Ivanpah Solar Electric Generating System, United States of America

The Ivanpah Solar Electric Generating System (ISEGS) is located in San Bernardino county of California's Mojave Desert in the US. With an installed capacity of 320MW, it is expected to be the largest solar thermal project in the world. It will be the first large-scale solar thermal project in California in two decades.

The project is being developed by a start-up company, BrightSource Energy. The project was approved by California Energy Commission (CEC) in October 2010. It is under construction and is scheduled to be completed by 2013.

A labour agreement was signed between the State Building and Construction Trades Council of California (SBCTC), the Building & Construction Trades Council of San Bernardino and Riverside counties, and Bechtel to ensure that the local workforce benefits from the project.  The project is estimated to generate $650m in wages over a 30-year period.

Ivanpah project details

The ISEGS will be spread over 3,471 acres of public land managed by the US Bureau of Land Management (BLM). It is being constructed near the existing roads and transmission lines, and in an area next to a natural gas power plant.

The project will have a total installed capacity of 370MW. It comprises three separate solar units – one of 120MW and two units of 125MW each.

Power generated by the three plants will serve more than 140,000 homes during peak hours of the day. The project will also help curb carbon emissions by more than 400,000t a year, which is equivalent to taking 70,000 cars off the road.

BrightSource will sell 1,300MW to Southern California Edison and 1,310MW to Pacific Gas and Electric Company under contracts signed in 2009. The project will contribute to California's target to generate 15,000MW-20,000MW of renewable energy by 2020.

On completion, ISEGS will double the production of commercial solar thermal power in the US and will also provide tax revenues of $400m.

The project will receive tax credit equivalent to 30% of the project cost under the American Recovery and Reinvestment Act (ARRA).

Finance

The project is being financed by a mix of equity and debt. BrightSource has so far raised more than $300m of equity. A total of $160m equity was raised in round D in 2010 from Silicon Valley Venture Capital, Morgan Stanley, BP, Chevron and Google.

Bechtel Enterprises, the financing arm of Bechtel, will also have an equity stake in the project. French power and transportation company Alstom has also purchased equity worth $55m. The other major non-power participant is the California State Teachers Retirement System.

In addition, the US Department of Energy (DOE) provided a conditional loan guarantee of $1.37bn as stimulus fund for the project.

Contracts

The ISEGS project is being developed by the company's engineering, procurement and construction (EPC) partner Bechtel. Riley Power, a subsidiary of Babcock Power, will supply solar boilers and Siemens will supply two steam turbines. One of the turbines was supplied in 2008.

Technology

The project will feature Luz Power Tower technology (LPT) developed by the company. It will use sunlight instead of fossil fuel or nuclear power to produce energy.

This technology creates high temperature steam by reflecting sunlight on small mirrors called heliostats, which will be placed onto a boiler on top of the tower.

The water inside the boiler will be heated using solar energy to generate steam which will be connected through pipes to a conventional turbine to generate electricity.

In addition to LPT, the project will also feature a dry-cooling technology that will reduce water consumption by 90%.

The plant will use 95% less water than other solar thermal technologies.

The boilers and LPT will together produce high-temperature steam of up to 550°C.

Environmental impact

In order to reduce the environmental impacts of the project, BLM in association with federal, state and local partners reduced the project size from 4,073 acres to 3,471 acres.

BrightSource will also acquire 7,300 acres of mitigation land to conserve the desert tortoise after being tested for disease onsite. BLM has assigned over 3m acres of land for conservation of the species.