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The utilization of solar energy for electrical power production was studied. Efforts underway on the central receiver solar thermal power system are presented. Preliminary designs are included of pilot plant utilizing large numbers of heliostats in a collector field. Safety hazards are also discussed, as well as the most beneficial location of such a plant within the United States.
This report presents the design of system interfaces enabling flexible thermal power extraction from two advanced nuclear reactor concepts: a sodium-cooled fast reactor (SFR) operating on a Rankine cycle, and a gas-cooled reactor (GCR) utilizing a Brayton cycle. The study addresses the dual challenge of ensuring reliable base-load electricity generation while meeting the variable high-temperature steam demands of industrial processes (IPs).
Requirements and constraints are established for power conversion subsystems, including heat engine, alternator and auxiliaries, of dish concentrator solar thermal power systems. In order to be competitive with conventional power systems, it is argued that the heat engine should be of less than 40 kW rated output, in a subsystem with an efficiency of at least 40% at rated output and at least 37% at half power. An interval between major overhauls of 50,000 hours is also desirable, along with minor maintenance and lubrication not more than four times a year requiring no more than one man-hour each time, and optimal reliability. Also found to be important are the capability for hybrid operation using heat from a solar receiver, fuel-fired combustor or both simultaneously, operation at any attitude, stability to transients in input power and output loading, operation at ambient temperatures from -30 to 50 C, and compatibility with environmental and safety requirements. Cost targets include a price of $180/kWe, and operation, maintenance and replacement costs averaging $0.001/kWh for 30 years of operation.
The bibliographical listings in this publication are documentation products associated with the solar thermal power system project carried out by the Jet Propulsion Laboratory from 1976 to 1983. Documents listed are categorized as conference and journal papers, JPL external reports, JPL internal reports, or contractor reports. Alphabetical listings by title were used in the bibliography itself to facilitate location of the document by subject. Two indexes are included for ease of reference: one, an author index; the other, a topical index.
Nuclear power plants are crucial to meeting net zero emission goals and achieving energy sustainability. Integrating these plants with clean energy technologies such as high-temperature steam electrolysis (HTSE) may improve the efficiency and economic competitiveness of these plants. Here, the current study investigates the design and operation of a thermal power dispatch (TPD) system for coupling boiling water reactors (BWRs) to HTSE plants. The TPD system extracts a portion of the steam from the reactor’s main steam line and transfers its thermal energy to an HTSE plant through a power transport loop. A TPD system for 5 % steam extraction has been designed and the system performance during steady and transient operations has been analyzed. The TPD system dispatched a total of 197 MW thermal energy to the HTSE plant under nominal design conditions. Saturated steam at 7.17 MPa from the BWR plant was condensed and subcooled to a temperature of 168 °C, while a mass flow rate of 91.1 kg/s of superheated steam was dispatched to the HTSE plant. Furthermore, the system performance during transient operation showed a continuous transition from the initial hot standby mode to the nominal power dispatch level. The transient simulation results emphasized the importance of investigating component level performance for the TPD system design. The current results will guide future works on the development of integrated energy systems for hydrogen production or process heat applications.
In 2012, the U.S Department of Energy defined aggressive targets to achieve lower component costs and higher system efficiencies for concentrated solar-thermal power (CSP), and this, in turn, has led to the exploration of technology options that can operate at higher temperatures [1]. These next-generation CSP options, referred to as Generation 3 (a.k.a. Gen3), are targeting temperatures at or above 700 °C for the energy being delivered to the power cycle, and the more challenging plant conditions have necessitated a review and selection of alternative receiver heat transfer fluids as well as a search for materials that can meet the associated high-temperature component requirements. Nickel-based alloys are currently being considered, but these generally experience a significant drop in strength at temperatures > 775 °C [2] and may not be able to achieve corrosion and other lifetime requirements. Furthermore, these alloys are expensive, frequently have cost and schedule volatility, and offer little potential for lower cost at high production volumes. As an alternative, Ceramic Tubular Products, LLC (CTP) has developed a multilayer silicon carbide composite that can complement or replace alloys currently being considered for these Gen3 CSP applications.
