ERI improves energy efficiency of mobile desalination plants

Thermodynamic optimization of power plants based on supercritical (SupC) and ultrasupercritical (USC) steam parameters is reported in this article. The objective is to compute the maximum attainable power plant efficiency in Indian climatic conditions using high ash (HA) indigenous coal. A unit size of 800 MWe presently under development in India is considered for energy and exergy analysis of power plants. Commercially established steam turbine parameters are used for the optimization of SupC power plant, whereas advanced steam turbine parameters currently under research and development are used for the optimization of USC power plant. The plant energy efficiency of the optimized SupC and USC power plant based on air-coal combustion (ACC) show considerable increases of 2.8 and 5.2% points, respectively compared with the current SupC ACC power plant (reference plant) being commissioned in India. The increases in plant exergy efficiency for the same power plants are 2.6 and 4.8% points and the corresponding CO2 reductions are about 6 and 11%, respectively. The maximum possible plant energy efficiency in Indian climatic conditions using HA Indian coal is about 42.7% (USC power plant). The effect of low ash coal on plant energy and exergy efficiencies compared with HA coal is also presented. Further, the effect of oxy-coal combustion (OCC) on the plant energy and exergy efficiencies compared with the ACC is studied for the double reheat SupC and USC power plants to account for the impact of CO2 capture. A significant reduction of 8.8 and 6.6% points in plant energy efficiency is observed for SupC and USC OCC power plants, respectively compared with the reference SupC ACC power plant.

To achieve high levels of municipal waste recovery through a system employing mechanical-biological waste processing technologies, effective management of the over-sieve fraction of mixed municipal waste (preRDF) is crucial. This preRDF cannot be landfilled due to its combustion heat exceeding 6 MJ/kg. Therefore, thermal treatment of waste and subsequent energy recovery become pivotal in the national waste management system, particularly amidst energy crises and fluctuating energy prices. Waste-derived energy can serve as a valuable renewable energy source. To ascertain the true efficiency of the plant in terms of energy, environmental impact, and economics, it is vital to organize the concepts of energy efficiency for thermal waste treatment plants. The energy efficiency of a waste gasification plant should be comprehensively assessed from three standpoints: energy efficiency of thermal waste treatment (i.e., energy efficiency index), energy efficiency of recovering chemical energy contained in waste (actual energy efficiency of the plant), and the efficiency of renewable energy production. A thermal waste processing plant qualifies as a renewable energy source, when it generates electricity and heat from the biodegradable fraction of waste. This article endeavours to determine the potential contribution of chemical energy from the biodegradable waste fraction, relying on preRDF fraction test results..

The urgency of the work is due to the feasibility of increasing the energy efficiency of solar power plants through the use of solar energy concentrators. Ways to improve the energy efficiency of solar panels using a sys-tem of directional mirrors, flat Fresnel lenses, spherical concentrators and trackers have been investigated. It is established that the most optimal way to improve the energy efficiency of solar panels is to use inexpensive track-ers with a simple design. The analysis of known types of solar panels, which differ in materials from which their elements are made, and the coefficients of efficiency – dependence of energy produced by a photocell on the intensity of solar radiation per unit of its surface has been carried out, and the type of solar panels by the criterion “price-quality” has been selected. A tracker design has been developed to track the angle of inclination of solar panels to increase efficiency. The electricity generated by the proposed solar power plant was calculated using an online calculator. It is projected to reduce losses when generating electricity for a given power plant due to the use of a tracker compared to a fixed power system, with the same number of solar panels. In order to reduce the cost of the tracker, it is suggested to orientate it to the south at once, and to change the inclination angles twice a year (in early April and late August). The energy efficiency of the power plant is calculated in two stages. At the first stage the amount of electricity from solar panels per year when adjusting only the angle of inclination of the panels to the south is calculated. At the second stage energy efficiency of the power plant is calculated taking into account the increase of energy efficiency of the solar power plant when using the tracker system. The calculated electricity generation of the proposed solar power plant with tracker confirmed the efficiency and feasibility of using the designed tracker system. The application of the designed tracker system allows to increase the energy efficiency of solar panels by an average of 25%.

Decision system based on neural networks to optimize the energy efficiency of a petrochemical plant

In this study, we measure the total-factor energy efficiency under the constraint of environment of 13 coal-fired power plants in Hebei province over the period of 2009 to 2011 using the DEA model which based on the environmental production technology and the directional distance function. The results indicate that the total factor energy efficiency of sample power plants is still at sub-optimal level of around 0.84 and the efficiency is over estimated when without looking at environmental impacts. This indicates that undesirable outputs have a significant influence on energy efficiency of power plants. Poor performance of few power plants is due to their ability to manage the undesirable outputs need to be improved. In order to improve energy efficiency and achieve sustainable development, plants should concentrate on both energy saving and emission reduction at the same time.

Evaluating the energy efficiency of wastewater treatment plants in the Yangtze River Delta: Perspectives on regional discrepancies

Improving energy efficiency in wastewater plants is an important goal for water distribution companies due to the high costs associated with wastewater treatment processes. Most of these costs are generated by the aeration process, respectively optimizing the oxygen control strategy and consequently affecting the ammonium and nitrate levels can lead to significant reduction in energy consumption. Most wastewater treatment plants are already implemented and functioning systems, respectively any interference in modifying invasively existing structures/algorithms is problematic. Following industrial internet of things principles in an Industry 4.0 context, the paper proposes an OPC UA client based model predictive control structure that will allow the solution development in a completely noninvasive manner for the functioning system. The solution is applied in a simulation environment with calibrated and validated model and using real input data. Also, a Node-red and Raspberry Pi platforms application is structured for future long-term testing and validation on real plant following the current research. The paper presents the results of current developments proving the efficiency of the concept.

