Wind Power Electricity Research Articles

Transition to sustainability with natural gas from fracking

This paper analyzes the energy requirements and cost of constructing a renewable energy system with the excess energy available from natural gas obtained by hydraulic fracturing. Using U.S. Energy Information Administration estimates of the future availability of natural gas and estimates from the literature of the energy required to build a wind power and photovoltaic (PV) electricity generation system, we develop a scenario for constructing a sustainable electricity system for the United States. A preliminary analysis is made of the cost of the renewable system. Net reductions in emissions of greenhouse gases and oxides of nitrogen are also estimated. The analysis suggests that it would be possible to build a sustainable electricity system from the excess natural gas from fracking in less than 30years. After that, the energy produced from the renewable system is sufficient to replace obsolete equipment and construct new generation technology as required by growth in demand. Even after accounting for the emissions associated with its construction and operation, the sustainable system would reduce greenhouse gas (GHG) and nitrogen oxides emissions compared to continued use of a fossil fuel system.

EFFECT OF BATTERY ENERGY STORAGE SYSTEMS ON THE VALUE OF AN INTERMITTENT WIND ENERGY SOURCE IN ISOLATED SYSTEMS

The increase in environmental protection awareness and the progressive exhaustion of conventional fossil energy sources have increased interests in integrating wind energy sources into existing power systems. Despite the various benefits of wind power, the intermittency and unpredictability of wind power generation cause operational concerns and waste usable capacity as the installation of the wind generation sources increases. To enhance the value of an intermittent wind energy source by using a battery energy storage system (BESS), an iterative algorithm that combines improved dynamic programming and a hybrid direct search method were developed for solving the optimal wind- thermal- battery coordination scheduling (WTBCS) problem in power systems. Key concerns in BESSs and the integration of wind energy and electric power systems were investigated and discussed using the proposed WTBCS software. In addition, the developed WTBCS software is useful in assessing the effect and economic benefits of installing BESSs and wind farms. Numerical experiments were conducted to provide information for both operational and planning problems in isolated power systems, such as the Penghu power system.

Power Generation from the Dynamic Wind Energy available during Maneuvering of Train

A wind power electricity generation system is the most cost competitive of all the environmentally clean and safe renewable energy sources in the world. This paper brings a new possibility for the utilization of the wind generated power, for various electrical components inside a typical railway train through the batteries charged by the wind energy harnessed by a series of wind turbines mounted near the rest room of each coaches of train coaches. This paper deals with the design and development of a wind turbine system with a concept of generation of electricity as an auxiliary source in the train. Aerodynamics is the study of air flow around a moving object where the dynamics of bodies moving relative to gases, especially the interaction of moving objects with the atmosphere. The aerodynamic profile is formed with a rear side, is much more curved than the front side facing the wind. Thus the movement of wind and its velocity can be studied based on this analysis. The simulation results and the theoretical results are verified.

What hinder the further development of wind power in China?—A socio-technical barrier study

Promoting wind power is a long-term strategy of China to respond to both energy shortage and environmental pollution. Stimulated by various incentive policies, wind power generation in China has achieved tremendous growth, with the cumulative installed capacity being the largest worldwide for five consecutive years since 2010. However, obstructed by various barriers, wind power provides only 2.6% of national electricity generation in China, despite the strong support from the government. From a socio-technical transition perspective, this paper aims to systematically analyze the barriers hindering the further development of China's wind power. A wind power niche model is established to illustrate the complex interactions among actors in the wind power industry and electricity supply regime. Then, qualitative content analysis is adopted to process the related evidence and data, and four categories of socio-technical barriers are identified, including technology, governance, infrastructure and culture barriers. The study shows that various interrelated barriers form a blocking mechanism which prohibits the further development of wind power in China. Policy suggestions are proposed to eliminate the barriers and further empower the wind power niche. The lesson learned from China can offer useful references for other economies to promote wind power industries of their own.

Multistage Wind-Electric Power Forecast by Using a Combination of Advanced Statistical Methods

A multistage advanced statistical method has been proposed for the real-time wind-electric power generation forecast of wind power plants (WPPs) based on a combination of artificial neural network (ANN) and support vector machine (SVM) models. In the first stage, output data of wind speed and wind direction from different numerical weather prediction (NWP) models are chosen among a set of grid points in the neighborhood of each WPP to train the ANN and SVM models. The best grids are then selected from those NWP grid data giving the minimum training error, and used for training and testing the developed wind-electric power forecast models. In the second stage, for each NWP data, ANN and SVM models are applied separately. The forecast errors are corrected by applying model output statistics (MOS) at the third stage. Different 48-h ahead forecasts of wind-electric power are then combined at the fourth stage by appropriate weighting factors to obtain an intermediate 48-h ahead forecast of the electrical power generated from wind. In the final stage, these forecast data are recombined to give an ultimate forecast. The proposed model is tested on 25 WPPs satisfactorily. The performance of the proposed multistage cascaded statistical model is compared with the available benchmark models and actual wind-electric power generation data. It has been shown that the proposed model performs better than the reference models in terms of short-term forecast accuracy, especially for WPPs in complex terrains with a scattered wind regime.

