Impact of Generator Flexibility on Electric System Costs and Integration of Renewable Energy PDF Download

Author: D. Palchak
Publisher:
ISBN:
Category : Coal-fired power plants
Languages : en
Pages : 24

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Book Description
Flexibility of traditional generators plays an important role in accommodating the increased variability and uncertainty of wind and solar on the electric power system. Increased flexibility can be achieved with changes to operational practices or upgrades to existing generation. One challenge is in understanding the value of increasing flexibility, and how this value may change given higher levels of variable generation. This study uses a commercial production cost model to measure the impact of generator flexibility on the integration of wind and solar generators. We use a system that is based on two balancing areas in the Western United States with a range of wind and solar penetrations between 15% and 60%, where instantaneous penetration of wind and solar is limited to 80%.

Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 27

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Book Description
Flexibility of traditional generators plays an important role in accommodating the increased variability and uncertainty of wind and solar on the electric power system. Increased flexibility can be achieved with changes to operational practices or upgrades to existing generation. One challenge is in understanding the value of increasing flexibility, and how this value may change given higher levels of variable generation. This study uses a commercial production cost model to measure the impact of generator flexibility on the integration of wind and solar generators. We use a system that is based on two balancing areas in the Western United States with a range of wind and solar penetrations between 15% and 60%, where instantaneous penetration of wind and solar is limited to 80%.

Author: Thomas A. Deetjen
Publisher:
ISBN:
Category :
Languages : en
Pages : 456

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Book Description
Environmental policies, reduced manufacturing costs, and technology improvements have all contributed to the growing installation of wind turbines and solar photovoltaic arrays in the electric grid. While these new sources of renewable electrical power provide environmental and economic benefits to the electric grid, they also complicate the balancing of supply and demand required to reliably operate the grid. The seasonal, daily, and sub-hourly fluctuations in the energy output of wind and solar generators must be compensated by operating the existing power plant fleet more flexibly or by providing more flexible sources of electricity demand. This dissertation categorizes and quantifies this compensation by studying the "flexibility requirements'' imposed by wind and solar generation, approximates the economically optimal capacities of regional wind and solar resources in the grid, and explores the ability of a central utility plant to add a flexible source of demand to the electric grid system. These topics are covered in the four chapters described below. Chapter 3 utilizes a unit commitment and dispatch (UC&D) model to simulate large solar generation assets with different geographic locations and orientations. The simulations show the sensitivity of the wholesale energy price, reserve market prices, total dispatch cost, fuel mix, emissions, and water use to changes in net load flexibility requirements. The results show that generating 22,500 GWh of solar energy in a 2011 simulation of the Electric Reliability Council of Texas (ERCOT) reduces total dispatch cost by approximately $900 Million (a 10.3% decrease) while increasing ancillary services costs by approximately $10 Million (a 3% increase). The results also show that solar PV reduces water consumption, water withdrawals, and CO2, NO [subscript x], and SO [subscript x] emissions. Installing sufficient solar panel capacity to generate that much electricity also reduces peak load by 4% but increases net load volatility by 40--79% and ramping by 11--33%. In addition, west-located, west-oriented solar resources reduce total dispatch cost more than the other simulated solar scenarios. The west-located, west-oriented solar simulation required greater system flexibility, but utilized more low-cost generators and fewer high-cost generators for energy production than other simulated scenarios. These results suggest that the mix of energy provided by different generation technologies influences the dispatch cost more than the net load flexibility requirements. Chapter 4 develops a quantitative framework for calculating flexibility requirements and performs a statistical analysis of load, wind, and solar data from the Electric Reliability Council of Texas (ERCOT) to show how wind and solar capacity impacts these grid flexibility requirements. Growing wind capacity shows only minor correlation with increasing flexibility requirements, but shows some correlation with ramp down rates and daily volatility in the net load. Growing solar capacity shows a direct correlation with increasing flexibility requirements if load patterns do not change. While adding 15.7 GW of wind power had only minor effects on system flexibility requirements, adding 14.5 GW of solar to the ERCOT grid increases maximum 1-hr ramp rates by 135%, 3-hr ramp rates by 30%, ramp factors by 140%, 1-hr volatility by 100%, and 1-day volatility by 30%. Wind and solar impact flexibility requirements at different times of the day: wind tends to intensify demand-driven flexibility events by ramping up energy production at night when demand is decreasing and ramping down energy production in the morning when demand is increasing, while solar tends to intensify flexibility requirements due to its quick changes in energy output driven by the rising and setting sun. Adding wind to a system with large amounts of solar does not tend to increase flexibility requirements except for the daily volatility. The geographic location and orientation of solar arrays also influences flexibility requirements, with fixed, southeast-facing panels providing a significant reduction. These results can inform strategies for managing the grid flexibility requirements created by growing renewable capacity. Chapter 5 develops a model for calculating the optimal amount of transmission, wind, and solar capacity that should be built in a grid's different regions. It also presents a framework for choosing CO2 prices by balancing increasing system cost and flexibility requirements with CO2 emissions reductions. In a simulation of the ERCOT grid, the model suggests a 60 $/ton CO2 price and an optimal investment of 27.0 GW of transmission capacity to five different regions. These regions install a total of 26.6 GW of wind and 11.1 GW of solar, representing a grid with about 60% thermal and 40% renewable capacity. This renewable mix produces 110 TWh of energy per year, 34% of the total electricity demand. The grid emits 82.2 million tons of CO2 per year under this scenario, a 65% reduction from the 237 million tons produced when no renewable capacity is installed. At the optimal renewable development solution, all coal and natural gas boiler generators have capacity factors less than 20% with many of them not being dispatched at all. While these results are specific to ERCOT, the methods and model can be used by any grid considering renewable energy capacity expansion. Chapter 6 develops a mixed-integer linear program for modeling the optimal equipment capacity and dispatch of a central utility plant (CUP) in a residential neighborhood and its ability to improve rooftop solar integration. The CUP equipment includes a microturbine, battery, chiller plant, and cooling storage. The CUP model is exposed to a variety of electricity rate structures to see how they influence its operation. The model finds the optimal capacity for each piece of CUP equipment, optimizing their hourly dispatch to meet neighborhood cooling and electric demand while maximizing profit. In an Austin, TX, USA base case, the neighborhood benefits economically by including the CUP, although the CUP demonstrates limited potential to integrate high penetrations of rooftop solar resources. While peak demand and reverse power flows are reduced under all tested rate structures, the CUP worsens net demand ramp rates. A time-of-use rate with no demand charge and moderate differences between off-peak and on-peak prices balances the output parameters, reducing reverse power flows by 43%, peak demand by 51%, and annual cost by 9.1% versus the "No CUP'' base case while limiting net demand ramp rate increase to 84% more than the base case. Building a clean, resilient, and reliable electric grid for the future is a worthwhile endeavor that will require innovative supply-side and demand-side solutions for integrating the intermittent power output of renewable generation into the electric grid. As a cohesive document, this dissertation communicates the scale and severity of the flexibility requirements that will be required to operate systems with large amounts of wind and solar generation and explores one demand-side method for providing that needed flexibility. There are many opportunities to expand these analyses and explore new sources of grid flexibility in future work.

