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The design of the latent heat thermal storage system (LHTESS) was developed with a thermal capacity of about 100 kW h as a part of small solar plant based on the organic Rankine cycle (ORC). The phase change material (PCM) used is solar salt with the melting/solidification temperature of about 220 °C. Thermophysical properties of the PCM were measured, including its phase transition temperature, heat of fusion, specific heat, and thermal conductivity. The design of the thermal storage was finalized by means of the 3D computational fluid dynamics analysis. The thermal storage system is modular, and the thermal energy is delivered with the use of thermal oil, heated by Fresnel mirrors. The heat is transferred into and from the PCM in the casing using bidirectional heat pipes, filled with water. A set of metallic screens are installed in the box with the pitch of 8–10 mm to enhance the heat transfer from heat pipes to the PCM and vice-versa during the charging and discharging processes, which take about 4 h. This work presents a numerical study on the use of metallic fins without thermal bonding as a heat transfer enhancement method for the solar salt LHTESS. The results show that the absence of the thermal bonding between fins and heat pipes (there was a gap of 0.5 mm between them) did not result in a significant reduction of charging or discharging periods. As expected, aluminum fins provide better performance in comparison with steel ones due to the difference in the material conductivity. The main advantage observed for the case of using aluminum fins was the lower temperature gradient across the LHTESS.

© 2019 MDPI AG. All rights reserved. Cooling the surface of large format batteries with solid conductive plates, or fins, has an inherent advantage of reducing the number of liquid seals relative to some mini-channel cold plate designs, as liquid is not passed through the numerous individual plates directly. This may reduce the overall pack leakage risk which is of utmost importance due to safety concerns associated with the possibility of a cell short circuit and thermal runaway event. However, fin cooling comes at a cost of an increased thermal resistance which can lead to higher cell temperatures and a poorer temperature uniformity under aggressive heat generation conditions. In this paper, a novel graphite-based fin material with an in-plane thermal conductivity 5 times greater than aluminium with the same weight is presented for advanced battery cooling. The thermal performance of the fin is benchmarked against conventional copper and aluminium fins in an experimental programme cycling real 53 Ah pouch cells. The results from the extensive experimental testing indicate that the new fin can reduce both the peak measured temperature and surface temperature gradient by up to 8 °C and 5 °C respectively, when compared to aluminium fins under an aggressive electric vehicle duty-cycle.

The small solar thermal power plant is being developed with funding from EU Horizon 2020 Program. The plant is configured around a 2-kWel Organic Rankine Cycle turbine and solar field, made of Fresnel mirrors. The solar field is used to heat thermal oil to the temperature of about 240 oC. This thermal energy is used to run the Organic Rankine Cycle turbine and the heat rejected in its condenser (about 18-kWth) is utilized for hot water production and living space heating. The plant is equipped with a latent heat thermal storage to extend its operation by about 4 hours during the evening building occupancy period. The phase change material used is Solar salt with the melting/solidification point at about 220 oC. The total mass of the PCM is about 3,800 kg and the thermal storage capacity is about 100 kWh. The operation of the plant is monitored by a central controller unit. The main components of the plant are being manufactured and laboratory tested with the aim to assemble the plant at the demonstration site, located in Catalonia, Spain. At the first stage of investigations the ORC turbine will be directly integrated with the solar filed to evaluate their joint performance. During the second stage of tests, the Latent Heat Thermal Storage will be incorporated into the plant and its performance during the charging and discharging processes will be investigated. It is planned that the continuous filed tests of the whole plant will be performed during the 2018- 2019 period. This study was funded by European Union’s Horizon 2020 Research and Innovation Program under Project Grant Agreement 723596 (Innova MicroSolar).

The design of the Latent Heat Thermal Storage System (LHTESS) was developed with thermal capacity of about 100 kWh as a part of small solar plant, based on the Organic Rankine Cycle (ORC). The phase change material (PCM) used is Solar salt with the melting/solidification temperature of about 220°C. Thermo-physical properties of the PCM were measured, including its phase transition temperature, heat of fusion, specific heat and thermal conductivity. The design of the thermal storage was finalized by means of the 3-D CFD analysis. The thermal storage system is made of six rectangular boxes with dimensions of 1 m (width) × 0.66 m (height) × 0.47 m (depth). The thermal energy is delivered to each of the thermal storage boxes with the use of thermal oil, heated by Fresnel mirrors. The heat is transferred into and from the PCM in the box using 40 bi-directional heat pipes with the external diameter of about 12 mm. The length of the heat pipe in the PCM box is 430 mm and it is placed in the cylindrical metallic protection cartridge, installed in the thermal storage vessel. The working fluid in the heat pipe is water. A set of metallic screens are installed in the box with the pitch of 8–10 mm to enhance the heat transfer from heat pipes to the PCM and vice-versa during the charging and discharging processes, which take about 4 hours. The one unit of the described thermal storage system is undergoing the laboratory tests. Preliminary results demonstrate that the performance of the thermal storage is in a good agreement with numerical predictions. After completion of final design modifications, all units will be assembled at the plant’s demonstration site and tested with the ORC turbine.

