scholarly journals Heat consumption scenarios in the rural residential sector: the potential of heat pump-based demand-side management for sustainable heating

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
José Campos ◽  
Csaba Csontos ◽  
Ádám Harmat ◽  
Gábor Csüllög ◽  
Béla Munkácsy

Abstract Background Poor air quality and inadequate domestic heating sources are tightly connected problems in the Eastern-European countryside. There are a few alternatives to comprehensively solve these problems with an emphasis on economic and environmental sustainability. In this paper, individual heat pumps and energy efficiency measures are analyzed in four scenarios to investigate their role for cleaner and sufficient heating in rural settings. From a high-level perspective, this paper assesses the potential for electricity demand flexibility based on the use of individual heat pumps equipped with hot water storage. Methods In a first step, the current annual residential heating energy consumption of a rural area in Hungary is estimated with a bottom-up model using data from field surveys and official datasets. In a second step, four scenarios estimate the future heating energy consumption considering demographic trends and the average number of building retrofits (thermal insulation) performed yearly in the region. Results The reference scenario is a 20-year projection of heating energy consumption with modest retrofit actions which resulted in small energy savings. Alternative scenarios based on more effective retrofit actions reaching higher rates of the building stock would result in a 23–69% reduction in final energy consumption. Phasing out lignite from the heating energy mix would reduce particulate matter emissions. Each well-insulated dwelling with a heat pump-based system and hot water storage tank could provide theoretical flexibility of approximately 3.4 kWh per 24 h. Conclusions The current energy retrofit practices are not sufficient to solve the challenges faced in this area. Demand-side management policies based on the widespread use of individual heat pumps are an alternative to promote access to cleaner residential heating. An additional benefit is the potential for flexibility in electricity demand. Thus, this paper calls for an integration of energy retrofit with efficient heating (including hot water storage tank) to achieve results that further contribute to a future of sustainable energy.

Energies ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4741
Author(s):  
María Gasque ◽  
Federico Ibáñez ◽  
Pablo González-Altozano

This paper demonstrates that it is possible to characterize the water temperature profile and its temporal trend in a hot water storage tank during the thermal charge process, using a minimum number of thermocouples (TC), with minor differences compared to experimental data. Four experimental tests (two types of inlet and two water flow rates) were conducted in a 950 L capacity tank. For each experimental test (with 12 TC), four models were developed using a decreasing number of TC (7, 4, 3 and 2, respectively). The results of the estimation of water temperature obtained with each of the four models were compared with those of a fifth model performed with 12 TC. All models were tested for constant inlet temperature. Very acceptable results were achieved (RMSE between 0.2065 °C and 0.8706 °C in models with 3 TC). The models were also useful to estimate the water temperature profile and the evolution of thermocline thickness even with only 3 TC (RMSE between 0.00247 °C and 0.00292 °C). A comparison with a CFD model was carried out to complete the study with very small differences between both approaches when applied to the estimation of the instantaneous temperature profile. The proposed methodology has proven to be very effective in estimating several of the temperature-based indices commonly employed to evaluate thermal stratification in water storage tanks, with only two or three experimental temperature data measurements. It can also be used as a complementary tool to other techniques such as the validation of numerical simulations or in cases where only a few experimental temperature values are available.


2020 ◽  
Vol 143 (1) ◽  
Author(s):  
Azzam Abu-Rayash ◽  
Ibrahim Dincer

Abstract This paper features the integration of two renewable energy sources, making a new trigeneration system for residential applications. The system is primarily powered by solar photovoltaic-thermal (PVT) along with geothermal energy. This trigeneration system consists of a ground source heat pump, solar system, high-grade and low-grade heat exchangers, a heat pump system, and a water storage tank (WST). The objective of this system is to provide the main commodities for residential use including domestic hot water (DHW), electricity, and space heating. The system is analyzed energetically and exergetically using thermodynamic-based concepts. The overall energy and exergy efficiencies of the proposed system are found to be 86.9% and 74.7%, respectively. In addition, the energy and exergy efficiencies of the PVT system are obtained to be 57.91% and 34.19%, respectively. The exergy destructions at the high-grade heat exchanger and the water storage tank add up to 36.9 kW, which makes up 80% of the total exergy destruction of the system. Additionally, parametric studies are conducted to evaluate the degree of impact that various important parameters have on the overall system performance.


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