For background on the Solar Energy Technologies Office (SETO) concentrating solar-thermal power projects and office-wide strategy, be sure to read the Solar Energy Technologies Office Multi-Year Program Plan and the Solar Futures Study. Learn more about projects in the areas below. In each research topic area, projects are organized alphabetically by awardee name.
Project Name: Loop Thermosyphon Enhanced Solar Collector
Awardee: Advanced Cooling Technologies
Location: Lancaster, Pennsylvania
DOE Award Amount: $1,500,000
Principal Investigator: Fangyu Cao
Project Summary: This team is developing a loop thermosyphon solar collection system for efficient, low-cost solar-thermal desalination that does not require fluid to be actively pumped throughout the system. The design takes advantage of nanofluids with higher solar absorptivity and a two-phase thermosyphon to improve the system’s efficiency and simplify the collection of solar-thermal energy used in desalination processes.Project Name: Polarimetry-Enhanced Imaging towards Autonomous Solar Field and Receiver Inspections
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $2,000,000
Principal Investigator: Yu Yao
Project Summary: This project is developing imaging systems using polarimetry, which is the measurement of how light rays are aligned, or polarized. Measuring polarization has the potential to be much more sensitive than conventional optical measurements. The imaging systems will be small enough to attach to drones and be deployed to evaluate the performance of concentrating solar-thermal power (CSP) collector systems. They can also be attached to CSP plant power towers. Autonomous imaging will reveal damage and soiling on collector mirrors, and reduce errors in mirror alignment, resulting in improved efficiency.Project Name: Technical and Commercial Assessment of a Newly Developed Secondary Reflector Design for Linear Fresnel Technology
Awardee: Hyperlight Energy
Location: Lakeside, California
DOE Award Amount: $600,000
Principal Investigator: Guangdong Zhu
Project Summary: The National Renewable Energy Laboratory is applying an innovative methodology to optimize a linear Fresnel secondary reflector technology for concentrating solar-thermal power plants. With Hyperlight Energy, NREL will create a solar field in California to test and demonstrate its methodology to improve the cost and optical efficiency of linear Fresnel collectors by optimizing the secondary reflector.Project Name: Wind-Loading on CSP Collectors, High-Fidelity Computational Fluid Dynamics Modeling, Experimental Field Measurement Campaigns, and Validation
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $1,600,000
Principal Investigator: Shreyas Ananthan
Project Summary: The project aims to significantly improve the understanding of the fundamental physics drivers behind wind-loading experienced by CSP collector and support structures. The project team will characterize the prevailing wind conditions and resulting operational loads at operating CSP plants and develop and validate a computationally efficient, high-fidelity modeling tool capable of predicting wind-loading in CSP installations.Project Name: CSP Optical Facilities
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $1,050,000
Principal Investigator: Judy Netter
Project Summary: This project will focus on the repair and maintenance of CSP optical research facilities and equipment at NREL. These resources will support ongoing and projected research needs of CSP researchers and enable NREL to repair and update its existing CSP research equipment that is essential to the optical characterization of CSP components. This funding will ensure the continual operation of this equipment and that CSP researchers will have the necessary tools to achieve the cost goals of the Solar Energy Technologies Office.Project Name: NREL-Led Consortium for Heliostat Research, Development, and Validation
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $25,000,000
Principal Investigator: Guangdong Zhu
Project Summary: NREL, in partnership with Sandia National Laboratories and the Australian Solar Thermal Research Institute, is developing and managing a consortium to support research, development, validation, commercialization, and deployment of low-cost and high-performance heliostats with optimized operation and maintenance for CSP applications. This heliostat consortium, known as HelioCon, will work closely with DOE, subject-matter experts, and a board of advisors composed of CSP developers, component suppliers, utilities, and international experts, to achieve DOE objectives for U.S.-manufactured heliostat cost, performance, and reliability.Project Name: Development of a Tracking Correction Algorithm for a Commercial-Scale Heliostat Field by Using the State-of-the-Art Non-Intrusive Optical Measurement Tool
Awardee: Tietronix Software
Location: Houston, Texas
DOE Award Amount: $300,000
Principal Investigator: Michel Izygon
Project Summary: Optical degradation of solar reflectors causes drastic efficiency losses in concentrating solar-thermal power tower plants, but there is no reliable or efficient way to correct it at the utility scale. This project team is conducting tests at Ivanpah power plant units using the non-intrusive optical measurement method and collect data with a drone to measure slope, canting, and tracking errors of heliostats at varying elevation angles and temperatures. The team will then develop software that provides full-field optical correction protocols and a tracking correlation algorithm so plant operators can optimize heliostat performance year-round.Project Name: Heliostat Observation System Commercial Qualification
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $300,000
Project Summary: Sandia National Laboratories plans to develop and commercialize a tool for CSP towers that corrects the orientation of heliostat mirrors and integrates a modular technology by Heliogen that uses a closed-loop optical control system. The tool will be able to correct a heliostat’s tracking system, improve operations, and advance optical systems for new and existing CSP plants.Project Name: Current-Activated Reactive Ultrafast Joining (CARUJ) of High Temperature Materials
Awardee: Argonne National Laboratory
Location: Lemont, Illinois
DOE Award Amount: $1,180,000
Principal Investigator: Dileep Singh
Project Summary: The high-temperature systems and components for the next generation CSP require new materials such as cermets, ceramics, refractory alloys, and composites that must be integrated with similar material types and/or with metal alloys. The joining of similar and dissimilar materials is extremely challenging. This project is developing current-activated reactive ultrafast joining (CARUJ) technology, which uses thin layers of precursor materials between the two parts and pass electric current through it. The team will perform various characterizations to evaluate the efficacy of the joints. Successful development and testing of CARUJ will benefit the deployment of next-generation thermal systems.Project Name: Design Methods, Tools, and Data for Ceramic Solar Receivers
Awardee: Argonne National Laboratory
Location: Lemont, Illinois
DOE Award Amount: $955,000
Principal Investigator: Mark Messner
Project Summary: While ceramic materials are extremely promising in achieving SETO’s 2030 LCOE target for CSP systems, there are currently no design methods suitable for designing high-temperature ceramic receivers. This project is developing design methods for ceramic receivers, implementing these methods in a publicly available, open-source receiver life estimation tool, generating the required design data for a promising ceramic system, and completing structural life and economic comparisons between metallic and ceramic receiver designs.Project Name: Robust Solar Receivers Using MAX Phase Materials
Lab: Argonne National Laboratory
Location: Lemont, Illinois
DOE Award Amount: $360,000
Principal Investigator: Dileep Singh
Project Summary: As operating temperatures for concentrating solar-thermal power plants continue to increase, current metal-based receivers have structural stability issues that need to be addressed to accommodate higher temperatures. This project is developing receivers using ceramic materials that can operate at temperatures higher than 800 degrees Celsius. The team aims to demonstrate the viability of these new class of materials.Project Name: Economic Weekly and Seasonal Thermochemical and Chemical Energy Storage for Advanced Power Cycles
Awardee: Arizona State University
