solar thermal power systems advanced solar thermal technology project, advanced subsystems development

The preliminary design for a prototype small (20 kWe) solar thermal electric generating unit was completed, consisting of several subsystems. The concentrator and the receiver collect solar energy and a thermal buffer storage with a transport system is used to provide a partially smoothed heat input to the Stirling engine. A fossil-fuel combustor is included in the receiver designs to permit operation with partial or no solar insolation (hybrid). The engine converts the heat input into mechanical action that powers a generator. To obtain electric power on a large scale, multiple solar modules will be required to operate in parallel. The small solar electric power plant used as a baseline design will provide electricity at remote sites and small communities

Combined Primary Frequency and Virtual Inertia Response Control Scheme of Variable-Speed Dish-Stirling System

The potential of variable-speed dish-Stirling (VSDS) solar-thermal generating plant in providing grid frequency support is investigated. In the proposed VSDS frequency support control scheme, the reference speed of the Stirling engine is regulated to track a deloaded power curve which is governed by the solar insolation level. The gain of a supplementary speed-frequency droop controller is then set to meet the primary frequency control requirement. Further uniqueness of the VSDS control scheme pertains to the provision of virtual inertia response by regulating the kinetic energy in the rotating mass of the engine-generator and the thermal energy in the heat absorber/receivers. Small-signal analysis shows that the frequency support scheme is inherently stable, and it will provide higher degree of damping as the penetration level of the VSDS system and/or the solar insolation level increase. The efficacy of the proposed scheme is validated by computer simulation

Activity and accomplishments of dish/Stirling electric power system development

The development of the solar parabolic-dish/Stirling-engine electricity generating plant known as the dish/Stirling electric power system is described. The dish/Stirling electric power system converts sunlight to electricity more efficiently than any known existing solar electric power system. The fabrication and characterization of the test bed concentrators that were used for Stirling module testing and of the development of parabolic dish concentrator No. 2, an advanced solar concentrator unit considered for use with the Stirling power conversion unit is discussed

Advanced subsystems development

The concept design for a small (less than 10 MWe) solar thermal electric generating plant was completed using projected 1985 technology. The systems requirements were defined and specified. The components, including an engineering prototype for one 15 kWe module of the generating plant, were conceptually designed. Significant features of the small solar thermal power plant were identified as the following: (1) 15 kWe Stirling-cycle engine/alternator with constant power output; (2) 10 meter point-focusing paraboloidal concentrator with cantilevered cellular glass reflecting panels; (3) primary heat pipe with 800 C output solar cavity receiver; (4) secondary heat pipe with molten salt thermal energy storage unit; (5) electric energy transport system; and (6) advanced battery energy storage capability

Proceedings of the Fifth Parabolic Dish Solar Thermal Power Program

The proceedings of the Fifth Parabolic Dish Solar Thermal Power Program Annual Review are presented. The results of activities within the Parabolic Dish Technology and Module/Systems Development element of the Department of Energy's Solar Thermal Energy Systems Program were emphasized. Among the topics discussed were: overall Project and Program aspects, Stirling and Brayton module development, concentrator and engine/receiver development along with associated hardware and test results; distributed systems operating experience; international parabolic dish development activities; and non-DOE-sponsored domestic dish activities. Solar electric generation was also addressed

Comparative market analysis and economic simulation for Morocco of the parabolic trough and dish CSP technologies

