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Using solar tower technology with ceramic particles as heat transfer and storage medium to preheat scrap for induction furnaces in foundries provides solar generated heat to save electricity. With such a system an unsubsidized payback time of only 4 years is achieved for a 70000t/a foundry in Brazil. The same system can be also used for heat treatment of metals. If electricity is used to heat inert atmospheres a favorable economic performance is also achievable for the particle system. The storage in a particle system enables solar boosting to be restricted to only peak times, enabling an interesting business case opportunity.

There is a growing demand from remote communities in Australia to increase the amount of decentralised renewable energy in their energy supply mix in order to decrease their fuel costs. In contrast to large scale concentrated solar power (CSP) plants, small solar-hybrid gasturbine systems promise a way to decentralise electricity generation at power levels in the range of 0.1-10MWe, and reduce to cost of energy production for off-grid, isolated communities. Thermal storage provides such CSP systems with an advantage over photovoltaic (PV) technology as this would be potentially cheaper than adding batteries to PV systems or providing stand-by back-up systems such as diesel fuelled generators. Hybrid operation withconventional fuels and solar thermal collection and storage ensures the availability of power even if short term solar radiation is not sufficient or the thermal storage is empty. This paper presents initial modellingresults of a centrifugal receiver (CentRec)system, using hourly weather data of regional Australia for a 100 kWemicroturbine as well as a more efficient and cost effective 4.6MWe unit. The simulations involve calculation and optimisation of the heliostat field, by calculating heliostat by heliostat annual performance. This is combinedwith a model of the receiver efficiency based on experimental figures and a model of the particle storage system and turbine performance data. The optimized design for 15 hours of thermal storage capacity results in a tower height of 35m and a solar field size of 2100m2 for the 100 kWe turbine, and a tower height of 115m and solar field size of 50 000m2 for the 4.6MWe turbine. The solar field provides a greater portion of the operational energy requirement for the 100kWe turbine, as the TIT of the 4.6MWe turbine (1150°C) is greater than what the solar system can provide. System evaluations of the two particle receiver systems, with a selection of cost assumptions, are then compared to the current conventional means

Coal power stations have been hybridised with concentrated solar thermal (CST) fields which producefeedwater or with turbine bleed steam (TBS) heating from directlinear Fresnel to steam technology. This paper assesses solar hybridisation of boiler based steam power plants, whichpreheat boiler combustion air with a novel high temperature CST system based on a solid particle receiver (SPR). This new method of preheating has the potential to increase the solar share of the overall system, improve fuel saving and therefore produce a higher solar to electric conversion efficiency. These benefits result from theSPR solar systems higher operating temperature and integrated thermal storage. The integrated thermal storage also allows a buffered response time for handling transients in the intermittent solar resource. Analysis indicates that air-solarisation of coal plants can result in significantly higher solar to electric conversion efficiency than existing solar hybridisation options. Solarisation by TBS decreases power cycle efficiency due to bleed steam reduction, while solarisation by air-preheating increases the power system efficiency, primarily due to enhanced boiler efficiency brought about by reduced stack losses. The air solarisation option proposed in this paper has beencompared to current TBS with Fresnel based technology. The comparison was conducted by modelling both systems and analysing the thermodynamic heat and mass balance of the steam cycle and boiler using EBSILON®Professional software. Annual simulation tools, which calculate the performance of the solar field, receiver, storage (when applicable) and other system components, were used to model the output of the solar technologies. These tools, coupled with available economic data and cost models for the newly developed solar components, were used to calculate the levelized cost of energy of the compared hybridisation options. It was calculated that the levelized cost of the solar electricity produced

A particle based solar tower system with storage for temperatures up to 1000°C can economically replace electricity in metallurgical applications like induction furnaces or heat treatment facilities or replace coal in baseload electricity plants.

