News Release: Solana Begins Serving Customers; Providing Solar Power at Night

October 09, 2013

World’s Largest Solar Plant of Its Kind Producing Enough Electricity to Power 70,000 APS Customers

PHOENIX – Abengoa (MCE: ABG.B), the international company that applies innovative technology solutions for sustainability in the energy and environment sectors, announced that the Solana Generating Station has successfully passed final production tests and entered commercial operation on Monday. At 280 megawatts (gross), Solana is the world’s largest parabolic trough plant and the first solar plant in the United States with thermal energy storage allowing for electricity to be produced at night.

Unlike other solar-powered electrical plants, Solana produces electricity at full capacity for up to six hours after sunset, using Concentrating Solar Power (CSP) technology with solar thermal storage. Solana is Abengoa’s first utility-scale solar plant in the country to begin operation.

“Abengoa is very proud to put the first solar plant with this scale of storage capability in the United States into commercial operation, and to supply APS with the added value that dispatchable Concentrating Solar Power provides,” said Manuel Sanchez Ortega, CEO of Abengoa.

Arizona Public Service (APS) will purchase the full output from Solana for its customers, adding to the company’s already substantial solar portfolio.

“Solana is a game-changer in that it is a large-scale solar power plant that continues to produce electricity even after the sun goes down, using an innovative process that is new to the United States,” said Don Brandt, APS President and Chief Executive Officer. “Abengoa has been a great partner. We worked with them to bring a plant of this size and this technology to Arizona, along with jobs and a positive impact on the state’s economy, all while producing clean, renewable energy for our customers.”

The ability to generate electricity when needed is one of the unique characteristics of the CSP technology versus other types of renewables. Solana’s thermal storage system will help satisfy Arizona’s peak electricity demand by storing energy that can be used by APS to produce electricity when needed by customers during the summer evenings and night time hours. The solar thermal storage also eliminates intermittency issues that other renewables, such as wind and photovoltaics, contend with, providing stability to the grid and thus increasing the value of the energy generated by CSP.

The process begins with 2,700 parabolic trough mirrors, which follow the sun to focus its heat on a pipe containing a heat transfer fluid. This fluid, a synthetic oil, can reach a temperature of 735 degrees Fahrenheit. The heat transfer fluid then flows to steam boilers, where it heats water to create steam. The steam drives two 140-megawatt turbines to produce electricity, much like a traditional power plant.

In addition to creating steam, the heat transfer fluid is used to heat molten salt in tanks adjacent to the steam boilers. The thermal energy storage system includes six pairs of hot and cold tanks with a capacity of 125,000 metric tons of salt, and the molten salt is kept at a minimum temperature of 530 degrees Fahrenheit.

When the sun goes down, the heat transfer fluid can be heated by the molten salt to create steam by running it through the tanks instead of the field of parabolic mirrors.

The total investment of the plant is approximately $2 billion and during financing, Solana received a federal loan guarantee for $1.45 billion from the United States Department of Energy Federal Loan Guarantee Program. This support, along with APS contracting to purchase the power, made the construction of Solana possible, creating more than 2,000 jobs and a national supply chain that spans 165 companies in 29 states.

Abengoa currently has a total installed capacity of 1,223 MW in operation and 430 MW under construction, including both PV and CSP. It is one of the few companies that constructs and operates both solar tower and parabolic trough plants.  

With the addition of Solana, APS will have 750 MW of solar power on its system by the end of 2013, enough to serve 185,000 Arizona customers.