rail corridor that passes through the region.
"We brought in people from all over the country," Pyfferoen says. "A
lot of people were from Hatch and Deming. We had the advantage that
some of the supervisors lived only 30 minutes away. We had craft
workers who had families and were happy because they could go home to
them at night."
At the project's peak, Blattner had about 60 workers on site.
CPV systems from Amonix Inc. use a Fresnel lens to concentrate the
sunlight on cells comprising three different materials. This allows
them to capture more energy from the same light wavelengths compared
with traditional PV systems.
The actual construction began in late January 2011 with site
Installation involved boring holes, then sinking the 3-foot-diameter
steel pedestals 21 feet deep.
"We brought in a pretty good sized drilling rig," Pyfferoen says of the
machine that's also used to install poles carrying transmission lines.
As part of the installation, the pedestals were encased in concrete.
Drive heads that control the angle of each panel were added atop the
pedestals as were service cages.
Then the MegaModules were hoisted in place using cranes.
The repetitive nature of the actual module installation is much like
turbine installation on a wind farm as are the technical aspects of the
installation, Pyfferoen says. Once the pedestal work was complete,
workers could install about a half MW per day.
Pyfferoen says the crews encountered few challenges along the way
except for some winter snow.
During the first week of February, a 2-inch snow stopped work on the
project for a couple of days.
"It shut the area down,"
Pyfferoen says of southern New Mexico. "It was a crisis for the whole
community." It was different to see coming from Minnesota where a few
inches of snow would have little to no effect, added Pyfferoen.
Because the project was only 5MW, he says, they were able to tie in to
the local distribution lines and didn't need to modify them."
"El Paso was able to off-take it without line upgrades," he says.