Electric Vehicles in India and its Impact on Grid

IC engine vehicles are the majority in the country’s transportation sector. The conventional IC engine vehicle uses fossil fuels as a source of propulsion. So, the amount of fossil fuel consumed has reached its maximum capacity and its resources are already on a decline. Meanwhile, due to the increase in population, the energy demand is also increased. In order to meet these challenges, electric mobility comes into the picture. But for a sustainable future, this sector is shifted drastically toward electrical mobility. Therefore electrical vehicles (EVs) are marking a revolution all around the world because of their environmental and socio-economical advantages. 

The Future of Electric Vehicles in India

EVs are making their mark in the transportation sector and are considered to be the best alternative solution to promote eco-friendly transportation in the world. Many smart city projects are implemented with the electrification of vehicles in India. With the electrification of mobility accelerating in the world, energy producers and distributors need to understand the potential impact of EVs on electricity demand and power distribution networks, as well. In India, the electrification of the mobility sector is developing rapidly so many industry experts believe that the domestic market is set to expand to a whole new level over the next 1-2 years.

According to research conducted by Datalabs, India is projected to require about 100 TWh of electricity (about 5% of total electricity) by 2030 given that 80% of the country’s population adopts electric vehicles. Currently, consumers have to either utilize less electricity during peak hours or pay more for usage. The electricity distributor provides electricity at an efficiency rate of 99.99% This figure shows EVs' impact on the power grid and it also shows that there is more power demand than total power generated. The number of electric vehicles (EVs) is gradually increasing and is expected to reach 3.8 million by 2020. Tesla and other competitors are expanding the production and manufacturing of electric vehicles to meet the demand. EV models are becoming more affordable as a result, which in turn fuels the adoption even further.

In India, the current demand for electricity is around 200-300 GWh. Assuming that India will have 30% electric vehicles of total vehicles on road by 2030. The increase of EVs relatively increases the power demand whereas electric vehicles will account for the most significant load capacity in the country, which is higher compared to industries such as steel. And the total electricity demand to power EVs is projected to increase to almost 640 TWh by 2030. The EVs generally require a battery for propulsion, in local trains, metro trains, trams and buses do not have these problems, simply because they do not need a battery. Their energy consumption is spread evenly throughout its operation time.

Electric motors are more efficient than gasoline engines but the fundamental problem here is not total energy consumption, but the peak load demand of the EV to charge its battery. The charging infrastructure has been growing along, often supported by local governments. But a lot of questions arise about how electric vehicles will impact the grid and accommodate the extra load.

What will happen during Peak Demand?

There is no major impact on the power grid until 10-15% of EVs come into mobility. But if each house gets one EV, the existing power load has to double the requirement which creates an imbalance in supply-demand equality constrain. The local distribution grids will not be able to accommodate the huge spikes in power demand. The EV constitutes a non-linear load and causes DC offset which results in harmonic disturbances, phase imbalance, and voltage deviations in the distribution network. By adding the power generating and transmission networks, the load is expected to come down thus the impact on the grid is negligible. Typically, an electric vehicle with a commuting distance of 50km requires 6-8kWh of energy to recharge for motion, which is approximately equal to the daily power needs of a household. In other words, introducing an electric vehicle is almost the same as adding another house with basic utilities.

Power transformers, which connect every home and business to the electric grid, are the most vulnerable and affected elements of the power system. Because most residential transformers are designed to serve between 10 and 50kVA of load limit, while a single plug-in vehicle (PEV) with a 240V Level 2 charging system consumes about 7kVA. If multiple electric cars is connected to the same transformer and used for charging the vehicle such a situation results in clustering of power networks, which may cause damage or outages from overloading the equipment or by reducing their normal cool-down period. A transformer in overload condition can, in turn, degrade power quality in other residential feeders of the network. Higher penetration rate of electric vehicles beyond the limit which in turn reduces the life factor of transformers, even by up to 10,000 times. As a result of EV-related overloads, an average estimated cost per transformer is 10 times increased. This leads to an increase in the overall cost of installation and maintenance.

Risks of Overloading and Their Solutions

The risk of overloading local transformers is particularly high during peak hours. Imagine what if all all-electric vehicles are connected to the grid at the same time for recharging. This pattern is analysed and the local transformers may not be able to withstand such extra load demand. Scheduling electric vehicle recharging during non-peak demand periods is called valley filling, which can save utilities millions of dollars by reducing their dependence on peaking power plants, which run only when the demand is high. This approach would have to rely on the smart grid system. Automatic Metering Infrastructure (AMI) would measure electric usage in real-time and communicate to the utility via radio frequency or broadband over power lines.

However, this approach is not a complete solution for the peak demand requirement in the local power consumption. But the central power generation plants are just fine, but again, the local transformers suffer the most from this sudden extra demand. Shifting the charging pattern from day to night will not actually solve the problem. The transformers are often designed to cool off at night. When depriving them of the cooling time of transformers may lead to local blackouts, as the sustained excess current will directly affect the copper windings transformers.

If an electric car is charged with a battery capacity of 25 kWh for 8 hours, it requires a power output of 3,125 watts (3.1 kilowatts x 8 hours = 25 kWh). But now the same car needs to be fully charged in just 20 minutes, so a power output of 75,000 watts is required. (75 kilowatts x 0.33 hours = 25 kWh). This amount of energy corresponds to the total energy output of 220 plasma televisions of 340 watts each. This amount of energy is required over a shorter period, but it has to be available. If recharging time is reduced to 10 minutes, the energy output will be 155,000 watts (155 kilowatts x 0.16 hours = 25 kWh). This equates to 450 plasma televisions. The charging time is with the amount of power required for the vehicle.

At first, the local grid has reached its limit those cylindrical metal things in the pole-top transformers create humming loudly on hot summer days. These spin down high voltage electricity from the transmission wires to tame the voltage levels of 120V and 240V suitable for residential use. No transformers installed by the utilities are increased and so more high voltage electricity can come down to residential levels to meet the demand. But if more people replace their conventional IC engine cars with EVs then the demand increases and the utilities will need to transmit more power to satisfy the demand. The transmission network is improved to transmit more power but the initial cost of setting up the infrastructure is expensive. Different case scenarios have been taken to test the EV power requirement and its impact on the grid.