A program capable of calculating the design-point and quasi-steady-state annual performance of a paraboloidal-concentrator solar thermal power plant without energy storage was written for a programmable calculator equipped with suitable printer. The power plant may be located at any site for which a histogram of annual direct normal insolation is available. Inputs required by the program are aperture area and the design and annual efficiencies of the concentrator; the intercept factor and apparent efficiency of the power conversion subsystem and a polynomial representation of its normalized part-load efficiency; the efficiency of the electrical generator or alternator; the efficiency of the electric power conditioning and transport subsystem; and the fractional parasitic loses for the plant. Losses to auxiliaries associated with each individual module are to be deducted when the power conversion subsystem efficiencies are calculated. Outputs provided by the program are the system design efficiency, the annualized receiver efficiency, the annualized power conversion subsystem efficiency, total annual direct normal insolation received per unit area of concentrator aperture, and the system annual efficiency.
This is the final technical report for the DOE MURI project on developing high-operating temperature heat transfer fluids for solar thermal power generation. This project aimed to evaluate liquid metals as a heat-transport fluid and potential energy storage medium for concentrated solar powered (CSP) systems. The project consisted of five phases, starting with fluid selection and screen and ending with potential CSP integration. The initial fluid selection arrived at heavy liquid metals as candidate fluids such as lead bismuth eutectic (LBE) as the prime liquid-alloy candidate to be studied, given the conditions above. Fifty-seven liquid compositions were initially identified with liquidus temperatures lower than 200°C, composed of elements that provide no driving force to the reduction of Cr 2 O 3 or Al 2 O 3 passivation layers in pipe material which is required for corrosion prevention. LBE was identified as the primary candidate fluid after these compositions were compared against computational thermodynamic modeling to screen all of the selected systems that would be compatible with our design objectives. Twenty-eight of these compositions were also investigated with the rapid characterization methods; the accuracies of the liquidus temperature and the specific heats predicted by the computations were better than 3 percent and 9 percent, respectively. We conducted numerus corrosion tests of various Fe-Cr-Al based steels in LBE and its variants at temperate as high as 800°C. It was found that minor additions to the liquid did not provide sufficient corrosion protection to warrant their use in real applications. Furthermore, we investigated the detailed mechanism of corrosion between heavy liquid metal and the pipe material at these very high temperatures. A liquid metal loop was constructed to operate at these high temperatures. The loop construction and operation lead to valuable lessons learned that will be needed for industrial scale loops. Furthermore, we learned that electromagnetic pumps at these extreme temperatures will have to be reengineered and redesigned to be used for CSP applications.
Bibliographies and abstracts are cited under the following topics: (1) energy overviews; (2) solar overviews; (3) conservation; (4) economics, law; (5) thermal power; (6) thermionic, thermoelectric; (7) ocean; (8) wind power; (9) biomass and photochemical; and (10) large photovoltaics.
An Idaho National Laboratory research team performed a human-in-the-loop study with two formerly licensed retired operators to evaluate thermal power dispatch operations supported by the modified GSE Systems GPWR plant simulator. Virtual representations of the analog control panels were presented on touch-screen bays configured to mimic the control room layout in the newly renovated Human Systems Simulation Laboratory. The operators performed 15 scenarios covering normal evolutions to transition the plant from full turbine operation to joint turbine and thermal power dispatch operations in addition to transient response scenarios induced with simulated faults to evaluate the impact of thermal power dispatch system on operator and plant responses. A prototype human-system interface (HSI) was developed and displayed in tandem with the virtual analog panels to support the operators executing the procedurally drive evolutions and transient responses. An interdisciplinary team of operations experts, nuclear engineers, and human factors experts observed the operators performing the scenarios to evaluate the operations. Only a preliminary analysis of the results has been performed. The full analysis will be shared in a milestone report scheduled for release at the end of September; however, some high-level conclusions were readily available. Two high level findings for the system design were captured in the study. The manual control supported by the HSI to transition from standard operations to thermal power dispatch operation imposed a considerable amount of workload on the operators due to tedious manual valve manipulations and system monitoring required to verify their intended effect. An additional operator would be required in the control room to support the daily evolution. Automatic control for the transition was deemed a requirement for plant adoption without imposing additional staffing costs. The second finding was the necessity for an automatic thermal power dispatch system trip isolation function linked to a turbine and reactor trip signal. The operators completed scenarios with automatic isolation functionality and manually required actuation of the thermal power dispatch system. The operator response was sufficiently slower in the manual trip condition, such that operators were unable to manually actuate key post trip safety functions an indicate a degraded control capability that should be avoided. With an automatic trip signal little to no impact of the thermal power dispatch system was identified on the primary plant response and therefore the system could be readily and safely adopted. Together these two findings represent the need to support the adoption of thermal power dispatch capability into existing operations by leveraging automation to augment any additional operator tasking required to control and monitor an additional system beyond existing operations.
