Vellore Institute of Technology (VIT) is a private university located in&nbsp;Tamil Nadu, India. Founded in 1984, as Vellore Engineering College, the institution offers 20 undergraduate, 34 postgraduate, four integrated and four research programs. It has campuses in Vellore, Amravati, Bhopal and Chennai.

VIT is one of the top ranked private universities in India according to NIRF, THE and QS Rankings.&nbsp;Govt. of India has recognized&nbsp;VIT, Vellore as an&nbsp;Institution of Eminence. This has allowed VIT to take independent quality initiatives and move up in world ranking.

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VIT University

VIT Unitversity

Department of Thermal and Energy Engineering

School of Mechanical Engineering

Vellore Campus

Fulltext

Energy Storage

Hydrogen storage in carbon materials—A review

Compressed air energy storage (CAES) is one of the most promising large capacity energy storage technologies and this technology which was used only for demand side management, it has not attained the status of an economic model due to its poor round-trip efficiency. However, in the emerging renewable power scenario, this technology has received a new interest among the scientists. In this paper, a comprehensive thermodynamic analysis is performed for conventional and modified configurations that enhances the round-trip efficiency appreciably. The results reveal that when the compressed air is kept at isothermal temperature at atmospheric condition, the mass of air stored in the tank will be high which will reduce the size of the storage tank appreciably for the given capacity. Further, the possibility of generating cool energy along with power generation during the expansion of compressed air from the atmospheric temperature is also addressed. Though this configuration yields a poor round-trip power efficiency, if the heat of compression and cool energy generated during expansion are utilized for other applications, then the overall polygeneration efficiency is very high. However, if the objective is to maximize the round-trip power efficiency then the compressed air in the storage tank to be heated by the stored heat along with the external heat source. The main conclusions drawn from this work will be of great help by providing guidelines for the future development of a high-efficiency Isothermal CAES (ICAES) system for enhanced power generation/combined with the concept of polygeneration. © 2019 Elsevier Ltd

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Energy

Thermodynamic analysis on compressed air energy storage augmenting power / polygeneration for roundtrip efficiency enhancement

Energy storage technologies have gained considerable momentum in the recent years owing to the rising tide of renewables. The deployment of energy storage is a trend set to continue into 2018 and beyond. In the near future, compressed air energy storage (CAES) will serve as an integral component of several energy intensive sectors. However, the major drawback in promoting CAES system in both large and small scale is owing to its minimum turn around efficiency. In the present work the major drawbacks associated with various existing configurations of CAES system are analysed. Interesting results of Isothermal CAES system are obtained through the present analysis to generate additional output energy compared to the supplied input by harnessing the free energy from the natural water bodies/ocean to enhance the overall turnaround efficiency of the system. The optimum operational characteristics of charging and discharging cycles are also addressed. In the present energy scenario, increasing the percentage of renewable energy (RE) share in the power generation is quite challenging since RE based power generation is intermittent in nature. The integration of energy storage technologies with RE source is imperative as it mitigates the intermittency of available energy. However, the development of efficient energy storage systems is one of the prime challenges in the promotion of renewable energy in a large scale. Among the various storage systems, electrochemical battery storage and pumped hydro storage (PHS) have attracted the commercial market. However, the shorter cycle life makes the battery storage more expensive and the PHS systems involves certain geographical and site constraints. Beyond the said storage systems, compressed air energy storage system which is one of the technically proven system has not been targeted the commercial market owing to its lower turnaround efficiency. Hence, the motivation behind the present research is towards developing efficient CAES configuration with higher turnaround efficiency thereby attaining economic feasibility and sustainability. © 2018 The Author(s).

Scientific Reports

Harnessing Free Energy from Nature for Efficient Operation of Compressed Air Energy Storage System and Unlocking the Potential of Renewable Power Generation

Energy storage has become a matter of great concern in the increasing Renewable Energy (RE) scenario and it plays a vital role in the renewable based micro and nano grids. Among the various energy storage systems, Compressed Air Energy Storage (CAES) system has received the attention of scientists during the recent years due to its long life cycle and the scope and potential of increasing roundtrip efficiency by introducing the concept of polygeneration along with other recent inventions in this technology. In the present work, an experimental investigation has been carried out on small capacity CAES system by constructing a 400 L capacity storage tank and the round trip efficiency is quantified by conducting several charging and discharging experiments. The results reveal that the expander efficiency is 41.79%, 54.25% and 68.3% for the mass flow rates of 0.005 kg/s, 0.0075 kg/s and 0.01 kg/s respectively and the roundtrip efficiency was 13.4%, 17.4% and 22.02% for the mass flow rates of 0.005 kg/s, 0.0075 kg/s and 0.01 kg/s respectively. © 2018 Elsevier Ltd

