Liquid droplet radiator (LDR) is characterized by the compact arrangement and the low mass per unit power. It is a promising cooling system for the high-power spacecraft. The characteristics of the droplet layer in LDR determine the performance of the heat dissipation. Thus, the study of the droplet radiation heat transfer mechanism is vitally important for the optimal design of the whole LDR system. In the present paper, the radiation heat transfer characteristics of a sparse LDR system are studied from the aspects of the single droplet. The results reveal that the smaller the droplet radius is, the higher the droplet radiation energy per unit mass is. The slower the initial emission speed is, the higher the radiation energy per unit mass is. The higher the initial temperature of the droplet, the higher energy of radiation power per unit mass of the droplet is. Meanwhile, the radiation heat transfer characteristics of different working mediums are also given. These conclusions can provide basis for the optimal design of the sparse droplet radiators and provide guidance for the subsequent research on LDR.
Urbanization is one of the major events in the 21st century has caused rapid growth in the global construction area, which resulted in high consumption of building resources and long term environmental impacts. Analyzing the resource consumption of public buildings and identifying the key factors that affect the consumption of building resources is therefore important for the development of targeted policies. In this paper, we analyzed each branch of the People’s Bank of China based on energy, water, and land resource consumption as well as the structure of energy consumption. Based on resource-consumption indicators, we divided 31provincial administrative into four resources consumption levels; of these, 65% were in the middle or low resource consumption levels. Medium-sized institutions had the highest energy consumption level and more balanced energy consumption structure. Energy consumption per capita, water consumption, and utilization rate of small-sized institutions were low. To reduce resource consumption by public institutions, construction of large-sized institutions should be limited.
Numerous aspects must be measured earlier for implementing a Three-phase power generation system based on sustainable energy sources. Longstanding necessary data must be composed before creating any conclusions concerning the implementation of such a system. Potential of Solar, wind and hydel energy are precisely measured at Kadamparai location in TamilNadu, India. In this research, an effective analytical hybridization method is suggested for grid systems comprising exclusively of sustainable energy source like solar photovoltaic (PV), wind, and pumped hydro sources. One of the method was tested numerically and analytically, the results can be applied to achieve emission free power grid. Hydro, wind, and solar photovoltaic energy are the deepest sustainable energy sources in worldwide installed capacity. However, no reports have been printed about hybrid grid systems encompassed of all three sources, simulation model and analysis are the first of its kind anywhere. This investigation may be pragmatic as a real-world guide for applying similar systems in various places. Wherever renewable sources are used in India, the main combination is about solar and wind only. This is the first novel analytical approach presents for connecting renewable energy sources to a utility grid. Simulink analysis and mathematical modelling of renewable resources can extend year-round power supply to switchyard with use of underground water batteries. In future carbon emission percentage will be nullified and cure global warming and climate changes once implementing this project into real.
Southern region of India has more peak and valley on its geological surface which leads more waterfalls. Sustainable energies are trending now due to zero emission power generation. Earth is gifted by natural energy resources every routine of time. Energy storage system for combining all the resources provides uninterrupted power supply to year around. India assures reduction of Green House Gas emissions intensity per unit gross domestic product 35% below level of year 2005, using sustainable energies in generating power to Grid. The intermittency nature of energies affects the stability of grid can be avoided by energy storage system. Energy storing system also solving the extension of power grid, increasing percentage contribution of sustainable energy in power generation, and tallying demand, and supply of energy. Technology implementing for storing power still needed more new experiments to improve the interest on development of sustainable energy generation. Pumped hydro storage is bulky potential storage technology commonly used, however power generation in low water level due to depletion of monsoon, current frequency lag for pumping and reserve spinning are achievable only by gravity hydro storage. This research technically designs and testing the proposed model of gravity hydro storage in SIMULINK analysis tool for Kadamparai location at Tamil Nadu, India. The optimum design of cylinder and piston are analyzed by ANSYS WORKBENCH also dynamic modeling analysis of hybrid sustainable energies with proposed gravity storage is done. Hybrid model with energy storage can implement in large and small hydro power houses for year around generation. This paper also suggesting model makes all abandoned mines as zero emission energy batteries.
The paper presents the study, Erturan, Cekirge and Thorsen , that is introducing facts and capacity of continuously changing and evolving situation in the environment. In this paper , it is presented facts and indicators of the Planet Earth capacity factor considering questions of existing human activities’ safety and sustainability. These questions can be extended for advancing and developing our home planet without encountering a dilemma and future generations and civilization developments’ sufferings because of our movements. In order to get positive answers to these questions, we definitely need to improve our technological skills. It might be an appropriate explanation to understand our current timeline. As the 2020 COVID-19 pandemic demonstrates, nature can quickly become a formidable foe—particularly if humans are caught unprepared. Although Earth’s ideal conditions have provided humans with a perfect environment to thrive socially and economically, her natural resources are not limitless and her natural balances are delicate. It is critical to begin developing solar technology to meet the human race’s energy needs. The human race currently meets its energy needs mainly through fossil fuels. But not only are fossil fuel reserves limited but also excessive reliance on fossil fuels can cause long-term environmental damage. On the other hand, solar energy is bountiful, free and clean. As such, solar energy is a great alternative source of energy that will ensure that future generations enjoy a hospitable planet and healthy and economically stable living conditions. Planet Earth supports our current lifestyles, but there are obvious indications of unusual changes in her cycles. Only recently have we begun to consider plans regarding Earth’s capacity; historically, we have mostly considered local environmental factors. Unfortunately, the time for only thinking of local factors has passed – we must consider the planet’s capacity for continued human survival in order to create a sustainable lifestyle. As humans, we believe that we live in some sort of “infinite time spiral” – that is, we believe that the human race will live forever – but this is simply illusionary cortical brain activity. The mitigation measures are also presented by .
