scholarly journals Thermodynamic Investigation of Concentrating Solar Power With Thermochemical Storage

2015 ◽  
Author(s):  
Brandon T. Gorman ◽  
Nathan G. Johnson ◽  
James E. Miller ◽  
Ellen B. Stechel
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Metal Oxide ◽  
Solar Power ◽  
Exothermic Reaction ◽  
Department Of Energy ◽  
Concentrating Solar Power ◽  
Ongoing Research ◽  
Performance Reduction ◽  
Solar Receiver

Concentrating solar power systems coupled to energy storage schemes, e.g. storage of sensible energy in a heat transfer fluid, are attractive options to reduce the transient effects of clouding on solar power output and to provide power after sunset and before sunrise. Common heat transfer fluids used to capture heat in a solar receiver include steam, oil, molten salt, and air. These high temperature fluids can be stored so that electric power can be produced on demand, limited primarily by the size of the capacity and the energy density of the storage mechanism. Phase changing fluids can increase the amount of stored energy relative to non-phase changing fluids due to the heat of vaporization or the heat of fusion. Reversible chemical reactions can also store heat; an endothermic reaction captures the heat, the chemical products are stored, and an exothermic reaction later releases the heat and returns the chemical compound to its initial state. Ongoing research is investigating the scientific and commercial potential of such reaction cycles with, for example, reduction (endothermic) and re-oxidation (exothermic) of metal oxide particles. This study includes thermodynamic analyses and considerations for component sizing of concentrating solar power towers with redox active metal oxide based thermochemical storage to reach target electrical output capacities of 0.1 MW to 100 MW. System-wide analyses here use one-dimensional energy and mass balances for the solar field, solar receiver reduction reactor, hot reduced particle storage, re-oxidizer reactor, power block, cold particle storage, and other components pertinent to the design. This work is part of a US Department of Energy (DOE) SunShot project entitled High Performance Reduction Oxidation of Metal Oxides for Thermochemical Energy Storage (PROMOTES).

Inert and Reactive Oxide Particles for High-Temperature Thermal Energy Capture and Storage for Concentrating Solar Power

2019 ◽  
Vol 141 (2) ◽  
Author(s):  
Gregory S. Jackson ◽  
Luca Imponenti ◽  
Kevin J. Albrecht ◽  
Daniel C. Miller ◽  
Robert J. Braun
Keyword(s):  
Heat Transfer ◽  
Energy Storage ◽  
Thermal Energy ◽  
Solar Power ◽  
Low Cost ◽  
Gas Flows ◽  
Concentrating Solar Power ◽  
Energy Capture ◽  
Oxide Particles ◽  
And Storage

Oxide particles have potential as robust heat transfer and thermal energy storage (TES) media for concentrating solar power (CSP). Particles of low-cost, inert oxides such as alumina and/or silica offer an effective, noncorrosive means of storing sensible energy at temperatures above 1000 °C. However, for TES subsystems coupled to high-efficiency, supercritical-CO2 cycles with low temperature differences for heat addition, the limited specific TES (in kJ kg−1) of inert oxides requires large mass flow rates for capture and total mass for storage. Alternatively, reactive oxides may provide higher specific energy storage (approaching 2 or more times the inert oxides) through adding endothermic reduction. Chemical energy storage through reduction can benefit from low oxygen partial pressures (PO2) sweep-gas flows that add complexity, cost, and balance of plant loads to the TES subsystem. This paper compares reactive oxides, with a focus on Sr-doped CaMnO3–δ perovskites, to low-cost alumina-silica particles for energy capture and storage media in CSP applications. For solar energy capture, an indirect particle receiver based on a narrow-channel, counterflow fluidized bed provides a framework for comparing the inert and reactive particles as a heat transfer media. Low-PO2 sweep gas flows for promoting reduction impact the techno-economic viability of TES subsystems based on reactive perovskites relative to those using inert oxide particles. This paper provides insights as to when reactive perovskites may be advantageous for TES subsystems in next-generation CSP plants.

Technical Challenges and Opportunities for Concentrating Solar Power With Thermal Energy Storage

2013 ◽  
Vol 5 (2) ◽  
Author(s):  
Joseph Stekli ◽  
Levi Irwin ◽  
Ranga Pitchumani
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Power ◽  
Heat Storage ◽  
The United States ◽  
Department Of Energy ◽  
Intermediate Step ◽  
United States Department ◽  
Concentrating Solar Power

Concentrating solar power (CSP) provides the ability to incorporate simple, efficient, and cost-effective thermal energy storage (TES) by virtue of converting sunlight to heat as an intermediate step to generating electricity. Thermal energy storage for use in CSP systems can be one of sensible heat storage, latent heat storage using phase change materials (PCMs) or thermochemical storage. Commercially deployed CSP TES systems have been achieved in recent years, with two-tank TES using molten salt as a storage medium and steam accumulators being the system configurations deployed to date. Sensible energy thermocline systems and PCM systems have been deployed on a pilot-scale level and considerable research effort continues to be funded, by the United States Department of Energy (DOE) and others, in developing TES systems utilizing any one of the three categories of TES. This paper discusses technoeconomic challenges associated with the various TES technologies and opportunities for advancing the scientific knowledge relating to the critical questions still remaining for each technology.

scholarly journals Techno-Economic Analysis of a Concentrating Solar Power Plant Using Redox-Active Metal Oxides as Heat Transfer Fluid and Storage Media

