Energy Procedia最新文献

The intensive energy requirements, the mismatch between the energy supply and demand and the nocturnal temperature drops are all crucial issues in the greenhouses solar heating. This paper seeks to evaluate the effect of a solar air heater with thermal latent storage on the greenhouse microclimate by pursuing the evolution of the internal climate before and after the heating. In this context, an experimental hydroponic greenhouse (HYDGR) and a solar air heater (SAHLSE) were realized in the Thermal Processes Laboratory in the Research and Technology Center of Energy of Borj Cédria in Tunisia. The solar heating with thermal energy storage enhanced the microclimate of the greenhouse and the temperature didn’t drop less than 32 and 15°C respectively the day and at night. The realized solar collector with thermal latent storage offered higher temperature even when the sun is unavailable and increased the internal temperature by more than 5°C. The studied solar system realized good improvement in the hydroponic greenhouse and appeared to be a beneficial alternative for ensuring optimal microclimate.

This paper deals with site selection problems for hydrogen production plants and aims to propose a structural procedure for determining the most feasible sites. The study area is Adrar province, Algeria which has a promising wind potential. The methodology is mainly composed of two stages: the first stage is to evaluate and select the best locations for wind-powered hydrogen production using GIS and MCDM technique. the AHP is applied to weigh the criteria and compute a LSI to evaluate potential sites, and the second stage is applying different filtration constraints to select the suitable petrol stations for such hydrogen refueling station modification. The result map showed that the entire Adrar province is almost suitable for wind-powered hydrogen production with varying suitability index. The LSI model groups sites into three categories: High suitable areas, Medium suitable areas, and Low suitable. As a result, 2.95 % (12808.97 km²) of the study area has high suitability, 54.59 % (236320.16 km²) has medium suitability, 1.12 %(4842.94 km²) has low suitability and 41.34 % (178950.35 km²) of the study area is not suitable for wind hydrogen production. By applying the constraints, about 4 stations are suitable for wind-powered hydrogen refueling system retrofitting in Adrar province.

Achieving independence from fossil fuels and reducing emissions by increasing energy efficiency and utilizing green vehicles, such as hybrid electric vehicles and alternative green fuels, are among the main goals of energy policies globally. Although electric cars were introduced many years ago, agricultural electric vehicles have recently gained attention. Beyond emissions reductions, the benefits of agricultural electric vehicles include precise control, continuous variable speeds, and overload capability functionality. Moreover, such technology paves the way for the emergence of autonomous connected vehicles, which enhance work quality and increase operator comfort. Along with the electrification of agricultural vehicles, on-site production of renewable energy to supply their required power enhances the benefits in terms of increased efficiency and energy independence as a future-oriented approach. This paper outlines the trends in development and future perspectives of autonomous farm vehicles premised on green energies, with on-site energy production as a byproduct.

Wind is one of the most widely used non-conventional sources of energy. The majority of wind farms use a variable speed Wind Turbines Generator (WTGs) equipped with Doubly-Fed Induction Generator (DFIG) due to their advantages over other WTGs. The analysis of Wind Energy (WE) dynamics with the DFIG – Wind Turbines (WTs) has become an interesting research issue during transient faults. This paper investigates the effects of the different faults on transient stability. The analysis is performed on a 6-bus test system during transient faults and loss of excitation in synchronous generators. The stator-flux oriented vector control approach used for both stator and Rotor Side Converter (RSC) is proposed to mitigate DFIGs impacts on the system stability. The dynamic performance of DFIG variable speed WT under faults conditions are simulated using Neplan® program, considering different disturbance natures.

Sources of renewable energy such as wind energy are indigenous and can help in decreasing the reliance on non-renewable energy sources. After introducing the history of wind energy production in Egypt and worldwide besides its techno-economic importance, this paper presents a comparative review on the wind energy conversion systems (WECS). The horizontal and vertical types of wind turbines with their mathematical dynamic models are discussed. Different types of electrical generators used in WECS in addition to their advantages and disadvantages are illustrated. The various AC-AC converters topologies for WECS are explained with a detailed discussion for their features.

Hybrid AC/DC microgrids (MGs) represent a significant step to go fast through the evolution of smart grids. The type, size, and location of distributed generation units (DGs) have significant impact on the operational cost and the gas emissions in hybrid AC/DC MGs. DGs can be used to supply AC and/or DC electrical energy to their MG local loads. In addition, DGs can supply AC electrical energy to the utility grid during grid-connected mode. With appropriate DGs fuel options, the operating cost and the gas emissions can be minimized. Furthermore, the power system reliability increases. This paper proposes a scheduling algorithm for hybrid AC/DC MGs with multiple fuel options. The operational cost and the gas emissions have been considered as multi-objectives based on particle swarm optimization (PSO) optimization. The approach was applied to a typical hybrid AC/DC MG as a case study, and the effectiveness of the proposed method was verified.

The constant research to eliminate wires in our everyday lives has been going on for years now. When the telephone or the telegraph was first invented, wires were needed to transmit communication between parties. Now, wireless power transfer is very beneficial for society. Wireless power transfer is already being implemented in today’s world in some cases, but it is not part of the "mainstream". Tesla had an ambition of transmitting wireless electricity to help the cause of not needing wires to be spread through the world. Thus, in 1891, he invented the Tesla-coil. The coil’s setup consisted of a primary coil with a capacitor and a secondary coil with a capacitor. Now, there is an essential need for expanding the utilization of wireless charging methods for electric vehicle technology to overcome the wired charging drawbacks and the cost. Various wireless power transfer (WPT) methods for electric vehicles charging are conferred in brief with some scientific examples and approaches. Inductive wireless power transfer prototype is experimentally implemented with 3D design is presented as well. Finally, some future points are mentioned in brief.