Coal power stations have been hybridised with concentrated solar thermal (CST) fields which producefeedwater or with turbine bleed steam (TBS) heating from directlinear Fresnel to steam technology. This paper assesses solar hybridisation of boiler based steam power plants, whichpreheat boiler combustion air with a novel high temperature CST system based on a solid particle receiver (SPR). This new method of preheating has the potential to increase the solar share of the overall system, improve fuel saving and therefore produce a higher solar to electric conversion efficiency. These benefits result from theSPR solar systems higher operating temperature and integrated thermal storage. The integrated thermal storage also allows a buffered response time for handling transients in the intermittent solar resource. Analysis indicates that air-solarisation of coal plants can result in significantly higher solar to electric conversion efficiency than existing solar hybridisation options. Solarisation by TBS decreases power cycle efficiency due to bleed steam reduction, while solarisation by air-preheating increases the power system efficiency, primarily due to enhanced boiler efficiency brought about by reduced stack losses. The air solarisation option proposed in this paper has beencompared to current TBS with Fresnel based technology. The comparison was conducted by modelling both systems and analysing the thermodynamic heat and mass balance of the steam cycle and boiler using EBSILON®Professional software. Annual simulation tools, which calculate the performance of the solar field, receiver, storage (when applicable) and other system components, were used to model the output of the solar technologies. These tools, coupled with available economic data and cost models for the newly developed solar components, were used to calculate the levelized cost of energy of the compared hybridisation options. It was calculated that the levelized cost of the solar electricity produced

There is a growing demand from remote communities in Australia to increase the amount of decentralised renewable energy in their energy supply mix in order to decrease their fuel costs. In contrast to large scale concentrated solar power (CSP) plants, small solar-hybrid gasturbine systems promise a way to decentralise electricity generation at power levels in the range of 0.1-10MWe, and reduce to cost of energy production for off-grid, isolated communities. Thermal storage provides such CSP systems with an advantage over photovoltaic (PV) technology as this would be potentially cheaper than adding batteries to PV systems or providing stand-by back-up systems such as diesel fuelled generators. Hybrid operation withconventional fuels and solar thermal collection and storage ensures the availability of power even if short term solar radiation is not sufficient or the thermal storage is empty. This paper presents initial modellingresults of a centrifugal receiver (CentRec)system, using hourly weather data of regional Australia for a 100 kWemicroturbine as well as a more efficient and cost effective 4.6MWe unit. The simulations involve calculation and optimisation of the heliostat field, by calculating heliostat by heliostat annual performance. This is combinedwith a model of the receiver efficiency based on experimental figures and a model of the particle storage system and turbine performance data. The optimized design for 15 hours of thermal storage capacity results in a tower height of 35m and a solar field size of 2100m2 for the 100 kWe turbine, and a tower height of 115m and solar field size of 50 000m2 for the 4.6MWe turbine. The solar field provides a greater portion of the operational energy requirement for the 100kWe turbine, as the TIT of the 4.6MWe turbine (1150°C) is greater than what the solar system can provide. System evaluations of the two particle receiver systems, with a selection of cost assumptions, are then compared to the current conventional means

Fuel reduction has been achieved for coal power stations by hybridisation with solar thermal systems. Current technology uses feedwater or turbine bleed steam (TBS) heating with linear Fresnel based concentrated solar power (CSP) fields. The low temperature heat produced by these systems results in low solar to power conversion efficiency and very low annual solar shares. In this paper the technical advantages of solarising coal fired power plants using preheated air by a novel CSP system based on a solid particle receiver (SPR) are examined. This system is compared to the current deployed state-of-the-art coal plant solarisation by modelling the systems and analysing the thermodynamic heat and mass balance of the steam cycle and coal boiler using EBSILON®Professional software. Annual performance simulation tools are also used to calculate the performance of the solarisation technologies. Solarisation using SPR technology for preheating air in solar-coal hybrid power stations has the potential to considerably increase the solar share of the energy input by 28% points at design point and improve the annual fuel reduction from 0.7% fuel saved to 20% over the year. This is a significant reduction in fossil fuel requirements and resulting emissions. These benefits are a result of SPR solar system’s higher operating temperature and integrated thermal storage, which also allow a buffered response time for handling transients in the intermittent solar resource. Analysis indicates air-solarisation of coal plants can enable 81% higher solar to electric conversion efficiency than currently existing solar hybridisation option. Thus, the cost of the thermal energy generated by Fresnel based TBS solarisation must be up to 38% lower than thermal energy generation of secondary air preheating SPR system for economic parity between the options. Initial calculations indicate that the required thermal energy cost levels for SPR systems for this application are already achievable.