Solar-biomass thermoelectric power generation simulation

An experimental investigation on the application of thermoelectric modules for cooling and heating supply air of the conventional fan system is performed. The thermoelectric cooling module is comprised of six thermoelectric plates, two cold water boxes and a hot water box. While the thermoelectric heating module is comprised of three thermoelectric plate, a cold and hot water boxes. The obtained results from the heating capacity of the sensible air cool-warm fan system are presented and compared with those from the conventional fan system (without thermoelectric module). It can be found that the minimum and maximum water temperature obtained from the thermoelectric module are 12 °C and 70 °C, respectively. For on-off modes every 5 min, average cool air obtained from the fan system with thermoelectric module is 2.0 °C lower than that without thermoelectric module while average warm air temperature is 2.5 °C higher than that without thermoelectric module. The obtained results are also expected to guideline that will allow designing and developing the sensible air cool-warm fan system with thermoelectric module system to higher thermal performance.

In recent years, environmental problems, for example global warming and depletion of energy resources, have become serious. Thermoelectric power generation has attracted attention as a means of reducing the effects of such problems. Thermoelectric conversion technology can convert thermal energy directly into electrical energy. Therefore, exhaust heat can be converted into electrical energy. Moreover, it is a clean method of power generation that does not discharge CO2 gas when the electricity is generated. The purpose of this study was to fabricate a thermoelectric (TE) module that can be used at mid-range temperatures of 573–873 K. The component materials selected were Mg2Si as n-type semiconductor and MnSi1.73 as p-type semiconductor. These compounds are non-toxic, environmentally benign, lightweight, and relatively abundant compared with other TE compounds. Ag paste was used to join the components. To prevent diffusion of Ag at the interface of the components and the electrodes, the top and bottom of the components were coated with Ni. The TE module was composed of 12 pairs of elements and Ag seats were used for the electrodes. The dimensions of both p and n-type components were 5.0 mm × 5.0 mm × 6.3 mm. Module size was 36.5 mm × 36.0 mm × 7.0 mm, and alumina was used as substrate. The module was inserted between hot and cold plates, in air, and output power was measured. The open circuit voltage and the maximum output power were 1.6 V and 5.6 W, respectively, at ΔT = 548°C (hot side 587°C; cold side 39°C), and the output power density estimated from these results was 4.4 kW/m2.

In the current study, the concept of building a power plant using thermoelectric generator (TEG) modules is investigated, both technically and economically. The hypothesized thermoelectric generation power plant is a modular system, consisting of a large array of electrically connected thermoelectric generator units for generating clean electricity with-out greenhouse gas (GHG) emissions, noise, or hazardous solid wastes. The envisioned thermoelectric generation power plant (TEGPP) considered here is assumed to utilize solar radiation as a heat source, and water as a heat sink. The viability of such a concept is examined in the current study based on available specifications of a high-output thermo-electric generator module released in the market (TEG1-24111-6.0). Benchmarking is car-ried out considering a high-efficiency photovoltaic (PV) panel in the market (SunPower SPR-MAX3-400), assuming that it operates under standard solar radiation of 1,000 W, and with a standard panel temperature of 25 C, causing it to give an output electric power of 400 W (DC or direct current). It is found that in order to have an electric power of a thermoelectric generator unit similar to that of a photovoltaic panel of equal surface area, the temperature at the hot side of the thermoelectric generator unit should be about 70 C if the cold-side temperature is 30 C. However; under this output power equiva-lence, the price of the thermoelectric generator unit is about 90 times that of a photovol-taic panel of equal size (based on prices of October 2023). At an elevated hot-side tem-perature of 300 C for the thermoelectric generator unit (with the cold-side temperature being still 30 C), the thermoelectric generator unit can generate electric power that is about 25 times the power generated by a photovoltaic panel of an equal geometric area. This big boost in the output power still does not counteract the large cost difference be-tween the thermoelectric generator technology and the photovoltaic technology, where the per-watt(electric) cost in the case of thermoelectric generators is 3.5 times its value in the case of photovoltaic panels. Thus, the TEG technology in its intensified generation mode is still relatively more expensive compared to the PV technology. The practical im-plications of the current study are excluding the thermoelectric generation (based on the Seebeck effect) concept from large-scale commercial power plants, and viewing thermoe-lectric generators as sources of small electric power for waste heat management or con-venient power sources for small mobile devices.

A photovoltaic (PV) and thermoelectric (TE) hybrid module was developed for application to high concentration solar systems. The waste heat from the solar cells under concentrated light illumination was utilized to generate additional electricity by assembling TE devices below the multi-junction solar cells (MJSCs). Considering the high operating temperature of the PV and TE hybrid module compared with conventional concentrator PV modules, the TE device could compensate a part of the MJSC efficiency degradation at high temperature. The performance investigation clarified the feasibility of the hybrid PV and TE module under highly concentrated sunlight illumination.

