SETO FY2021 – Concentrating Solar-Thermal Power

Dimensional Energy

Project Name: Silicon-Carbide Receiver/Reactor by Additive Manufacturing for Concentrated Solar Thermocatalysis with Thermal Energy Storage
Location: Ithaca, NY
DOE Award Amount: $2.7 million
Cost Share: $700,000
Project Summary: Dimensional Energy is partnering with Heliogen to design, develop, and test a solar-driven chemical reactor produces feedstocks for sustainable jet fuel. The reactor will turn captured carbon dioxide and green hydrogen into feedstocks, with a fuel target price below $2 per gallon. The team will leverage an additively manufactured silicon carbide material that is stable at temperatures greater than 1,000°C to enable this technology. The concept integrates thermal energy storage to enable continuous operation of the reactor.

General Electric Company, GE Research

Project Name: Ultra-High Operating Temperature Silicon-Carbide-Matrix Solar Thermal Air Receivers Enabled by Additive Manufacturing (Ultra-HOTSSTAR)
Location: Niskayuna, NY
DOE Award Amount: $2.6 million
Cost Share: $900,000
Project Summary: The Ultra-HOTSSTAR project applies GE’s high-temperature manufacturing technologies to design volumetric silicon carbide (SiC) receivers to efficiently convert sunlight to thermal energy. SiC enables solar receivers to go beyond the temperature limits of metal alloys and will allow the team to design receivers appropriate for very-high-temperature industrial processes. In collaboration with Heliogen, the team will use 3D-printing to optimize promising designs by improving manufacturability, lowering cost, and validating thermo-mechanical reliability under realistic conditions.

National Renewable Energy Laboratory

Project Name: Light Trapping, Enclosed Planar-Cavity Receiver for Heating Particles to Enable Low-Cost Energy Storage and Chemical Processes
Location: Golden, CO
DOE Award Amount: $3 million
Cost Share: $750,000
Project Summary: This project team will design, develop, and test a 100-kilowatt solar-thermal receiver that will deliver energy to particles at temperatures greater than 700°C. The innovative approach encloses the particles in a nickel-alloy receiver, shaped to “trap the light” by preventing energy from being re-emitted back to the environment. Light trapping will be a key component of the team’s efforts to design a receiver with thermal efficiency above 90%. The team will also use a coating to prevent the receiver structure from overheating, as well as a gas to get particles to behave like a fluid inside the receiver to maximize heat transfer.

Palo Alto Research Center

Project Name: Scalable, Infiltration-Free Ceramic Matrix Composite (CMC) Manufacturing for Molten Salt Receiver  
Location: Palo Alto, CA
DOE Award Amount: $2.5 million
Cost Share: $600,000
Project Summary: This project will develop scalable manufacturing processes for CMCs that will aim to reduce the cost of these high-temperature-stable materials by more than three times below the cost of current commercial products. To achieve this, they will develop production methods that avoid steps that take a long time and use costly materials. This technology will help address the need for scalable, corrosion-resistant receiver materials compatible with high-temperature molten chloride salts.

Texas Tech University

Project Name: Intensified Solar Reactor for Green Ammonia Manufacture and Gen3 Thermochemical Energy Storage
Location: Lubbock, TX
DOE Award Amount: $2 million
Cost Share: $500,000
Project Summary: This project team will develop a solar-thermal system to enable an ammonia synthesis reactor that does not require fossil fuel input. By using a process intensification strategy, the team will design an ammonia reactor that efficiently uses heat throughout the process to drive the ammonia reaction. The ammonia can be used either as part of a closed thermochemical energy storage system, for electricity production, or to produce ammonia as a commodity chemical. In this project, the team will focus on the design and validation of their heat-recovery technology that can enable significantly higher efficiency than previous designs.