Tese de mestrado integrado em Engenharia da Energia e do Ambiente, apresentada à Universidade de Lisboa, através da Faculdade de Ciências, 2014Nos últimos anos tem-se notado um rápido desenvolvimento, ainda que diferenciado das tecnologias de concentração solar CSP (concentradores parabólicos lineares e de Fresnel, discos parabólicos e torres de concentração solar). O objetivo desta Tese consiste em comparar a tecnologia parabólica linear com o disco parabólico e em analisar a viabilidade económica para um projeto em Marrocos. É apresentada uma análise geral da tecnologia e uma análise de mercado. Por fim é construída uma base de dados contendo as centrais atualmente existentes e planeadas em projetos para o futuro. A comparação dos dois mercados leva a concluir que os sistemas parabólicos lineares se encontram num estado muito mais avançado do que os sistemas baseados em discos parabólicos. Desenvolver uma análise de projeto para o disco parabólico não faria sentido, visto que não existem produtos comerciais para aplicações em larga escala, o que levaria à necessidade de fazer várias suposições para vários parâmetros-chave. Foi então desenvolvido uma análise de projeto para o sistema parabólico linear. Foram escolhidas as cidades com maior número de habitantes em Marrocos, para as quais se construiu uma base de dados de condições ambientais e recurso solar para, por fim, calcular a produção de eletricidade utilizando o programa SAM. Para dois dimensionamentos diferentes da central, adaptados a uma integração de CSP na rede elétrica de 5% e 20% respetivamente, foram calculados indicadores tais como o LCOE, a TIR e o VAL. Os melhores resultados foram obtidos para locais com maior recurso solar e com o dimensionamento adaptado a uma integração de 20% de CSP. A TIR foi estimada com 10.2% para Tânger e 9.9% para a zona de Salé, Rabat e Kenitra.Developments in the past years have differentiated CSP (concentrating solar power) technologies (parabolic trough, power tower, parabolic dish and linear Fresnel) in terms of matureness. The aim of this Thesis is to compare the parabolic trough technology with the parabolic dish and to evaluate the economic feasibility of a project in Morocco. A general survey of the technology is presented and a market analysis is carried out. Finally the currently running power plants and planned projects are brought together in a database and presented. After comparing the two technologies, it was clear that parabolic trough is in a much more mature state than the parabolic dish, in terms of market penetration. In fact, project analysis for the parabolic dish would not make sense as there are no commercial products for large scale and many assumptions would need to be made. Therefore a project analysis was developed only for the parabolic trough technology. For the location, the largest cities in Morocco were chosen, an ambient and solar database was created and the annual electricity generation was calculated using the program SAM. Indicators such as the LCOE, IRR and NPV were calculated for two different power plant designs, one adapted for 5% of CSP integration in the grid and one for 20% of CSP integration. Locations with higher solar resource and 20% of CSP integration have the best results. For the IRR 10.2% is estimated for Tangier and 9.9% for the area of Salé Rabat and Kenitra. Estimated net present values are 3.7 M€ for Tangier and 0.7 M€ for Sale, Rabat and Kenitra

Proceedings: Fourth Parabolic Dish Solar Thermal Power Program Review

The results of activities within the parabolic dish technology and applications development program are presented. Stirling, organic Rankine and Brayton module technologies, associated hardware and test results to date; concentrator development and progress; economic analyses; and international dish development activities are covered. Two panel discussions, concerning industry issues affecting solar thermal dish development and dish technology from a utility/user perspective, are also included

Summary assessment of solar thermal parabolic dish technology for electrical power generation

An assessment is provided of solar thermal parabolic dish technology for electrical power generation. The assessment is based on the development program undertaken by the Jet Propulsion Laboratory for the U.S. Department of Energy and covers the period from the initiation of the program in 1976 through mid-1984. The program was founded on developing components and subsystems that are integrated into parabolic dish power modules for test and evaluation. The status of the project is summarized in terms of results obtained through testing of modules, and the implications of these findings are assessed in terms of techno-economic projections and market potential. The techno-economic projections are based on continuation of an evolutionary technological development program and are related to the accomplishments of the program as of mid-1984. The accomplishments of the development effort are summarized for each major subsystem including concentrators, receivers, and engines. The ramifications of these accomplishments are assessed in the context of developmental objectives and strategies

Solar thermal plant impact analysis and requirements definition study

The technology and economics of solar thermal electric systems (STES) for electric power production is discussed. The impacts of and requirements for solar thermal electric power systems were evaluated

Theoretical and experimental investigation of a Solar Free-Piston Stirling Engine (FPSE) using a flexible bellow for water pumping/power generation

Fossil fuels are the primary energy source globally and currently represent more than 80% of the overall energy consumption. Fossil fuels such as natural gas, oil and coal remain the principal fuels for supply and off-grid power generation in remote areas. Concerns over the negative environmental impact of greenhouse gases emission have shifted toward deploying and developing renewable and low carbon energy technologies. In the last decades, many sustainable and clean energy alternatives have been exploited to make energy and power generation clean and affordable to mitigate the negative impact of fossil fuels on the environment. The Stirling engine is considered one of the most promising solutions of sustainable power technologies to generate electricity from external heat sources. This research develops the computer model of a free-piston Stirling engine (FPSE) prototype operated by a solar simulator for small-scale power generation. The mathematical model was based on solving the working fluid's mass, energy and momentum conservation equations in different engine components. The engine's performance was evaluated based on the other three models: Schmidt, Adiabatic and Simple analysis. It is found that Simple analysis gave the most accurate result because the model considers the heat losses of the Stirling cycle. This research also investigated a novel design of a solar Free-piston Stirling engine for power generation and water pumping, which can be used in remote world regions. The design incorporates flexible bellows or diaphragm working as a power piston and two pre-compressed springs to support the displacer. This mechanical arrangement of the moving components in the engine reduces mechanical friction and air leakage. The experimentally testable FPSE was carried out, including a linear electric generator to develop and validate the theoretical simulation model. It was demonstrated the engine could operate successfully at an input heat temperature of 300C°, at 1 bar pressure and a frequency of 10 Hz. Moreover, a novel design is added to the engine to convert the linear motion to rotary motion. Overall, the engine's measured power and efficiency are low, and more tests of increasing the pressure of the engine for more than 1 bar are required to obtain better performance