Simulation of Power System with Stochastic Energy Resources and Compressed Air Energy Storage

Abstract Wind and solar power production depends on available energy resources, which are not always accessible, a backup system has to be introduced to cover unpredictable energy deficiency in systems with large quantities of wind and solar power. This publication introduces a model to simulate a system with wind power generation and electricity storage.

Optimal scheduling of a microgrid with a fuzzy logic controlled storage system

Abstract This paper presents an algorithm for reducing the operating cost of microgrids. The proposed algorithm determines the day-ahead microgrid scheduling and builds a fuzzy expert system to control the power output of the storage system. To perform such tasks, two genetic algorithms were employed. One of them generates the microgrid scheduling and determines the fuzzy rules of the expert system, whereas the other is used to tune the membership functions. In this way it is possible to optimize the expert system according to load demand, wind power availability and electricity prices. Simulations were carried out in a microgrid comprising a diesel generator, a microturbine, a fuel cell, a wind turbine and a battery. Both interconnected and island operation modes were considered. Simulation results verify the effectiveness of the proposed algorithm.

A New Study for Hybrid PV/Wind off-Grid Power Generation Systems with the Comparison of Results from Homer

This article presents the development of a computational model for the sizing optimization of an off-grid hybrid solar wind electric power generation system. The model includes a PV model, wind power model, and a model for the required battery. The developed mathematical model also comprises a model for a diesel generator as an alternative for the storage battery. A simulation code has been developed using MATLAB to solve the mathematical model and simulate the performance of the hybrid system with different configuration for performance analysis and optimal sizing purpose. The mathematical model and the computer code have been developed using a general approach. This approach can be used to simulate, analyze and optimize any hybrid solar/wind/battery/diesel off-grid electric power generation systems. Also, it can be utilized for any remote area in the world depending on the weather data used as input to the developed simulation code. The results obtained via the presently developed model and code have been validated against previously published work and also against that obtained via the widely used software (HOMER). The model is used for the sizing optimization and assessment of a hybrid solar wind system based on the weather conditions for Dhahran city in the eastern province of the Kingdom of Saudi Arabia.

Dynamic simulation and analysis of ancillary service demand response strategies for variable air volume HVAC systems

Output variability and low generating inertia associated with solar and wind electric power generation resources increase the requirement of grid-scale ancillary service capacity and add strain to existing firm generators that provide these services. Buildings consume the majority of electricity in the United States and can play a significant role in helping to meet these challenges by using their HVAC systems as a link to thermal energy storage. However, predicting a building's ancillary service demand response performance continues to be a challenge, particularly for complex multi-zone systems, such as the variable air volume. A dynamic model of a representative variable air volume system was developed and simulated to investigate the response of the system to implementation of four common demand response strategies over a range of cooling loads and implementation intensities: zone air dry-bulb temperature adjustment, duct static pressure adjustment, supply air temperature adjustment, and chilled water temperature adjustment. Curves are presented that map power reduction as a function of cooling load and implementation intensity on a 10-min spinning reserve timescale. A study of these maps along with simulated data reveal that terminal unit damper position is a significant determining factor of performance effectiveness for each strategy.

Evaluation of distributed building thermal energy storage in conjunction with wind and solar electric power generation

Energy storage is often seen as necessary for the electric utility systems with large amounts of solar or wind power generation to compensate for the inability to schedule these facilities to match power demand. This study looks at the potential to use building thermal energy storage as a load shifting technology rather than traditional electric energy storage. Analyses are conducted using hourly electric load, temperature, wind speed, and solar radiation data for a 5-state central U.S. region in conjunction with simple computer simulations and economic models to evaluate the economic benefit of distributed building thermal energy storage (TES). The value of the TES is investigated as wind and solar power generation penetration increases. In addition, building side and smart grid enabled utility side storage management strategies are explored and compared. For a relative point of comparison, batteries are simulated and compared to TES. It is found that cooling TES value remains approximately constant as wind penetration increases, but generally decreases with increasing solar penetration. It is also clearly shown that the storage management strategy is vitally important to the economic value of TES; utility side operating methods perform with at least 75% greater value as compared to building side management strategies. In addition, TES compares fairly well against batteries, obtaining nearly 90% of the battery value in the base case; this result is significant considering TES can only impact building thermal loads, whereas batteries can impact any electrical load. Surprisingly, the value of energy storage does not increase substantially with increased wind and solar penetration and in some cases it decreases. This result is true for both TES and batteries and suggests that the tie between load shifting energy storage and renewable electric power generation may not be nearly as strong as typically thought.