This paper presents black box models to represent a LHTESS (Latent Heat Thermal Energy Storage System) coupled with heat pipes, aimed at increasing the storage performance and at decreasing the time of charging/discharging. The presented storage system is part of a micro solar CHP plant and the developed model is intended to be used in the simulation tool of the overall system, thus it has to be accurate but also fast computing. Black box data driven models are considered, trained by means of numerical data obtained from a white box detailed model of the LHTESS and heat pipes system. A year round simulation of the system during its normal operation within the micro solar CHP plant is used as dataset. Then the black box models are trained and finally validated on these data. Results show the need for a black box model that can take into account the different seasonal performance of the LHTESS. In this analysis the best fit was achieved by means of Random Forest models with an accuracy higher than 90%. This study is a part of the Innova MicroSolar Project, funded in the framework of the European Union’s Horizon 2020 Research and Innovation Programme (grant agreement No 723596). Prof. Cabeza would like to thank the Catalan Government for the quality accreditation given to their research group (2017 SGR 1537). GREA is certified agent TECNIO in the category of technology developers from the Government of Catalonia. Dr. Alvaro de Gracia has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 712949.

Conductively cooling the surface of lithium-ion pouch cells may simplify the external cooling mechanism, as heat transfer mediums are not routed across the cell surface. In this paper, the thermal performance of cooling cells with metallic fins is analysed using a developed test rig and thermal model. Results indicate that single edge fin cooling with aluminum sheets is effective in limiting surface temperature gradients to below circa 5℃ for cells subject to realistic EV and mild PHEV duty cycles. For aggressive track racing EV cycles, double edge fin cooling is required to limit surface temperature gradients to below 12℃.\ud

This article examines how wind and solar integration studies have evolved, what analysis techniques work, what common mistakes are still made, and what and why calculating integration costs is such a difficult problem that should be undertaken carefully, if at all. Examples of integration costs for other generation technologies are examined to help illuminate underlying cost causation principles.

Solar photovoltaics (PV) is the dominant type of distributed generation (DG) technology interconnected to electric distribution systems in the United States, and deployment of PV systems continues to increase rapidly. Considering the rapid growth and widespread deployment of PV systems in United States electric distribution grids, it is important that interconnection procedures be as streamlined as possible to avoid unnecessary interconnection studies, costs, and delays. Because many PV interconnection applications involve high penetration scenarios, the process needs to allow for a sufficiently rigorous technical evaluation to identify and address possible system impacts. Existing interconnection procedures are designed to balance the need for efficiency and technical rigor for all DG. However, there is an implicit expectation that those procedures will be updated over time in order to remain relevant with respect to evolving standards, technology, and practical experience. Modifications to interconnection screens and procedures must focus on maintaining or improving safety and reliability, as well as accurately allocating costs and improving expediency of the interconnection process. This paper evaluates the origins and usefulness of the capacity penetration screen, offers potential short-term solutions which could effectively allow fast-track interconnection to many PV system applications, and considers longer-term solutions for increasing PV deployment levels in a safe and reliable manner while reducing or eliminating the emphasis on the penetration screen.

This white paper evaluates the origins and usefulness of the capacity penetration screen, offer short-term solutions which could effectively allow fast-track interconnection to many PV system applications, and considers longer-term solutions for increasing PV deployment levels in a safe and reliable manner while reducing or eliminating the emphasis on the penetration screen. Short-term and longer-term alternatives approaches are offered as examples; however, specific modifications to screening procedures should be discussed with stakeholders and must ultimately be adopted by state and federal regulatory bodies.

This project sought to develop a team-based ministry with the staff at Cadiz Baptist Church in Cadiz, Kentucky. Chapter 1 describes a proposal for team based ministry using goals, a church and community context, and the rationale for the project. Chapter 2 examines the biblical and theological principles of team leadership focusing on the ministry of Jesus. Chapter 3 explores the benefits of effective teamwork, including choosing a team, developing a team, and common denominators between effective secular teamwork and effective team-based ministry in a local church. Chapter 4 gives details of the actual implementation of the project, including a personality test, a spiritual gifts test and question, questions from books, and meetings with an independent group of church leaders. Chapter 5 reviews the effectiveness of the project. The data is analyzed and the goals and process are evaluated.

The field of photovoltaics has undergone dramatic growth over the past few years. This growth has been accompanied by two significant changes in the commercial photovoltaic (PV) market. 1.The major PV market has shifted from the residential and commercial building markets to central station utility power markets. With this switch has come a new focus on the long-term reliability and durability of PV modules and systems. If you are installing tens or even hundreds of megawatts of PV modules, it is absolutely necessary to ensure that they will continue to perform adequately throughout their expected lifetime of at least 25 years. 2.Selling prices for PV modules have decreased from more than $4 per watt to less than $1 per watt in the last 5 years. This reduction in selling process has been driven by low-cost production in the developing world. This means that most of today's PV modules are being manufactured by companies that did not exist 10 or, in many cases, even 5 years ago. Yet the modules must carry 25-year warranties and are expected to survive at least that long without having the benefit of long-term field experience.