scholarly journals Heat pumps in the future

2021 ◽  
Vol 345 ◽  
pp. 00004
Author(s):  
Tímea Gresz ◽  
Dávid Faragó ◽  
Péter Bencs

It has been discovered long ago that geothermal energy can be used to substitute various types of fossil fuels. Heat pumps are devices that can transfer the earth’s thermal energy from a cooler to a warmer space. Their deployment would not only benefit large companies but could even reduce the everyday costs of individuals. Among their many advantages, possibly the most important one is that it is environmentally friendly. Their power demand can ideally be satisfied using other renewable energy sources. In this article, the current situation of heat pumps and geothermal energy in Hungary, Sweden and Germany are examined including incentives and grants. Afterwards, the current situation and operation of hybrid systems in Sweden and Egypt are studied.

For the enormously increased power demand in the modern world, the existing fossil fuel sources seem to be inadequate to meet the demands. Hence, it is necessary to switch over to use Renewable Energy Sources (RES). Besides the demand concerns, the power generation from fossil fuels causes environmental pollution prominently. As a result, the utilization of RES has been encouraged. When RES is interconnected with the grid, this system becomes an excellent solution to fulfill the power demand of the present scenario. The energy generated from renewable energy sources varies according to seasonal variations. The power generated from RES can be delivered to the load by interconnecting it with the grid. When a small size RES system is connected with the distribution network, it can deliver energy to the isolated zones where the energy cannot be drawn from the conventional network. In this work, the Artificial Neural Network based Maximum Power Point Tracking scheme has been introduced with Photovoltaic (PV) power generation. Also, a bi-directional charger is introduced to overcome the battery issues. The model is evaluated in the MATLAB/SIMULINK package. The performance of the system is analyzed by applying different voltage levels to qZSI. The voltage gain, effectiveness of the scheme, MPPT and the regulation of the voltages are observed


10.14311/278 ◽  
2001 ◽  
Vol 41 (6) ◽  
Author(s):  
L. Böszörményi ◽  
G. Böszörményi

The need for more intensive utilization of local renewable energy sources is indisputable. Under the current economic circumstances their competitiveness in comparison with fossil fuels is rather low, if we do not take into account environmental considerations. Integrating geothermal sources into combined heat and power production in a municipal CHP plant would be an excellent solution to this problem. This concept could lead to an innovative type of power plant - a gas-steam cycle based, geothermal energy supported cogeneration unit.


2021 ◽  
Vol 13 (13) ◽  
pp. 7025
Author(s):  
Shiva Gorjian ◽  
Behnam Hosseingholilou ◽  
Laxmikant D. Jathar ◽  
Haniyeh Samadi ◽  
Samiran Samanta ◽  
...  

The food industry is responsible for supplying the food demand of the ever-increasing global population. The food chain is one of the major contributors to greenhouse gas (GHG) emissions, and global food waste accounts for one-third of produced food. A solution to this problem is preserving crops, vegetables, and fruits with the help of an ancient method of sun drying. For drying agricultural and marine products, several types of dryers are also being developed. However, they require a large amount of energy supplied conventionally from pollutant energy sources. The environmental concerns and depletion risks of fossil fuels persuade researchers and developers to seek alternative solutions. To perform drying applications, sustainable solar power may be effective because it is highly accessible in most regions of the world. Greenhouse dryers (GHDs) are simple facilities that can provide large capacities for drying agricultural products. This study reviews the integration of GHDs with different solar technologies, including photovoltaic (PV), photovoltaic-thermal (PVT), and solar thermal collectors. Additionally, the integration of solar-assisted greenhouse dryers (SGHDs) with heat pumps and thermal energy storage (TES) units, as well as their hybrid configuration considering integration with other renewable energy sources, is investigated to improve their thermal performance. In this regard, this review presents and discusses the most recent advances in this field. Additionally, the economic analysis of SGHDs is presented as a key factor to make these sustainable facilities commercially available.


2021 ◽  
Vol 50 (4-5) ◽  
pp. 433-444
Author(s):  
Olusola Joshua Olujobi ◽  
Temilola Olusola-Olujobi

Fossil fuels have been the mainstream of energy supply and a major source of foreign exchange earnings for the Federal Government of Nigeria, in spite of being an unrenewable and unsustainable source of energy. Nigeria is yet to tap into the full benefits after privatising its power sector, including the new global evolution in the energy sector and the resulting increasing demand for renewable energy sources, which some consider to be cheaper and more environmentally friendly than fossil fuels and their allied products. Energy security is a challenge to socio-economic development in Nigeria, due to the country’s over-dependency on fossil fuels. In terms of their impact and the potentials to preserve energy sources for longevity and sustainability, however, fossil fuels will come to be seen as an out-dated alternative in the power sector as the energy industry evolves. The implications for Nigeria’s oil sector will not be limited to dwindling crude oil prices. The concerns include poor energy utilisation in Nigeria and the need to promote energy efficiency and sustainability. They have led to the formulation of new energy policies around the world to serve as a vehicle for translating solutions into reality. This study has adopted a library-based legal research method with a comparative approach. The study reveals that it is the lack of a coherent legal framework with incentives for using renewable energy that is largely seen as the key issue causing slow uptake of renewable energy as an alternative source of energy in Nigeria. As well as the need for a coherent legal framework on energy and incentives for using renewable energy sources, the study advocates stringent enforcement of existing energy regulatory policies.


