We
spent the night at the Holiday Inn Express; it was pricey but
new and clean. We discovered the following morning that
every room in Pahrump was sold out. Again. It was
only that we reserved the room early in the day that we were
able to get one. From Pahrump, we decided to go past the
Ivanpah Solar Generation Plant to get a photo or two.
The
photos below are what we saw.
From the
web, I found this aerial shot of the Ivanpah plant.
Wikipedia,
the source of all knowledge, had this to say about Ivanpah (a
highly selected extract):
The Ivanpah Solar Electric Generating System is a concentrated solar thermal plant in the California Mojave Desert, 64 km (40 miles) southwest of Las Vegas, with a gross capacity of 392 megawatts (MW).[6] It deploys 173,500 heliostats, each with two mirrors, focusing solar energy on boilers located on three centralized solar power towers.[6] Unit 1 of the project was connected to the grid in September 2013 in an initial sync testing.[7] The facility formally opened on February 13, 2014,[1] and it is currently the world's largest solar thermal power station.[8][9]
The Ivanpah Solar Electric Generating System consists of three solar thermal power plants on a 4,000 acres (1,600 ha) tract of public land near the Mojave Desert and the California—Nevada border in the Southwestern United States[16] near Interstate 15 and north of Ivanpah, California.[17] The site is visible from adjacent Mojave National Preserve, Mesquite Wilderness, and Stateline Wilderness.[17]
The facility consists of fields of heliostat mirrors focusing sunlight on receivers located on centralized solar power towers. The receivers generate steam to drive specially adapted steam turbines. For the first plant, the largest ever fully solar-powered steam turbine-generator set was ordered, using a 123 MW Siemens SST-900 single-casing reheat turbine.[18]Besides steam-turbine generators Siemens supplied instrumentation and control systems.[19]
The LPT 550 solar system produces electricity the same way as traditional power plants – by creating high temperature steam to turn a turbine. BrightSource uses thousands of mirrors called heliostats to reflect sunlight onto a receiver being developed by Riley Power Inc. filled with water that sits atop a tower. When the sunlight hits the receiver, the water inside is heated and creates high temperature steam. The steam is then piped to a conventional turbine, which generates electricity.[26]The local irradiance near this area is about 7.4 kW·h/m2/day[43][44] (annual average) for a total solar energy flow in the visible spectrum of 2.717 MW·h/m2 yearly.
A claimed capacity factor of 31.4%[44] implies that the plant will operate for 365 days × 24 hours × 31.4% = 2751 hours per year. At 377 MW (net nameplate capacity) constant power, this means a generation of 377 MW × 2751 h/y = 1,037,127 MW·h/y rounding up to 1.04 TW·h/y.
One heliostat mirror is a 75.6 square feet (7.02 m2) reflecting surface,[45] for a total of 151.2 square feet (14.05 m2) per heliostat. Total plant heliostat reflecting surface results in 173,500 heliostats × 14.05 m2/heliostat = 2,437,144 m2. Based on irradiance, the intercepted solar energy flow is 2.717 MW·h/m2/year × 2,437,144 m2 = 6,621,720 MW·h yearly. Thermal yield, after taking into consideration reflection, transmission, radiation and absorption losses, is about 55%, resulting in a thermal power input to the steam turbines of 6,621,720 MW·h × 55% = 3,641,946 MW·hth. Resulting expected energy output is 3,641,946 MW·hth × 28.72% efficiency = 1,045,967 MW·h/y, rounding up to 1.05 TW·h/y. Lack of published performance data has caused speculation that the plant is not meeting expectations.[46]
From
I-15 you can see the Ivanpah plant. Actually there are 4
of them. Three are "solar towers" and the fourth is some
kind of black, ground-mounted head absorption system seemingly
unrelated to the other 3. One of the three towers is
visible above. I never got the scoop on the black material
technology.
Shot
from the freeway "at speed" we could see another one of the
towers.
We
pulled off the freeway to get a better look at things. The
tower above captures solar heat as reflected off of hundreds of
acres of mirrors. The heat creates steam and the steam
turns turbines. While there is plenty of open area in the
desert, this area is unique as it straddles the high voltage
transmission line that runs from the hydroelectric generators at
Hoover Dam to Los Angeles. So, the cost of transmission
infrastructure was already covered. The transmission
towers are barely visible on the ridge-line of the mountain near
the left of the photo above. The plume at the top of the
tower is venting excess pressure steam. Note that despite
the clear conditions, the intensely concentrated sunlight near
the tower illuminates the dust and contamination in the air.
This
panorama shows all three of the solar-thermal towers.
All
three towers appeared to be in use when we were there.
As far
as I could tell there was no visitor center, so we drove as far
as we could and shot a few photos through the fence. The
heliostats are visible and they are as simple as possible.
Each set turns to follow the sun to keep its beam focused on the
tower. The actual layout of the mirrors is not critical,
but each heliostat's tracking motor must know its relative
position to the tower to perform correctly. So, the
location of each heliostat is custom and recorded with precision.
I assume that there is a centralized control for the heliostats
that allow for all mirrors to be returned to the neutral
position if required.
Keeping
these mirrors clean and free from dust damage must be a
challenge. I surmise that even a small degradation in
mirror reflectivity would substantially impact the output of the
plant.
In November 2014, Associated Press reported that the plant was producing only "about half of its expected annual output". The California Energy Commission issued a statement blaming this on "clouds, jet contrails and weather".[14]However, in the first quarter of 2015, Ivanpah generation was up 170 percent over the same quarter in 2014 – 108 gigawatt-hours compared to 40 GWh, according to the Energy Information Administration.[15]
From
Ivanpah we continued southwest on I-15 to Baker and after a
mediocre-tasting, exploitively priced meal, we headed south of
Kelbaker Road to the Kelso Depot. The photo above is from
the NPS and shows the Kelso Depot building which is now a
historical landmark. "Back in the day", Kelso was
important because it was on the Union Pacific main line.
To the east is the so-called Cima grade that required helper
steam engines and these engines were based at Kelso.
Since
the heyday and the introduction of the diesel-electric
locomotive, the maintenance shop and roundhouse at Kelso has
been demolished, but there are still railroad facilities
present. I assume the silver towers are for water, but did
not ask.
To the
southwest are the Kelso Dunes.
Kelso
was important to the Union Pacific due to its proximity to water
from the Providence Mountains in the distance. Reliable
spring water was piped to the station to supply the steam
engines working the Cima grade. I do not know if the
structures in the photo above are railroad owned or private
property.
Little
remains of Kelso, just the station building and this post
office.
We
continued south on Kelbaker road and were given a nice view of the
Providence Mountains to our southeast.
The
Kelso Dunes are pretty good sized (although puny compared to the
Altar Dunes in Sonora, MX) and are now within the National Park.
The
mountain pass on the path south had some nice rock hoodoos.
Some of
the desert bushes were in bloom.
Our path
home took us past Joshua Tree National Park. Kathleen's
research suggested that there was a train museum just outside
the park so we attempted to check it out. It was
closed. But, from the access road we could see a portion
of the narrow gauge track.
This
facility is on private land and they have several miles of
track. Some of their cars are visible in the center of the
photo above.
The
access road to the site was dirt and made my M5 quite
unhappy. The view above is looking north toward the Yucca
Valley area.
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Photos and Text Copyright Bill Caid 2016, all rights
reserved.
For your enjoyment only, not for commercial use.