Electric vehicles (EV) are featured within the greater energy ecosystem as distributed energy resources: not only as energy consumers, but also as energy prosumers through grid services. The additional benefit to the circular economy is that EV batteries contribute to stationary energy storage through ‘second life’ deployments after their end of life within the vehicle.
Globally, the total number of EVs on the road surpassed four million worldwide at the end of 2018, with expectations of reaching the five million mark in early 2019. The growth of EVs has largely been driven by government policy, including public procurement programmes, financial incentives reducing EVs’ purchase price, tightened fuel-economy standards and low- and zero-emission vehicle mandates.
The rapid uptake of EVs has also been helped by the improved performance and reduced cost of lithium-ion batteries. The average energy density of EV batteries is also improving at around 5-7% annually. EVs require large amounts of energy, a thousand times stronger than that of a smartphone; hence they require dozens of battery cells – up to thousands. The supporting EV charging infrastructure technologies have also advanced for expanded versatility and charging times, with added benefits of including renewable energy and storage systems. The EV batteries are typically charged through standard AC charge points or fast chargers, which are predominantly DC based, but also available in AC options. These DC fast chargers directly interface with the EV battery pack and provide a variety of power delivery options, where typically a 50kW fast charger will charge an EV within 15-20 minutes to 80% capacity.
Opportunities for EV owners also exist across ancillary services to the grid specifically load regulation and spinning reserves. Plug-in EVs can assist in distributed energy storage and have the potential to discharge power back to the grid through bidirectional flow, known as vehicle-to-grid (V2G). Aligning with the circular economy, after 10-15 years the typical driving range reduces and the battery packs within the vehicle are removed and enter into second life in which they can then serve as stationary storage devices. In this regard, EV battery packs can be reused, refabricated and then finally recycled. Reuse applications include when EV battery packs as a whole are directly utilised for grid or home storage.
Refabrication involves dismantling the EV battery packs, assessing the cells and modules and then remanufacturing reconditioned battery packs. The resultant case across all uses of batteries is the recycling for e-waste of complete battery packs. This further contributes to energy security access through storage provided by second life EV batteries. The overarching message is to have resilient smart energy systems for the needs of citizens and cities. This includes sustainable energy generation, storage, utilisation and overall efficient energy management. With this holistic view point, we can manage transitions towards smart energy with the inclusions of smart transportation. ESI
About the author
Hiten Parmar is a leading expert, thought leader, and executive within the energy and power industry extending over 15 years in the profession. As Director of the uYilo eMobility Programme, Hiten’s passion extends across global contribution of technological interventions to solve major economic, competitiveness, and societal challenges.