Risk Management Strategies for a Wind Power Producer in Electricity Markets

Under a market framework, the development of optimal offering strategies is crucial for wind power producers to achieve maximum profit. In this paper, a two-stage stochastic programming approach is proposed, considering the uncertainties on wind power production and electricity market prices. An artificial intelligence model allows generating wind-price scenarios. Also, risk management is appropriately addressed. Results from a real-world case study are presented, in order to illustrate the proficiency of the proposed approach.

Risk Management Strategies for a Wind Power Producer in Electricity Markets

Under a market framework, the development of optimal offering strategies is crucial for wind power producers to achieve maximum profit. In this paper, a two-stage stochastic programming approach is proposed, considering the uncertainties on wind power production and electricity market prices. An artificial intelligence model allows generating wind-price scenarios. Also, risk management is appropriately addressed. Results from a real-world case study are presented, in order to illustrate the proficiency of the proposed approach.

The impact of wind power generation on the electricity price in Germany

This paper investigates the relationship between intermittent wind power generation and electricity price behaviour in Germany. Using a GARCH model, I evaluate the effect of wind electricity generation on the level and the volatility of the electricity price in an integrated approach. The results show that variable wind power reduces the price level but increases its volatility. This paper's results also indicate that regulatory change has stabilised the wholesale price. The electricity price volatility has decreased in Germany after a modification of the marketing mechanism of renewable electricity. This gives confidence that further adjustments to regulation and policy may foster a better integration of renewables into the power system.

Enhanced Nationwide Wind-Electric Power Monitoring and Forecast System

This paper describes an enhanced monitoring and forecast system for the electrical power generated from wind in Turkey. Wind power plant (WPP) owners, transmission system operator, distribution system operators, and renewable energy experts are the shareholders of this system. The developed monitoring and forecast system is composed of wind electricity analyzers and reference wind masts, one for each WPP, a Wind-Electric Power Monitoring and Forecast Center (WPMFC) equipped with database, data processing, and application servers, and the associated monitoring and forecast software. All shareholders can communicate with the developed WPMFC in order to retrieve preprocessed wind-electric power forecast data and power quality data, through the IP network according to their authorization level. The electrical and meteorological raw data can also be retrieved for postprocessing. The developed system is based on global positioning system (GPS) synchronized, real-time field measurements taken from each WPP, in addition to the use of mesoscale numerical weather prediction models. Instantaneous electrical and meteorological quantities of each WPP can be monitored continuously through the WPMFC. The forecast system employs physical, statistical, and hybrid models combining both approaches. Some sample monitoring and forecast results are given in the paper to illustrate the benefits and abilities of the developed system.

The impact of the CDM (clean development mechanism) on the cost price of wind power electricity: A China study

As a renewable energy source, wind power is playing an increasingly important role in China's electricity supply. Meanwhile, China is also the world's largest market for clean development mechanism (CDM) wind power projects. Based on the data of 27 wind power projects of Inner Mongolia registered with the Executive Board of the United Nations (EB) in 2010, this paper constructs a financial model of net present value (NPV) to analyze the cost price of wind power electricity. A sensitivity analysis is then conducted to examine the impact of different variables with and without certified emission reduction (CER) income brought about by the CDM. It is concluded that the CDM, along with static investment and annual wind electricity production, is one of the most significant factors in promoting the development of wind power in China. Additionally, wind power is envisaged as a practical proposition for competing with thermal power if the appropriate actions identified in the paper are made.

Opportunities and Challenges of Wind Power Generation in China

China's wind power market development is set to continue its growth trend of 2011. The newly added installed capacity will be in the range of 15-18GW and is expected to reach approximately 18GW. By 2015, the installed wind power capacity will reach 100GW. The percentage of decentralized wind power will further increase, but large-scale development and land-based wind power development will still be the focus, while the ratio of decentralized wind power has the potential to reach a maximum of 30%. As power grid corporations continue to improve their ultra-high voltage power transmission lines, intelligent power grids and other infrastructure, the power grids' ability to absorb wind power electricity on a largescale, and the scale of cross-region wind power transmission will increase, with the wind power grid-connection rate also significantly increase. The wind power manufacturing industry has entered a low-profit era; competition will intensify, the market will become more mature, and wind power manufacturers will face greater market challenges. However, the wind power industry's maturity and lowering costs have enhanced wind power's competitiveness compared to traditional energy sources. Wind power has become a highstrength emerging power supply technology and its contribution to China's electricity mix will gradually increase.

