Day-ahead allocation of operation reserve in composite power systems with large-scale centralized wind farms

This paper focuses on the day-ahead allocation of operation reserve considering wind power prediction error and network transmission constraints in a composite power system. A two-level model that solves the allocation problem is presented. The upper model allocates operation reserve among subsystems from the economic point of view. In the upper model, transmission constraints of tielines are formulated to represent limited reserve support from the neighboring system due to wind power fluctuation. The lower model evaluates the system on the reserve schedule from the reliability point of view. In the lower model, the reliability evaluation of composite power system is performed by using Monte Carlo simulation in a multi-area system. Wind power prediction errors and tieline constraints are incorporated. The reserve requirements in the upper model are iteratively adjusted by the resulting reliability indices from the lower model. Thus, the reserve allocation is gradually optimized until the system achieves the balance between reliability and economy. A modified two-area reliability test system (RTS) is analyzed to demonstrate the validity of the method.This work was supported by National Natural Science Foundation of China (No. 51277141) and National High Technology Research and Development Program of China (863 Program) (No. 2011AA05A103)

Wind-pv-thermal power aggregator in electricity market

This paper addresses the aggregation of wind, photovoltaic and thermal units with the aim to improve bidding in an electricity market. Market prices, wind and photovoltaic powers are assumed as data given by a set of scenarios. Thermal unit modeling includes start-up costs, variables costs and bounds due to constraints of technical operation, such as: ramp up/down limits and minimum up/down time limits. The modeling is carried out in order to develop a mathematical programming problem based in a stochastic programming approach formulated as a mixed integer linear programming problem. A case study comparison between disaggregated and aggregated bids for the electricity market of the Iberian Peninsula is presented to reveal the advantage of the aggregation

Implementation of wind power in the Dutch power system

We present the current status of wind power in the Netherlands and its future prospects, in particular for the development of offshore wind. An overview is given of the performance of the wind power on land. We briefly discuss the experience with OWEZ, the first offshore wind park commissioned April 2007, and the expectations for Q7, to be completed March 2008. The organization of the energy and imbalance markets in the Netherlands is described. Balancing requirements due to variability and limited predictability of wind energy are estimated, at system and market participant level. Next, we present the results of a wind power integration study performed in order to estimate the amount of wind curtailment due to the technical limitations of the conventional units in the Netherlands. It is found that due to must-run constraints on the combined heat and power units, which constitute over 50% of the Dutch production park, sufficient reserve is available to cover wind fluctuations and prediction errors for up to 8000 MW installed wind power. The only limiting factor is the minimum output of the conventional units, which may result in increasing curtailed wind starting around 4000 MW installed capacity. Changes in system operating costs, curtailed wind and total emissions due to the application of various large-scale storage technologies are described in the final section of the paper

Optimal Planning of Electric Power Systems

International audienceElectric power systems provide an essential service to any modern society. They are inherently large-scale dynamic systems with a high degree of spatio-temporal complexity. Their reliability and security of supply are central considerations in any regional or global energy-related policy. Methods for power systems planning have typically ensured key operational reliability aspects under normal operating conditions and in response to anticipated demand variability, uncertainty and supply disruptions, e.g. due to errors in load forecasts and to unexpected generation units outages. Solutions have been commonly built on capacity adequacy and operating reserves requirements, among others. However, recent objectives for environmental sustainability and the threats of climate change are challenging the reliability requirements of power systems in various new ways and necessitate adapted planning methods. The present chapter describes some of the issues related to the development of the integrated techno-economic modeling and robust optimization framework that is needed today for power systems planning adapted. Such planning framework should cope with the new context by addressing the challenges associated with the sustainability targets of future power systems, and most notably ensuring operational flexibility against the variability of renewable energy sources, ensuring resilience against extreme weather events and ensuring robustness against the uncertainties inherent in both the electric power supply and system load