A vapor compression cycle (VCC) with integrated thermoelectric (TE) modules to boost the heating capacity of the system in an energy-efficient way, especially for cold climate operation, is suggested in this paper. While a baseline heat pump (HP) cycle absorbs heat from a source through an evaporator, the proposed system utilizes TE modules as an intermediate (or third) stage of an otherwise two-stage vapor compression system with a vapor injection compressor. This increases the overall system efficiency and augments the system capacity through the high coefficient of performance (COP) of the TE for small temperature lift conditions. To demonstrate the concept, a prototype refrigerant-to-solid (TE) heat exchanger, consisting of TE modules and microchannel flat tubes, was designed and fabricated so that the whole system could realize an additional 1 kW of heating capacity compared with the baseline system. The TE heat exchanger was integrated into a residential HP unit that uses R-410A as a refrigerant, and the system was tested in a laboratory under the severe condition of −17.8°C, in order to investigate the capacity improvement and the overall COP. Finally, an application of this technique in an automotive heating, ventilating, and air-conditioning system with HFC134a working fluid has been studied for the purpose of providing supplemental heating for electric vehicles and hybrid electric vehicles by establishing a detailed simulation model of a HP system with the TE heat exchanger. Both the laboratory test and the calculation study show that a VCC with integrated TE modules has both reasonable efficiency and increased heating capacity.

The research conducted and described in this paper focuses on the design of a cooling system using thermoelectric or peltier module (TEM) and heatsinks with considerations for temperate climatic conditions. A case study of Nigeria has been chosen. Nigeria as a tropical region experiences high temperature difference between the year (18 - 40 with sunhours ranging between (100 – 210 hrs) monthly, such that the desire for chilled beverages almost throughout the day becomes paramount neccesitating the need for a peltier mobile cooler in tropical regions especially with inadequate electricity supply. A 9-litre rectangular shaped cooler was chosen with an area of 1.155m 2 , a dimension of 0.65 estimated to contain 120 beverages with an estimated heat load of 483W. It is estimated to use five thermoelectric modules, a temperature sensor, tec controller, DC powered battery and ten heat sinks. Comparatively, the design criterias of these peltier cooler were compared with the performance evaluation of existng similar designs and found to be within optimum performance levels. At 10 , the thermoelectric modules are powered to start cooling until the beverages are at 0 estimated to be a period of fifteen minutes), afterwhich the tec controller turns off power and the system is temporarily off until a temperature of 10 is detected by the temperature sensor and a re-cooling is initiated. With these the frozen beverage products received in the morning can be re-cooled as many times as possible.

Energy cost analysis and optimization of thermoelectric (TE) power generators burning fossil fuel show a lower initial cost compared with commercialized micro gas turbines but higher operating cost per energy due to moderate efficiency. The quantitative benefit of the thermoelectric system on a price-per-energy ($/J) basis lies in its scalability, especially at a smaller scale (<10 kW), where mechanical thermodynamic systems are inefficient. This study is based on propane as a chemical energy source for combustion. The produced heat generates electric power. Unlike waste heat recovery systems, the maximum power output from the TE generator is not necessarily equal to the economic optimum (lowest $/kWh). The lowest cost is achieved when the TE module is optimized between the maximum power output and the maximum efficiency, dependent on the fuel price and operation time duration. The initial investment ($/W) for TE systems is much lower than for micro gas turbines when considering a low fractional area for the TE elements, e.g., 5% to 10% inside the module. Although the initial cost of the TE system is much less, the micro gas turbine has a lower energy price for longer-term operation due to its higher efficiency. For very long-term operation, operating cost dominates, thus efficiency and material ZT become the key cost factors.

There is enormous military and commercial interest in developing quiet, lightweight, and compact thermoelectric (TE) power generation systems. This paper investigates design integration and analysis of an advanced TE power generation system implementing JP-8 fueled combustion and thermal recuperation. In the design and development of this portable TE power system using a JP-8 combustor as a high-temperature heat source, optimal process flows depend on efficient heat generation, transfer, and recovery within the system. The combustor performance and TE subsystem performance were coupled directly through combustor exhaust temperatures, fuel and air mass flow rates, heat exchanger performance, subsequent hot-side temperatures, and cold-side cooling techniques and temperatures. Systematic investigation and design optimization of this TE power system relied on accurate thermodynamic modeling of complex, high-temperature combustion processes concomitantly with detailed TE converter thermal/mechanical modeling. To this end, this paper reports integration of system-level process flow simulations using CHEMCAD™ commercial software with in-house TE converter and module optimization, and heat exchanger analyses using COMSOL™ software. High-performance, high-temperature TE materials and segmented TE element designs are incorporated in coupled design analyses to achieve predicted TE subsystem-level conversion efficiencies exceeding 10%. These TE advances are integrated with a high-performance microtechnology combustion reactor based on recent advances at Pacific Northwest National Laboratory (PNNL). Predictions from this coupled simulation approach lead directly to system efficiency–power maps defining potentially available optimal system operating conditions and regimes. Further, it is shown that, for a given fuel flow rate, there exists a combination of recuperative effectiveness and hot-side heat exchanger effectiveness that provides a higher specific power output from the TE modules. This coupled simulation approach enables pathways for integrated use of high-performance combustor components, high-performance TE devices, and microtechnologies to produce a compact, lightweight, combustion-driven TE power system prototype that operates on common fuels.