The excess thermal energy produced by nuclear power plants (NPPs) during low electricity demands can be utilized in industrial processes, such as hydrogen production, through a thermal power dispatch (TPD) system. Initial testing of the first iteration of a single-train TPD design with a manual control mode at the Idaho National Lab (INL) revealed a high operator workload and degraded control capability. The current study evaluated the impact of an enhanced dual-train TPD design on operators’ subjective mental workload and evolution task-time while completing two operating scenarios in manual and automatic control modes. The results showed no statistically significant difference between participants’ mental workload using both control modes. Evolution time in automatic control mode took a shorter time than in manual control, with participants completing all evolutions in less than the 10-min set as the design specification limit. The shorter evolution time is discussed within the context of plant safety and operational efficiency.
Technologies for solar thermal plants are being developed to provide energy alternatives for the future. Implementation of these plants requires consideration of siting issues as well as power system technology. While many conventional siting considerations are applicable, there is also a set of unique siting issues for solar thermal plants. Early experimental plants will have special siting considerations. The siting issues associated with small, dispersed solar thermal power plants in the 1 to 10 MWe power range for utility/small community applications are considered. Some specific requirements refer to the first 1 MWe engineering experiment for the Small Power Systems Applications (SPSA) Project. The siting issues themselves are discussed in three categories: (1) system resource requirements, (2) environmental effects on the system, and (3) potential impact of the plant on the environment. Within these categories, specific issues are discussed in a qualitative manner. Examples of limiting factors for some issues are taken from studies of other solar systems.
The development of a natural gas-fired Brayton engine is discussed. It is intended to be the prime mover for a 10-ton commercial heat pump. This engine has many attractive features that make it an ideal candidate for solar thermal-power generation applications. The unique feature of this engine is its subatmospheric mode of operation. It operates between atmospheric pressure and a partial vacuum. This means that heat is added to the cycle at atmospheric pressure; this permits the receiver to be unpressurized, greatly simplifying its design and cost.
Future plans for the 1.5 MWth solid fuel fired system with sCO2 power cycle at Utah San Rafael Energy Lab
Waste heat from radioisotope thermal generators in spacecraft is transported to keep instruments warm by two-cylinder reciprocating pump powered by energy from warm heat exchange fluid. Each cylinder has thermally nonconductive piston, heat exchange coil, and heat sink surface.
Since the insolation is intermittent, thermal energy storage is necessary to extend the time of power generation with solar heat past sunset. There are two approaches to specifying the size of turbine-generator units depending on the system operation. In the first approach, the turbine operates at its full capacity when operating on direct solar heat, and at reduced capacity when operating on collected heat out of energy storage. In the second approach, the turbine will always operate at a uniform level either on derated energy from the receiver or from energy storage. Both of these approaches have certain advantages and disadvantages. In this paper, a simple analysis is outlined and exercised to compare the performance and economics of these two approaches.
The development status is reviewed of some thermal energy storage technologies specifically oriented towards providing diurnal heat storage for solar central power systems and solar total energy systems. These technologies include sensible heat storage in caverns and latent heat storage using both active and passive heat exchange processes. In addition, selected thermal storage concepts which appear promising to a variety of advanced solar thermal system applications are discussed.
A study was performed to assess the potential economic impact of small solar thermal electric power systems in statistically representative synthetic small utilities of the Southwestern United States. Power supply expansion plans were compared on the basis of present worth of future revenue requirements for 1980-2000 with and without solar thermal plants. Coal-fired and oil-fired municipal utility expansion plans with 5 percent solar penetration were 0.5 percent and 2.25 percent less expensive, respectively, than the corresponding conventional plan. At $969/kWe, which assumes the same low cost solar equipment but no improvement in site development costs, solar penetration of 5 percent in the oil-fired municipal reduced revenue requirements 0.88 percent. The paper concludes that some solar thermal plants are potentially economic in small community utilities of the Southwest.