Author: International Energy Agency
Publisher:
ISBN: 9789264208032
Category : Technology & Engineering
Languages : en
Pages : 234

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Book Description
Wind power and solar photovoltaics (PV) are crucial to meeting future energy needs while decarbonizing the power sector. Deployment of both technologies has expanded rapidly in recent years, one of the few bright spots in an otherwise bleak picture of clean energy progress. However, the inherent variability of wind power and solar PV raises unique and pressing questions. Can power systems remain reliable and cost-effective while supporting high shares of variable renewable energy (VRE)? And if so, how? Based on a thorough review of the integration challenge, this publication gauges the economic significance of VRE integration impacts, highlights the need for a system-wide approach to integrating high shares of VRE and recommends how to achieve a cost-effective transformation of the power system. This book summarizes the results of the third phase of the Grid Integration of VRE (GIVAR) project, undertaken by the IEA over the past two years. It is rooted in a set o

Author: Bethany Ann Frew
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Book Description
The effects of aggregating 1) electric load alone and 2) electric load with dispersed renewable generators through an enhanced transmission infrastructure in the United State (U.S.) were evaluated. First, a transmission network topology was created to estimate the additional transmission capacity needed for aggregating electric load. Aggregation benefits (generator capacity capital cost savings, load energy shift operating cost savings, and reserve requirement cost savings) were found to be significantly outweighed by the transmission costs required to achieve these benefits for nearly all cases. To evaluate the effects of aggregating electric load with dispersed renewables, a large-scale linear programming model was built to deterministically find the least-cost portfolio of generators (baseload, dispatchable, variable), storage, and transmission that met the electric load and reserve requirements (exogenously determined) each hour while attaining a given renewable portfolio standard (RPS) target. Various scenarios and sensitivity tests were completed of regional and U.S. spatial extents to evaluate the effect of flexibility mechanisms (aggregation, overgeneration, storage, and electric vehicle charging) and tradeoffs in modeling "levers" (temporal and spatial resolution and extent). For the set-up examined, a 100% RPS system for CA and the full U.S. was found to be technically feasible, but with significantly higher costs and overgeneration (curtailment) levels than lower RPS targets. Of the flexibility mechanisms considered, geographic aggregation had the greatest total system cost benefit, especially at high RPS levels. In interconnected scenarios, transmission was found to occupy a very small percentage of the total cost, and the contribution of each region to the aggregate RPS was significantly disproportionate, highlighting the need for regional-and-resource-specific RPS targets. Electric vehicle charging, which adds new load to the system, some of which was assumed to be flexible, always resulted in a larger total system cost but less expensive total system levelized cost (cost per unit of load served). This revealed the growing need for demand-side flexibility as the penetration of renewables increases; however results indicated that demand response price structures may need to be adjusted to encourage ideal flexible load in highly renewable systems. The cost tradeoffs of temporal and spatial modeling levers revealed small changes in accuracy and computational load as each lever was adjusted. Storage was found to be particularly sensitive to the temporal treatment in the model, highlighting the need for proper daily/weekly/seasonal storage balancing constraints. The findings presented here reflect technically feasible scenarios for a simplified U.S. electricity system and ignore many social, environmental, and political barriers, which may slow or prevent actual implementation.