University of California, Davis

Project Name: Enabling Micro-pin Array Receivers for Power Generation and High-temperature Process Heating Using Metal Additive Manufacturing: Development, Design, and De-risk
Location: Davis, CA
DOE Award Amount: $4.6 million
Cost Share: $1.2 million
Project Summary: University of California, Davis, partnered with Carnegie Mellon University, Oregon State University, University of Michigan, Utah State University, Sandia National Laboratories, Materials Resources, Sunvapor, Specialty Metal Products, and Ametek, will design, develop, and de-risk a 150-kilowatt solar-thermal receiver able to heat supercritical carbon dioxide or air to temperatures from 600-900°C. The receiver will be built out of advanced nickel alloys using additive manufacturing techniques to develop a robust receiver that can withstand concentrated solar light equivalent to more than 1,000 suns. This new manufacturing method will be applied to a ‘micro-pin’ receiver design previously developed by Oregon State University. Taken together, these innovations can enable efficient, low cost CSP for power generation or a wide variety of high temperature solar thermal process heat applications.

University of Michigan

Project Name: Design and Manufacturing of Transparent Refractory Insulation for Next-Generation Receivers
Location: Ann Arbor, MI
DOE Award Amount: $2.5 million
Cost Share: $600,000
Project Summary: The University of Michigan is partnering with AeroShield to develop a manufacturing strategy for a novel aerogel material developed by the project team. This material has the potential to substantially improve the efficiency of concentrating solar-thermal power parabolic trough collectors. The aerogel is transparent to the solar spectrum and can be modified to absorb heat that would otherwise be lost from the receiver tube. The team plans to show the aerogel can enable efficient solar-thermal energy collection at 700°C, to enable parabolic trough collectors to couple with high-temperature and high-efficiency power cycles.

Echogen Power Systems

Project Name: Advanced Ice Slurry Generation System for a Carbon Dioxide-Based Pumped Thermal Energy Storage System
Location: Akron, OH
DOE Award Amount: $1.2 million
Cost Share: $400,000
Project Summary: Echogen will develop a heat exchanger that will reduce the cost of using ice as a cold thermal reservoir in thermal energy storage systems. The team will accomplish this by simplifying the design of existing commercial systems that mechanically scrape ice from heat-transfer surfaces. This project could improve the cost and operational complexity of efficient thermal energy storage systems that use heat pumps to convert electricity into heat for long-duration storage.

Southwest Research Institute (1)

Project Name: Characterization of Inlet Guide Vane Performance for Discharge Compressor Operation near the Dome of an sCO₂ Pumped Heat Electricity Storage
Location: San Antonio, TX
DOE Award Amount: $500,000
Cost Share: $100,000
Project Summary: This project will advance the design of inlet guide vanes (IGV), which are a critical component in supercritical carbon dioxide compressors. They are used to direct fluid flow in a compressor to optimize flow over the rotating blades. This project will integrate IGVs into a compressor to collect data on fluid-flow profiles that can be used across the industry. The compressor is a key component in charging and discharging cycles for long-duration thermal energy storage

Southwest Research Institute (2)

Project Name: Development of a Multiphase-Tolerant Turbine for Pumped Thermal Energy Storage
Location: San Antonio, TX
DOE Award Amount: $2.4 million
Cost Share: $600,000
Project Summary: Southwest Research Institute will design a turbine to maximize the efficiency of a carbon dioxide–based heat pump cycle, which is a promising technology to efficiently store electricity in long-duration thermal energy storage systems. This project will optimize turbine designs that will be able to tolerate constantly shifting fluid properties, since it will interact with both liquid and gas phases within the machine. This heat-pump turbine is a critical component to enable cost-effective thermal energy storage of electricity, with potential round-trip system efficiencies above 65%.

Electric Power Research Institute

Project Name: Improved O&M Reliability for CSP Plants through Application of Steam Generator Damage Mechanisms Theory & Practice
Location: Charlotte, NC
DOE Award Amount: $1.9 million
Cost Share: $500,000
Project Summary: This project aims to improve the reliability, operability, and productivity of CSP plants by developing a “theory and practice” document for CSP steam generators, with input from technology end-users, such as plant operators, designers, and other stakeholders. This reference and guidance document will cover the evolution of damage to CSP steam cycle equipment and the necessary operations and maintenance practices to manage this damage. It will fully describe the mechanisms that lead to damage in each component and provide guidance on identifying issues and understanding how to manage and prevent its recurrence.

