Search results for "electricity generation"
showing 10 items of 133 documents
To the theory of high-power gyrotrons with uptapered resonators
2010
In high-power gyrotrons it is desirable to combine an optimal resonator length with the optimal value of the resonator quality factor. In resonators with the constant radius of the central part, the possibilities of this combination are limited because the quality factor of the resonator sharply increases with its length. Therefore the attempts to increase the length for maximizing the efficiency leads to such increase in the quality factor which makes the optimal current too small. Resonators with slightly uptapered profiles offer more flexibility in this regard. In such resonators, one can separate optimization of the interaction length from optimization of the quality factor because the …
Modelling and optimization of modular system for power generation from a salinity gradient
2019
Abstract Pressure retarded osmosis has been proposed for power generation from a salinity gradient resource. The process has been promoted as a promising technology for power generation from renewable resources, but most of the experimental work has been done on a laboratory size units. To date, pressure retarded osmosis optimization and operation is based on parametric studies performed on laboratory scale units, which leaves a gap in our understanding of the process behaviour in a full-scale modular system. A computer model has been developed to predict the process performance. Process modelling was performed on a full-scale membrane module and impact of key operating parameters such as h…
The influence of the stochastic features of the energy source on the design of an electromagnetic generator
2009
The purpose of this paper is to clarify in a general way how the unavoidable randomness of renewable energy sources influences the magnetic design of electric generator. A general model of electro magnetic generator based on the well known d-q axes analysis is given. The energy source is modelled as a stochastic variable and is included in the equations of the system. The equations are solved and, therefore, the energy output of the system is linked to the random characteristic of the energy source. As a result, the magnetic circuit and the parameters of the generator that maximize the energy extraction can be found and generally linked to the stochastic details of the source.
Grid interaction and environmental impact of a net zero energy building
2020
Abstract The concept of Net Zero Energy Building (NZEB), as a grid-connected building that generates as much energy as it uses over a given period, has been developing through policies and research agendas during the last decade as a contribution towards the decarbonization of the building sector. However, since the most applicable and widely used renewable energy supply options are non-programmable, the large-scale NZEBs diffusion into the existing power grids can seriously affect their stability having a relapse on operation costs and environmental impacts. In this context, the study aims at performing the design of the energy systems to be used in the case-study through a wide numbers of…
Evaluation of the optimal renewable electricity mix for Lampedusa island: The adoption of a technical and economical methodology
2020
Abstract Worldwide, the majority of small islands not connected to the main grid is still dependent on fossil fuels. From an economic and environmental point of view, this condition is no more sustainable given the high costs for electricity generation and the high level of pollutant emissions. Furthermore, the dependence on fossil fuel represents a risk for the security of the supply of several small developing Countries since they are obliged to import those resources from foreign Countries. The introduction of renewable energy sources in small islands represents a valid solution to solve these problems. In this context, the paper investigates the case of Lampedusa, a small Italian island…
Towards an integrated design of renewable electricity generation and storage systems for NZEB use: A parametric analysis
2021
Abstract Although nearly zero energy buildings have attracted growing research attention, literature analysis shows that only a limited number of researches try to couple load match/grid interaction issues and environmental impacts in early design stages. The study proposes a novel multidisciplinary design approach that allows to integrate these two conflicting aspects aiming to find trade-offs. The proposed approach has been applied to a building case study, equipped with a photovoltaics system without energy storage. The results show that even though on yearly basis the energy use (5,290 kWhe) is largely overcome by the on-site energy generation (8069 kWhe), an oversized PV system alone m…
Assessment of the Present and Future Offshore Wind Power Potential: A Case Study in a Target Territory of the Baltic Sea Near the Latvian Coast
2013
Offshore wind energy development promises to be a significant domestic renewable energy source in Latvia. The reliable prediction of present and future wind resources at offshore sites is crucial for planning and selecting the location for wind farms. The overall goal of this paper is the assessment of offshore wind power potential in a target territory of the Baltic Sea near the Latvian coast as well as the identification of a trend in the future wind energy potential for the study territory. The regional climate model CLM and High Resolution Limited Area Model (Hirlam) simulations were used to obtain the wind climatology data for the study area. The results indicated that offshore wind en…
A new method for forecasting energy output of a large-scale solar power plant based on long short-term memory networks a case study in Vietnam
2021
Abstract This paper proposes a new model for short-term forecasting power generation capacity of large-scale solar power plant (SPP) in Vietnam considering the fluctuations of weather factors when applying the Long Short-Term Memory networks (LSTM) algorithm. At first, a configuration of the model based on the LSTM algorithm is selected in accordance with the weather and operating conditions of SPP in Vietnam. Not only different structures of LSTM model but also other conventional forecasting methods for time series data are compared in terms of error accuracy of forecast on test data set to evaluate the effectiveness and select the most suitable LSTM configuration. The most suitable config…
Flexibility Services to Minimize the Electricity Production from Fossil Fuels. A Case Study in a Mediterranean Small Island
2019
The design of multi-carrier energy systems (MESs) has become increasingly important in the last decades, due to the need to move towards more efficient, flexible, and reliable power systems. In a MES, electricity, heating, cooling, water, and other resources interact at various levels, in order to get optimized operation. The aim of this study is to identify the optimal combination of components, their optimal sizes, and operating schedule allowing minimizing the annual cost for meeting the energy demand of Pantelleria, a Mediterranean island. Starting from the existing energy system (comprising diesel generators, desalination plant, freshwater storage, heat pumps, and domestic hot water st…
Environmental assessment of 2030 electricity generation scenarios in Sicily: An integrated approach
2020
Abstract This paper deals with the environmental assessment of two electricity scenarios in Sicily, for 2030, characterized by a high exploitation of renewable energy sources in order to quantify the potential contribution of the local strategies in the achievement of the European climate policies and the potential improvement in the future electricity mix, compared to the current one (2014). In order to match these goals, authors integrate the Life Cycle Assessment with a scenario analysis. The future electricity mix scenarios, characterized by a share of renewables (57% for 2030-BS scenario and 51% for 2030-DS scenario) show a reduction of the greenhouse gases emissions per kWh of electri…