Cleaner Energy Systems最新文献

Plant factory is one of the controlled environment agriculture forms with huge potential to alleviate food crisis, but the high energy cost restricts its widespread adoption. Numerous researches have explored various factors for energy-saving in plant factories in their settings, but there is a lack of analysis of the importance of these factors in energy saving. In this work, the energy-saving effect assessment of various factors in the container plant factory is investigated. Four cities (Harbin, Taiyuan, Shanghai, and Guangzhou), three plant densities (cultivation area: floor area=100 %, 150 %, and 200 %), and two temperature/humidity setpoints (20/22 ℃, 60/70 %, and 16/22 ℃, 50/95 %) are selected as operating conditions to cover different weather conditions and plant heat loads. The energy-saving effect of each factor is calculated using a random forest algorithm based on large amounts of energy simulation data. We identify that envelope overall heat transfer coefficient (U), air conditioner coefficient of performance (COP), and light efficacy (Efficacy) are three factors that have the largest impact on energy-saving in plant factories, in which light efficacy is the most important factor. Simultaneous optimization of these three factors could possibly reduce electricity consumption by ∼50 % compared to the base case. Finally, employing weight-light intensity correlation, the minimum specific energy consumption is approximately 4.76 kWh/kg lettuce fresh weight. This study utilizes advanced machine learning methods to sort out important factors and shows that significant energy reduction may be achieved by optimizing dominant factors, which gives a general guidance for future designers to build energy-efficient plant factories.

Energy is directly related to the economy and its demand would increase with development in the industrial, residential, transportation, and commercial sectors. It is projected that by 2050, the global energy demand will experience a two-fold increase. Currently, almost 85 % of the consumed energy globally is generated by burning non-renewable sources like oil, coal, and gas. Open car parking areas at universities, shopping malls, hospitals, etc. are unexploited areas that have enormous potential to generate renewable energy without disturbing the flora and fauna of the region. This study analyses the techno-economic feasibility of generating grid-connected energy using solar photovoltaic, PV panels on the parking lots of academic institutions and utilizes a part of it for charging the parked EVs . The best system is found to produce energy at a cost of 0.0529 USD/kWh, almost 54 % less compared to the grid. In the proposed design, 69 % of the total energy is produced by solar PV and almost 52.5 % is sold to the grid. The capacity factor of the PV system, at this location, is 19.8 %. The annual utility bill saving is around US $ 798,100. The internal rate of return and simple payback period are 7.35 % and 10.9 years. The proposed system architecture also caters to an EV charging capacity of 195 MWh, about 1.5 % of the total energy consumption, and a charging load of 578 kWh/day. This proposed PV energy system, for the parking areas, can be adopted in any other region with similar climatic conditions.

Energy harvesting systems can capture and convert small amounts of energy from various natural sources, contributing to offsetting the growing global energy challenges without incurring the depletion of additional energy resources. Human kinetic energy can be obtained from physical exercise - in indoor cycling, the athlete's metabolic energy converts into heat, enthalpy (to the environment), and work. This study reports on the concept development of the Green&Healthy Power system, an energy harvesting system that collects energy from physical activities. A case study based on an indoor bike generator as a conceptual innovation is presented. The user can select the intensity of effort in which the exercise occurs to produce electricity. Using situations based on literature results, the gains are evaluated by measuring aerobic endurance. The user is informed about the health benefits of the exercise (traditional indices), the energy produced, and the greenhouse gas emissions avoided. This study also reviews some aspects of precedent practices, highlighting the concept's challenging characteristics and setting out the initial formulation of the Green&Healthy Power system. This contribution defines research, development, and demonstration priorities for new ideas and technologies to improve energy efficiency and reduce the final consumption of primary energy. As results of the study case, initial figures indicate that 1000 people performing 20 min of activities on the energy harvesting system three times a week can avoid annual emissions of 180 kg CO₂ and produce 800 kWh/year of electricity, resulting in savings of R$ 800/year. Brazil has a population of 200 million inhabitants and if 1 % of the population carried out this activity, electricity generation could reach up to 1.6 TWh/month (= 19.2 TWh/year), representing 3.4 % of electricity flows within the Brazilian electricity matrix.

