Renewables and EVs: Myths and Reality

Dr. Prabhjot Kaur is Co-Founder and Director of Esmito Solutions Pvt Limited

There is no doubt that Electric vehicles are a Global saviour for our planet against the pollution being caused by transportation. Reduced greenhouse emissions with EVs is supposed to be offering its accelerated benefits when fueled through renewables. The benefits of this combination thus are inevitable. But there are implementation challenges that places limits on the benefits. Renewables are not everywhere and are an intermittent source of power, and time to fuel the vehicles cannot be fixed or be based on renewable’s availability. Both the generation and consumption of energy thus cannot be synched with space, time and availability. Reliability in available renewable power when one needs can only be ensured through addition of a good amount of energy storage. Thus, to recharge the EV fuel, there are levels of energy conversions at play which raise a question mark on the end-to-end efficiency of the entire system.

Powering EVs with Renewables lll

The mixing of power with grid at decentralised level can be from any means of renewable sources like Solar, Hydro, wind, geothermal or biomass. For India, we have a good opportunity for Solar power. To overcome the issue of intermittency with solar, the most prevalent means to supply a stable renewable supply is through the batteries. In this case, these are the battery banks that shall be charged first to charge the EV batteries. But in this case both the system performance and economics get compromised. That makes centralized energy generation through renewable source or a good mix of it with the traditional fossil fuel power as a good means to utilize renewables for feeding EVs.

Another big fascinating myth in the EV world is V2G bringing in promising climate saving. We should instead view this as a tool to add more flexibility to the users of the EVs to utilize the stored EV power for other purposes when in need. Economic viability for V2G is possible only in scenarios where either the direct grid is not available or the power back up is a secondary / tertiary source of powering the demand.

The secondary possible applications of stored energy in EVs should be considered as add-on or emergency power instead of considering EVs to be used for stabilizing the grid, V2G, or major source of backup power. The system in such cases shall work on multiple conversions, leading to losses, inefficiencies and poor economics.

How to benefit from EVs?

Some good measures to make the best out of the Renewables aiding EVs to contribute towards Greener planet are:

1. Make EV and batteries manufacturing plants to be operated on renewables, with constant demand of power for production
2. Make centralised charging / swapping hubs to be fed by renewable sources of power
3. Use better technology to harness the energy from vehicle motion such as regenerative braking where other sources of power are not required
4. Create a high mix Grid of various sources of renewable plants especially at centralised level.

In a nutshell, the increasing global warming demands high attention and intervention to bring in as much renewables as possible to feed in the fuel requirements of transportation but the cost ineffectiveness and system ineffectiveness can make it unviable for the duo to coexist. For Metro cities or cities with stable grid networks, renewable mixing is a great solution. For areas with low grid stability or poor grid availability where renewable energy are priortised to support the larger load of EVs, we will have to bear with system inefficiencies due to the involvement of energy storages.

The newer infrastructure can greatly benefit from a high renewable mix of power generation and centralising the charging / swapping infrastructure to be fed on such renewable dominant substations.

About the author-

Esmito provides advanced battery swap solutions, battery management systems and infra management platforms combined with sophisticated analytics. Prior to Esmito, she served as Founder and CEO, Centre for Battery Engineering and EVs at IIT Madras and Director, Reliance-TCOE. With several patents, publications, and technology transfers to her credit, she has been leading various initiatives on design, development and setting up the innovative EV charging solutions, and been aggressively leading standardization and policy efforts for EVs in India.

She is a recent recipient of Vasvik Industry Research Award, only women getting this award in the category of electrical and electronics engineering since its inception. She was also bestowed for IEEE Technology of the year award in Service of Society, USA and Microgrid 2019 Greater Good Award, USA.