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Sustainable development calls for a larger share of intermittent renewable energy. To mitigate this intermittency, Compressed Air Energy Storage (CAES) technology was introduced. This technology can be made more sustainable by recovering the heat of the compression phase and reusing it during the discharge phase, resulting in an adiabatic CAES without the need for burning of fossil fuels. The key process parameters of CAES are temperature, pressure ratios, and the mass flow rates of air and thermal fluids. The variation in these parameters during the charge and discharge phases significantly influences the performance of CAES plants. In this chapter, the transient thermodynamic behavior of the system under various operating conditions is analyzed and the impact of heat recovery on the discharge phase energy efficiency, power generation, and CO₂ emissions is studied. Simulations are carried out over the air pressure range from 2,500 to 7,000 kPa for a 65 MW system over a five-hour discharge duration. It is also assumed that the heat loss in the air storage and the hot thermal fluid tank is insignificant and standby duration does not impact the status of the system. This result shows that the system exergy and the generated power are more sensitive to pressure change at higher pressures. This work also reveals that every 10°C increase on the temperature of the stored air can lead to a 0.83% improvement in the energy efficiency. The result of the transient thermodynamic model is used to estimate the reduction in CO₂ emissions in CAES systems. According to the obtained result, a 65 MW ACAES plant can reduce about 17,794 tons of CO₂ emission per year compared to a traditional CAES system with the same capacity.

This chapter will introduce three novel technologies demonstrated in Sino-Italian Green Energy Lab of Shanghai Jiao Tong University for the hot summer and cold winter climate zone.

Experimental and modeling works have been conducted on the application of these systems. A comprehensive review on the features of these novel technologies, their adaptability to local climate condition have been carried out, and some initial study results have been reported.

Solar PV direct-driven air conditioner with grid connection, home used small temperature difference heat pump, smart house energy information and control system are appropriate energy technologies with reduced CO₂ emission, which can be applied efficiently in the hot summer and cold winter climate zone. More useful data will be obtained in the future demonstration tests in Sino-Italian Green Energy Lab.

This work shows combining renewable energy technologies and information technologies is crucial to improve the energy efficiency and the comfortableness for indoor environment.

Currently heating and cooling in buildings is responsible for over 30% of the primary energy consumption in the United Kingdom with a similar amount in China. We analyze heat pumps and district thermal energy network for efficient buildings. Their advantages are examined (i.e., flexibility in choosing heat sources, reduction of fuel consumption and increased environmental quality, enhanced community energy management, reduced costs for end users) together with their drawbacks, when they are intended as means for efficient building heating and cooling.

A literature review observed a range of operating conditions and challenges associated with the efficient operation of district heating and cooling networks, comparing primarily the UK’s and China’s experiences, but also acknowledging the areas of expertise of European, the United States, and Japan. It was noted that the efficiency of cooling networks is still in its infancy but heating networks could benefit from lower distribution temperatures to reduce thermal losses. Such temperatures are suitable for space heating methods provided by, for example, underfloor heating, enhanced area hydronic radiators, or fan-assisted hydronic radiators. However, to use existing higher temperature hydronic radiator systems (typically at a temperatures of >70°C) a modified heat pump was proposed, tested, and evaluated in an administrative building. The results appears to be very successful.

District heating is a proven energy-efficient mechanism for delivering space heating. They can also be adaptable for space cooling applications with either parallel heating and cooling circuits or in regions of well-defined seasons, on flow and return circuit with a defined change-over period from heating to cooling. Renewable energy sources can provide either heating or cooling through, for example, biomass boilers, photovoltaics, solar thermal, etc. However, for lower loss district heating systems, lower distribution temperatures are required. Advanced heat pumps can efficiently bridge the gap between lower temperature distribution systems and buildings with higher temperature hydronic heating systems

This chapter presents a case for district heating (and cooling). It demonstrates the benefits of reduced temperatures in district heating networks to reduce losses but also illustrates the need for temperature upgrading where building heating systems require higher temperatures. Thus, a novel heat pump was developed and successfully tested.

This chapter presents mathematical model for geothermal energy allocation. The objective is to a find the minimal length of connections between sources and demand points. The problem is formulated as a transportation problem. The model presented in this case study finds optimal assignment of energy sources to urban areas, with full demand for energy satisfied in all districts using one type of energy.

The use of fossil fuels in developing countries places increasing economic, health, and environmental costs on the population. In decentralized and rural communities without existing grid systems, direct solar technologies provide the basis for electricity production, for water pumping and hot water, and for heating of houses. Examples and case studies for each of these direct solar technologies are presented which may be directly applicable or potentially modified for rural development in countries such as Uzbekistan and Turkmenistan, which have ample direct solar resources. Related design involving both daylighting and passive cooling are described as part of the incorporation of passive solar heating techniques.

This chapter aims to identify new perspectives of geothermal energy investments. For this purpose, all studies in the Web of Science regarding the geothermal energy are taken into consideration. These studies are evaluated with the help of text-mining approach. In this framework, most frequently stated words, two words, and three words are identified. It is concluded that technological development with respect to the geothermal energy is an important issue in this framework. After that, it is also determined that risk is another important factor in this regard. Finally, new implications regarding the geothermal energy are also considered by the researchers. Geothermal energy has a positive contribution to solve many different problems, such as energy dependency, current account deficit problem, and carbon emission. Hence, this study generated the significant issues to improve these investments. While considering the results, it is understood that technological developments related to the geothermal energy projects should be followed effectively. In addition, an effective risk evaluation should be conducted before implementing these projects.

This study has covered many types of solar-powered air-conditioning systems that may be used as an alternative to traditional electrically powered air-conditioning systems in order to reduce energy usage. Solar adsorption air cooling is a great alternative to traditional vapor compression air-conditioning. Solar adsorption has several advantages over traditional vapor-compression systems, including being a green cooling technology which uses solar energy to drive the cycle, using pure water as an eco-friendly HFC-free refrigerant, and being mechanically simple with only the magnetic valves as moving parts. Several advancements and breakthroughs have been developed in the area of solar adsorption air-conditioners during the previous decade. However, further study is required before this technology can be put into practise. As a result, this book chapter highlights current research that adds to the understanding of solar adsorption air-conditioning technologies, with a focus on practical research. These systems have the potential to become the next iteration of air-conditioning systems, with the benefit of lowering energy usage while using plentiful solar energy supplies to supply the cooling demand.