scholarly journals Combined Radiative Cooling and Solar Thermal Collection: Experimental Proof of Concept

Energies ◽  
2020 ◽  
Vol 13 (4) ◽  
pp. 893 ◽  
Author(s):  
Sergi Vall ◽  
Marc Medrano ◽  
Cristian Solé ◽  
Albert Castell
Keyword(s):  
Material Properties ◽  
Renewable Energy Sources ◽  
Hot Water ◽  
Solar Thermal ◽  
Radiative Cooling ◽  
Spectral Transmittance ◽  
Solar Thermal Energy ◽  
Cooling Mode ◽  
Infrared Band ◽  
Experimental Proof

Climate change is becoming more important day after day. The main actor to decarbonize the economy is the building stock, especially in the energy used for Domestic Hot Water (DHW), heating and cooling. The use of renewable energy sources to cover space conditioning and DHW demands is growing every year. While solar thermal energy can cover building heating and DHW demands, there is no technology with such potential and development for space cooling. In this paper, a new concept of combining radiative cooling and solar thermal collection, the Radiative Collector and Emitter (RCE), through the idea of an adaptive cover, which uses different material properties for each functionality, is for the first time experimentally tested and proved. The RCE relies on an adaptive cover that uses different material properties for each functionality: high spectral transmittance in the solar radiation band and very low spectral transmittance in the infrared band during solar collection mode, and high spectral transmittance in the atmospheric window wavelength during radiative cooling mode. Experiments were performed during the summer period in Lleida (Dry Mediterranean Continental climate). The concept was proved, demonstrating the potential of the RCE to heat up water during daylight hours and to cool down water during the night. Daily/nightly average efficiencies up to 49% and 32% were achieved for solar collection and radiative cooling, respectively.

scholarly journals Overall Efficiency of On-Site Production and Storage of Solar Thermal Energy

2021 ◽  
Vol 13 (3) ◽  
pp. 1360
Author(s):  
Teodora M. Șoimoșan ◽  
Ligia M. Moga ◽  
Livia Anastasiu ◽  
Daniela L. Manea ◽  
Aurica Căzilă ◽  
...  
Keyword(s):  
Energy Efficiency ◽  
Thermal Energy ◽  
Urban Areas ◽  
Renewable Energy Sources ◽  
Multicriteria Analysis ◽  
High Energy ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
The Impact ◽  
And Storage

Harnessing renewable energy sources (RES) using hybrid systems for buildings is almost a deontological obligation for engineers and researchers in the energy field, and increasing the percentage of renewables within the energy mix represents an important target. In crowded urban areas, on-site energy production and storage from renewables can be a real challenge from a technical point of view. The main objectives of this paper are quantification of the impact of the consumer’s profile on overall energy efficiency for on-site storage and final use of solar thermal energy, as well as developing a multicriteria assessment in order to provide a methodology for selection in prioritizing investments. Buildings with various consumption profiles lead to achieving different values of performance indicators in similar configurations of storage and energy supply. In this regard, an analysis of the consumption profile’s impact on overall energy efficiency, achieved in the case of on-site generation and storage of solar thermal energy, was performed. The obtained results validate the following conclusion: On-site integration of solar systems allowed the consumers to use RES at the desired coverage rates, while restricted by on-site available mounting areas for solar fields and thermal storage, under conditions of high energy efficiencies. In order to segregate the results and support optimal selection, a multicriteria analysis was carried out, having as the main criteria the energy efficiency indicators achieved by hybrid heating systems.

scholarly journals Potential Savings in DHW Facilities through the Use of Solar Thermal Energy in the Hospitals of Extremadura (Spain)

2020 ◽  
Vol 17 (8) ◽  
pp. 2658 ◽  
Author(s):  
Gonzalo Sánchez-Barroso ◽  
Jaime González-Domínguez ◽  
Justo García-Sanz-Calcedo
Keyword(s):  
Public Sector ◽  
Thermal Energy ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Domestic Hot Water ◽  
The Public ◽  
Hospital Managers ◽  
Energy Ratios ◽  
Environmental Savings

Hospitals need to prepare large amounts of domestic hot water (DHW) to develop their healthcare activity. The aim of this work was to analyse potential savings that can be achieved by installing solar thermal energy for production of domestic hot water in the hospitals of Extremadura (Spain). For this purpose, 25 hospitals between 533 and 87,118 m2 and between 15 and 529 beds were studied, three solar factor scenarios were simulated (0.70, 0.75 and 0.80) and the necessary investment and corresponding economic and environmental savings were calculated. Better economic results and energy ratios for 70% of solar contribution were obtained. These results show an average payback of 4.74 years (SD = 0.26) reaching 4.29 kWh/€ per year (SD = 0.20). Undertaking an investment of 674,423 €, 2,895,416 kWh/year of thermal energy could be generated with which to save both 145,933 € and 638 tons of CO2 per year. It was statistically demonstrated the priority of carrying out an installation with a solar factor of 70%, investing preferably in hospitals in Cáceres over those in Badajoz, especially in the public sector with more than 300 beds. These findings will provide hospital managers with useful information to make decisions on future investments.