Location: Tempe, Arizona
DOE Award Amount: $3,300,000
Principal Investigator: Ellen Stechel
Project Summary: This project seeks to integrate multiple thermochemical energy storage components into a CSP design so that a plant can have multiple storage durations, including daily and long-term. These components will be designed for integration with supercritical carbon dioxide power cycles. The team will conduct techno-economic analyses to improve CSP system design and operation for guaranteed year-round energy dispatchability.Project Name: Enabling High Heat Transfer Heat Exchangers through Binary Particle Size Distributions
Awardee: Boise State University
Location: Boise, Idaho
DOE Award Amount: $260,000
Principal Investigator: Todd Otanicar
Project Summary: This team is investigating a novel strategy to mix two different particle sizes with the aim of significantly increasing the thermal conductivity in heat exchangers that use packed bed of particles. These binary particle mixtures can be realized for little to no additional cost as they only require mixing of two unique particle sizes. This project will investigate how binary particle size distribution affects bulk effective thermal conductivity through high temperature characterization of the particles mixtures. The team will also analyze changes in thermal resistance on the wall of the heat exchanger using modulated photothermal radiometry. If successful, the project will culminate in a demonstration of the heat exchanger performance improvement using Sandia National Laboratory’s particle-to-sCO2 subscale demonstration heat exchanger.Project Name: Coatings for CSP Lifetime
Awardee: BrightSource Energy
Location: Oakland, California
DOE Award Amount: $800,000
Principal Investigator: Yaniv Binyamin
Project Summary: Next generation CSP receivers will operate at temperatures of up to 800°C, which will require new receivers to use high-strength nickel super-alloys. In order to develop new high-performance coatings (HPCs) for these receivers, this project is validating a lifetime assessment methodology for HPCs by comparing failure modes and degradation rates seen in lab tests with real operational results. This will be performed by developing models and test suites that simulate the failure modes and degradation rates under a combination of realistic conditions. The suite will be used to test existing coatings in comparison with their actual performance in operational projects as well as the new HPC, resulting in a tool that can be used for lifetime assessment of any future coating.Project Name: High-Temperature Silicon Carbide Composite Receiver Assembly for Liquid Pathway Concentrating Solar Power Operating Above 700° Celsius
Awardee: Ceramic Tubular Products
Location: Lynchburg, Virginia
DOE Award Amount: $1,900,000
Principal Investigator: Farhad Mohammadi
Project Summary: This project team is developing silicon carbide composite receiver tubes for molten chloride salt and liquid sodium receivers in CSP plants. The tubes have thermomechanical properties and corrosion resistance that are superior to metal alloys at high temperatures. As a result, the lifetimes of these tubes could increase, enhancing CSP system performance.Project Name: Improving Economics of Gen3 CSP System Components through Fabrication and Application of High-Temperature Nickel-Based Alloys
Awardee: Electric Power Research Institute
Location: Palo Alto, California
DOE Award Amount: $1,500,000
Principal Investigator: John Shingledecker
Project Summary: In order to reduce high-temperature concentrating solar thermal power plant costs, this team is investigating manufacturing methods for alloys that had previously been designed for high-temperature power service in advanced ultra-supercritical steam. They will examine the cost and performance advantages of manufacturing pipes and tubes from flat sheets after further processing, which can lower capital costs. If these alternate manufacturing routes of alloys can produce pipes that are able to maintain operating lifetimes similar to piping produced from other nickel-based alloys, they have the potential to reduce the cost of these components by about 30 percent.Project Name: Innovative Method for Welding in Generation 3 CSP to Enable Reliable Manufacturing of Solar Receivers to Withstand Daily Cycling at Temperatures Above 700°C
Awardee: Electric Power Research Institute
Location: Charlotte, North Carolina
DOE Award Amount: $300,000
Principal Investigator: John Shingledecker
Project Summary: This project seeks to rapidly develop an innovative method to improve material, welding, and design specification guidance for Inconel® Alloy 740H® to avoid stress relaxation cracking in Generation 3 concentrating solar-thermal power receivers. Inconel 740H is a newly developed, high-performance superalloy that has the strength at high temperatures required for Gen3 CSP applications, but does not have well-developed manufacturing and fabrication specifications. The work done by this team will accelerate the ability of plant designers to use this promising alloy.Project Name: Advanced Characterization of Particulate Flows for Concentrating Solar Power Applications
Awardee: Georgia Institute of Technology
Location: Atlanta, Georgia
DOE Award Amount: $1,352,195
Principal Investigator: Peter Loutzenhiser
Project Summary: This project addresses a knowledge gap within the field of particulate flows for CSP applications. The team will characterize the flow and heat transfer of particulate media over a range of operating conditions, including temperature, particle size, and construction material. Through experimentation and modeling, the team will determine the properties needed for inputs at these high temperatures. These results will provide guidance to the CSP industry for ongoing work related to the design and modeling of solar particle heat receivers and reactors.Project Name: Thermophysical Property Measurements of Heat Transfer Media and Containment Materials
Awardee: Georgia Institute of Technology
Location: Atlanta, Georgia
DOE Award Amount: $1,966,440
Principal Investigator: Shannon Yee
Project Summary: This project researches and analyzes the thermophysical properties supporting the Gen3 integrated thermal system. This team will look at thermal conductivity, thermal diffusivity, and specific heat across the range of temperatures and materials of interest to Gen3 CSP systems. The team will perform measurements on molten salt chemistries, as well as containment materials that include alloy, ceramic, and cermet materials. This research will be shared to address the knowledge gap in Gen3 thermophysical properties.Project Name: 3D Printing of Solar Absorber Tube with Internal/External Structures for Heat Transfer Enhancement and Temperature Leveling using Additive Manufacturing Technology
Awardee: Mississippi State University
Location: Starkville, Mississippi
DOE Award Amount: $240,000
Principal Investigator: Ben Xu
Project Summary: This project team plans to prevent heat damage in solar absorber tubes used in high-temperature concentrating solar-thermal power systems. The team will 3D-print the absorber tube with its internal structures (fins) and external surface textures while optimizing fin shapes and surface patterns. These improvements could triple heat-transfer performance and prevent pressure loss. The goal is to double the lifespan of absorber tubes compared with conventional systems and decrease the manufacturing, operations, and maintenance costs by 50%.Project Name: Efficient Thermal Energy Storage with Radial Flow in Packed Beds
Awardee: Montana State University
Location: Bozeman, Montana
DOE Award Amount: $180,000
Principal Investigator: Ryan Anderson
Project Summary: The efficiency of packed-bed thermal energy storage systems will be significantly improved by flowing gas through the bed radially instead of axially, which is the more common method. Traditional axial flow methods cause heat to disperse, lowering system efficiency. Radial flow overcomes this limitation. The team will design, fabricate, test, and model several radial flow designs for charging and discharging in a lab-scale facility. The project will determine if this approach can increase exergetic efficiency and reduce pressure drop in concentrating solar-thermal power systems.Project Name: Electrochemical Control for Corrosion in Molten Chlorides During CSP Plant Operation
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $500,000
Principal Investigator: Kerry Rippy