Renewable energy trading could be considered the next step in power trading's development. It is probable that individuals currently involved in power trading will need to upgrade their data collection, processing, and reporting systems. This article provides a comprehensive evaluation of renewable energy trading utilizing Blockchain technology. Initially, the paper examines country-specific renewable energy trading with a focus on India, China, the US, France, and Germany's renewable energy policies. Moreover, the paper presents potential renewable energy trading markets such as peer-to-peer, over the grid, and partially or fully independent microgrid's. This paper shows the appraisal of bond, commodity, derivative, and algorithm-based renewable energy trading using different Blockchain methods, including Ethereum and R3 Corda. It is find out during the renewable energy trading, proposers of bid, also include capital cost of the renewable energy power plant, salvage value after useful life of different component of renewable energy power plant. It is also find out proper trading is to be done with offering subsidies of up to 70 % of the capital cost, and with a 30 % viability gap finance (VGF) at this cost.

At present, China is in a stage of high-quality economic development. Rising demand for electricity has created a lot of CO₂ emissions, which has put great pressure on the low-carbon development of China's power industry. Therefore, China attaches great importance to the potential of various clean power generation to replace thermal power generation. Given this, the study examines the potential for substitution of non-clean energy generation (thermal power generation) and clean energy generation (hydropower, nuclear power generation, and other energy generation) from 1993 to 2022 by using the translog production function and provides a scenario analysis of energy substitution for power generation. Firstly, the k-fold cross-validation method is used for ridge regression estimation in this paper, which avoids the subjective bias caused by the ridge trace diagram method used in most of the previous literatures. Secondly, compared with the previous research on the substitution elasticity of the power sector, this paper subdivides the types of clean power energy when estimating the substitution elasticity, which can better analyze the substitution relationship between thermal power and various clean power. Finally, the estimated substitution elasticity of thermal power and various clean energy sources is greater than 1, which indicates that clean energy generation can effectively replace non-clean energy generation. This provides an effective substitution elasticity parameter for the power sector to study low-carbon development. The scenario analysis show China's power sector can increase the proportion of clean power generation to reduce the carbon emission intensity while ensure power supply, which can help the Chinese government adjust the implementation of policies to promote the early peak of carbon emissions and keep carbon emission at a low level in the power sector.

In Uganda, biogas is a low-value product considered a pro-poor renewable energy source. Farmers with excess biogas release it into the atmosphere, contributing to global warming. This study used mixed data sources and methods to explore how biogas can be valorised to become a valued commercial energy source in Uganda and reduce greenhouse gas emissions. The results reveal the inefficiency of current biogas purification processes: the concentration of methane (CH₄) in the upgraded gas was only 58 %, far below the standard specification of 98 %. The pilot production process never came close to even the lower specification level of 95 % for upgraded methane and the upper specification level of 5 % for carbon dioxide (CO₂). The presence of traces of H₂S, water and oxygen could lead to the corrosion of storage equipment and complicate the use of the gas. The study also found that small-scale biogas producers with excess gas have a high desire to sell it but have currently no clear idea of how to valorise it to reach the market. Our market analysis revealed three promising customer segments: bioenergy entrepreneurs, gas companies and electricity suppliers. Taken together, our findings imply that to become a commercially viable energy source, the quality of biogas needs to be improved using valorisation strategies like monitoring gas quality, shaping the market, market research and certification and controls. The national bioenergy policy could consider subsidising valorisation technologies to make them affordable for farmers and thus support a more climate-smart biogas commercialisation process.

