Heliostats are mirrors that track the sun in order to reflect highly concentrated sunlight to a receiver, where it can be stored as heat for long-duration energy storage and converted into electricity. Projects from this solicitation, which will be implemented over the next 1–3 years, will focus on lowering the cost of heliostats and heliostat technologies and creating new market opportunities for the heliostat industry.
Low-cost heliostats offer significant renewable energy potential. They enable 5 cents per kWh concentrating solar-thermal power with energy storage capacity of 12 or more hours, which would help to support a fully decarbonized electricity grid.
The expansion of low-cost, quality-built heliostats will reduce emissions in greenhouse-gas-heavy industries by providing needed high-temperature thermal energy. The projects that result from this RFP would significantly enhance the country’s ability to hit 2050 targets for energy sector decarbonization.
“These projects address a broad range of needs in the heliostat and concentrating solar power community,” said Guangdong Zhu, Heliostat Consortium (HelioCon) executive director and NREL senior researcher and group manager of thermal energy systems. “They range from design and manufacturing, automation, wireless controls, and education and outreach that will create course materials for students, graduate students, and even people already working in the heliostat industry.”
The seven projects selected to collectively receive $3.5 million in funding are:
- SunRing: Advanced Manufacturing and Field Deployment: This project by Solar Dynamics LLC and partners will develop processes to maximize cost-competitiveness, performance, and reliability of Solar Dynamics’ existing SunRing heliostat design. The project will implement off-site preassembly and kitting for the heliostat subassemblies, conceptually develop and prototype an automated manufacturing cell that is transportable and redeployable for future projects, develop a comprehensive installation and commissioning schedule, and compile a holistic cost model of the SunRing to develop a business case and aid in site and design decision-making.
- HELIOCOMM: A Resilient Wireless Heliostats Communication System: This components-and-controls project by the University of New Mexico will model a resilient wireless communication system based on the principles of integrated access and backhaul (IAB) technology, entropy-based routing, dynamic spectrum management, and interference mitigation. These technical advances will enable an industry pathway to low-cost, wirelessly controlled heliostat fields through photovoltaic-powered controls and communications with reduced energy usage, as well as safety and resilience through faster (milliseconds) communication and reduced risk of communication breakdowns or losses.
- An Educational Program on Concentrating Solar Power and Heliostats for Power Generation and Industrial Process: This project by Northeastern University will develop an educational program focused on concentrating solar power (CSP) and heliostats for power generation and industrial processes. It will be developed during the two-year project and then become part of the Northeastern curriculum for undergraduate and graduate engineering students.
- Demonstration of a Heliostat Solar Field Wireless Control System: Solar Dynamics LLC, with partners Remcom and Vanteon Corporation, will carry out a project aimed at demonstrating the reliable operation of a wireless heliostat solar field control system using commercially available products and developing analytical tools to de-risk the large-scale deployment of the wireless technology to solar fields with tens of thousands of heliostats. In parallel, a wireless radio frequency computer simulation of the demonstration system will be developed. The overall project goal is to prove that the wireless technology is fully capable of replacing traditional wired networks with minimal compromises.
- Twisting Heliostats With Closed-Loop Tracking: This project will design, manufacture, and test a new type of heliostat and study its application for high-concentration CSP. The University of Arizona will integrate a DOE Small Innovative Projects in Solar (SIPS)-type reflector with a high-accuracy mount and tracking camera to demonstrate an accurately focused and centered image of the solar disc. This will be maintained automatically throughout the day by mechanically coupled twisting of the reflector. Even when using perfectly focused facets, distortions of the reflected image on the receiver are introduced due to the non-normal incidence between the heliostat and the receiver. The dynamic focusing of the mirror facet can result in a reflected image that approaches the theoretical limit, potentially leading to higher operating temperatures for concentrated solar power (CSP) and industrial process heat applications.
- Digital Twin and Industry 4.0 in Support of Heliostat Technology Advancement: The Tietronix project aims to leverage technologies from the Fourth Industrial Revolution (Industry 4.0) to enhance the CSP industry and achieve the cost reduction experienced by other industries that have already adopted such advancements. This project will use a model-based systems engineering approach to improve the design, analysis, and verification of heliostats and overall solar fields. The project will also use digital twin technology during the heliostat manufacturing process, conducting thorough testing before achieving full functionality. This approach ensures quality and enables optimization of solar field operations by providing comprehensive insights into heliostat performance. The project will demonstrate the potential of machine learning algorithms, virtual-reality training, and augmented-reality techniques in reducing operational costs and enhancing overall performance.
- Robotic-Assisted Facet Installation (RA-FI): Sarcos Technology and Robotics Corp., in collaboration with Heliogen, will investigate the feasibility of a novel mobile robotic system capable of supporting the installation of mirror facets onto a heliostat. The primary goal of this proposed effort is to refine the understanding of the challenges related to mirror facet installation to analytically determine the feasibility to address this task robotically from the vantage point of both technical and business considerations.
“This is a broad, diversified set of awards that covers a large swath of topics,” said Mark Mehos, NREL principal researcher in the thermal energy systems group. “This collection of projects hits immediate short-term needs as well as long-term needs, including education of the future workforce in the industry.”
Some of the projects will start immediately, with others being implemented in the coming months. Projects are expected to be completed in the next 12–36 months. An advantage for the project teams will be access to the members of the Heliostat Consortium.
“There will be strong collaboration and communication between our core members and new members that result from the awards of this RFP,” said Margaret Gordon, HelioCon leadership team member and manager of the National Solar Thermal Test Facility at Sandia.
“We’re already seeing researchers from NREL and Sandia working with the awardees and connecting them to valuable resources at the labs. The consortium confers that benefit and brings together a community of researchers leveraging each other’s knowledge to attack a large challenging problem from several angles.”
The Heliostat Consortium, called HelioCon, was established in 2021 to integrate all types of stakeholder input to address the challenges in heliostat technology advancement and market adoption. Funded by the DOE Solar Energy Technologies Office (SETO), HelioCon is led by NREL and Sandia National Laboratories. The U.S. national laboratories are partnering with the Australian Solar Thermal Research Institute (ASTRI) and are closely working with developers, utilities, and other experts.
