Showing papers in "Renewable Energy in 2007"

TL;DR: In this paper, the results of cavitation tunnel and tank tests on an 800 mm diameter model of a marine current turbine (MCT) were presented, and the results provided useful information for the hydrodynamic design of MCTs and detailed data for the validation of numerical models.

TL;DR: In the literature, several calculation models are found for ground heat exchangers as discussed by the authors, which can accommodate for any type of grid geometry that may give greater detail of the temperature variation around the pipes and in the ground.

TL;DR: In this paper, a comprehensive review of past and present converter topologies applicable to permanent magnet generators, induction generators, synchronous generators and doubly fed induction generators is presented and compared on the basis of topology, cost, efficiency, power consumption and control complexity.

TL;DR: In this article, the potential for additional collection and utilization of landfill gas in the US and worldwide was estimated based on the landfill gas situation in the United States and worldwide, and a conservative estimate of methane generation of about 50 nm3 of methane per ton of municipal solid waste (MSW) landfilled was made.

TL;DR: In this article, a general model was developed to find an optimal combination of energy components for a typical rural community minimizing the life cycle cost of a hybrid energy system, which is an excellent solution for electrification of remote rural areas where the grid extension and not economical.

TL;DR: In this article, the main compositions of cellulose and lignin contents for several types of biomass are analyzed chemically, and the experimental results for the actual biomass samples are compared with those for the simulated biomass, which is made of the mixture of the cellulose with Lignin chemical.

TL;DR: The results showed that the higher the enzyme concentration, the more accentuated was the inhibition of methane production and the process was able to recover from the inhibition.

TL;DR: In this paper, a suspended thin flat metallic sheet at the middle or fins at the back wall of an air duct was used as heat transfer augmentations in an air-cooled photovoltaic/thermal (PV/T) solar collector to improve its overall performance.

TL;DR: In this paper, a genetic algorithm is used to optimize the control of a stand-alone hybrid renewable electrical system with hydrogen storage, which can be composed of renewable sources (wind, PV and hydro), batteries, fuel cell, AC generator and electrolyzer.

TL;DR: In this paper, a multivariable control strategy for variable speed, variable pitch wind turbine is proposed for the above-rated power operating condition, which is realized by combining a nonlinear dynamic state feedback torque control strategy with a linear control for blade pitch angle.

TL;DR: In this paper, the thermal behavior of a packed bed of combined sensible and latent heat thermal energy storage (TES) unit with a constant temperature bath/solar collector is investigated.

TL;DR: In this article, the authors focus on the fault ride-through capability of doubly fed induction generator (DFIG) wind turbines and the ability of the DIG to protect itself without disconnection during grid faults.

TL;DR: In this article, the influence of expanded graphite (EG) and carbon fiber (CF) as heat diffusion promoters on thermal conductivity improvement of stearic acid (SA), as a phase change material (PCM), was evaluated.

TL;DR: In this article, a self-heated downdraft gasifier was used as the reactor and char as the catalyst to study the characteristics of hydrogen production from biomass gasification.

TL;DR: In this paper, the authors report on the development and verification of simulation tools based on blade element momentum theory for marine current turbines, including a commercial code (GH-Tidal Bladed) and an academic in-house code (SERG-tidal).

TL;DR: In this paper, artificial neural networks (ANNs) were applied to predict the mean monthly wind speed of any target station using the mean month wind speeds of neighboring stations which are indicated as reference stations.

TL;DR: In this article, the parameters of wind turbine visibility and impact at different distances from the viewer, under different lighting and atmospheric conditions and with moving or stationary blades, were established through an online survey involving an 18 turbine wind farm at three different distances (4, 8 and 12 kilometers).

TL;DR: In this article, the effects of a high level of grid connected photovoltaic (PV) in the middle voltage distribution network have been analyzed and the emphasis is put on static phenomena, including voltage drop, network losses and grid benefits.

TL;DR: In this paper, the replacement of conventional technologies such as diesel generators and/or batteries with hydrogen technologies, including fuel cells in an existing PV-diesel stand-alone power system providing electricity to a remote community was simulated and optimised, using the hybrid optimisation model for electric renewables simulation tool.

TL;DR: In this paper, a series of laboratory experiments were performed in continuously stirred tank reactors at mesophilic conditions, fed semi-continuously with various mixtures of diluted poultry manure and whey.

TL;DR: In this article, a mathematical model for fluid dynamics wind turbine design based on the blade element momentum theory has been implemented and improved, and several simulations were performed in order to maximize the agreement between the simulated and experimental data.

TL;DR: In this article, the authors determined the input-output energy consumption and made a cost analysis of intermediate type stake-tomato grown in open field in Tokat province of Turkey.

TL;DR: In this paper, an attempt has been made to evaluate exergy analysis of a hybrid photovoltaic-thermal (PV/T) parallel plate air collector for cold climatic condition of India (Srinagar).

TL;DR: In this paper, the wind characteristics and wind energy potential of Kirklareli province in the Marmara Region, Turkey were analyzed taking into account the wind data measured as hourly time series.

TL;DR: In this paper, a comparison of two techniques for wind speed forecasting in the South Coast of the state of Oaxaca, Mexico is presented, where the Autoregressive Integrated Moving Average (ARIMA) and the Artificial Neural Networks (ANN) methods are applied to a time series conformed by 7 years of wind speed measurements.

TL;DR: In this article, the authors identify and discuss a number of theoretical and econometric issues involved in the estimation of learning curves, including omitted variable bias and simultaneity, but also methodological problems related to the operationalization of theoretical concepts and the associated use of data.

TL;DR: In this paper, a single-cylinder diesel engine was operated under HOT EGR levels of 5-25% and the EGR level was optimized as 15% based on adequate reduction in NO emissions, minimum possible smoke, CO, HC emissions and reasonable brake thermal efficiency.

TL;DR: In this paper, three of the most frequently used methods in the estimation of the five parameters of the two-component mixture Weibull distribution (pdf) and the numerical methods employed are described.

TL;DR: In this paper, the authors deal with the normalisation of the modules data by considering a base that allows for obtaining a "per unit" representation, and show the influence of these resistances in the module behaviour.