The global fossil fuel source is limited and is getting depleted rapidly. The growth in energy demand worldwide is ever increasing, thus increasing fossil fuel consumption. Use of fossil fuels in electrical energy generation have environmental impacts like global warming , CO2 emissions etc., This necessitated use of alternate renewable energies like solar, wind to meet energy requirements. But the limitation of renewable energy sources are that they are intermittent in supply, uncertainty of availability etc., lead to difficulties in ensuring stability in electrical grid networks. These constraints led to the development of various energy storage technologies so that available surplus energy from renewable sources can be stored and released as and when needed to maintain grid supply stability both in terms of power and frequency. Thus Electrical Energy Storage (EES) is of great importance to ensure striking a balance between demand and supply .Many storage technologies have been developed and used at present like pumped hydro, solar thermal, batteries, compressed air, flywheel etc., Compressed air storage technology has the advantage of reduced emission and possibility of large capacity plants. About 440 MW installations of CAES are available at present around the world. Compared with other energy storage technologies, CAES is proven to be a clean and sustainable type of energy storage with the unique features of high capacity and long-duration of the storage.
The intention of this paper is to model and analyse a small scale compressed air storage system useful for standalone and micro-grid applications. The economics of CAES is also discussed. Thermodynamic analysis of the charging and discharging cycles in the storage tank is modelled and analysed for a small capacity CAES. A thermodynamic study on the proposed system covering all components like compressor, expander is also done and related models analysed. The heat energy released during compression
stage is recovered, utilized during expansion so that the round trip efficiency improves. This paper also covers this aspect, comparing the efficiencies of systems with and without heat recovery.
With the proliferation of distributed energy resources and the volume of data stored due to advancement in metering infrastructure, energy management in power system operation needs distributed computing. In this paper, we propose a fully distributed Alternating Direction Method of Multipliers (ADMM) algorithm to solve the distributed economic dispatch (ED) problem, where the optimization problem is fully decomposed between participating agents. In our proposed framework, each agent estimates the dual variable and the average of the total power mismatch of the network using dynamic average consensus, which replaces the dual updater in the traditional ADMM with a distributed alternative. Unlike other distributed ADMM, the proposed method does not rely on any specific assumption and captures the real-time demand change. The algorithm is validated successfully via case studies for IEEE 30-bus and 300-bus test systems with the penetration of solar photovoltaic.
Electric power systems in many parts of the world are undergoing a transformation from relying almost exclusively on dispatchable power (e.g., fossil, nuclear, and large hydropower) toward incorporating more variable nondispatchable generation (e.g., wind and solar PV). We show for the first time that solar generation can decrease some aspects of variability in the peak residual load in power systems. The electric load minus generation from nondispatchable resources is known as the “residual load.” The maximum or peak residual load provides an estimate of the quantity of dispatchable generation capacity required to supply electric load during all hours. We study the peak residual load as a function of increasing wind and solar generation for three power systems in the U.S.: the PJM system in the Mid-Atlantic, the ERCOT system in Texas, and the NYISO system in New York. We analyze more than a decade of historical data for each region. The introduction of variable renewable power is often thought to increase the variability of most characteristics of power systems. Contrary to this idea, we show the inter-annual variability in peak residual load decreases for all three systems as a function of increasing solar generation. We attribute this effect to correlations between solar generation and peak electric load values. Peak electric load values for all three systems occur during summer heat waves, when air conditioning is used. We find that as solar generation increases, the quantity of dispatchable generation capacity needed to supply the residual load becomes more similar year-to-year. Therefore, in some systems, expansion of variable solar generation can increase predictability of the peak residual load. Thus, an increase in solar generation could ease achievement of certain system reliability targets.
Renewable energy is attracting much attention due to limited traditional energy sources and severe environmental issues caused by the over-consumption of fossil fuels. It is promising to use renewable energy for the power supply to buildings, as the building sector accounts for a large portion of global energy consumption with a continuous increasing trend. This study aims to analyze the technical and economic feasibilities of applying hybrid photovoltaic-wind-battery systems for high-rise buildings in Hong Kong based on the TRNSYS platform. Detailed economic benefits of the hybrid renewable energy system are estimated considering the feed-in tariff, transmission line loss saving, network expand and infrastructure saving, and social benefit of carbon reduction. It is found that the hybrid photovoltaic-wind-battery system can cover 24.79% of the annual electrical load of a high-rise building. The average self-consumption and self-sufficiency ratio of the hybrid system is 100% and 46% respectively. Battery storage in the hybrid system can not only improve the self-consumption and self-sufficiency performance, but also benefit the utility grid relief. The levelized cost of energy of the hybrid photovoltaic-wind-battery system is about 0.431 US$/kWh. This study can provide references for the development of hybrid renewable energy systems in Hong Kong and guide the application of renewable energy and battery systems to high-rise buildings in urban regions.
For the unconventional reservoirs, advances in drilling and fracturing technologies prompt operators to tend to the designs of large-scale, staged fracturing with multi-cluster in one stage. However, with the well spacing getting closer, it must be noted that the risk of inter-well interference increases since the hydraulic fractures can interfere, even hydraulically communicate. In the past few years, inter-well interference became more prominent and thus received significant attention in the development of unconventional reservoirs. The interferences in fracturing to adjacent wells have negative effects as: (1) abnormal changes in wellhead pressure, daily gas production and daily water production of adjacent wells; (2) water flood out, mud backflow or sand production, etc. In some extreme cases, production wells may never fully recover or stop production permanently.