California’s Ivanpah ‘Solar Tower’ now online

The 392 megawatt (MW) Ivanpah Solar Project has at long last come online in California. The solar thermal plant, located south of Las Vegas, Nevada across the California border will be the largest of its kind anywhere in the world, producing enough electricity to power over 140,000 homes. Ivanpah’s path to becoming operational has not been a smooth one, but it has accelerated the learning curve for both the project’s developers–NRG Energy, BrightSource Energy and Google–as well as the USA’s burgeoning solar industry as a whole. 

The Ivanpah plant uses concentrating solar thermal (CST, sometimes called CSP) technology as opposed to the more common solar photovoltaic (PV) technology. The latter has experienced a massive boom in recent years, becoming a common sight in countries like Germany, Australia, the US and numerous others. One of the main drivers of this boom has been the falling cost the materials & processes used to manufacture solar PV modules. CST technology, by contrast, is not usually applicable at smaller scales and whose technologies are more varied in their basic approach to converting solar energy into electricity, have not yet seen the dramatic cost reductions that PV technology has. Not insignificantly, the Blythe Solar Project, also located in the California desert, decided to switch from CST to solar PV technology to take advantage of its increasing cost-effectiveness.

The Ivanpah plant utilises the ‘solar tower’ approach to CST, where sun-tracking mirror arrays (called heliostats) are arranged semi-concentrically around huge, 160-meter collector towers. As the sun moves through the sky, the heliostats turn and concentrate its light on a boiler mounted atop the towers, heating up water to create steam and spin turbines, generating electricity in the same way that coal, nuclear or gas plants would–except with the sun as fuel.

In the case of the Ivanpah Solar Project, the plant is comprised of 3 towers, uses 170,000 heliostats and is spread across 3,500 acres of land owned by the federal government. It is just one of a suite hundreds of large-scale solar projects either already deployed, under construction or in the pipeline to help California meet its ambitious renewable energy target: 33% of electricity to come from renewable sources by 2020.

Ivanpah’s arrival at the operational stage came about thanks in large part to a $1.6 billion loan guarantee from the US government, but its getting here was by no means smooth sailing as could be expected with a groundbreaking, milestone project of this nature. The biggest holdup with construction of the plant were issues associated with its environmental impact; its location is in the middle of endangered desert tortoise territory, and the number of tortoises actually found on the site was about 5 times the original estimate. Each one had to be protected and relocated, which in conjunction with threats of legal action from environmental groups resulted in significant delays to the commencement of the project.

The troubles faced by the project developers were not for naught, however: They were at least partially responsible for the federal government’s eventual clarification & consolidation of rules for future developments. In the end, a streamlining process for assisting large-scale solar project developers in identifying potential locations was devised–and thus the ‘solar zones‘ for the southwest US’s sun-drenched desert regions were born.

In Australia, a similar type of CST solar tower plant–albeit one with energy storage capacity in the form of molten salt–has been discussed as a potential replacement for ageing coal plants in Port Augusta, South Australia. ARENA recently announced that it will help fund a feasibility study for such a plant. Currently, very few large-scale solar power plants are in operation in Australia, and was recently found to rank in 34th place for large-scale solar worldwide.

Top image by Craig Dietrich via Wikipedia

© 2014 Solar Choice Pty Ltd

James Martin II

Contributor at Solar Choice
James was Solar Choice's primary writer & researcher between 2010 and 2018.

He is now the communications manager for energy technology startup SwitchDin, but remains an occasional contributor to the Solar Choice blog.

James lives in Newcastle in a house with a weird solar system.
James Martin II