scholarly journals All-Day Energy Harvesting Power System Utilizing a Thermoelectric Generator with Water-Based Heat Storage

2020 ◽  
Vol 12 (9) ◽  
pp. 3659 ◽  
Author(s):  
Yasuki Kadohiro ◽  
Shuo Cheng ◽  
Jeffrey S. Cross

Solar thermal systems, especially solar hot water household heating/storage systems, are considered the most cost-effective alternatives to fossil fuel hot water heating energy systems. Recently, solar hot water systems are combined with a thermoelectric generator, forming hybrid systems. However, these hybrid systems described in the literature cannot generate electricity from sunset to sunrise, or at night, when residential consumers use the most electricity. In this paper, an all-day energy harvesting power system utilizing a thermoelectric generator with water-based heat storage is presented to generate electricity all-day and also produce warm water. The experimental and theoretical analyses were conducted to evaluate and verify the performance of the systems. In the case study, the scaled-up system shows potential to provide 198.9 L of warm water per day, 0.912 kWh of electricity in the daytime, and 0.0332 kWh of electricity at nighttime for a typical house with 6.34 m2 of available surface area in Tokyo, Japan. Although the electric power at night is low, this novel lab-scale system shows the potential to be a viable source of electricity and warm water throughout the day, without emitting any greenhouse gas.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Qian Zhang ◽  
Qijie Liang ◽  
Dilip Krishna Nandakumar ◽  
Hao Qu ◽  
Qiongfeng Shi ◽  
...  

AbstractHybrid energy-harvesting systems that capture both wave and solar energy from the oceans using triboelectric nanogenerators and photovoltaic cells are promising renewable energy solutions. However, ubiquitous shadows cast from moving objects in these systems are undesirable as they degrade the performance of the photovoltaic cells. Here we report a shadow-tribo-effect nanogenerator that hybrids tribo-effect and shadow-effect together to overcome this issue. Several fiber-supercapacitors are integrated with the shadow-tribo-effect nanogenerator to form a self-charging power system. To capture and store wave/solar energy from oceans, an energy ball based on the self-charging power system is demonstrated. By harnessing the shadow-effect, i.e. the shadow of the moving object in the energy ball, the charging time shortens to 253.3 s to charge the fiber-supercapacitors to the same voltage (0.3 V) as using pure tribo-effect. This cost-effective method to harvest and store the wave/solar energy from the oceans in this work is expected to inspire next-generation large-scale blue energy harvesting.


2003 ◽  
Vol 17 (08n09) ◽  
pp. 1421-1426 ◽  
Author(s):  
Byung Chul Woo ◽  
Hee Woong Lee

The thermoelectric generation is the direct energy conversion method from heat to electric power. The conversion method is a very useful utilization of waste energy because of its possibility using a thermal energy below 423K. This research objective is to establish the thermoelectric technology on an optimum system design method and efficiency, and cost effective thermoelectric element in order to extract the maximum electric power from a wasted hot water. This paper is considered in manufacturing a thermoelectric generator and manufacturing of thermoelectric generator with 32 thermoelectric modules. It was also found that the electric voltage of thermoelectric generator with 32 modules slowly changed along temperature differences and the maximum power of thermoelectric generator using thermoelectric generating modules can be defined as temperature function.


Proceedings ◽  
2020 ◽  
Vol 65 (1) ◽  
pp. 25
Author(s):  
Antonio Garrido Marijuan ◽  
Roberto Garay ◽  
Mikel Lumbreras ◽  
Víctor Sánchez ◽  
Olga Macias ◽  
...  

District heating networks deliver around 13% of the heating energy in the EU, being considered as a key element of the progressive decarbonization of Europe. The H2020 REnewable Low TEmperature District project (RELaTED) seeks to contribute to the energy decarbonization of these infrastructures through the development and demonstration of the following concepts: reduction in network temperature down to 50 °C, integration of renewable energies and waste heat sources with a novel substation concept, and improvement on building-integrated solar thermal systems. The coupling of renewable thermal sources with ultra-low temperature district heating (DH) allows for a bidirectional energy flow, using the DH as both thermal storage in periods of production surplus and a back-up heating source during consumption peaks. The ultra-low temperature enables the integration of a wide range of energy sources such as waste heat from industry. Furthermore, RELaTED also develops concepts concerning district heating-connected reversible heat pump systems that allow to reach adequate thermal levels for domestic hot water as well as the use of the network for district cooling with high performance. These developments will be demonstrated in four locations: Estonia, Serbia, Denmark, and Spain.


2021 ◽  
Vol 13 (5) ◽  
pp. 2685
Author(s):  
Mohammad Ghalambaz ◽  
Jasim M. Mahdi ◽  
Amirhossein Shafaghat ◽  
Amir Hossein Eisapour ◽  
Obai Younis ◽  
...  

This study aims to assess the effect of adding twisted fins in a triple-tube heat exchanger used for latent heat storage compared with using straight fins and no fins. In the proposed heat exchanger, phase change material (PCM) is placed between the middle annulus while hot water is passed in the inner tube and outer annulus in a counter-current direction, as a superior method to melt the PCM and store the thermal energy. The behavior of the system was assessed regarding the liquid fraction and temperature distributions as well as charging time and energy storage rate. The results indicate the advantages of adding twisted fins compared with those of using straight fins. The effect of several twisted fins was also studied to discover its effectiveness on the melting rate. The results demonstrate that deployment of four twisted fins reduced the melting time by 18% compared with using the same number of straight fins, and 25% compared with the no-fins case considering a similar PCM mass. Moreover, the melting time for the case of using four straight fins was 8.3% lower than that compared with the no-fins case. By raising the fins’ number from two to four and six, the heat storage rate rose 14.2% and 25.4%, respectively. This study presents the effects of novel configurations of fins in PCM-based thermal energy storage to deliver innovative products toward commercialization, which can be manufactured with additive manufacturing.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1576
Author(s):  
Piotr Jadwiszczak ◽  
Jakub Jurasz ◽  
Bartosz Kaźmierczak ◽  
Elżbieta Niemierka ◽  
Wandong Zheng

Heating and cooling sectors contribute to approximately 50% of energy consumption in the European Union. Considering the fact that heating is mostly based on fossil fuels, it is then evident that its decarbonization is one of the crucial tasks for achieving climate change prevention goals. At the same time, electricity sectors across the globe are undergoing a rapid transformation in order to accommodate the growing capacities of non-dispatchable solar and wind generators. One of the proposed solutions to achieve heating sector decarbonization and non-dispatchable generators power system integration is sector coupling, where heat pumps are perceived as a perfect fit. Air source heat pumps enable a rapid improvement in local air quality by replacing conventional heating sources, but at the same time, they put additional stress on the power system. The emissions associated with heat pump operation are a combination of power system energy mix, weather conditions and heat pump technology. Taking the above into consideration, this paper presents an approach to estimate which of the mentioned factors has the highest impact on heat pump emissions. Due to low air quality during the heating season, undergoing a power system transformation (with a relatively low share of renewables) in a case study located in Poland is considered. The results of the conducted analysis revealed that for a scenario where an air-to-water (A/W) heat pump is supposed to cover space and domestic hot water load, its CO2 emissions are shaped by country-specific energy mix (55.2%), heat pump technology (coefficient of performance) (33.9%) and, to a lesser extent, by changing climate (10.9%). The outcome of this paper can be used by policy makers in designing decarbonization strategies and funding distribution.


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