Uncertainty and sensitivity of the maximum power in thermoelectric generation with temperature-dependent material properties: An analytic polynomial chaos approach

The increasing demand for energy and the efforts to meet this demand cleanly have drawn experts' attention towards renewable energy sources such as solar energy. In this article, a novel hybrid system consisting of a thermoelectric module for converting the heat from a solar module into electrical energy, coupled with a solar cell, has been utilized to maximize energy utilization. This unique integration of thermoelectric and photovoltaic technologies has been shown to take advantage of the fact that the thermoelectric module reduces the temperature of the solar module, consequently increasing its efficiency. The results of this study have been examined in five different cities and for five different climate types through three energy, exergy, and environmental analyses, which were conducted under two distinct scenarios. The PVSyst software was used to simulate environmental conditions and solar cell performance, while MATLAB was employed to code and connect the solar cell and thermoelectric modules. In the first scenario, by varying the thermoelectric merit constant and the intensity of solar radiation, it has been observed that the placement of the thermoelectric module increases the energy and exergy efficiency by approximately 5 % and 4 % respectively, and carbon dioxide pollution is reduced by 194 tons on a specific day of the month (July). Moreover, in the second scenario, by examining the hybrid system in the city of Ahvaz and determining the material and quantity of the thermoelectric and solar cell modules, it has been found that the energy and exergy efficiency of the hybrid system (in the maximum state) reach 20.12 % and 21.23 % respectively, in May. This system in the city reduces carbon dioxide pollution by approximately 41 tons on a specific day of the month (maximum reduction).

Abstract

Mg2Si thermoelectric (TE) elements and modules were fabricated using a commercial polycrystalline Mg2Si source. A monobloc plasma-activated sintering technique was used to fabricate the TE elements and Ni electrodes. The TE modules were composed of n-type Mg2Si, using pin–fin structure elements, in order to achieve simple assembly and to realize stable operation at a temperature of ~800 K. The dimensions of each pin–fin element were 4.2 mm × 4.2 mm × 9.8 mm, and the TE module comprised nine pin–fin elements connected in series. The output characteristics of the pin–fin elements and the TE module were evaluated at temperature differences, ΔT, ranging from 100 K to 500 K. The observed values of open-circuit voltage (V OC) and output power (P) of a single pin–fin element were 98.7 mV and 50.9 mW, respectively, at the maximum ΔT of 500 K. The maximum V OC and P values for the TE module were 588 mV and 174.3 mW, respectively, at ΔT = 500 K.

With the extensive demand for energy harvesting systems from various renewable resources, researches have been carried out in several areas among which thermo-electric generator (TEG) based system is an emerging one. In this paper, eight solar PV modules are interconnected in numerous fashions in order to investigate the behavior of the hybrid system. The transiency of the solar PV modules inside the network has been examined under Healthy Irradiance and Sectional Irradiance. Rise in solar concentration tends to decrease the solar PV module efficiency and this curse to solar PV becomes the boon to the TEG giving rise to higher power output at the terminals. Incorporation of solar photovoltaic (SPV) and thermoelectric (TE), termed as solar photovoltaic-thermoelectric (SPV-TE) hybrid system is found to be a very promising technique to broadening the utilization of solar spectrum and enhancing the power output effectively-cum-efficiently. This hybrid architecture caters electrical energy with additional thermal energy that signifies upon harnessing of solar insolation in an exceptional way.

This paper reviews recent advancements in integrated thermoelectric power generation and water desalination technologies, driven by the increasing global demand for electricity and freshwater. The growing population and reliance on fossil fuels for electricity generation pose challenges related to environmental pollution and resource depletion, necessitating the exploration of alternative energy sources and desalination techniques. While thermoelectric generators are capable of converting low-temperature thermal energy into electricity and desalination processes that can utilize low-temperature thermal energy, their effective integration remains largely unexplored. Currently available hybrid power and water systems, such as those combining conventional heat engine cycles (e.g., the Rankine and Kalina cycles) with reverse osmosis, multi-effect distillation, and humidification–dehumidification, are limited in effectively utilizing low-grade thermal energy for simultaneous power generation and desalination, while solid-state heat-to-work conversion technology, such as thermoelectric generators, have low heat-to-work conversion efficiency. This paper identifies a key research gap in the limited effective integration of thermoelectric generators and desalination, despite their complementary characteristics. The study highlights the potential of hybrid systems, which leverage low-grade thermal energy for simultaneous power generation and desalination. The review also explores emerging material innovations in high figure of merit thermoelectric materials and advanced MD membranes, which could significantly enhance system performance. Furthermore, hybrid power–desalination systems incorporating thermoelectric generators with concentrated photovoltaic cells, solar thermal collectors, geothermal energy, and organic Rankine cycles (ORCs) are examined to highlight their potential for sustainable energy and water production. The findings underscore the importance of optimizing material properties, system configurations, and operating conditions to maximize efficiency and output while reducing economic and environmental costs.

Empirical study on thermal performance through separating impacts from a hybrid PV/TE system design integrating heat sink