Bri-Mathias S. Hodge

Operating reserve policies with high wind power penetration

Abstract The rapid increase in installed wind generation capacity in the United States has raised concerns about electricity system reliability because of the intermittent and variable nature of the wind power. To help manage the wind power variability new ways of determining the amount of operating reserve capacity that must be kept available are necessary. A two-stage stochastic programming approach for the unit commitment problem had been introduced to mimic the short-term power operation decision process, i.e., day-ahead unit commitment and hour-ahead economic dispatch. Within this framework, a new formulation is proposed to determine the spinning and non-spinning reserve levels for large-scale systems over a 24-h optimization horizon with economic considerations. The proposed model is then applied to a large-scaled California test system. Simulation results illustrate the impact of stochastic wind power generation behavior and increased installed wind capacity on operating reserve requirements and the system cost as a whole.

The Effects of Vehicle-to-Grid Systems on Wind Power Integration in California

Abstract Renewable energy portfolio standards have already caused a large increase in the amount of electricity produced from renewable sources and this amount is expected to increase as the policy target dates draw closer. One technology that has benefited greatly from these standards is wind energy. The uncertainty inherent in wind electricity production dictates that nearly equal amounts of conventional generation resources be kept in reserve should wind electricity output should suddenly dip. The introduction of plug-in hybrid electric vehicles into the personal transportation fleet presents an interesting possible solution to this problem through the concept of vehicle-to-grid power. The ability of these vehicles to increase the wind production fraction for the California market when high levels of wind energy are present in the supply portfolio is examined.

A multi-paradigm modeling framework for energy systems simulation and analysis

Abstract The modern world energy system is highly complex and interconnected and the effects of energy policies may have unintended consequences. Modeling and analysis tools can therefore be crucial to gaining insight into the interactions between system components and formulating policies that will shape the future energy system. We present in this work a multi-paradigm modeling framework that allows for the continual adjustment and refinement of energy system models as the understanding of the system under study increases. This flexible and open framework allows for the consideration of different levels of model aggregation, timescales and geographic considerations within the same model through the use of different modeling formalisms. We also present a case study of the combined California natural gas and electricity systems that illustrates how the framework may be used to account for the significant uncertainty that exists within the system.

The Impact of PHEV Adoption on Natural Gas Demand in Electricity Generation

Publisher Summary Natural gas is an important energy resource that, because of its versatility, exerts an influence over many disparate sectors of the energy system. One such area is the electricity grid where natural gas serves as an important fuel for most electricity produced during peak periods. The widespread adoption of plug-in hybrid electric vehicles (PHEVs) could significantly change the current electricity load profile and hence, the demand for natural gas from the electricity sector. Integrated electricity supply and demand model is developed to help quantify the changes to the energy system that are anticipated due to the adoption of PHEVs. While PHEVs are an attractive option to reduce the consumption of gasoline in the transportation sector and hence the United States total petroleum imports, the shift in energy demand from petroleum to electricity can create unforeseen problems. If the adoption of PHEVs becomes widespread throughout the country, the aggregated demand increase would be significant. It is therefore important to be careful when planning for this transition from petroleum-based transportation to an electricity-based system in order to anticipate these and other foreseeable effects of the transition.

Improved Wind Power Forecasting with ARIMA Models

Abstract The introduction of large amounts of wind power into the electricity system raises potential reliability issues for the grid due to the intermittent nature of wind power. Wind power cannot be scheduled in advance like conventional generation units and thus forecasts of the wind power that will be produced in future hours are used to schedule the amount of wind power available. Any improvements in wind power forecasting have the potential to reduce the amount of reserves necessary in systems with significant amounts of wind power, and eventually lower the cost of electricity in such systems. In this work we examine the ability of statistical time series analysis tools, namely autoregressive integrative moving average (ARIMA) models, to forecast future wind power output from historical data. A systematic approach to determine the best values for the assortment of variables associated with the models, such as training period length and model orders, has been developed and applied. The ability of the models to outperform a standard forecasting benchmark has been examined at a number of different forecast period lengths. The application of the tools to total power output of the many wind farms that may be present within the territory of a single independent system operator is studied. Finally, a case study involving wind farm data from Ontario, Canada is used to show how the improvements that these statistical techniques offer may be beneficial for the independent system operator.

The Value of Battery Storage and Discharge Logic with Solar Microgeneration

Abstract Microgeneration using solar photovoltaic systems is becoming increasingly popular in residential households as such systems allow for households use a renewable energy source while also reducing their reliance on the electricity grid to fulfill their electricity demand. In this study we explore the added value of a battery storage system with regards to a solar photovoltaic system during the summer months. A battery storage system is able to capture the excess electricity generated by a photovoltaic system and use it to displace some portion of the household electricity demand at a later period. California is used as a case study to determine the value of adding a battery storage system for a household with a solar photovoltaic array.

A Multi-Paradigm Energy Model for Liquid Natural Gas Analysis

The current complex world energy system dictates that energy policy decisions can have far reaching and often unintended consequences. Therefore, sophisticated modeling techniques which allow possible future scenarios to be simulated and analyzed in advance are necessary in order to improve the decision making process. Multiparadigm modeling allows different parts of the system under consideration to be represented using the modeling technique most appropriate. This approach has been applied to the United States natural gas system and the future prospects of liquid natural gas imports over a medium term time frame have been examined.

A prototype agent-based modeling approach for energy system analysis

Abstract The current world energy system is highly complex and is rapidly evolving to incorporate emerging energy technologies. An understanding of how these technologies will be incorporated into the existing system is needed in order to make intermediate and long term research and infrastructure decisions. We propose an agent-based modeling and simulation approach for energy system analysis that can be used to investigate the mechanisms by which changes occur within the system. The approach has been applied to the Indiana state energy system.

Long-Term Planning of Wind Farm Siting in the Electricity Grid

Abstract Wind power is the fastest growing electricity generation source in the United States and is expected to play an increasing role in the electricity system. The variable and uncertain nature of wind power will require changes in the operation of the grid under higher penetration rates. In order to understand the changes necessary at both the planning and operational levels we propose a stochastic optimization approach that enables the consideration of the variable output of wind power as well as the costs of wind farm construction. Results from a small example system are used to illustrate the advantages of the approach.

The Effects of Electricity Storage on Large Scale Wind Integration

Abstract As wind energy takes on an increasingly larger role in regional electricity generation portfolios, the power generation variability introduced into the system by wind farms may begin to diminish the positive effect of further additions of such farms. Large scale energy storage systems as a result of which otherwise wasted wind power could be stored and used when needed could become an attractive alternative for investment. The interplay between investment in new wind farms and energy storage is examined in this paper. A multi-paradigm model is adapted to examine increasingly higher levels of wind power generation and to undertake a comparison between equivalent investments in wind farms and electricity storage facilities.