Project Summary: Due to their high thermal stability and low-cost, molten chloride salts are a promising heat-transfer fluids for concentrating solar-thermal power plants. However, associated corrosion concerns must be addressed. This project focuses on designing electrochemical methods and reactors for controlling and mitigating identified corrosion mechanisms expected during plant operation. Through redox control mechanisms, the team uses electrochemical elimination of corrosive impurities formed by salt hydrolysis in the presence of oxygen or water. If galvanic coupling occurs, the team plans to use cathodic protection of dissimilar alloys. These approaches aim to keep corrosion to less than 20 microns per year.Project Name: Environmental Design of Cost-Effective, High-Temperature, Sensible Thermal Energy Storage Using Industrial Byproducts
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $1,700,000
Principal Investigator: Youyang Zhao
Project Summary: This project is designing a cost-effective structure for thermal energy storage (TES) tanks using composite concrete instead of metals to help achieve the TES cost target of $15 per kilowatt-hour thermal. The team will also improve the mechanical strength and thermal stability of the tanks’ internal insulation materials by creating a new composite ceramic material with cenospheres—small, lightweight, hollow balls of silica or alumina that are filled with gas—added to prevent salt from seeping in.Project Name: Failure Analysis for Molten Salt Thermal Energy Storage Tanks for In-Service CSP Plants
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $570,000
Principal Investigator: Julian Osorio
Project Summary: This project addresses mechanical failure mechanisms in molten salt TES tanks for in-service CSP plants. The team will conduct simulations on a commercial hot tank design to evaluate low-cycle thermal fatigue, stress distribution, and lifetime as a function of plant operation conditions. Based on the simulation results, the team will identify regions in the tank system susceptible to failure and will perform data analysis to develop failure probability criteria and/or correlation charts. This will allow tank manufacturers to enhance their designs and CSP plant operators to determine safe plant operation conditions, avoiding excessive stresses that may lead to failure. This work will lead to recommendations in design, manufacturing, materials, and plant operation conditions for existing TES tanks that allow for effective detection and monitoring of potential failures.Project Name: Mechanical Failure Risk Management for In-Service CSP Nitrate Hot Tanks
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $430,000
Principal Investigator: Judith Vidal
Project Summary: The thermal energy storage tanks that store molten salt in CSP plants are susceptible to stress cracking without post-weld heat treatment. This project aims to reduce residual stresses with two heat-treatment methods: a ceramic pad heater and induction heating. The goal is to improve reliability of 347H stainless-steel tanks by optimizing cost-effective procedures while evaluating whether the post-weld heat treatments can be used for commercial applications. Researchers will use phased-array ultrasonic testing to determine the detection limits of defects and cracks and compare the detectable defects before and after the heat treatments.Project Name: Thermomechanical Behavior of Advanced Manufactured Parts, Subcomponents, and Their Weldments for Gen3 CSP
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $2,000,000
Principal Investigator: Judith Vidal
Project Summary: This project is developing strategies to prevent cracking of welded pipe and other components that would be in contact with molten chlorides in Generation 3 concentrating solar power (Gen3 CSP) systems. The team will explore advanced manufacturing techniques for heat exchangers and solar receivers, as well as dissimilar-alloy cladding, or metal coating bonded to a metal core, for pipes. This will extend the lifetime of CSP components and plants.Project Name: Development of Advanced Diagnostic Tools, Models, and Technoeconomic Analyses for High-Heat-Transfer Coefficient Particle Heat Exchangers
Awardee: Princeton University
Location: Princeton, New Jersey
DOE Award Amount: $300,000
Principal Investigator: Kelsey Hatzell
Project Summary: In next-general CSP systems, moving packed-bed heat exchangers are promising due to their relatively simple design and operation, especially relative to fluidized heat exchanger designs, which require costly fluidization infrastructure. Parallel plates in the heat exchanger enable a consistent flow of particles, but their design makes it difficult to achieve high-heat-transfer coefficients. Operating conditions, channel design, and particle selection require advanced designs, diagnostics, modeling, and technoeconomic analyses. This project is developing advanced diagnostic and metrology techniques to help develop advanced heat exchanger designs for Generation 3 CSP systems.Project Name: Development of In-Situ Corrosion Kinetics and Salt Property Measurements
Awardee: Rensselaer Polytechnic Institute
Location: Troy, New York
DOE Award Amount: $1,799,892
Principal Investigator: Li (Emily) Liu
Project Summary: This project is developing in-situ experimental techniques and methodologies to gain a fundamental understanding of the mechanisms of molten-salt surface corrosion kinetics and molten-salt properties. Four complementary approaches will be developed to achieve these objectives: in-situ transmission electron microscopy; neutron reflectometry of molten salt and alloy cells; macroscopic electrochemical studies; and vibrational spectroscopy analysis and modeling. By addressing the knowledge gaps in high-temperature molten-salt properties and corrosion mechanisms, this research can guide the selection of salts and containment materials.Project Name: Development and Full Load Demonstration of a 1,000° Celsius Solid Particle Receiver for Concentrating Solar Power Applications
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $750,000
Principal Investigator: Hendrik Laubscher
Project Summary: The German Aerospace Center’s advanced particle receiver concept, an inclined rotating drum in which concentrated sunlight heats particles, is being tested at Sandia’s National Solar Thermal Test Facility at temperatures above 800° Celsius, heat-throughput levels greater than 5 megawatts, and solar-concentration ratios greater than 1,000 suns. Heliogen is a commercialization partner for this project.Project Name: Extreme Intensity Concentrating Solar Heat Flux Sensor Development and Calibration
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $1,200,000
Principal Investigator: Henk Laubscher
Project Summary: This project is developing a high-intensity flux sensor for CSP that is cost effective and can be purchased with relatively short lead times. The sensor will also have shorter response times and longer exposure times when compared to state-of-the-art commercial sensors. A calibration facility will also be developed to regulate the flux sensors. Without accurate flux measurements, especially at high intensities, proper CSP-related research is not possible.Project Name: High-Temperature Freeze and Leak Resistant Advanced Salt Valve
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $2,000,000
Principal Investigator: Kenneth Armijo
Project Summary: This project team is developing a robust molten salt valve that can mitigate leaking and freezing in operating temperatures up to 750° Celsius in concentrating solar-thermal power plants. The design will use passive and active heat management strategies suitable to different valve types. This will ensure long-term valve operation at high temperatures, promote a 30-year system lifetime, and reduce operation and management burdens due to freezing and downtime.Project Name: Non-Contact Thermophysical Characterization of Solids and Fluids for Concentrating Solar Power
Awardee: University of California, San Diego
Location: La Jolla, California
DOE Award Amount: $1,180,000
Principal Investigator: Renkun Chen
Project Summary: This team is developing a non-contact characterization technique called modulated photothermal radiometry (MPR). The technique will measure the high-temperature thermophysical properties of heat transfer fluids and the associated solids, like tubing and solar absorbing coating, in various components and sub-systems used in concentrating solar power (CSP) plants. The MPR technology can provide low-cost and fast characterization of heat transfer fluids and solids for Gen3 CSP facilities.Project Name: Carbonized Microvascular Composites for Gas Receivers
