Yehicle-to-grid technology assisted microgrid in Ghana: Opportunities and challenges

Abstract

Plug-in electric vehicles are the driving force behind a paradigm not only in the auto industry but also in the electric power sector. This paper explores the possibility of plug-in electric vehicles serving as electrical energy storage (EES) devices in a microgrid-in the so called vehicle-to-grid concept in Ghana. A vehicle-to-grid technology assisted microgrid is proposed as a solution to address the shortcomings that are likely to prevent the widespread adoption of renewable energy resource (RES) based microgrid and the use of electric vehicles in Ghana. Interestingly, when RES based microgrid and plug-in electric vehicles are put together into the so called vehicle-to-grid assisted microgrid, they compensate for the shortcomings of each other. An overview of the essential components of the vehicle-to-grid concept is presented. Vehicle-to-grid technology presents an opportunity to offer services such as frequency regulation (in an aggregated scheme), voltage regulation and power balance to a microgrid despite the intermittent nature of power from renewable energy resources used in the grid. In spite of these attractive opportunities, high initial cost, rapid battery degradation and increased stresses on power system equipment are inhibiting the wide scale adoption of the vehicle-to-grid concept. It was determined that, in Ghana where frequent power outage is common, an additional battery switch station needs to be created to guarantee continuous supply of power to both electric vehicle and other loads connected to the microgrid especially in islanding mode of operation.