Power Purchase Model of Provincial Grids Based on Diverse Energy Coordination Hedging Optimization

Under the background of energy conservation, the grid companies should give priority to consumptive hydropower, wind power and other clean electricity to fulfill their social responsibility and promote the carbon emission reduction in power industry. But under the current power purchase mode, grid companies must first perform the contract. This is extremely uneconomical and not environmentally friendly. Based on hedging theory, this paper proposes a power purchase optimization model using the strategy of “compression and compensation”. If outer price is lower than the contract price, the grid can compress contract power appropriately, leaving more space for purchasing electricity; if outer price is not attractive enough, the grid should timely improve contract proportion, compensating the deviations of contract caused by compression. Based on the strategy of compression and compensation, it can effectively reduce the abandoned wind and water, enhance the economic and social benefits of provincial power grid.

New Smart Passive Graphical Islanding Detection Method

As there is still a great argument on islanding detection methods, this paper presents a new smart passive graphical islanding detection method. The new method depends on measuring the instantaneous variation in phase voltage angle (θ) related to the instantaneous variation in phase voltage magnitude (V) and drawing the relationship between them. The traditional passive methods have performance deficiencies. On the other hand, the active methods are more accurate islanding detection methods, but perturb the electrical system. So, the need for a new detection method which can be accurate, doesn't affect the system behavior, and through which both active and passive methods disadvantages can be avoided is an essential requirement. The continuous updates in Wide Area Monitoring, Protection and Control (WAMPC) technology and Phasor measurement units (PMU) facilitate the idea of measuring and tracing the voltage angle variation. The concept of the new proposed smart passive islanding detection method depends on observing the behavior of the variation of voltage magnitude versus the voltage angle variation (V - θ) of the bus which connects the suggested island with the main power grid. During islanding, sometimes the variation of the voltage magnitude is not significant to be detected, especially in case of low power island. The variation of the voltage angle presents an accurate indication with high sensitivity to the different sorts of system transients. The angle variation behavior differs in load changing, islanding, faulted network, and normal operation conditions. The relationship between (V - θ) is confirmed by the graphical relationship between their derivatives (dV/dt - dθ/dt). V versus θ and dV/dt versus dθ/dt are studied and analyzed in this research to verify the concept of the new method. The new proposed smart method is applied to four different power systems having the same main power grid. The wind electrical power generation unit of the studied power systems has different generation and loading capacities in each of the four studied cases. The studied cases are classified into low, high, and medium (with two different loading status) wind electrical power generation capacity. For each studied case, the system normal operation, load disconnection, islanding, and three phase fault conditions are discussed. In the four studied cases, the results verify the completely different graphical behaviors for each transient condition. So, the concept of the new method is verified.

Wind Power Generation in India: Evolution, Trends and Prospects

In the present context of shrinking conventional resources coupled with environmental perils, the wind power offers an attractive alternative. Wind power generation in India started way back in early 1980s with the installation of experimental wind turbines in western and southern states of Gujarat and Tamil Nadu. For first two decades of its existence until about 2000 the progress was slow but steady. In last one decade Indian wind electricity sector has grown at very rapid pace which has promoted the country to the fifth position as largest wind electric power generator and the third largest market in the world. The galvanization of wind sector has been achieved through some aggressive policy mechanisms and persistent support by government organizations such as MNRE and C-WET. This paper articulates the journey of Indian wind program right since its inception to the present trends and developments as well as the future prospects.

Determining wind turbine power curves based on operating conditions

ABSTRACTThe relation between wind speed and electrical power—the power curve—is essential in the design, management and power forecasting of a wind farm. The power curve is the main characteristic of a wind turbine, and a procedure is presented for its determination, after the wind turbine is installed and in operation. The procedure is based on both computational and statistical techniques, in situ measurements, nacelle anemometry and operational data. This can be an alternative or a complement to procedures fully based on field measurements as in the International Electrotechnical Commission standards, reducing the time and costs of such practices. The impact of a more accurate power curve was measured in terms of the prediction error of a wind power forecasting system over 1 year of operation, whereby the methodology for numerical site calibration was presented and the concepts of ideal power curve and nacelle power curve introduced. The validation was based on data from wind turbines installed at a wind farm in complex topography, in Portugal, providing a real test of the technique presented here. The contribution of the power curve to the wind power forecasting uncertainty was found to be from 10% to 15% of the root mean square error. Copyright © 2013 John Wiley & Sons, Ltd.