Awardee: University of Tulsa
Location: Tulsa, Oklahoma
DOE Award Amount: $1,277,345
Principal Investigator: Michael Keller
Project Summary: This project is developing and characterizing a novel material and fabrication method that can be used in advanced concentrating solar-thermal power receivers. To enhance the transfer of thermal energy from the sun into the heat transfer fluid, the team will create a polymer-fiber composite that integrates microchannels within the material to form a lightweight, highly absorptive material. The team will form channels within a composite material and then add carbon to it to create a mechanically robust carbon-carbon composite that has an absorptivity of 95-96% without the application of an additional coating. Compared to steal or nickel alloy receiver systems, the proposed system could lower manufacturing costs, increase higher heat transfer efficiency, and provide mechanical reliability at temperatures well above 700° Celsius.Project Name: Durable and Low-Cost Fractal Structured Multifunctional Coatings for Next Generation CSP
Awardee: Virginia Polytechnic Institute and State University (Virginia Tech)
Location: Blacksburg, Virginia
DOE Award Amount: $399,991
Principal Investigator: Ranga Pitchumani
Project Summary: This project team is developing fractal-textured barrier coatings for conventional, low-cost alloys like stainless steel to protect against corrosion from supercritical carbon dioxide, molten chloride, and carbonate salts used in CSP plants. Multi-scaled, fractal textured surfaces can be fabricated directly on the underlying material using a process called electrodeposition, helping to create a robust and durable coating that preserves the thermal properties of the substrate. The textured surfaces of the coating will prevent wetting of the corrosive fluids with the surface, leading to a lower power requirement to pump fluids, less corrosion and wear, and reduced heat loss. This will help to increase the overall efficiency and lifetime of a CSP plant.Project Name: Fractal Nanostructured Solar Selective Surfaces For Next Generation Concentrating Solar Power
Awardee: Virginia Polytechnic Institute and State University (Virginia Tech)
Location: Blacksburg, Virginia
DOE Award Amount: $903,045
Principal Investigator: Ranga Pitchumani
Project Summary: This project aims to increase the thermal efficiency of solar receivers by fabricating multiscale fractal nano- and micro-structured high-temperature coatings that can be applied to the receiver in a concentrating solar-thermal power system. Called a selective solar surface, this multiscale surface has texturing, which could enable the coating to enhance light trapping in the solar receiver, improve energy absorption, and eliminate the need for anti-reflection coatings. The team seeks to develop durable solar selective surfaces that enable absorption efficiency rates greater than 90% at temperatures higher than 750° Celsius, and with a degradation rate of less than 0.2% per 1,000 hours.Project Name: Gen3 Gas-Phase System Development and Demonstration
Awardee: Brayton Energy
Location: Hampton, New Hampshire
DOE Award Amount: $8,500,000
Principal Investigator: Shaun Sullivan
Project Summary: In this project, a commercial-scale gas-phase CSP system will be developed in the first two Gen3 phases and, if selected for the third phase, developed into a test facility. The megawatt-scale test system will absorb energy from a heliostat field and deliver it into a thermal energy storage system, storing nine megawatt-hours of heat at a temperature of 750 °C for a minimum of 10 hours. The energy then moves into a working fluid that could have a round-trip efficiency of 99 percent, creating a CSP solution that enables on-demand renewable energy.Project Name: Development, Build and Operation of a Full-Scale, Nominally 5MWe, Supercritical CO2 Power Cycle Coupled with Solid Media Energy Storage
Awardee: Heliogen
Location: Pasadena, California
DOE Award Amount: $39,000,000
Principal Investigator: Chranjeev Kalra
Project Summary: This project is working to develop, build, and operate a supercritical carbon dioxide (sCO2) power cycle integrated with thermal energy storage, heated by a concentrated solar thermal energy supplied by a newly built heliostat field. This plant will operate as a demonstration of a sCO2 power cycle, integrated with thermal energy storage (TES), at a turbine inlet temperature of 600°C to be able to use conventional stainless steel alloys widely available today. This project will generate real operational data of a TES-driven sCO2 power cycle, to enable commercial adoption of this novel technology.Project Name: CSP Systems Analysis
Lab: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $2,250,000
Principal Investigator: Chad Augustine
Project Summary: This project estimates CSP system performance, including emerging systems that may not yet be well defined. The work also includes upgrading the National Renewable Energy Laboratory System Advisor Model (SAM) related to CSP, as well as developing new modules within SAM to expand the types of CSP systems that can be simulated. Tracking CSP costs and performance using a consistent method is required to achieve the cost targets of the Solar Energy Technologies Office and provide strategic guidance to DOE.Project Name: Liquid-Phase Pathway to SunShot
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $7,035,309
Principal Investigator: Craig Turchi
Project Summary: This team will test the next generation of liquid-phase concentrating solar thermal power technology by advancing the current molten-salt power tower pathway to higher temperatures and efficiencies. The project will design, develop, and test a two megawatt thermal system consisting of the solar receiver, thermal energy storage tanks and associated pumps, heat exchangers, piping, valves, sensors, and heat tracing. If selected for the third phase, the system will be validated in a commercial-scale test facility.Project Name: Pumped Thermal Energy Storage Using Low-Cost Particles and a Fluidized Bed Heat Exchanger for Maximum Power Efficiency (PUMP)
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $2,000,000
Principal Investigator: Zhiwen Ma
Project Summary: This project combines particle TES with pumped thermal energy storage (PTES) technology to improve power cycle efficiency by 5–10% and reduce costs by more than 50% compared to molten-salt PTES. The team will integrate particle TES and PTES in a stand-alone configuration and a configuration hybridized with CSP, develop a direct-contact pressurized fluidized bed heat exchanger for charging and discharging, investigate incorporation of PTES turbomachinery and cycle optimization, develop system and component modeling tools, and conduct technoeconomic analysis.Project Name: Behind-the-Meter, Distributed-Scale CSP System Enabled by Very Low-cost Working Fluid and Thermal Storage
Awardee: Norwich Technologies
Location: White River Junction, Vermont
DOE Award Amount: $1,300,000
Principal Investigator: Troy McBride
Project Summary: This project team is developing a small-scale concentrating solar power system incorporating a long-duration, low-cost storage system that will create a solar system capable of round-the-clock operation.Project Name: Enabling High-Temperature Molten Salt CSP through the Facility to Alleviate Salt Technology Risks
Awardee: Oak Ridge National Laboratory
Location: Oak Ridge, Tennessee
DOE Award Amount: $4,300,000
Principal Investigator: Kevin Robb
Project Summary: This project focuses on the design, construction, and operation of a lab-scale test facility to alleviate salt technology risks (FASTR). FASTR is a versatile high-temperature molten chloride salt facility designed for temperatures greater than 700°C and for a variety of testing in support of the Gen3 CSP molten salt pathway. FASTR and the accompanying research will provide the foundational capabilities necessary to support Gen3 CSP awardees.Project Name: Advanced Materials for Concentrating Solar Power Molten Salt Storage
Awardee: Powdermet
Location: Euclid, Ohio
DOE Award Amount: $1,350,000
Principal Investigator: Brian Werry
Project Summary: This project is working to demonstrate suitable construction materials that enable the cost-effective, reliable building of high-efficiency concentrating solar power thermal energy storage systems, which are among the most scalable and efficient methods to store renewable energy.Project Name: Gen3 Particle Pilot Plant: Integrated High-Temperature Particle System for CSP