In this paper comparison of experimentally obtained results of energy efficiency of PV solar plant of 2.08 kWp installed on the roof of the Academy of Sciences and Arts (ASARS) in Banja Luka (Republic of Srpska) in the real climate conditions in 2013 and 2014 are given. It was found that energy efficiency of PV solar plant from April till November 2013 was 12.28%, and in same period in 2014 was 13.03%. Also, it was found that the increase in the ambient temperature by 1°C, PV solar plant efficiency decreases by 0.43% from April till November 2013, and by 0.27% in the same period in 2014.

This paper presents a detailed investigation into enhancing the energy efficiency of wastewater treatment plants (WWTPs) by integrating photovoltaic (PV) systems, emphasizing power flow analysis and experimental validation. Recognizing the substantial energy demands of aeration processes in WWTPs, this study proposes an innovative integration of PV panels with aeration tanks. This approach generates renewable energy and optimizes energy use through the thermal interaction between the PV panels and the aeration tanks. Key findings demonstrate a 15% overall increase in energy efficiency and a 5% improvement in PV efficiency due to aeration-induced cooling, along with a reduction in voltage fluctuations by up to 30% during high-demand periods. Additionally, the integration offsets approximately 20% of the WWTP's total energy consumption. The research is structured into two main components: a comprehensive power flow study using DIgSILENT PowerFactory and a laboratory experiment to validate the integration's effectiveness. The power flow analysis evaluates the electrical impact of PV integration on the WWTP's power grid, focusing on scenarios such as load fluctuations, grid disturbances, and the synchronization of PV generation with plant energy needs. The simulation results indicate that the integration significantly enhances the stability and efficiency of the plant's electrical system, reducing reliance on traditional energy sources. Concurrently, a laboratory experiment explored the practical effects of integrating PV systems with aeration tanks. The experiment demonstrated that the cooling effect provided by the aeration tanks leads to increased PV efficiency and notable energy savings. These experimental results align with the simulation findings, confirming the efficacy of this integrated approach. This study introduces a novel methodology for integrating renewable energy technologies into industrial processes, showcasing the potential for significant energy savings and improved operational efficiency in WWTPs. Future research will focus on scaling this integration strategy and assessing its long-term impacts on energy efficiency and wastewater treatment effectiveness.

Study on a novel co-operated heat and power system for improving energy efficiency and flexibility of cogeneration plants

Energy efficiency evaluation and optimization for wastewater treatment plant

Evaluation of energy efficiency of wastewater treatment plants: The influence of the technology and aging factors

Utilization of solar energy in lieu of traditional feed water heating process in thermal power plants could be a milestone when the world is impending on to analyze critically the present scenario of energy consumption and liberation of greenhouse gases to the atmosphere. For it to occur, a theoretical cycle is thus proposed, which utilizes a feed water heat exchanger (FWHE) based on solar assisted system (parabolic trough), which would work in tandem to the heaters of a 210 MWe thermal power plant. Out of the listed six cases (LPH-2 to HPH-7), a congruent alternative has been proposed in this work, which relies on multi-criteria decision approach, based on analytical hierarchy process (AHP). AHP has been applied on the listed criteria, i.e., improvement in energy efficiency of plant, improvement in exergy efficiency of plant, Reduction in unit heat rate, improvement in exergy efficiency of solar field, solar contribution, and reduction in fuel consumption. After a thorough analysis, HPH-6 has been found as the most suitable alternative and the least one is LPH-2. The outcomes relied on its weightage and the relative significance/importance that have been assigned to them. Outcomes could differ with a change in the significance of various criteria, based on the necessities of the situation.

This article shows the environmental benefits of renewable energy and particularly solar energy. Given the trend of introducing new solar power capacities in the world, the necessity of the energy efficiency evaluation of photovoltaic power plants is substantiated. The components of bound energy in the structure of PVPP energy payback are considered. It is shown that the main issues in the balance of bound energy are the primary energy costs on the technological processes for the production of solar gradation silicon and manufacture of solar cells. The latest technology of manufacturing thin-film photovoltaic converters reduces their production costs. The results of the calculation of the average annual electricity generation at PVPP under conditions of South Urals are adduced. Advantages of solar energy compared to fuel include environmental parameters, energy efficiency and payback of photovoltaic power plants.

The paper provides basic information on the 2 kWp PV solar power plant with monocrystalline silicon solar modules installed on the roof of the Faculty of Sciences and Mathematics (FSM), University of Nis, and the equipment for the investigation of its energy efficiency depending on the real climate conditions. Furthermore, results of the simulation and experimental determination of the energy efficiency of the PV solar power plant at FSM in Nis, in the period from July 1, 2013 to January 1, 2014, are given. It was found that in this time period the average values of the experimental and simulation calculated energy efficiencies of the PV solar power plant were 9.52% and 8.44%, respectively. The increase in the ambient temperature caused a decrease in the PV solar power plant energy efficiency; with an increase in ambient temperature by 1 ?C, the experimental energy efficiency decreased by 0.22%, and the simulation calculated energy efficiency decreased by 0.07%. The obtained data could be used for the planning and application of PV solar power plants in places with a similar climate.