POWER August 2014 - 30

PLANT OF THE YEAR
2. Focused approach. A redesign of Ivanpah's layout reduced
the number of heliostats and power towers to limit the environmental
impact. The original design used multiple smaller towers per plant; the
new one used a single tower and heliostat field for each unit. Source:
POWER/Tom Overton
3. Center of attention. The power towers generate steam in
2,100-ton boilers heated by concentrated sunlight. Here, one of the
boiler walls is being lifted into place. Courtesy: Bechtel
April 2011, Google was ready to make a more significant move, committing
$168 million to the project.
Google's investment was part of its goal to spur development of
renewable energy. At the time, Rick Needham, Google's director of
energy and sustainability said, " We hope [Ivanpah] can serve as a
proof point and spur further investment in this exciting technology. "
Google's contribution helped close financing for the final $2.1 billion
price tag.
Construction of the plant required precise organization and management
of many moving parts. The materials alone included 42
million heliostat components, including 22 million rivets, more than
7,500 tons of steel, 1,200 miles of cable, and more than 36,000 cubic
yards of concrete.
Installing the 173,500 heliostats according to schedule meant that
500 mirrors had to be delivered to the solar field every day for two
years. To make this work, the team devised a special transportation
system that would allow the project to meet its delivery targets.
With so much repetition at such a large scale, well-coordinated planning
and innovative solutions helped create efficiencies. Equipment
was redesigned in order to develop a more efficient way of augering
holes and installing heliostat pylons, while allowing the project to better
protect the desert landscape and reduce impact to the environment.
Construction of the power towers and boilers represented signifiThe
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cant first-of-a-kind elements that tested engineering teams and craft
labor. The towers were assembled in sections and in multiple assembly
areas in order to maintain the schedule, while the boilers were
built in ten 90-ton structures in a common area. Boiler sections were
carefully lifted into place with specialized cranes (Figure 3).
A partial list of vendors and contractors is given in Table 2.
Environmental Impact
Ivanpah was designed from the beginning to minimize impact on the
desert ecosystem despite the large size of the facility. In addition to
revising the tower designs to shrink the footprint and relying on dry
cooling, the majority of the 170,000-plus heliostats were mounted in
place with little or no grading or even concrete foundations. Instead,
the supports were simply placed into the desert soil as is. While a lot
of holes still needed to be drilled, it avoided what would have amounted
to a " clear-cut " wiping out thousands of acres of habitat.
Yet more obstacles were to come. By the spring of 2011, with construction
under way, it became clear that there were many more desert
tortoises occupying the site than anticipated by the BLM's original
Biological Opinion for the project. BrightSource had already expended
considerable effort and expense finding and relocating the tortoises.
Nearly 16 miles of fencing had to be installed around the project
as part of the relocation effort, with another 50 miles being installed
off-site as a mitigation requirement (this latter project is ongoing). In
addition, more than 7,000 acres of tortoise habitat were purchased,
and endowments were posted for the long-term management of these
lands. BrightSource also employed teams of biologists (peaking at
more than 160) to work alongside the construction crews to ensure the
protection of tortoises (Figure 4).
But in April 2011, after the Western Watersheds Project filed a lawCIRCLE
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