Collective effects and synchronization of demand in real-time demand response

Abstract

Future energy systems will be dominated by variable renewable power generation and interconnected sectors, leading to rapidly growing complexity. Flexible elements are required to balance the variability of renewable power sources, including backup generators and storage devices, but also flexible consumers. Demand response aims to adapt the demand to the variable generation, in particular by shifting the load in time. In this article, we provide a detailed statistic analysis of the collective operation of many demand response units. We establish and simulate a model for load shifting in response to real-time electricity pricing using local storage systems. We show that demand response drives load shifting as desired but also induces strong collective effects that may threaten system stability. The load of individual households synchronizes, leading to extreme demand peaks. We provide a detailed statistical analysis of the grid load and quantify both the likeliness and extent of extreme demand peaks.

The stochastic nature of power-grid frequency in South Africa

“…Power generation, both conventional but particularly renewable, is manifestly volatile [20][21][22][23] and non-Gaussian behaviour permeates the statistics of most power system [19,24,25]. Similarly, the demand side can be equated to a complex stochastic process [26]. Thus, we take a complex-system approach to modelling and analysing power-grid systems from a complex system perspective [27,28].…”

Microscopic Fluctuations in Power-Grid Frequency Recordings at the Subsecond Scale

“…One key quantity for control and monitoring purposes of the power system is the power-grid frequency. It follows the balance of generation and consumption and allows insights into the general stability of the grid as well as the impact of renewable generators [10][11][12]. So far, only a few studies have investigated power laws or even multifractality in power grids [13], partially because data are not easily available.…”