Author: Lawrence E. Jones
Publisher: Academic Press
ISBN: 0124081223
Category : Business & Economics
Languages : en
Pages : 529

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Book Description
Renewable Energy Integration is a ground-breaking new resource - the first to offer a distilled examination of the intricacies of integrating renewables into the power grid and electricity markets. It offers informed perspectives from internationally renowned experts on the challenges to be met and solutions based on demonstrated best practices developed by operators around the world. The book's focus on practical implementation of strategies provides real-world context for theoretical underpinnings and the development of supporting policy frameworks. The book considers a myriad of wind, solar, wave and tidal integration issues, thus ensuring that grid operators with low or high penetration of renewable generation can leverage the victories achieved by their peers. Renewable Energy Integration highlights, carefully explains, and illustrates the benefits of advanced technologies and systems for coping with variability, uncertainty, and flexibility. Lays out the key issues around the integration of renewables into power grids and markets, from the intricacies of operational and planning considerations, to supporting regulatory and policy frameworks Provides global case studies that highlight the challenges of renewables integration and present field-tested solutions Illustrates enabling and disruptive technologies to support the management of variability, uncertainty and flexibility

Author: U. S. Department U.S. Department of Energy
Publisher: CreateSpace
ISBN: 9781508860549
Category :
Languages : en
Pages : 46

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Book Description
This book provides a detailed roadmap of technical, economic, and institutional actions by the wind industry, the wind research community, and others to optimize wind's potential contribution to a cleaner, more reliable, low-carbon, domestic energy generation portfolio, utilizing U.S. manu-facturing and a U.S. workforce. The roadmap is intended to be the beginning of an evolving, collaborative, and necessarily dynamic process. It thus suggests an approach of continual updates at least every two years, informed by its analysis activities. Roadmap actions are identified in nine topical areas, introduced below.

Author: National Research Council
Publisher: National Academies Press
ISBN: 030913708X
Category : Science
Languages : en
Pages : 386

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Book Description
A component in the America's Energy Future study, Electricity from Renewable Resources examines the technical potential for electric power generation with alternative sources such as wind, solar-photovoltaic, geothermal, solar-thermal, hydroelectric, and other renewable sources. The book focuses on those renewable sources that show the most promise for initial commercial deployment within 10 years and will lead to a substantial impact on the U.S. energy system. A quantitative characterization of technologies, this book lays out expectations of costs, performance, and impacts, as well as barriers and research and development needs. In addition to a principal focus on renewable energy technologies for power generation, the book addresses the challenges of incorporating such technologies into the power grid, as well as potential improvements in the national electricity grid that could enable better and more extensive utilization of wind, solar-thermal, solar photovoltaics, and other renewable technologies.

Author: International Renewable Energy Agency IRENA
Publisher: International Renewable Energy Agency (IRENA)
ISBN: 9292601970
Category : Technology & Engineering
Languages : en
Pages : 161

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Book Description
This study presents options to speed up the deployment of wind power, both onshore and offshore, until 2050. It builds on IRENA’s global roadmap to scale up renewables and meet climate goals.

Author: Majid Al-Gwaiz
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
We study supply function competition among conventional power generators with different levels of flexibility. Inflexible generators commit production before uncertainties are realized, while flexible generators can adjust their production after uncertainties are realized. Both types of generators compete in an electricity market by submitting supply functions to a system operator, who solves a two-stage stochastic program to determine the production level for each generator and the corresponding market prices in the first and second stages. Our goal is to gain an understanding of how generators' (in)flexibility affects their equilibrium behavior and the market price. We also investigate the impact of intermittent renewable power generation on the equilibrium, focusing on the effects of renewable energy penetration level, dispatch priority, and production-based subsidies. We find that the classic supply function equilibrium model overestimates the intensity of the market competition, and even more so as renewable energy introduces more intermittency into the system. The policy of economically curtailing intermittent generation intensifies the market competition, reduces price volatility, and improves the system's overall efficiency. Moreover, we show that these benefits are most significant when the production-based subsidies are absent.