Pratt & Whitney Rocketdyne (PWR), a rocket-engine manufacturer based in Los Angeles, Calif., has marked a major milestone in technology that will provide reliable solar energy on demand – even when the sun isn’t shining.
The last of 14 Concentrated Solar Power (CSP) receiver panels and heat shields have been installed at the Crescent Dunes Solar Energy project, and construction of the 10,400 articulating mirrors, or heliostats, on the 1600-acre heliostat field is underway in Tonopah, Nevada. PWR has provided the worldwide exclusive license to SolarReserve, a developer of large-scale solar energy projects based in Santa Monica, Calif., for the molten salt power tower and heliostat technologies.
PWR developed technology for the receiver panels, as well as critical components for the molten salt power tower. It also supplied the technology for the receiver structure, onto which the heliostats will direct sunlight. When commissioned in 2014, the 110-megawatt project will be the nation’s first commercial-scale, molten salt solar power tower and world’s largest plant with fully integrated energy storage system, able to provide enough energy to supply 75,000 homes 24/7.
“This is a major milestone for Pratt & Whitney Rocketdyne and molten salt technology,” said Bill Leinart, CSP Program Manager for PWR. “The receiver panels and heat shields are installed and we’re now in the process of installing the interconnecting piping between pans at the top and bottom of the receiver panels. We will be ready to start commissioning the receiver in a few weeks, in preparation for converting reflected sunlight from the heliostat field into electrical power that is will go directly into NV Energy’s transmission lines and the nation’s power grid.”
“SolarReserve, which was founded on the basis of commercializing the PWR-engineered molten salt power tower technology, is excited to see the Crescent Dunes Project bringing American innovation to fruition,” said Kevin Smith, CEO of SolarReserve. “PWR’s innovative and advanced engineering has helped progress this project to showcase the world’s leading solar thermal energy storage technology.”
For more than 40 years, PWR has successfully powered payloads into orbit that have included astronauts, cargo and satellites vital to space exploration, worldwide communication, navigation, defense, research and development, and weather prediction. In recent years, PWR has been leveraging its rocket-propulsion engineering experience in a number of energy-related technologies, such as compact coal gasification, oxy-combustion, down-hole steam generation for enhanced oil recovery and concentrated solar power.
PWR also recently received about $2.3 million from the Environmental Security Technology Certification Program (ESTCP) office of the U.S. Department of Defense to design and develop a 200-kilowatt high-concentration photovoltaic (HCPV) solar-power field at Edwards Air Force Base in California. That project is designed to demonstrate the high-performance and cost-effectiveness of HCPV technology for use at DoD installations, and ultimately large utilities and other industrial applications.
So why is a rocket engine manufacturer applying their technologies and expertise to the energy sector?
“Rocket engines are about large amounts of power in a very small amount of space,” said Don Stevenson, deputy director of Energy Systems at PWR. “It requires expertise in fluid dynamics, high temperature thermal management, combustion, structural analyses, advanced materials, rotating machinery and cryogenic applications. PWR has decades of experience in all these areas. So it makes sense for customers to look to us to solve demanding energy needs.”
PWR developed the key molten salt technology that is featured at SolarReserve’s Crescent Dunes Project. The plant will use thousands of heliostats, to track the sun and concentrate the sun’s energy, equaling approximately 1,300 suns, onto a 100-foot receiver mounted atop a 540-foot tall tower. Liquid molten salt is circulated from the “cold” tank, up the tower and through the receiver, where it captures the sun’s thermal energy, heating the salt from 500 to about 1,050-degrees Fahrenheit. The hot salt is then pumped back down the tower where it is stored in the “hot” tank until electricity is needed. The thermal energy from this stored molten salt is then used to generate steam to drive a steam turbine generator to create electricity. Because of the energy storage capability, the plant will generate firm, predictable electricity on demand, day or night, even on cloudy days, which is something conventional Photovoltaic solar panel technology cannot provide.
The Crescent Dunes plant is designed to generate more than 500,000 megawatt hours per year, enough to power 75,000 homes during peak electricity period. 100 percent of the power generated will be sold to NV Energy under a long-term power purchase agreement that has been fully approved by the Nevada Public Utilities Commission.
“PWR has a history of dealing with tough technological challenges and energy is just one of those challenges,” said Neeta Patel, director of Energy Systems at PWR. “The world’s demand for energy is growing at an unprecedented rate as global population grows and as many developing nations continue to urbanize and industrialize.
“This is putting incredible pressure on our natural resources, whether its natural gas, coal, oil and even water in some parts of the world,” Patel added. “Technology has to be part of that solution for helping the world meet those challenges.”
Carri Karuhn was raised in the west suburbs of Chicago, where she got her start in journalism as a reporter for the Chicago Tribune, writing about everything from crime and urban development, to strange fishing habits in the community, to an investigative piece about a mayor who received a free house from a local road builder. She went on to write for the Los Angeles Times and Associated Press. She now works as a Communications specialist for Pratt & Whitney Rocketdyne in Canoga Park, Calif.