Some non-conventional concrete mixes are a new generation of concrete characterised by reduced energy requirements during their production. Compared with conventional concrete, some non-conventional concrete mixes incorporating waste materials have reduced energy requirements due to their excellent abilities in constraining high energy requirement values of conventional concrete ingredients. Despite several studies on energy requirement of non-conventional concrete, the underlying reduction of energy requirement of concrete containing waste tire rubber (WTR) and waste brick powder (WBP) is not completely understood due to the absence of appropriate studies in this area. In this study, the energy requirements of control and non-conventional concrete mixes among various concrete grades (20 MPa, 25 MPa and 30 MPa) are developed in conjunction with the compressive strength results of concrete, to generate eco-concrete mixes with reduced energy requirements and considerable strength performances. The results indicate that inclusion of WTR and WBP in concrete reduces the energy consumption of concrete. It is shown that the choice of amounts of WTR and WBP in concrete should not only be based on the drive to reduce energy consumption, but also the motivation to avoid substantial reduction in concrete compressive strength. For all concrete grades, the reductions in compressive strength of 5P20T mixes (5 % WBP and 20 % WTR) need to be greater than 32.57 % compared with 0P0T mixes, to achieve concrete energy requirement reductions of less than 5.56 %. Moreover, the reductions in energy requirements of concrete for 5P10T mixes are nearly 5 % for all concrete grades, with reductions in compressive strength being in the range of 11.67 % – 16.87 %. The study establishes that 5P10T concrete mixes provide a route for reductions in energy requirement of concrete without substantial reductions in compressive strength. These results therefore imply the exciting possibility that the energy requirement of concrete can be tailored by controlling the replacement levels of conventional concrete ingredients.

Citizens' views should be clearly and openly presented to policymakers in decision-making processes regarding energy policies. Policy makers need to take into account the views of the public in order to provide support for the policies they will pursue. In this study, which was conducted using quantitative research methods, a scale was developed to determine the electricity generation preferences of individuals. Within the scope of the study, the validity and reliability analyses of this scale, whose items were developed by the researchers based on the literature review, were carried out. The results of the analyses show that the items under different factors exemplify similar behaviors and the internal consistency of the scale is high. The scale consists of 15 items and three sub-dimensions related to renewable, nuclear and thermal energy sources. Using this scale, the preferences of individuals in certain regions regarding energy production can be determined in a valid and reliable manner.

This work investigates a novel approach in terms of design, configuration, heat integration and optimization of a 6 kWe total energy system fueled with natural gas. Specifically, a Solid Oxide Fuel Cell (SOFC) is used for both electricity generation and fuel reforming, since its exhaust stream fuels a polybenzimidazole (PBI)-based, High Temperature-Proton Exchange Membrane Fuel Cell (HT-PEMFC). The study investigates the possible advantages of such a system in both technical and economic terms. After modeling each component/subsystem, the total system model is optimized with the objective function aiming to maximize the net electrical efficiency of the total hybrid system. The system is optimized with a genetic algorithm-based optimization strategy, reaching a net electrical efficiency of 43.6 %. In comparison to standalone fuel cell systems with the same net electrical power output, the proposed hybrid system outperforms both an HT-PEMFC system and an SOFC system, which perform at net electrical efficiencies of 23.2 % and 40.7 %, respectively. Also, the lifecycle cost for the proposed system is $64,097, which is lower than both standalone HT-PEMFC and SOFC systems. Therefore, with the current high rising costs for natural gas, such highly efficient systems are likely to become important elements of the future energy infrastructure.

The prosumers are the new performers progressing towards a low-carbon future. Renewable-based power generation is essential, even in rural areas, to pave a path toward sustainable development. This study establishes a simulation model for two identical residential buildings to assess the prosumer's impact on future local (standalone) energy systems. According to the climate condition of Pakistan, the technical, economic, and environmental performance of the standalone system is evaluated using TRNSYS software. Assumptions and modeling of different components, photovoltaic (PV) panels, and batteries are also discussed. This study provides the starting point of a real-time framework of energy trade between two rural houses connected with a common microgrid. Both houses are medium-sized family houses with almost identical electricity demands. One house has PV mounted on the rooftop, with the battery as an optimal energy storage option. Attention is given to peak demand management and surplus energy during enough production hours. A dynamic energy management approach between two buildings is proposed based on TRNSYS and blockchain. Simulation results show that the real-time implementation of local energy production and energy trading at the household level facilitates achieving the dual benefits of reducing consumer costs and maximizing self-consumption.