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $35,000,000
Principal Investigator: Clifford Ho
Project Summary: This project is designing and testing a multi-megawatt thermal falling particle receiver CSP system in the first two Gen3 CSP phases. It will have the potential to operate for thousands of hours, provide six hours of energy storage, and heat a working fluid like supercritical carbon dioxide or air to a temperature of at least 700 °C. In Phase 3, if selected, the team will validate the ability to meet the Solar Energy Technologies Office CSP cost and performance goals via a commercial-scale test facility. This project was selected to enter Phase 3 and will build out a megawatt-scale pilot facility.Project Name: High-Temperature Particle/Supercritical Carbon Dioxide Test Loop for Accelerated Heat Exchanger Performance Testing
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $750,000
Principal Investigator: Kevin Albrecht
Project Summary: This project expands upon earlier SETO-funded research to improve particle-to-supercritical carbon dioxide (sCO2) heat exchangers. Researchers plan to conduct performance evaluation and control studies of particle heat exchanger technology at higher temperatures. They will use data from the previous project to test heat exchanger performance, including the design, construction, system integration, and manufacturing technique of a moving packed-bed particle/sCO2 heat exchanger. This project will address underlying performance issues through a controlled testing environment. A 20 kilowatt-thermal particle-to-sCO2 heat exchanger testing platform is available to test future novel concepts.Project Name: DOE’s National Solar-Thermal Test Facility Operations and Maintenance
Lab: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $3,000,000
Principal Investigator: Francisco Alvarez
Project Summary: The National Solar-Thermal Test Facility operated by Sandia National Laboratories is the only large-scale CSP research and test facility in the United States. It provides established test platforms and researchers and technologists experienced in the CSP field on staff for assistance. This project will support the operations and maintenance needed to provide a safe, fully operational facility with testing capabilities that support DOE CSP awardees as they work to achieve the CSP cost goals of the Solar Energy Technologies Office.Project Name: National Solar Thermal Test Facility Voucher
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $1,000,000
Principal Investigator: Jeremy Sment
Project Summary: This project supports Sandia National Laboratories in its administration of a voucher program for participants to use the world class facilities and expertise available at the National Solar Thermal Test Facility (NSTTF). The NSTTF offers analysis, design and testing capabilities to accelerate the advancement of CSP technologies. This includes optics (heliostats, dishes, metrology), control systems, high temperature receivers, heat exchangers including sCO2 loops, balance of plant systems, heat transfer fluids/media, heat flux measurements, solar-thermal chemistry including water splitting, thermochemical energy storage, and commodity chemical processes. The applicants of the voucher program are responsible for their own costs in the partnership. Work is funded in increments of one year or less.Project Name: Optimization of Parabolic Trough Operations & Maintenance (OPTOM)
Awardee: Solar Dynamics
Location: Broomfield, Colorado
DOE Award Amount: $300,000
Principal Investigator: Henry Price
Project Summary: This project is developing a suite of tools to help optimize the operation and maintenance (O&M) of CSP solar fields. The backbone of the system is a cloud-based data platform that will allow the tools to share information. A custom computerized maintenance management system (CMMS) enables tracking of corrective, preventive, and predictive maintenance for collectors, heliostats, and heliostat components. The system will tie in with drone-based solar field monitoring and machine learning to automate the identification of component issues. The system will integrate data analytics to help optimize O&M decisions and include a reporting capability so that data can be synthesized and summarized to optimize O&M resources.Project Name: Learned Productivity Under Variable Solar Conditions
Awardee: University of Wisconsin
Location: Madison, Wisconsin
DOE Award Amount: $750,000
Principal Investigator: Michael Wagner
Project Summary: This project leverages artificial intelligence and machine learning techniques to model a number of CSP plant operations in order to assist human operators in their decisions, especially during variable cloudiness conditions. The machine learning techniques will be applied to extensive, high-resolution, inferred DNI data, cloud profile and vector data, and related solar field thermal collection data in order to develop prescriptive models to optimize solar field collection under variable conditions while minimizing long-term receiver damage and other negative effects. The project will validate the method at an operating CSP facility and publish methodological details for broader use.Project Name: Development and Demonstration of Ceramics Based Moving Bed Particle-to-Supercritical Carbon Dioxide Heat Exchanger for Operation at Temperatures Higher than 750°C
Awardee: Argonne National Laboratory
Location: Lemont, Illinois
DOE Award Amount: $2,050,000
Principal Investigator: Dileep Singh
Project Summary: Silicon carbide (SiC) and its composites are attractive materials for CSP thermal applications because they have excellent stability at temperatures up to 1400ºC. They are also suitable for the use in packed-bed, particle-based heat exchangers. This project aims to leverage SiC materials and additive manufacturing in order to reduce the overall manufacturing costs and meet SETO cost targets for CSP. The prototypes under development will be validated at temperatures higher than 750ºC using particles and supercritical carbon dioxide as the working fluids at Sandia National Laboratories’ test facility.Project Name: Low-Cost, High-Temperature Ceramic Heat Exchangers
Awardee: Argonne National Laboratory
Location: Lemont, Illinois
DOE Award Amount: $2,385,000
Principal Investigator: Dileep Singh
Project Summary: As CSP systems move to power cycles with temperatures greater than 700° Celsius, high-temperature metallic alloys become prone to degradation from corrosion and/or oxidation, which can increase costs. This project will use high-temperature, low-cost ceramic materials with new designs and 3D printing to develop ceramic heat exchangers. Ceramic system components can potentially reduce corrosion issues created by molten salt heat-transfer fluids and oxidation from gas phases. As a result, high-performance, high-reliability ceramic heat exchangers could provide a cost-effective pathway for operating CSP systems at elevated temperatures and enhance overall system efficiency.Project Name: 740H Diffusion Bonded Compact Heat Exchanger for High Temperature and Pressure Applications
Awardee: CompRex
Location: De Pere, Wisconsin
DOE Award Amount: $1,242,525
Principal Investigator: Zhijun Jia
Project Summary: There is growing demand for high-temperature, high-pressure heat exchangers that can meet the stressful operating requirements of novel supercritical carbon dioxide Brayton cycles systems in a way that’s cost-effective at commercial scale. CompRex has developed a heat exchanger design using 740H, a new alloy that can endure significantly higher stress at temperatures over 700° Celsius, making it ideal for use with supercritical carbon dioxide cycles. In collaboration with Special Metals, the University of Wisconsin-Madison, and Advanced Vacuum Systems, CompRex seeks to develop a manufacturing process for producing 740H printed circuit heat exchangers using its proprietary ShimRex® flow path design. This design will address the challenges that the material poses in etching and diffusion bonding that prevent the cost-effective manufacturing of 740H heat exchangers.Project Name: Advanced Compressors for CO2-Based Power Cycles and Energy Storage Systems
Awardee: Echogen Power Systems
Location: Akron, Ohio
DOE Award Amount: $4.4 million
Principal Investigator: Timothy Held