Journal of Energy Storage

Experimental investigation on small capacity compressed air energy storage towards efficient utilization of renewable sources

Compressed air energy storage (CAES) is one of the most promising mature electrical energy storage technologies. CAES, in combination with renewable energy generators connected to the main grid or installed at isolated loads (remote areas, for example), are a viable alternative to other energy storage technologies. Indeed, because of the advantage of fast response, high economic performance, and small environmental impacts, CAES has an extensive application prospect in renewable power generation. In the present work, the thermodynamic response of the charging and discharging cycles in the storage tank is numerically analyzed for a 2 kW small capacity CAES. The prediction of the system parameters from the thermodynamic analysis is essential in designing the tank, compressor, and expander. The energy extracted from the CAES system is being used for several applications such as power, heating, and cooling. Hence the real time challenge is to quantify the energy utilized for the various services provided by the system to maximize the output and overall efficiency. A thermodynamic study on the proposed system optimizes and compares the charging and discharging characteristics for adiabatic and isothermal compression. The system performance is evaluated using the TRNSYS V17 platform for CAES direct usage (using the heat of compression before the expansion process and cool energy from expansion before the CAES tank), advanced adiabatic - CAES (AA-CAES), CAES with solar system under various parametric conditions. All necessary design parameters are studied and the optimum values are determined using TRNSYS software. © 2017 Author(s).

Journal of Renewable and Sustainable Energy

Performance analysis of a small capacity compressed air energy storage system for renewable energy generation using TRNSYS

Biodiesel is presently available all over the world and can be produced from several types of biomass. Biodiesel fuels are gaining more and more importance as an attractive alternate fuel in various transport sectors due to their renewable nature and lower pollution impact. However, the ports and the shipping sector are still in the early stage of orientation towards biofuels. In the present work, an experimental investigation on the use of diesterol blend (a mixture of diesel, ethanol with biodiesel) with cerium oxide as a nanoadditive (D80JBD15E4S1 + cerium oxide) in a compression ignition engine is performed to assess the emission characteristics. The results reveal that the presence of the cerium oxide nanoparticle changes the reaction patterns and heat transfer rate that reduces both the CO and CO2 percentage concentration in the exhaust gas appreciably. Further, the reduction in CO2 emission in the port of Chennai is quantified considering the replacement of neat diesel with those of modified diesel blend in port owned trucks and vehicles. © 2017 Society of Thermal Engineers of Serbia.

Thermal Science

Role of biodiesel with nanoadditives in port owned trucks and other vehicles for emission reduction

Ports as an industry account for 3% of global greenhouse gas emissions. Sustainable initiatives and zero net energy goals are driving the use of renewable energy sources, such as solar photovoltaic, wind, and other systems. The main objective of this article is to discuss ways to reduce greenhouse gas emissions inside the port by integrating renewable energy technologies in an efficient manner using micro grids. Clean energy-based, direct current (DC) microgrids are considered as a revolutionary power solution. In several development sectors, they are becoming increasingly attractive to researchers since they generate less greenhouse gases (GHGs), lower operating costs, and offer flexibility. This article highlights and details the benefits of implementing renewable-based DC microgrids with suitable energy storage technologies to achieve sustainable port energy management. ©, Copyright Association of Energy Engineers (AEE).

Strategic Planning for Energy and the Environment

Renewable Energy Based Smart Microgrids—A Pathway To Green Port Development

The increase in energy demand and reduction in resources for conventional energy production along with various environmental impacts, promote the use of renewable energy for electricity generation and other energy-need applications around the world. Wind power has emerged as the biggest renewable energy source in the world, whose potential, when employed properly, serves to provide the best power output. In order to achieve self-sustenance in energy supply and to match the critical needs of impoverished and developing regions, wind power has proven to be the best solution. However, wind power is intermittent and unstable in nature and hence creates lot of grid integration and power fluctuation issues, which ultimately disturb the stability of the grid. In such cases, energy storage technologies are highly essential and researchers turned their attention to find efficient ways of storing energy to achieve maximum utilization. The use of batteries to store wind energy is very expensive and not practical for wind applications. Compressed Air Energy Storage (CAES) is found to be a viable solution to store energy generated from wind and other renewable energy systems. A detailed review on various aspects of a CAES system has been made and presented in this paper which includes the thermodynamic analysis, modeling and simulation analysis, experimental investigation, various control strategies, some case studies and economic evaluation with the role of energy storage towards smart grid and poly-generation. © 2016 Elsevier Ltd