IDOM

Project Name: Improved Design Standard for High Temperature Molten Nitrate Salt Tank Design
Location: Minneapolis, MN
DOE Award Amount: $2 million
Cost Share: $500,000
Project Summary: This project will develop a comprehensive design guide for thermal energy storage tanks for molten nitrate salt. The team will develop methodologies for the tank’s structural design, considering corrosion effects and other factors for material selection, welded joints, fatigue evaluation, the design of the tank foundation, and its leak detection systems, in addition to the effects of choosing internal versus external tank insulation. This guide could be a standard for nitrate salt tanks for developers to adopt and implement in new plant builds.

Solar Dynamics (1)

Project Name: CSP Plant Optimization Study for the California Power Market
Location: Broomfield, CO
DOE Award Amount: $1 million
Cost Share: $250,000
Project Summary: This project team will conduct a detailed systems study to determine the optimal configuration of CSP plants to support the emerging needs of the California market. Working with grid operators and utilities, like the California Independent System Operator (CAISO) and the Sacramento Municipal Utility District (SMUD), this study will evaluate the technoeconomic potential of different CSP technologies and configurations, and the key challenges preventing deployment to lower the barriers preventing CSP project development and commercialization.

Solar Dynamics (2)

Project Name: Design Basis Document/Owners Technical Specification for Nitrate Salt Systems in CSP Projects
Location: Broomfield, CO
DOE Award Amount: $450,000
Cost Share: $100,000
Project Summary: This project team will develop a design basis document for CSP systems that use nitrate salts and will make it widely available to the public. This document will collect key information on best practices and lessons learned from existing commercial CSP plants and will provide a key tool to develop a common understanding among future power plant owners, engineering-procurement-construction (EPC) contractors, and operations and maintenance contractors. Focuses of the document will include receiver tube material decisions, avoidance of stress relaxation cracking, appropriate welding procedures, heat exchanger fabrication techniques, and heat trace design, among others. The project will engage a large portion of the CSP industry to ensure wide relevance of the document.

Sporian Microsystems

Project Name: Evaluation of High-Temperature Sensors for Molten Solar Salt Applications
Location: Lafayette, CO
DOE Award Amount: $1 million
Cost Share: $250,000
Project Summary: Sporian Microsystems will design and fabricate sensors for use in molten salt CSP plants. The sensors will be able to monitor flow rates, fluid pressures and chemical impurities, to ensure reliable plant operations. Sporian is teaming with three national labs to evaluate and validate the performance of these sensors. Precise measurements of molten salt flow, pressure, and chemical composition at operating temperature will provide CSP plant operators with information that can allow for enhanced control to improve performance and prolong the life of key CSP subcomponents.

University of Wisconsin, Madison

Project Name: Performance Improvement in CSP Plant Operations
Location: Madison, WI
DOE Award Amount: $1.6 million
Cost Share: $500,000
Project Summary: This project will improve performance in existing CSP plants by creating a model of plant operations that will simulate real plants to allow training of CSP operators. This model will be capable of evaluating alternative operating and control strategies to improve plant performance and cost-effectiveness. CSP operators will be able to test control decisions in a low-risk, realistic model environment, which is especially beneficial for rare events that can have a significant effect on plant output. Data from operating commercial plants will be used to ensure the fidelity of plant emulation models.

Brayton Energy

Project Name: Performance Optimization of Sold Particle TES Heat Exchanger by Combining Benefit of Extended Surfaces and Particle Fluidization
Location: Hampton, NH
DOE Award Amount: $1.9 million
Cost Share: $500,000
Project Summary: Solid particles have several advantages over conventional molten nitrate salts as a heat-transfer media in CSP tower systems. For a particle system to work with a steam Rankine power cycle, new designs for particle-to-steam heat exchangers are needed. This project team will design and develop such a heat exchanger utilizing both particle fluidization and extended surface fins to maximize the heat transfer performance of the component. The team will build and test a prototype heat exchanger to validate performance models and operability.