Project Summary: This project is developing a large-scale, low-cost, single-shaft compressor for supercritical carbon dioxide (sCO2) power cycles and energy storage systems to improve the performance of concentrating solar-thermal power systems. Conventional systems have multiple shafts but lower mechanical efficiency and higher costs. The team will build and test a prototype at the University of Notre Dame’s test facility.Project Name: Additively Manufacturing Recuperators via Direct Metal Laser Melting and Binder Jet Technology
Awardee: GE Global Research
Location: Niskayuna, New York
DOE Award Amount: $1,400,000
Principal Investigator: William Gerstler
Project Summary: This team is developing additive manufacturing processes for the heat exchangers used in supercritical carbon dioxide (sCO2) power cycles in concentrating solar-thermal power plants. To overcome the expensive manufacturing process for heat exchangers, the team will use binder jet printing, a type of additive manufacturing, to significantly lower costs and enable new heat exchanger geometries, such as 3D channels, and curved features not accessible using traditional fabrication processes. The team will then evaluate the new process and determine if it’s capable of producing CSP compatible power cycles that cost $900 per kilowatt or less. The team will also perform mechanical tests to ensure that the resulting heat exchangers can withstand the high operating temperatures and pressures of the sCO2 power cycle. The team will also create a risk reduction plan for scaling the heat exchanger design from lab-scale to a full-scale, including, a modular design.Project Name: Near-Net-Shape Hot Isostatic Press Manufacturing Modality for sCO2 CSP Capital Cost Reduction
Awardee: GE Global Research
Location: Niskayuna, New York
DOE Award Amount: $2,500,000
Project Summary: GE Research is fabricating advanced super critical carbon dioxide (sCO2) power cycle structures for CSP plants from metal powders by pressing these powders at high temperatures. This process is estimated to reduce the manufacturing cost of these components by at least half and lower equipment costs. This will enable a U.S.-based supply chain and strengthens the nation’s role in advanced manufacturing and high-efficiency power generation.Project Name: Reduced Levelized Cost of Energy in CSP Through Utilizing Process Gas Lubricated Bearings in Oil-Free Drivetrains
Awardee: GE Global Research
Location: Niskayuna, New York
DOE Award Amount: $2,373,442
Principal Investigator: Jason Mortzheim
Project Summary: This project is de-risking a novel bearing design for the turbines used in CSP plants with sCO2 power cycles. The bearing is a critical component that ensures the turbine, which converts heat into mechanical energy, performs reliably and at a high efficiency level. The turbine is the greatest single contributor to the sCO2 cycle’s efficiency. These bearings must be durable and able to withstand the high temperatures and pressures associated with next generation sCO2 power cycles. The team will then perform mechanical tests and simulate rotor tests in order to optimize the design for CSP plants that provide consistent baseload power or operate as a rapidly-responding peaker plant. The team will perform technoeconomic analysis to determine if the design can achieve a 50% efficient power cycle in order to lower costs to $.05 per kilowatt-hour.Project Name: Ultra-High-Temperature Ceramic Triply Periodic Minimal Surface (UHTC-TPMS) Heat Exchangers for Concentrated Solar Power Applications with Thermal Energy Storage in Molten Chlorides
Awardee: Lawrence Livermore National Laboratory
Location: Livermore, California
DOE Award Amount: $1,500,000
Principal Investigator: James Kelly
Project Summary: This project is developing an ultra-high-temperature ceramic (UHTC) heat exchanger based on triply periodic minimal surface (TPMS) geometries. TPMS geometries are symmetric crystallographic structures that are observed in nature, architectural design and art. Some UHTC materials have excellent molten chloride corrosion resistance at temperatures up to 800 ºC and can potentially double heat exchanger power density compared to nickel superalloys. UHTC heat exchangers could also double as a resistive heating element to convert excess electricity back into thermal energy to further improve efficiency. TPMS geometries require additive manufacturing methods and can provide 10 to 100 times higher heat transfer capability compared to tube or plate heat exchangers.Project Name: Enhancing Particle-to-sCO2 Heat Exchanger Effectiveness Through Novel High-Porosity Metallic Foams
Awardee: Mississippi State University
Location: Starkville, Mississippi
DOE Award Amount: $300,000
Principal Investigator: Prashant Singh
Project Summary: This project team aims to increase the effectiveness of particle-to–supercritical carbon dioxide (sCO2) heat exchangers by packing the particle-side channels with high-porosity cellular structures. The goal is to increase the interstitial heat-transfer coefficient between moving particles and metallic fibers, and the effective thermal conductivity of particle channel. The approach includes metal additive manufacturing of small length-scale fibers with complex three-dimensional interconnections. The team will use Sandia National Laboratories’ sCO2-particle heat exchanger model design and flow loop to optimize, test, and eventually scale the technologies.Project Name: Metal-to-Ceramic Joining Methods to Support Development of Advanced Ceramic-Based CSP Components
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $2,000,000
Principal Investigator: Youyang Zhao
Project Summary: This project is designing, developing, and testing a macroscopic ceramic-metal structural composite material with an axially graded chemical composition, which means its composition varies along its axial direction This material will be used to achieve a ceramic-to-metal joint between the metal loop material and a candidate ceramic component material used by the Gen3 CSP technology pathway. Due to the axial gradation of the chemical composition, the joint interface between the ceramic and metal will have similar properties, enabling better reliability and performance under thermal stress.Project Name: Vertically Aligned Carbon Nanotube Arrays as Novel, Self-Lubricating, High-Efficiency Brush Seal for CSP Turbomachinery
Awardee: Oak Ridge National Laboratory
Location: Oak Ridge, Tennessee
DOE Award Amount: $1,400,000
Principal Investigator: Jun Qu
Project Summary: In advanced turbines for CSP plants that use supercritical carbon dioxide as a working fluid, metal brush seals prevent internal energy leakage, but this project will develop a new scalable seal brush on a flexible base that will improve the seal’s efficiency and durability. The seal will be made of a vertically aligned carbon nanotube array and use a chemical vapor deposition process without a catalyst. The project aims to improve turbine efficiency and reduce the manufacturing cost by at least half.Project Name: Solid-Phase Additive Manufacturing of Oxide Dispersion Strengthened-Iron-Chromium-Aluminum Alloy Components for High-Temperature Supercritical Carbon Dioxide Power Cycle Applications
Awardee: Pacific Northwest National Laboratory
Location: Richland, Washington
DOE Award Amount: $615,000
Principal Investigator: Saumyadeep Jana
Project Summary: This project team is developing a sintering-based, solid-phase, additive manufacturing method to make heat exchanger components—including recuperators, heaters, and microturbines—for sCO2 Brayton power cycles in Generation 3 concentrating solar-thermal power plants. The team will use strong iron-chromium-aluminum (FeCrAl) alloy powders to make the components, which cost about eight times less than nickel-based alloys. This project could reduce the cost of compact heat-exchanger components by more than 40%.Project Name: Oxidation-Resistant, Thermomechanically Robust Ceramic-Composite Heat Exchangers
Awardee: Purdue University
Location: West Lafayette, Indiana
DOE Award Amount: $3,500,000
Principal Investigator: Kenneth Sandhage
Project Summary: This project team is developing cost-efficient ceramic-composite primary heat exchangers that are highly resistant to corrosion by supercritical carbon dioxide and molten salt and will not deform or fracture at temperatures as high as 800° Celsius. These heat exchangers will last longer than conventional ones and improve the efficiency and lifetime of concentrating solar-thermal power plants.Project Name: Compact Counterflow Fluidized-Bed Particle Heat Exchanger
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $2,000,000
Principal Investigator: Clifford Ho