scholarly journals Domestic hot water consumption vs. solar thermal energy storage: The optimum size of the storage tank

2012 ◽  
Vol 97 ◽  
pp. 897-906 ◽  
Author(s):  
M.C. Rodríguez-Hidalgo ◽  
P.A. Rodríguez-Aumente ◽  
A. Lecuona ◽  
M. Legrand ◽  
R. Ventas
Keyword(s):  
Energy Storage ◽  
Thermal Energy ◽  
Water Consumption ◽  
Thermal Energy Storage ◽  
Storage Tank ◽  
Hot Water ◽  
Solar Thermal ◽  
Optimum Size ◽  
Solar Thermal Energy ◽  
Domestic Hot Water

Utilizing Solar Thermal Energy for Hot Water

2010 ◽  
Author(s):  
Mohammad Moradi ◽  
Simin Fazel Dehkordi ◽  
Akbar Alidadi
Keyword(s):  
Thermal Energy ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy

scholarly journals Application of Solar Thermal Energy for Medium Temperature Heating in Automobile Industry

2017 ◽  
Vol 7 (2 (S)) ◽  
pp. 19
Author(s):  
Anagha Pathak ◽  
Kiran Deshpande ◽  
Sandesh Jadkar
Keyword(s):  
Solar Energy ◽  
Thermal Energy ◽  
Automobile Industry ◽  
Storage Tank ◽  
Fossil Fuel ◽  
Heating System ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Medium Temperature

There is a huge potential to deploy solar thermal energy in process heat applications in industrial sectors. Around 50 % of industrial heat demand is less than 250 °C which can be addressed through solar energy. The heat energy requirement of industries like automobile, auto ancillary, metal processing, food and beverages, textile, chemical, pharmaceuticals, paper and pulp, hospitality, and educational institutes etc. can be partially met with solar hybridization based solutions. The automobile industry is one of the large consumers of fossil fuel energy in the world. The automobile industry is major economic growth driver of India and has its 60 % fuel dependence on electricity and remaining on oil based products. With abundant area available on roof top, and need for medium temperature operation makes this sector most suitable for substitution of fossil fuel with renewable solar energy. Auto sector has requirement of heat in the temperature range of 80-140 oC or steam up to 2 bar pressure for various processes like component washing, degreasing, drying, boiler feed water preheating, LPG vaporization and cooling. This paper discusses use of solar energy through seamless integration with existing heat source for a few processes involved in automobile industries. Integration of the concentrated solar thermal technology (CST) with the existing heating system is discussed with a case study for commonly used processes in auto industry such as component washing, degreasing and phosphating. The present study is undertaken in a leading automobile plant in India. Component cleaning, degreasing and phosphating are important processes which are carried out in multiple water tanks of varying temperatures. Temperatures of tanks are maintained by electrical heaters which consumes substantial amount of electricity. Non-imaging solar collectors, also known as compound parabolic concentrators (CPC) are used for generation of hot water at required process temperature. The CPC are non-tracking collectors which concentrate diffuse and beam radiation to generate hot water at required temperature. The solar heat generation plant consists of CPC collectors, circulation pump and water storage tank with controls. The heat gained by solar collectors is transferred through the storage tank to the process. An electric heater is switched on automatically when the desired temperature cannot be reached during lower radiation level or during non-sunny hours/days. This solar heating system is designed with CPC collectors that generate process heating water as high as 90OC. It also seamlessly integrates with the existing system without compromising on its reliability, while reducing electricity consumption drastically. The system is commissioned in April, 2013 and since then it has saved ~ 1,75,000 units of electricity/year and in turn 164 MT of emission of CO2 annually.

scholarly journals Modelling of solar thermal energy for household use in equatorial latitude by using the F-Chart model

2021 ◽  
Vol 19 ◽  
pp. 269-275
Author(s):  
Mateo Astudillo-Flores ◽  
◽  
Esteban Zalamea-Leon ◽  
Antonio Barragán-Escandón ◽  
M.R. Pelaez Samaniego ◽  
...  
Keyword(s):  
Thermal Energy ◽  
Geographic Region ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Water Heating ◽  
Equatorial Latitude ◽  
Solar Water Heating ◽  
Solar Water ◽  
Residential Sector

