Energy businesses from re-used electric vehicle batteries

Abstract

The energy and transportation sectors are responsible of the higher part of the greenhouse gas emissions in EU and the world. If the climate change is to be fought, a change in the paradigm should be done. The road transportation sector is shifting to an electrified mode. The electric vehicles are mostly powered by Li-ion batteries having an eight to ten years warranty, when they are expected to have an 80% of its original capacity and are considered inappropriate for traction services. On the other hand, energy storage devices are called to have an important role in the electricity market. They can provide a wide range of environmental and practical benefits, such as the support to renewable electricity generation, the distributed generation and the energy management among others. But nowadays, the Li-ion batteries are too expensive to provide such services with economic profit. The particular case presented in this paper is a demonstrator project that connects both sectors by providing a second life to the electric vehicle batteries and offering low cost batteries to the energy sector. Its four plug-in electric vehicle batteries are connected to solar panels, electric vehicle chargers and the electricity grid. The aim of this project is to verify that there are profitable and clean energy businesses for these batteries. An electric battery ageing model is presented in the paper. It has been developed in Matlab including the different ageing mechanisms, such as calendar ageing, C-rate, Depth-of-discharge and heat losses. This model simulates the battery capacity fading for the different applications and determines its rest of useful life. The demonstrator will validate the model and it will enhance the re-use of batteries for grid and home services before recycling, with the environmental profit and energy savings derived by its use.