Project Summary: This project is designing and testing an alternative compact counterflow fluidized-bed particle heat exchanger in order to reduce the levelized cost of energy and levelized cost of storage for electrical grid and process-heat applications. In a counterflow heat exchanger, the direction of flow of the working fluids are opposite to each other. This enables lower observed stresses and a more uniform rate of heat transfer when compared to parallel flow heat exchangers. Moving-packed bed heat exchangers have historically been expensive to manufacture and the desired performance requires very small plate or tube spacing, which may cause flowability issues at high temperatures. The project team will work with Babcock & Wilcox and TU Wien to develop and design the new technology.Project Name: Evaluating Microchannel Heat Exchanger Lifetime for Concentrating Solar Power Applications
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $2,590,000
Principal Investigator: Kevin Albrecht
Project Summary: This project investigates microchannel heat exchanger technology for next-generation CSP concepts. The economics of these plants depends on heat exchangers with 30-year lifetimes and operational characteristics like fast ramping and the ability to withstand thermal shock. However, the lifetime and operational limits of microchannel heat exchangers, particularly those constructed from high-nickel alloys, are not well known. The project team will evaluate these limits for the manufacturing and prototype design for next-generation CSP heat exchanger technology by collecting experimental data and modeling studies.Project Name: Development of a High-Efficiency Hybrid Dry Cooler System for sCO2 Power Cycles in CSP Applications
Awardee: Southwest Research Institute
Location: San Antonio, Texas
DOE Award Amount: $1,550,000
Principal Investigator: Tim Allison
Project Summary: This project aims to develop a compact dry cooling heat exchanger for sCO2 power cycles in CSP plants. Dry cooling drastically reduces the water used by power plants. However, it can reduce the thermal-to-electric conversion efficiency of the power cycle. An efficient heat exchange between sCO2 and ambient air can both conserve water while maintaining peak power cycle performance. The team will create and optimize a dry cooling heat exchanger with microchannels on the sCO2 side and a geometry that uses plates and finned chambers on the air side. The team will test the dry cooling system at the megawatt-scale with an sCO2 test loop, in order to determine the reliability of the fabrication method, validate the performance of the heat exchanger geometry, and show that the new dry cooling concept is compatible with an efficient CSP plant. These improvements could reduce the cooler cost from $168 per kilowatt to $95 per kilowatt and reduce cooling power consumption in CSP plants by 14%.Project Name: High-Temperature Dry-Gas Seal Development and Testing for sCO2 Power Cycle Turbomachinery
Awardee: Southwest Research Institute
Location: San Antonio, Texas
DOE Award Amount: $2,000,000
Principal Investigator: Jason Wilkes
Project Summary: CSP plants with sCO2 power cycles requires a mechanical seal to prevent working fluid leaks and support efficient operations. The increased temperatures and pressures of the sCO2 power cycle requires a novel seal design to support a target thermal-to-electric power conversion efficiency of 50%. This project is developing a high-temperature dry gas seal (DGS) by replacing the temperature sensitive elements with more durable components, enabling the DGS to reach operating temperatures over 500° Celsius and enable the higher efficiency levels. Because the DGS design would also be significantly smaller in size, the DGS would reduce the complexity of the sCO2 turbine design, helping to increase operation reliability and improve turbine efficiency.Project Name: Narrow-Channel, Fluidized Beds for Effective Particle Thermal Energy Transport and Storage
Awardee: Colorado School of Mines
Location: Golden, Colorado
DOE Award Amount: $1,858,170
Principal Investigator: Gregory Jackson
Project Summary: Using particles to replace the heat transfer fluid in a CSP system may be the simplest way to increase the operation temperature and therefore increase the power cycle efficiency of a CSP plant. Colorado School of Mines is working with Sandia National Laboratories and Carbo Ceramics to develop and test a narrow-channel, counterflow fluidized bed receiver and heat exchanger designs. These will be used to analyze flow conditions and improve heat transfer rates in the receiver and heat exchanger. The team will then use these insights to test a modular panel for an indirect particle receiver and/or particle to supercritical carbon dioxide power cycle heat exchanger. The program will deliver detailed multiphase flow modeling tools to assess how receiver and heat exchanger designs can meet receiver cost targets of $150 per kilowatt hours of heat and thermal-energy system targets of $15 per kilowatt hours of heat.Project Name: Additively Manufactured Molten Salt-to-Supercritical Carbon Dioxide Heat Exchanger
Awardee: University of California, Davis
Location: Davis, California
DOE Award Amount: $2,219,315
Principal Investigator: Vinod Narayanan
Project Summary: This team seeks to develop an additively manufactured, nickel superalloy primary heat exchanger (PHX) for advanced molten salt CSP systems. The PHX will be made using nickel superalloys and laser powder bed 3D printing, resulting in a compact design that is durable under cyclic operation at high temperatures and pressures in a corrosive salt environment. During the first phase of the project, different alloy powders will be fabricated and characterized and then tested, both in conditions representative of Generation 3 CSP systems—720° Celsius and supercritical carbon dioxide pressures of 200 bar—and at conditions relevant to current commercial systems—molten nitrate salt at temperatures up to 550° Celsius. The team aims to validate a thermal model that can predict performance in a chloride salt environment and plans to use this model to develop a 20-kilowatt design to test the mechanical integrity of the fabricated PHX.Project Name: Enabling Robust Compressor Operation under Various sCO2 Conditions at Compressor Inlet
Awardee: University of Central Florida
Location: Orlando, Florida
DOE Award Amount: $300,000
Principal Investigator: Jayanta Kapat
Project Summary: This project team is studying how sCO2 flows in a compressor cascade in a concentrating solar-thermal power system. The main compressor is a key component for any sCO2 power cycle, but rapid variations of properties near the critical temperature and pressure and the proximity of compression conditions to the phase change between supercritical and liquid fluids make the compressor susceptible to unexpected performance or damage. This project team will develop a new design methodology for the compressor’s leading-edge suction surface so that the compressor can work well over a range of ambient conditions, without problems caused by condensation. This effort will identify and quantify condensation at the compressor’s leading edge, and characterize detailed sCO2 flows within the compressor.Project Name: Modular Design of High-Temperature and -Pressure Heat Exchangers Using 3D Printing
Awardee: Utah State University
Location: Logan, Utah
DOE Award Amount: $240,000
Principal Investigator: Hailei Wang
Project Summary: This project team is 3D-printing functionally graded material, which is a composite that changes along with its size, and use the metal powder-bed fusion (PBF) additive-manufacturing process to make low-cost, high-performance nickel-alloy heat exchangers. The high- and low-temperature modules consist of two materials, which the mid-temperature module will bond. To address challenges associated with joining dissimilar materials and achieve high performance, the team plans to print the low-temperature module using PBF, deposit the functionally graded mid-temperature module using direct energy deposition (DED), and finish the high-temperature module using DED.Project Name: Hawaii Solar Desal Project
Awardee: Natural Energy Laboratory of Hawaii Authority
Location: Kailua-Kona, Hawaii
DOE Award Amount: $1,928,238
Principal Investigator: Gregory P. Barbour