The Andean Equatorial Region, due to its geographic location, shows great potential for using solar energy. Solar thermal energy is of interest in the residential sector in Ecuador and other Andean countries as a method to avoid fossilderived fuels consumption. However, previous learnings of the operation of solar water heating systems in other latitudes cannot be used in the conditions of Ecuador. Thus, the performance of the solar thermal energy systems in this geographic region deserves further study that consider typical high levels of cloudiness and fast climate oscillations. The objective of this work was to investigate the effect of the orientation of solar thermal plates on their energy efficiency and model the behaviour of these systems to predict their operation under Equatorial Andean climate conditions. For the F-Chart calibration different slopes angles were used, according to the typical roofs slopes in Cuenca, Ecuador. Results showed a monthly solar fraction, contributed by an evacuated tube collector is 26% higher than the flat plate collectors. The results also depict that, in the conditions of Cuenca, the greater solar water heating occurs when the collector is inclined 14° and facing towards the south. These findings can be used to predict the best operational conditions for using solar thermal energy collectors to produce hot water in the residential sector under equatorial highland altitude conditions.

A System Modeling Approach for Active Solar Heating and Cooling System With Phase Change Material (PCM) for Small Buildings

2012 ◽  
Author(s):  
Rajeevan Ratnanandan ◽  
Jorge E. González
Keyword(s):  
Phase Change ◽  
Thermal Energy ◽  
Cooling System ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Adsorption Chiller ◽  
Heating And Cooling ◽  
Solar Thermal Collectors ◽  
Change Material

The paper presents a study of the performance of an active solar thermal heating and cooling system for small buildings. The work is motivated by the need for finding sustainable alternatives for building applications that are climate adaptable. The energy demand for heating and cooling needs in residential and light commercial buildings in mid-latitudes represent more than 50% of the energy consumed annually by these buildings. Solar thermal energy represents an untapped opportunity to address this challenge with sustainable solutions. Direct heating could be a source for space heating and hot water, and for heat operated cooling systems to provide space cooling. However, a key limitation in mainstreaming solar thermal for heating and cooling has been the size of thermal storage to implement related technologies. We address this issue by coupling a Phase Change Material (PCM) with an adsorption chiller and a radiant flooring system for year round solar thermal energy utilization in Northern climates. The adsorption chiller allows for chill water production driven by low temperature solar thermal energy for summer cooling, and low temperature radiant heating provides for space heating in winter conditions, while hot water demand is supplied year round. These active systems are operated by high performance solar thermal collectors. The PCM has been selected to match temperatures requirements of the adsorption chiller, and the tank was designed to provide three levels of temperatures for all applications; cooling, heating, and hot water. The material selection is paraffin sandwiched with a graphite matrix to increase the conductivity. The specific objective of the preset work is to provide a system optimization of this active system. The system is represented by a series of mathematical models for each component; PCM tank with heat exchangers, the adsorption machine, the radiant floor, and the solar thermal collectors (Evacuated tubular collectors). The PCM modeling allows for sensible heating, phase change process, and superheating. Parametric simulations are conducted for a defined small building in different locations in US with the objective of defining design parameters for; optimal solar collector array, sizing of the PCM tank, and performance of the adsorption machine and radiant heating system. The monthly and annual solar fractions of the system are also reported.

scholarly journals Design optimization of multi energy systems for domestic hot water uses on the building sector

2021 ◽  
pp. 1-18
Author(s):  
Vasileios Kilis ◽  
Nikolaos Ploskas ◽  
Giorgos Panaras
Keyword(s):  
Linear Programming ◽  
Integer Linear Programming ◽  
Goal Programming ◽  
Renewable Energy Sources ◽  
Energy Systems ◽  
Hot Water ◽  
Solar Thermal ◽  
Objective Functions ◽  
Building Sector ◽  
Time Step

The burden that has come upon the environment, combined with the ever-declining fossil fuel reserves, has led to the need of reducing the conventional energy consumption in building sector and to the promotion of systems based on Renewable Energy Sources (RES). This paper deals with the optimization of multi energy systems in order to cover the needs of hot water in domestic use. In particular, integer linear programming models are formulated and the optimal solutions regarding the degree of participation of the multi energy systems are explored; economic, energy, and environmental criteria are assumed. The respective mathematical programming approaches include linear objective functions, multiple objective functions that either do or do not use weights, as well as goal programming-based ones. The modeling and solution of the problems is done with the General Algebraic Modeling System (GAMS). The case study refers to residential use; both conventional and RES systems are selected for the respective energy demand coverage. The time step of the analysis is 1 hour, in the context of annual operation. According to the results, in the case of the energy criterion, biomass predominates, or heat pumps, when biomass is not included, with an increase in participation of solar thermal collectors when the environmental criterion is introduced. The participation of solar thermal factor is also reinforced in the case of goal programming, because of the relaxation of the initial targets. The analysis demonstrated that the existing integer linear programming methodological tools can be used for investigating problems of multiple energy systems or comparing subsystems.

