Solar Electric | Largest Thermal Tower Facility

Ivanpah Solar Electric Generating System in California officially opened in February 2014 after four years of construction. Visit the location link in Google Maps. It consists of three towers and thousands of surrounding mirrors. They stand near the Mojave National Preserve and the Nevada border, 65 kilometers from Las Vegas along Interstate 15. All photos are by Gilles Mingasson/Getty Images.

The operating principle is simple. Mirrors follow the sun and reflect light to the top of each tower. The collective heat generates steam which in turn spins a turbine that produces electricity distributed on the grid. What is not simple is the sheer immensity and scale.

The plant sits within Ivanpah Dry Lake on 3,500 acres of public land. The location receives 330 – 350 sunny days each year. The three power units generate 377 megawatts of electricity. That is enough to power 140,000 homes. Smaller similar systems are in Spain and China.

This closer view shows a thermal tower illuminated a small amount at the top by reflections from a few mirrors. A total of 170,000 heliostats are spread out over 13 square kilometers. That is 5 square miles. Each heliostat is a steerable pair of flat mirrors.

They are mounted on slender posts inserted into the desert floor so as to cause the least disruption to the ecology.

Here are a few more views of the mirrors. The first image is of some ready to be mounted in the array around the tower.

When the mirrors are aligned to point the reflection of sunlight onto the 460 ft. tall tower, they raise the temperature of the water in the closed loop piping to 1000˚F. The super heated steam drives the turbines to make electricity. As you can see in this image, only some of the mirrors are aligned during this testing phase.

According to the owners and proponents, this power system will reduce carbon dioxide emissions by 400,000 tons per year compared to the same energy output by conventional generating systems. The owners are NRG Energy, Inc., BrightSource Energy, Inc. and Google. Construction is managed by Bechtel.

More images are available at this Flickr site.

Several virtual 360˚ tours are available at this site. On-screen controls let you move around and zoom your view.

The Ivanpah promotional site is here.

The BrightSource site is here.

13 thoughts on “Solar Electric | Largest Thermal Tower Facility

  1. Hi Jim,
    I hear a lot of criticism of this plant, and also of the wind farms that are popping up, but to me, this is a better option than the risks of nuclear energy. One of the criticisms is that the efficiency of solar and wind power is low. But then, the model T was just the beginning, wasn’t it? ….Or, we could all agree to turn off our lights. I’m excited by the possibilities here, and appreciate your posts about it.


    • Each technology brings some positives and some negatives. I think we want to choose the ones with the most benefits overall for the long term. This and windfarms are investments that use the large amount of available energy from the sun. I would choose them over fossil fuels. I would choose nuclear over fossil.

      Your point about cutting back on our own use of energy is an excellent one. Waste and misuse of energy is especially high in our society. It will get worse as more third world regions develop into more modern ones. Their demands for energy are going to rise.

      Thanks for your comments today.


  2. As it happens, I just read a clutch of articles over the past week about pilots’ concerns about this installation. It’s easy to see how blinding could take place. I suppose that would go under the heading of unintended consequences.


    • If all the mirrors were lying flat and not tracking the sun, their reflections would be similar to that off of a quiet body of water. That doesn’t seem to be a big concern.

      If the mirrors are operating to aim reflections toward the tower, a pilot would have to steer their plane where the tower is located in order to be blinded.

      I hope their concerns are not going to be a problem.


  3. I too thought of the danger to pilots’ eyes as a possible problem, particularly on reading that the mirrors are flat and therefore not precisely focused on the target tower. However, the Wikipedia article on this doesn’t mention the concern. What it does say about environmental concerns and efficiency was interesting however:

    The Ivanpah installation will reduce carbon dioxide emissions by more than 400,000 tons annually. It is also designed to minimize impacts on the natural environment through land-use efficiency, and a low impact heliostat layout which allows the solar field to follow the natural land contours and avoid key vegetation areas.[25]
    The Ivanpah Solar power project required disturbance of over 5.5 square miles of public land in the northeastern Mojave Desert. In 2012 the National Parks Conservation Association (NPCA) issued a report on the project, citing water concerns, damage to visual resources, and impacts on important desert species. In order to conserve scarce desert water, LPT 550 uses air-cooling to convert the steam back into water. Compared to conventional wet-cooling, this results in a 90 percent reduction in water usage. The water is then returned to the boiler in a closed process.[21] Many desert tortoises found on the site were relocated to other parts of the Mojave Desert. However, environmentalists have raised concerns that relocated tortoises are more likely to die due to the stresses involved.[31][32] BrightSource has also installed fencing that will keep wildlife out of the area.[33] In 2010, the project was scaled back from the original 440-megawatt (590,050 hp) design, to avoid building on the habitat of the desert tortoise.[34]
    During the trial of the solar thermal power plant in September 2013, 15 of the 34 dead birds found at the plant had heavily burned feathers. The feathers were burned and charred in flight by the intense radiation from the heliostat mirrors of solar thermal plant which resulted in the falling of the dead birds from the sky.

    All steam systems require a heat sink of course and the fact that Ivanpah uses air is significant. That makes it more efficient in winter than summer. However, things like this have to be the future if there’s any hope of not ruining our atmosphere. Nothing’s perfect.


    • Yes, nothing’s perfect. I think large scale facilities like this located in remote areas with ample sun are good. They allow us to test the design and behavior or the system. I don’t believe this type of installation would be suitable in populated areas or where there is much animal and plant life.

      Thanks for the comments. I hope the engineers will learn a lot from this and see improvements for our future use of solar.


    • I went through the Flickr set two or three times. It was hard to select only a few for the post.

      Two years ago we went to Las Vegas. We drove toward Needles on I-15 to go see a friend. We passed the solar power facility. It really got my attention. It was partially complete. But, I could tell what it was.


  4. There’s a lot of potential in solar energy, even at a small scale. You wouldn’t think the gray rainy Pacific NW would be practical for that, but it is. I have a neighbor who sends power into the grid sometimes, and overall, supports her household with panels on her roof. The problem is the upfront cost of the installation. A million houses supporting themselves (maybe even powering their cars) would lessen the need for as many large scale projects like this one that have raised objections mentioned in previous comments. Either way, solar, wind and tidal energy sources, combined with conservation, are the obvious solution to our energy needs, if it weren’t for political inertia. Thanks for these great pics showing the installation. Impressive.


    • Yes, no one solution fits all our needs. I believe in having a large number of different ones. Probably the largest impact would come with conservation. Melanie and I work hard to have a small carbon footprint. Our home energy use is now at about 50% of the typical home of our size in our region. It is important that we all cut back on our energy waste.


I'd like to hear from you.

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s