## 2 New Challenges Emerged from EVs' Popularity  
EVs' increasing popularity leads to numerous new challenges that must not be conveniently ignored. These challenges can be categorized into three classes, namely; challenges in ensuring the sustainability of the EV production, challenges in meeting the increasing demand of electricity due to EV penetration, and, challenges in managing the migration of ICE-to-EV in terms of number of vehicles and the industry eco-system. In the context of EV production sustainability, it was argued in [2] that, although EVs emit zero emission, the same cannot be said for their production. This is because the production process involves a significant amount of depletable materials, like heavy rare earth materials, for the production of motors and batteries. Moreover, the process also leads to higher amounts of emissions of heavy metals like lead, nickel and molybdenum, as compared to the production of ICE vehicles, and this was claimed to be detrimental to human health. According to the study by [3], the carbon footprint from these activities is currently very high due to their localization. At the moment, these activities are mainly located in China, South Korea and Japan, where a significant portion of the power is generated by fossil fuels, resulting in a high carbon footprint. To address this, refs. [3,4] proposed either diversifying the production locations to places with high concentration of renewable power generation, or intensifying the amount of renewable power generation at the existing locations. At the same time, ref. [3] also suggested stopping the trend of increasing the battery size because it has direct relationship with the aforementioned carbon footprint issue. This suggestion can be achieved by improving the efficiency of EV powertrains. The increasing demand for EVs also causes electricity demand to shoot up and this leads to the second challenge emerged from the increasing EV popularity. According to [5], the amount of electricity used for EVs, on a daily basis, is about the same as the average daily electricity usage of a typical household in the United States. As such, when EVs reach 20% of a total vehicle market share globally, the electricity peak demand is expected to increase by 36%. In some countries, like China, research by [6] indicated that the popularity of EVs will strain not only its national grid, but also to its national water supply. This is because in China, two major contributors to power generation are hydroelectric and coal power plants that rely heavily on the national water supply. Thus, building and operating additional hydroelectric dams and coal power plants to meet the demand for EVs will divert vast amounts of water away from household usage, causing water scarcity if not properly planned. To address this challenge, two fundamental strategies must be seriously evaluated; efficient power grid management, which can be achieved via either implementation of vehicle to grid technology or implementation of extensive battery swapping activity, and efficient, sustainable and economical EV powertrains, which include the application of optimum motors, transmissions and batteries, with, possibly, a significant amount of carry-over technologies from ICE vehicles. Finally, it is also critical to properly manage the ICE-to-EV migration so that a smooth transition phase can be realized. Simply increasing the market share of EVs alone is not enough if the total number of existing ICE vehicles, especially those that have low emission standards, is not drastically reduced. Besides, such migration must also be managed from the perspective of the existing industrial supply chain. For instance, an appropriate strategy has to be planned for the existing ICE-related manufacturing plants which are expected to face redundancy once EVs take over ICE vehicles' market share. In this aspect, one of the strategies is to repurpose the existing manufacturing plants to focus on EV-related products.