In an exciting development for the concentrating solar power (CSP) sector, researchers at Sandia National Laboratories (SNL) are making significant strides in advancing the capabilities of heliostat fields through a closed-loop controls test bed. This initiative, part of the U.S. Department of Energy’s Solar Energy Technologies Office (SETO) sponsored Heliostat Consortium, is designed to enhance the efficiency and precision of solar energy collection.
The core of this research is the extremum seeking control (ESC) algorithm, which employs a batch least squares (BLS) technique to automate feedback control for heliostat pointing. Kenneth Armijo, the lead author from Sandia National Laboratories, emphasized the importance of this technology, stating, “By reducing pointing errors to zero, we are not only improving the accuracy of energy collection but also paving the way for more efficient solar power systems.”
The test bed is designed to manage a field of 218 heliostats, which are crucial for directing sunlight to a central receiver. The innovative approach utilizes two aim point strategies—a four-point QuadCell and a concentric aim point—to optimize energy flux. This flexibility is vital for adapting to changing environmental conditions, thus enhancing the overall performance of solar thermal systems.
Moreover, the integration of both wired and wireless communication protocols allows for a sophisticated distributed control system (DCS) that can adapt in real-time. This system will utilize programmable logic controllers (PLCs) at each heliostat to manage energy flux distribution across various test articles and solar receivers. Armijo noted, “Incorporating real-time environmental data into our control algorithms enables us to refine solar field management and significantly boost energy capture efficiency.”
As the energy sector increasingly turns towards renewable sources, the implications of this research are profound. By improving the accuracy and responsiveness of heliostat fields, the test bed could lead to more commercially viable solar thermal power systems, ultimately contributing to lower energy costs and a reduced carbon footprint.
The ongoing work at Sandia National Laboratories represents a pivotal step in harnessing solar energy more effectively. As these technologies mature, they hold the potential to transform how we capture and utilize solar power, making it a cornerstone of the future energy landscape. This research has been detailed in the ‘SolarPACES Conference Proceedings,’ reflecting its significance in advancing solar thermal technology.
