Energy Storage for the Smart Grid

Abstract

This report is the continuation of a project report written fall 2010 that evaluated different energy storage technologies in connection with large-scale integration of intermittent renewable energy sources. This report aims to study energy storage in connection with smart grid. Energy storage systems in distribution nets and in connection with power electronics is an important part to integrate storage. Power electronics and belonging control systems and techniques are vital in the inclusion of energy storage systems into the distribution grid. Batteries and flywheels can be integrated in connection with intermittent renewable energy. The control system belonging to the power electronics is used to balance supply and demand in an optimal way in small-scale storage systems. Internet-communication-technology (ICT) is an important part to monitor, control and protect the power grid. PMUs in connection with SCADA are used to gather information and monitor the power grid. AMS is a smart grid application that makes the power grid easier to monitor and control. Development of new ICT technologies will open for new solutions where future homes will be able to both generate and consume power. ICT technology, power electronics and energy storage can form local power grids that can be monitored and controlled locally. DC-nets in buildings is also an solution that is considered to achieve higher energy efficiency and utilization of intermittent renewable sources such as wind and PV. Virtual power networks including these technologies can be formed and this may contribute to higher energy efficiency and lower losses in the power grid that is a problem basically in the distribution grid. Future integration of electric vehicles is also considered as an alternative to give extra storage capacity and flexibility to the power grid. EVs can be used in connection with smart homes to balance out load variations by charging the vehicle during night when demand and prices are low. And can discharge during day when prices and demand are higher.