Report
Teaser, summary, work performed and final results
Periodic Reporting for period 1 - NewSOL (New StOrage Latent and sensible concept for high efficient CSP Plants)
Teaser
NEWSOL project addresses the specific challenge towards high efficiency solar energy harvesting by advanced materials solutions and architectures that are in line with those specified in SET-plan (insert link to EU website on subject). Its main objective is to develop advanced...
Summary
NEWSOL project addresses the specific challenge towards high efficiency solar energy harvesting by advanced materials solutions and architectures that are in line with those specified in SET-plan (insert link to EU website on subject). Its main objective is to develop advanced materials solutions based on innovative storage media and concepts for Concentrated Solar Power (CSP) up to validation in field of their performance by real time monitoring. This will be supported by an innovative thermal energy storage design based on the combination of new functional and advanced materials, like heat thermal fluid, sensible and latent energy storage media and insulating materials, into two innovative plant architectures: single tank thermocline storage and concrete type module.
The main challenges of NEWSOL are the development of two new system Architectures: I) Thermocline Concrete Tank, (combining sensible and latent heat up to 550ºC), and II) Concrete module tank (sensible heat up to 550ºC). (See TES page on these concepts) The scope to fulfil the challenges is to validate four new advanced materials: 1) High thermal performance concrete, 2) Molten Salts (including nanoparticles) 3) Filler Material re-usage.
From the careful combination of the materials solutions within the two concept solutions six high relevant impacts are expected: a) Reduced LCOE,10-12cEuro/kWh via higher material performance, b) New designs that enable a reduction of CAPEX and OPEX, c) Increase material understanding enabling long term performance, d) Deployment of high tech monitoring technologies included in the demo activities, e) Environmental re-usage of materials f)Through innovative materials, higher world market penetration of European materials supply sector.
Moreover, investments foreseen at prototype level will be integrated into the Évora Molten Salts Platform site (EMSP.s), part of the European Research Infrastructure Network.
Work performed
Overall in terms of Project Management following activities have been developed::
• Project handbook and templates
• Data Management Plan and Quality Management Plan
• Project Management Collaborative Space
• Project Corporate Image and website
For the Material and new Design following activities have been achieved:
• A pre-selection of material compositions to be used in the thermocline tank and concrete module
• Definition of KPIs required to evaluate the materials and TES systems
• A predesign of the thermocline tank and the module
• An evaluation of the actual implementation for the CSP technology and definition of business cases
Material development activities had a strong laboratorial component, namely:
High performance concrete
• CAC and OPC+FA concretes and thermal aggregates as an alternative to OPC based concretes to increase the stability of the cementitious mix. The results obtained up to this moment show that these mixes improve the thermal properties.
• Selection and optimum combination of aggregates, combining basalt, calcareous, slag and calcium alumina clinker aggregate, with better chemical and physical stability characteristics at high temperatures, when compared to siliceous type aggregates.
Molten Salt:
• Innovative low-melting point and high stability new ternary mixture NaNO3–KNO3–Ca(NO3)2 required an optimization in the preparation process (1kg done,100kg ongoing),especially in terms of upscaling
• A novel Li-salt system, LiNO3-NaNO3-KNO3 obtained at lab scale, has been characterized and is being used as a benchmark to assess the thermal performance compared to the selected Ca-ternary mixture.
• MS incorporating two types of nanoparticles to increase the specific heat capacity of molten salts. A new Ca/K/Na ternary mixture nano salt was investigated by dispersing Al2O3 nanoparticles, an increase in the specific heat capacity has been achieved however this was a short term enhancement, that has not been proved to be stable permanently.
Slag re-usage from past mining activity with high metallic content suitable to be used as a heat storage material. Selection of material, long term stability and characterization (DRX, SEM, etc.) was done, the mineralogic composition identified and a study in terms of grain size and chemical stability was performed.
Insulating concretes for the isolation of the walls and foundation of the tank and module, in order to improve the current solutions based on mineral wool and expanded clay bed.
• Foam concrete-aerogel composites with low density and low thermal conductivity achieving values of density and thermal conductivity below 250 kg/m3 and 0.1 W/mK
• Lightweight high thermal aggregate concretes to achieve lower densities by decreasing the ratio of aggregates and maximizing the content of thermal stable aggregates are being developed.
Concerning the compatibility of materials following activities took place:
• Compatibility between Ca-ternary MS and CAC concrete mixtures,also by means of applying the selected coatings on concrete samples followed by characterization: EDS analysis of the attacked concrete´s surface, Mechanical strength compression, XRD diffraction analysis of molten salt before and after heat treatment tests
• Interaction between Molten Salts and 5 different Filler samples (slag type) were performed with full characterization
• Isothermal static corrosion tests for two stainless steels in Ca(NO3)2-NaNO3-KNO3 eutectic mixture were carried out
• Incorporation of calcium nitrate into concrete
Concerning the developments in terms of Thermal simulation and Sensor technology:
• Start setting up numerical models for the Thermocline concrete tank, investigating the designs for the optimum configuration
• Investigation of trade-off between thermal performance and cost for the basic module design
• Setting up numerical models for investigation of designs with enhanced heat transfer
• Sensor development for ma
Final results
\"Several technological areas have reached significant results that go beyond state of the art:
Molten Salts:
• Innovative low-melting point (131ºC) and high stability (up to 525ºC) Molten Salt ternary have been investigated: NaNO3 – KNO3 – Ca(NO3)2. Corrosion experimental work with stainless steel shows a lower velocity rate than with Solar Salt. This mixture has a lower cost than current solar salt or oil used in power plants, thus using such a mixture would have an important socio-economic impact
• \"\"NaNO3 – KNO3 – Ca(NO3)2\"\" safety sheets produced from the laboratorial tests
• A novel Li-salt system, LiNO3-NaNO3-KNO3 obtained at lab scale was verified to be stable up to 490ºC has been characterized and its advantages highlighted
Slag:
• Slag re-usage has been validated that it is suitable to be used as a heat storage material. A significant environmental advantage was identified, meaning an important positive environmental impact would occur in Sao Domingos area where this slag is currently accumulated next to a river stream in SE Portugal.
Sensor Development
• Sensors have been successfully developed to be embedded into concrete up to 500ºC
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Website & more info
More info: http://www.newsol.uevora.pt.