Small Innovative Projects in Solar (SIPS) will focus on novel ideas that dramatically lower the cost of CSP technologies to produce power or industrial heat. If successful, these technologies could move to the next stage of research and development after one year.

Arizona State University (1)

Project Name: Concentrated Solar Thermal Fuels Production by Electric Field Enhanced Two-Step Gas Splitting
Location: Tempe, AZ
DOE Award Amount: $310,000
Cost Share: $80,000
Project Summary: This team will develop a novel solar thermochemical cycle to produce renewable fuels from carbon dioxide (CO₂). Current concepts that thermally activate CO₂ are limited by the extreme temperatures (around 1,500°C) needed to execute the reaction. The team will design a prototype reactor that applies a small voltage to cerium oxide immersed in a molten salt to generate an electric field, which lowers the required temperature for the reaction. The project targets a 600°C reduction in the CO₂ splitting temperature, making the process feasible for integration in a concentrating solar-thermal power plant.

Arizona State University (2)

Project Name: Technology for Electrically Enhanced Thermochemical Hydrogen
Location: Tempe, AZ
DOE Award Amount: $400,000
Cost Share: $100,000
Project Summary: The team will develop and test a thermo-electrochemical process to produce “green” hydrogen from steam with solar energy. This approach combines high-temperature solar-thermochemical water splitting (TCWS) with electrochemical pumping of hydrogen through a proton conducting membrane. This mitigates or eliminates many of the key challenges to implementing TCWS. The technology will enable low-cost solar-to-hydrogen efficiencies that exceed 25% (theoretical limit > 50%).

Calnetix Technologies

Project Name: Development and Test of Active Magnetic Bearing (AMB) for Supercritical Carbon Dioxide (sCO₂) Turbomachinery
Location: Cerritos, CA
DOE Award Amount: $375,000
Cost Share: $100,000
Project Summary: The development of turbomachinery for advanced sCO₂ power cycles requires reliable and efficient bearings that can support very high rotational speed at high temperatures. Calnetix Technologies is developing a novel active magnetic bearing (AMB) system for sCO₂ turbogenerators, which will improve efficiency, lower costs, and eliminate the need for complex lubrication mechanisms. A prototype system will be installed and tested in a 100-kW sCO₂ turbogenerator test facility at Sandia National Laboratories. The team will assess the viability of the novel bearing for sCO₂ power cycles by determining its performance during operation and impact on the turbogenerator’s performance.

Regents of University of California, San Diego

Project Name: In-Operando Thermal Transport Characterization of Moving Particle Bed Heat Exchanger
Location: San Diego, CA
DOE Award Amount: $400,000
Cost Share: $100,000
Project Summary: This project team will integrate a novel heat-transfer measurement technique into an operating 1-megawatt heat exchanger at Sandia National Laboratories. The technique measures a dynamic surface radiation signal to determine thermal transport rates at different distances from the surface. The technique will be used to observe both near-wall and bulk-particle heat-transport rates in a particle-to–supercritical carbon dioxide heat exchanger. The heat exchanger is a key component in Sandia’s Generation 3 Particle Pilot Plant (G3P3).

Southwest Research Institute (3)

Project Name: High-Temperature Permanent Magnet-Biased Active Magnetic Bearing Development for Supercritical Carbon Dioxide Machinery Applications
Location: San Antonio, TX
DOE Award Amount: $400,000
Cost Share: $110,000
Project Summary: This project seeks to identify and test magnetic materials that can be used for bearings in CSP plants that use a supercritical carbon dioxide (sCO₂) power cycle and operate at temperatures higher than 540°C. The team will design permanent magnet-biased active magnetic bearings (PM-AMBs), an enabling technology for hermetic sCO₂ machinery, which is expected to increase cycle efficiency. PM-AMBs may have advantages over gas bearings, including greater tolerance to misalignment, reduced wear, tunability, and diagnostic capabilities. The team will also test key materials for compatibility to exposure in a high-temperature CO₂ environment. Machine layouts with PM-AMBs will be developed to demonstrate feasibility.

