Electric Vehicles (EVs) are more than just means for transport. All EVs are inherently equipped with battery storage, making them energy resources on wheels. From the electricity distribution perspective, EV charging can be viewed as dynamic loads that may pop up anywhere on the electric grid at any time. For every electricity distribution company an EV is a double-edged sword, presenting an opportunity and a challenge. Unmanaged EV charging can cause sudden demand spikes in the distribution system and hamper smooth power system operation of the power system.
There is a need for solutions that mitigate the negative impact of EVs on the electricity grid and enable their use as grid resources, commonly referred to as Vehicle to Grid integration (VGI). VGI is often defined as “the many ways in which a vehicle can provide benefits or services to the grid, society, the EV driver, or charge point operator by optimising electric vehicle interaction with the electrical grid”.
There are two aspects of VGI; V1G for managing the EV charging, and V2G for supplying power back from EV to the grid. For V1G, smart charging is relatively easier to accomplish as it is associated with unidirectional control of electricity flow. To enable power to flow from the vehicle to grid, a complex bidirectional control is needed. With V2G the benefits of VGI extend beyond managing the EV charging load, as EV can provide useful services to the grid. Active management of electricity flow between the grid and EV is a promising solution to manage EV charging load, and the easier way to use EVs as a flexible grid resource. Going one step further, and enabling the EV batteries to feed electricity back into the grid, the complex V2G technology allows EVs to provide additional flexibility to the power system at the distribution level.
Flexibility requirement of Indian electricity grid is interlinked with its decarbonisation. It is anticipated that the need for flexibility in the power system will rise in the future, due to an increase in the penetration of intermittent renewable energy (RE) sources such as wind and solar. Hence, enabled by V2G technology, EVs can help shape the future load curve to match RE supply and provide ancillary services to improve grid security and stability. Despite these grid benefits, V2G is yet to see commercial adoption beyond a few small pilot projects, even in advanced EV markets in Europe or the US. The reason for this is that there are several significant technical and practical challenges to implementing V2G at scale, especially in India, which are highlighted below.
- Lack of hardware for V2G: Currently, there are a limited number of EVs that support V2G and none of these models are available in the Indian market. Moreover, globally, there are few V2G-ready EV chargers. Furthermore, vehicle manufacturers are concerned about the impact of V2G on battery health, and, hence, they derecognise the warranty on the EV battery if it is used for purposes other than mobility.
- Aggregation challenge: A single EV battery is too small to effectively provide grid service by itself. Hence aggregation of EVs is important to achieve the size to support a commercial V2G programme. Vehicles are highly distributed and mobile assets by default, and to use them as a grid resource, one would require advanced communication and control infrastructure, which is still at an early stage of development. Furthermore, the concept of “resource aggregation” and the role of “aggregators” are largely non-existent in India’s electricity market and regulatory framework.
- Unfavourable regulatory ecosystem: The existing regulatory frameworks in the transport and power sectors are not adequate for V2G implementation. While EV regulations need to allow commercial use of EVs for grid services, the electricity regulatory framework must recognise mobile distributed energy resources. Moreover, the ancillary service market is largely absent in India.
- Low-capacity EV batteries: Unlike in the developed markets, light EVs (e-2Ws and e-3Ws) are gaining more traction than e-4Ws in India. For example, of the total sales of 1.56 lakh EVs (excluding e-rickshaws) in FY 2019-20, 1.52 lakh units were reportedly e-2Ws, 3400 e-4Ws, and 600 e-buses. Since scaling of aggregated EV batteries is critical to making V2G a viable business case, EVs with large battery sizes are more desirable. This means that, due to the lower battery sizes in India, a greater number of EVs will need to be aggregated to participate in V2G, which makes implementation more challenging, both logistically and financially.
Based on the aforementioned challenges, one can infer that, with V2G yet to evolve from a concept into a commercial project in advanced EV markets, it may only remain a topic of academic interest in India for the near future. However, as the penetration of EVs increase the benefit of having commercially viable V2G technology will have an exponential impact on the renewable energy capacity addition in India and improve the efficient operation of the future electricity grid. Thus, to make V2G a reality in the country in the future, not only does India’s EV market have to evolve, but its power sector regulations also need to undergo a major transformation.
To know more about Vehicle to Grid Integration please refer to AEEE report available at https://aeee.in/our_publications/vehicle-grid-integration/
The blog is written by Chandana Sasidharan with inputs from Nitin Kesar.