Project Summary: This project is advancing the techno-economic viability of solar-powered forward osmosis (FO) by reducing the levelized cost of water (LCOW) 40 percent less than that of current state-of-the-art technology. The team will demonstrate a system that incorporates a concentrating solar thermal collector array delivering heat to a FO system. This system will utilize a new generation of membranes whose energy efficiency and durability will be demonstrated in this project. This system will then be installed and operated at an oceanic facility and the results will be used to scale up to a commercial-sized facility that can achieve the low targeted LCOW.Project Name: High-Efficiency, Zero Liquid Discharge, Multiple-Effect Adsorption Distillation
Awardee: GreenBlu
Location: Hamilton, New Jersey
DOE Award Amount: $1,600,000
Principal Investigator: Dr. Howard Yuh
Project Summary: Adsorption distillation, a technology based on using materials that are able to adsorb large volumes of water vapor, is well-suited for zero liquid discharge applications where the incoming brine or waste water must be completely separated to produce only purified water and solid salt. This team is developing a multistage adsorption water distiller with the ability to use the same adsorbent beds for both a liquid-only distiller to concentrate brine and a liquid-solid crystallizer to generate solid salt by-products, by only altering only the input mechanics.Project Name: Solid-State Solar Thermochemical Fuel for Long-Duration Storage
Awardee: Michigan State University
Location: East Lansing, Michigan
DOE Award Amount: $2,000,000
Project Summary: Michigan State University and partners will develop a low-cost, zero-emission, solid-state fuel that enables energy storage for short or long periods. This environmentally sound fuel can be stored in a bin until it is used to provide low-cost solar energy storage. Since it can be readily scaled up to 100 megawatts, this novel fuel will aim to be economically competitive at long durations and large capacities.Project Name: Pathways to Achieving Pipe Parity for Solar Thermal Desalination of High Salinity Brines
Awardee: National Renewable Energy Laboratory
Location: Golden, Colorado
DOE Award Amount: $2,400,000
Principal Investigator: Parthiv Kurup
Project Summary: Currently, no consistent framework exists for evaluating solar thermal and desalination technologies suited for high-salinity brines. This project is building onto the existing Water-TAP3 tool in order to develop it into an industry standard, a flexible, open-source platform for evaluating solar industrial process heat desalination technologies for high-salinity brines that reverse osmosis cannot effectively treat.Project Name: Zero Liquid Discharge Water Desalination Process using Humidification-Dehumidification in a Thermally Actuated Transport Reactor
Awardee: Oregon State University
Location: Bend, Oregon
DOE Award Amount: $2,000,000
Principal Investigator: Bahman Abbasi
Project Summary: This project is developing a hybrid process to treat high-salinity water with zero liquid discharge. The cost and efficiency of energy consumption are targeted to be competitive with large reverse osmosis desalination plants at a fraction of the capital cost. This will be accomplished by using thermally actuated nozzles—components that operate in response to temperature changes—that are heated with low-grade solar heat. These hot air jets are humidified with brine and the solid particles can be separated out. By condensing the water vapor and recouping the heat, this process will target a highly energy efficient cycle.Project Name: Solar Hydrogen from Water Splitting using Liquid Metal Oxidation/Reduction Cycles Promoted by Electrochemistry
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $3,300,000
Principal Investigator: Anthony McDaniel
Project Summary: This project is developing a solar-powered hydrogen production process based on a stoichiometric, two-step, metal oxide water splitting cycle that combines thermochemical hydrogen production with electrochemical metal oxide reduction. Hybridizing the two-step cycle avoids costly separation processes and ultra-high cycle temperatures, enabling a practical and efficient route to cost-effective solar fuels. This will be accomplished by using molten salt electrolysis to manipulate cycle thermodynamics. Knowledge gained from this project will inform system studies that yield cost projections for large-scale plant construction and operation, from which a credible path towards commercialization can be derived.Project Name: Solar-Thermal Energy Ammonia Production (STEAP)
Awardee: Sandia National Laboratories
Location: Albuquerque, New Mexico
DOE Award Amount: $2,800,000
Principal Investigator: Andrea Ambrosini
Project Summary: This project enables the use of solar-thermal energy to produce ammonia, a common industrial chemical that requires a lot of energy to produce. First, sunlight will activate solid particles in a concentrating solar-thermal power system to isolate nitrogen from air. Then the nitrogen will be activated to form a metal nitride, which can react with hydrogen to generate ammonia. The project team will develop materials that can be reliably and cost-effectively cycled for both the nitrogen separation and ammonia generation steps in the process.Project Name: Low-Cost Buffer Storage for Solar Industrial Steam Applications
Awardee: Sunvapor
Location: Livermore, California
DOE Award Amount: $2,500,000
Principal Investigator: Phillip Gleckman
Project Summary: This project demonstrates how using enormous tanks that normally store liquefied petroleum gas can be used to accumulate and store solar-generated steam—and use that steam for manufacturing processes. This technology should be cost-effective due to the low cost of pressurized water and the ability to operate at temperatures above 100° Celsius. In addition, the project team will size the tanks to achieve a low cost of solar thermal energy storage per gallon, and the solar steam will be able to be used in various industrial applications.Project Name: Energy Where it Matters: Delivering Heat to the Membrane/Water Interface for Enhanced Thermal Desalination
Awardee: University of California, Los Angeles
Location: Los Angeles, California
DOE Award Amount: $1,995,249
Principal Investigator: David Jassby
Project Summary: This project modifies a typical membrane distillation (MD) system by deploying layers of materials with high thermal and electrical conductivity at the membrane/water interface. These conductive materials will be able to deliver solar-thermal energy directly to where it’s needed in the MD system. By directly coupling the membrane surface to a thermal input, this technology has the potential to be substantially more energy efficient than current MD systems.Project Name: Solar-Driven Desalination by Membrane Distillation using Ceramic Membranes
Awardee: Fraunhofer USA Center for Energy Innovation
Location: Storrs, Connecticut
DOE Award Amount: $800,000
Principal Investigator: Jeffrey McCutcheon
Project Summary: This project is developing and testing ceramic membranes for solar-driven membrane distillation (MD) systems for desalination. The challenges that ceramic membranes face for MD applications are mass and heat transfer, wetting, scaling, and fouling. These challenges will be addressed by designing and optimizing membranes at a small scale, and later applying the lessons learned to larger-scale elements that can be used with a solar-thermal test bed.Project Name: Ultra-Compact and Efficient Heat Exchanger for Solar Desalination with Unprecedented Scaling Resistance
Awardee: University of Illinois at Urbana-Champaign
Location: Urbana, Illinois
DOE Award Amount: $1,584,349
Principal Investigator: Anthony Jacobi
Project Summary: This project is designing, developing, and testing novel coatings for heat exchanger surfaces in high-temperature thermal desalination applications, which aim to increase heat exchanger efficiency by 150 percent or more than current state-of-the-art technology. This will help address challenges like fouling and scaling as well as corrosion resistance that occurs at temperatures above 200 °Celsius.Project Name: Low-Cost Desalination Using Nanophotonics-Enhanced Direct Solar Membrane Distillation
Awardee: Rice University
Location: Houston, Texas
DOE Award Amount: $1,700,000
Principal Investigator: Qilin Li
Project Summary: This project is developing and testing a novel solar-thermal desalination process called Nanophotonics-Enabled Solar Membrane Distillation (NESMD), which uses a porous, photothermal membrane to simultaneously convert sunlight to heat and desalinate water by membrane distillation with very high thermal efficiency. The NESMD technology will go through a system-level integration and evaluation at the pilot-scale.