scholarly journals Modeling of the Solar Thermal Energy Use in Urban Areas

2020 ◽  
Vol 6 (7) ◽  
pp. 1349-1367 ◽  
Author(s):  
Drita Qerimi ◽  
Cvete Dimitrieska ◽  
Sanja Vasilevska ◽  
Arlinda Alimehaj Rrecaj
Keyword(s):  
Thermal Energy ◽  
Urban Areas ◽  
Model Simulation ◽  
Hot Water ◽  
Solar Thermal ◽  
Solar Thermal Energy ◽  
Promising Alternative ◽  
Solar Water ◽  
Water Heaters ◽  
The City

Most of the generated electricity in Kosovo is produced from fossil fuel, a part of the energy comes from the import, while participation of renewable resources is symbolic, and a bias between the grid extension and the load of power generated sometimes results in shortage of electricity and thus frequent power cuts. The use of renewable energy and particularly the solar thermal energy represents one of the most promising alternative strategies. In Kosovo, the global horizontal radiation ranges from 1241 kWh/m2 per year in Shterpce to 1461 kWh/m2 per year in Gjakova, while the average for Kosovo can be estimated at 1351 kWh/m2 per year. The average sun duration for the city of Pristine is 5.44 h, while the average horizontal irradiation is 3.79 kWh/m² per day. Participation of energy consumption in household is still dominant - about 41.4% of the total consumption in Kosovo, 15% of this energy is used for domestic hot water. This energy demand can be lowered significantly by using improved building construction techniques and utilization of RES-s, especially solar thermal. The first step is to map the city in different areas to locate suitable locations for the installation of solar collectors serving sanitary hot water. The demand for sanitary hot water varies from object to object, this variation depends on whether the building is individual or collective, school institutions or religious buildings, for this reason the classification of buildings was done according to the request for sanitary hot water. After that the demand for sanitary hot water is calculated for several different institutions: Residential houses, Dormitories and Hospitals. For all of the above-mentioned cases the data for: solar fraction, solar contribution, CO2 avoided, collector temperature, financial analysis etc. are gained using the TSOL 2018 software. To evaluate the active energy for a time period, the daily, monthly and annual performance for three systems which are located in University Clinical Center of Pristine, Kosovo have been analyzed. In addition the results of the mathematical model, simulation and measured solar energy contribution for solar station in Infective disease clinic have been compared. In this paper, a proposal for replacing the conventional water heaters with the domestic solar water heaters (DSWH) is made. A case study for 38289 Residential households in Pristine has been selected. The initial cost of the solar water heater for the city is 60113730 €. The system saves 7274910 € annually and reduced C𝑂2 emission by 22973400 kg. The results from the paper show that the DSWH is economically feasible in Pristine and can result in fuel saving and CO2 emission reduction.

Economic Analysis of Liquefied Petroleum Gas Gasification Utilizing Solar Thermal Energy

2009 ◽  
Author(s):  
Guohua Shi ◽  
Songling Wang ◽  
Youyin Jing ◽  
Yuefen Gao
Keyword(s):  
Heat Source ◽  
Thermal Energy ◽  
High Energy ◽  
Optimal Operation ◽  
Hot Water ◽  
Solar Thermal ◽  
Electric Heater ◽  
Liquefied Petroleum Gas ◽  
Solar Thermal Energy ◽  
New System

Liquefied petroleum gas (LPG) is an important source of residential gas in China due to its advantages. Traditional LPG vaporizer mainly depends on electric heating as its heat source, which leads to high energy cost and can not meet the demand of energy conservation policy. For a community with 1000 families in Beijing, a new LPG gasification system utilizing solar thermal energy has been designed in this paper. This system uses hot water produced by a solar water heating system as vaporization heat source and uses an electric heater as assisted heat source. In order to understand the economic efficiency of the whole system better, we compare the economic feasibility of the new system with that of traditional LPG vaporization system using annual cost method (AC). In addition, a spreadsheet computer program is used in this paper for purpose of the sensitivity analysis of the parameters. The optimal operation life for each system is calculated. The result shows that the new system is more economical than the traditional system and is an environmentally friendly alternative.

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