U.S. Department of Energy

Heliostat System with Wireless Closed-Loop Control

Thermata logo Photo of a man standing next to a row of silver, metallic panels anchored to the ground with a horizontal bar.

Self-powered, factory-assembled heliostats use closed-loop control to lower the cost of a solar collector field. Tower-mounted cameras sense reflections from small "solar proxies" mounted on each mirror; these reflections are then used to determine the real-time aiming point.

Thermata, under the 2012 SunShot Concentrating Solar Power (CSP) R&D funding opportunity announcement (FOA), is demonstrating a collector system with enhanced optical tracking capability. The unit includes a control system that provides real-time information to adjust the location of the reflected sunlight. It demonstrates a prototype heliostat system that meets the cost, performance, and reliability objectives of the SunShot Initiative.

Approach

The research team is working to demonstrate that a heliostat system using Thermata's innovative closed-loop optical tracking technology can satisfy key technical requirements, including total optical error and wind-load requirements. The goals of this project are to:

  • Demonstrate the effectiveness of a camera-based tracking system
  • Validate the cost of Thermata heliostats going to $75/m2 when installed in high volumes
  • Characterize the optical performance of the heliostat system.

Innovation

Thermata's transformative concept is an innovation in closed-loop tracking. A camera system mounted on the central-receiver tower optically senses the focus of each individual heliostat and uses end-to-end closed-loop control to accurately place the sun on any receiver target. In addition, Thermata's heliostat is controlled through a wireless mesh network, is self-powered by photovoltaics, and is factory prewired, which eliminates field wiring, trenching, and related costs.

Publications, Patents, and Awards

At this time, this project does not have published articles, patents, or awards.

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Quarterly Progress Reports

Project Fact Sheet

The SunShot CSP R&D program seeks to accelerate progress toward the cost target of $0.06 per kilowatt-hour through novel and revolutionary research into CSP technologies. Learn about other DOE competitive awards for concentrating solar power research that are in progress.