2021 ◽  
Vol 11 (11) ◽  
pp. 5142
Author(s):  
Javier Menéndez ◽  
Jorge Loredo

The use of fossil fuels (coal, fuel, and natural gas) to generate electricity has been reduced in the European Union during the last few years, involving a significant decrease in greenhouse gas emissions [...]


2009 ◽  
Vol 15 (1) ◽  
pp. 25-36
Author(s):  
Branko Blazevic

In this paper, the author focuses on the fundamental hypothesis that the adoption of a concept of regional sustainable development and the use of renewable energy sources are preconditions to organising an acceptable regional tourism offering based on an eco-philosophy The renewable development of tourism regions is the basic framework for research regarding opportunities for introducing renewable energy sources such as hydro energy, wind power, solar energy, geothermal energy, and biomass energy. The purpose of this paper is to indicate the real opportunities that exist for substituting conventional energy sources with renewable ones and the role of renewables in regional development from economic, environmental and sociological viewpoints. It should also be noted that renewable energy sources have a strong regional importance and can contribute significantly to local employment.


Author(s):  
Я.М. КАШИН ◽  
Л.Е. КОПЕЛЕВИЧ ◽  
А.В. САМОРОДОВ ◽  
Ч. ПЭН

Описаны конструктивные особенности трехвходовой аксиальной генераторной установки (ТАГУ), преобразующей кинетическую энергию ветра и световую энергию солнца и суммирующей механическую, световую и тепловую энергию с одновременным преобразованием полученной суммарной энергии в электрическую. Показаны преимущества ТАГУ перед двухвходовыми генераторными установками. Дополнительное включение стабилизатора напряжения в схему ТАГУ позволило расширить область применения стабилизированной трехвходовой аксиальной генераторной установки за счет стабилизации ее выходного напряжения. The design features of the three-input axial generating installation (TAGI), which converts the kinetic energy of wind and light energy of the sun and sums the mechanical, light and thermal energy with the simultaneous conversion of the total energy into electrical energy, are described. The benefits of TAGI in front of the two-input generating installation shown. The additional introduction of a voltage regulator into the TAGI scheme allowed to expand the scope of the stabilized three-input axial generating installation by stabilizing its output voltage.


1992 ◽  
Vol 3 (4) ◽  
pp. 430-443 ◽  
Author(s):  
Ruud Pleune

Present energy use - largely dependent on fossil fuels - is incompatible with the sustainable world concept. In a sustainable world, energy sources are renewable and used in a way that damage to the environment is minimalized. This study investigates the possibility of a sustainable world using renewable energy sources. It appears that - when strict energy conservation is applied - such a sustainable world seems to be attainable. This requires, however, drastic changes in most parts of society.


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7525
Author(s):  
Mariusz Niekurzak

The aim of the manuscript was to present the collective results of research on the profitability of using various renewable sources in Poland with the greatest development potential. In the paper, the economic parameters of various investment projects were determined and calculated, i.e., Net Capital Value (NPV), Internal Rate of Return (IRR) and the Period of Return on Invested Capital (PBT). The economic assessment of the use of RES technologies was supplemented with the assessment of environmental benefits. The ecological criterion adopted in the study was the assessment of the potential and costs of reducing greenhouse gas emissions as a result of replacing fossil fuels with renewable energy technologies. On the basis of the constructed economic model to assess the profitability of investments, it has been shown that the analyzed projects will start to bring, depending on their type and technical specification, measurable economic benefits in the form of a reduction in the amount of energy purchased on an annual basis and environmental benefits in the form of reduction of carbon dioxide emissions to the atmosphere. Moreover, the calculations show a high potential for the use of certain renewable sources in Poland, which contributes to the fulfillment of energy and emission obligations towards the EU. The analyzes and research of the Polish energy market with the use of the presented models have shown that the project is fully economically justified and will allow investors to make a rational decision on the appropriate selection of a specific renewable energy source for their investment. The presented economic models to assess the profitability of investments in renewable energy sources can be successfully used in other countries and can also be a starting point for a discussion about the direction of energy development. Due to the lack of collective, original and up-to-date research on the domestic market, the manuscript provides the reader with the necessary knowledge regarding the legitimacy of using renewable energy sources, investment and environmental profitability.


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