2021 ◽  
Vol 9 ◽  
Author(s):  
Brandon T. Gorman ◽  
Mariana Lanzarini-Lopes ◽  
Nathan G. Johnson ◽  
James E. Miller ◽  
Ellen B. Stechel
Keyword(s):  
Heat Transfer ◽  
Solar Radiation ◽  
Metal Oxide ◽  
Department Of Energy ◽  
Concentrating Solar Power ◽  
Storage Media ◽  
Redox Active ◽  
Active Metal ◽  
And Storage ◽  
Redox Active Metal

We present results for a one-dimensional quasi-steady-state thermodynamic model developed for a 111.7 MWe concentrating solar power (CSP) system using a redox-active metal oxide as the heat storage media and heat transfer agent integrated with a combined cycle air Brayton power block. In the energy charging and discharging processes, the metal oxide CaAl0.2Mn0.8O2.9-δ (CAM28) undergoes a reversible, high temperature redox cycle including an endothermic oxygen-releasing reaction and exothermic oxygen-incorporation reaction. Concentrated solar radiation heats the redox-active oxide particles under partial vacuum to drive the reduction extent deeper for increased energy density at a fixed temperature, thereby increasing storage capacity while limiting the required on sun temperature. Direct counter-current contact of the reduced particles with compressed air from the Brayton compressor releases stored chemical and sensible energy, heating the air to 1,200°C at the turbine inlet while cooling and reoxidizing the particles. The cool oxidized particles recirculate through the solar receiver subsystem for another cycle of heating and reduction (oxygen release). We applied the techno-economic model to 1) size components, 2) examine intraday operation with varying solar insolation, 3) estimate annual performance characteristics over a simulated year, 4) estimate the levelized cost of electricity (LCOE), and 5) perform sensitivity analyses to evaluate factors that affect performance and cost. Simulations use hourly solar radiation data from Barstow, California to assess the performance of a 111.7 MWe system with solar multiples (SMs) varying from 1.2 to 2.4 and storage capacities of 6–14 h. The baseline system with 6 h storage and SM of 1.8 has a capacity factor of 54.2%, an increase from 32.3% capacity factor with no storage, and an average annual energy efficiency of 20.6%. Calculations show a system with an output of 710 GWhe net electricity per year, 12 h storage, and SM of 2.4 to have an installed cost of $329 million, and an LCOE of 5.98 ¢/kWhe. This value meets the U.S. Department of Energy’s SunShot 2020 target of 6.0 ¢/kWhe (U. S Department of Energy, 2012), but falls just shy of the 5.0 ¢/kWhe 2030 CSP target for dispatchable electricity (U. S Department of Energy, 2017). The cost and performance results are minimally sensitive to most design parameters. However, a one-point change in the weighted annual cost of capital from 8 to 7% (better understood as a 12.5% change) translates directly to an 11% decrease (0.66 ¢/kWhe) in the LCOE.

scholarly journals Profit-Based Unit Commitment for a GENCO Equipped with Compressed Air Energy Storage and Concentrating Solar Power Units

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 576
Author(s):  
Mostafa Nasouri Gilvaei ◽  
Mahmood Hosseini Imani ◽  
Mojtaba Jabbari Ghadi ◽  
Li Li ◽  
Anahita Golrang
Keyword(s):  
Energy Storage ◽  
Solar Power ◽  
Unit Commitment ◽  
Thermal Power ◽  
System Structure ◽  
Compressed Air ◽  
Mixed Integer ◽  
Compressed Air Energy Storage ◽  
Concentrating Solar Power ◽  
Unit Commitment Problem

With the advent of restructuring in the power industry, the conventional unit commitment problem in power systems, involving the minimization of operation costs in a traditional vertically integrated system structure, has been transformed to the profit-based unit commitment (PBUC) approach, whereby generation companies (GENCOs) perform scheduling of the available production units with the aim of profit maximization. Generally, a GENCO solves the PBUC problem for participation in the day-ahead market (DAM) through determining the commitment and scheduling of fossil-fuel-based units to maximize their own profit according to a set of forecasted price and load data. This study presents a methodology to achieve optimal offering curves for a price-taker GENCO owning compressed air energy storage (CAES) and concentrating solar power (CSP) units, in addition to conventional thermal power plants. Various technical and physical constraints regarding the generation units are considered in the provided model. The proposed framework is mathematically described as a mixed-integer linear programming (MILP) problem, which is solved by using commercial software packages. Meanwhile, several cases are analyzed to evaluate the impacts of CAES and CSP units on the optimal solution of the PBUC problem. The achieved results demonstrate that incorporating the CAES and CSP units into the self-scheduling problem faced by the GENCO would increase its profitability in the DAM to a great extent.

Numerical Analysis of Latent Thermal Energy Storage System With Embedded Thermosyphons

2012 ◽  
Author(s):  
Karthik Nithyanandam ◽  
Ranga Pitchumani
Keyword(s):  
Thermal Conductivity ◽  
Energy Storage ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Solar Power ◽  
Storage System ◽  
High Energy ◽  
Concentrating Solar Power ◽  
Discharge Performance ◽  
Low Thermal Conductivity

Latent thermal energy storage (LTES) system offers high energy storage density and nearly isothermal operation for concentrating solar power generation. However, the low thermal conductivity possessed by the phase change material (PCM) used in LTES system limits the heat transfer rates. Utilizing thermosyphons to charge or discharge a LTES system offers a promising engineering solution to compensate for the low thermal conductivity of the PCM. The present work numerically investigates the enhancement in the thermal performance of charging and discharging process of LTES system by embedding thermosyphons. A transient, computational analysis of the LTES system with embedded thermosyphons is performed for both charging and discharging cycles. The influence of the design configuration of the system and the arrangement of the thermosyphons on the charge and discharge performance of the LTES installed in a concentrating solar power plant (CSP) is analyzed to identify configurations that lead to improved effectiveness.

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