University of Dayton

Project Name: Development and Experimental Optimization of High-Temperature Modeling Tools and Methods for Concentrated Solar Power Particle Systems
Location: Dayton, OH
DOE Award Amount: $400,000
Cost Share: $100,000
Project Summary: Accurately modeling flow and heat transfer of solid particles in next-generation CSP systems is challenging compared to conventional systems that use liquid heat transfer fluids. The University of Dayton will perform a variety of particle flow and heat transfer experiments to develop and validate a broadly applicable computational model that can be used by researchers working on particle-based systems. DCS Computing will integrate the validated framework into a modeling toolkit. If successful, a broad range of researchers and technology developers could use these modeling tools to study their system without further fundamental property measurements.

University of Maryland, College Park

Project Name: Low-cost and High-performance Heat Exchangers for CSP
Location: College Park, MD
DOE Award Amount: $400,000
Cost Share: $100,000
Project Summary: University of Maryland will design and manufacture a low-cost, high-performance particle-to-supercritical carbon dioxide (sCO₂) heat exchanger for CSP. Three enabling technologies will be integrated together to achieve the cost and performance. First is a new high‐speed laser additive manufacturing technique that utilizes a specially designed powder-feeding nozzle to achieve 100 times faster deposition rate than conventional laser deposition. The second technology is an innovative helical heat exchanger geometry that can be easily made using additive manufacturing. The third technology is a low-cost, novel alumina-forming steel invented at Oak Ridge National Laboratory that has high creep and oxidation resistance up to 1100 ̊C. These technologies will enable high-performance and low-cost heat exchangers for particle-to-sCO₂ and other CSP heat exchanger needs.

University of Michigan

Project Name: Spectral and Temperature-Dependent Optical Metrology: Towards More Robust, Effective and Durable Materials for Concentrated Solar Power
Location: Ann Arbor, MI
DOE Award Amount: $240,000
Cost Share: $60,000
Project Summary: This project team will explore the impact of temperature on the optical properties of materials relevant to CSP. Traditional optical spectroscopy measurements focus on room-temperature properties, which may not be representative of properties at high temperature. This team will develop standardized spectroscopic measurement techniques, protocols, and procedures to determine radiative properties of materials. They will incorporate their data into a digitized database of optical properties and utilize both experimental data and predictive modeling tools.

University of Nevada, Las Vegas

Project Name: Development of Gas Bearings for Supercritical Carbon Dioxide Recompression Brayton Cycle
Location: Las Vegas, NV
DOE Award Amount: $250,000
Cost Share: $60,000
Project Summary: The project team will explore using porous graphite in the gas bearings that support the turbine shaft of supercritical carbon dioxide (sCO₂) cycle turbomachinery. Gas bearings inject high-pressure gas to avoid friction caused by rotation of the turbine shaft, which lowers efficiency. They will test their bearings in a high-pressure and high-temperature CO₂ gas environment to validate their performance. If successful, these bearings allow for nearly frictionless operation of the turbomachinery, minimizing wear and simplifying system operation, which would reduce maintenance costs and improve cycle efficiency.

University of Nevada, Reno

Project Name: Innovative Technology for Continuous, Online (In Situ) Monitoring of Corrosivity of Molten Salts to Prevent Catastrophic Failure of Solar Thermal Plants
Location: Reno, NV
DOE Award Amount: $400,000
Cost Share: $100,000
Project Summary: This project team will develop and evaluate an innovative sensor for molten chloride salts based on the measuring “optical basicity,” which represents the corrosivity of the fluid. The team will develop and validate the concept, and design an online monitoring system that could be used in commercial plants.

University of Wisconsin, Madison

Project Name: Low-Cost Heliostat for High-Flux Small-Area Receivers
Location: Madison, WI
DOE Award Amount: $330,000
Cost Share: $80,000
Project Summary: This project team will design a novel heliostat for small solar fields that may drastically reduce the component cost compared to commercial systems. The concept uses a two-step design in which a first stage of reflection is accomplished via a set of rotating heliostats that share a common set of tracking drives, enabling significant cost reduction. A second stage of stationary mirrors concentrates solar light on the receiver.