BENEFITS OF USING EVs
Hello everyone. So we have already covered the historical background related to EV development in our previous interaction. Let us begin the discussion on the next topic underintroduction to EV which is benefits of using EV compared to other modes of transport. So the big question is why EVs
It seems that the global population which is 6 billion currently, if it increases with the current trend, may become 10 billion by 2050. So what that means? It means the vehicles in use may increase from 700 million which was there in 2000 to 2.5 billion by 2050. And if all these vehicles are IC engine based vehicles then most likely all the cities will be covered with permanent smog with extreme air pollution. And this is very drastic in terms of health. According to one of the reports of ARB which is Air Research Board, which came in 2011, around 9000 people die every year in California due to fine particle matter. So these numbers are alarming and there is a necessity to think ahead. So what is the way out? One of the promising solutions is sustainable transport. So what is sustainable transport? It means use of low or zero emission vehicles, promotion of public transport so that very less vehicles will be on the road. Use of more and more renewable energy sources for charging these zero emission vehicles. It also means we will be less dependent on fossil fuels which is the large source of air pollution. So to better understand the advantages and shortcomings of EV, let us compare the EVs with other modes of transport. The comparison can be done on following parameters.Energy sources. Pollution. Energy diversification. Efficiencies. Capital and operating cost and performance. Now let us compare the different types of energy sources used in different types of vehicles.
We all know gasoline which is petrol, diesel, compressed natural gas, which is CNG, hydrogen, batteries, and the upcoming ultra-capacitors, and ultra-flywheels. So petrol and diesel are liquid fuels. While CNG and hydrogen are gaseous fuels. Battery stores the energy in chemical form and provides energy in electrical form. Ultra-capacitors stores the energy in electrostatic form while ultra-flywheel stores the energy in mechanical form. Both petrol and diesel have similar energy content per unit mass which means they have same specific energy. But since diesel is more denser compared to petrol, it has higher energy content per unit volume. The energy per unit volume is also known as energy density. By having higher energy density the diesel is more fuel economical compared to petrol. The CNG has higher specific energy compared to liquid fuels but it has very low energy density. On the other hand, hydrogen requires storage at a very high compressed state by using high pressure and therefore it requires lot of ancillaries around its fuel tank but on the positive side it has very high energy density compared to petrol, diesel and CNG. Therefore, there is a serious effort to make hydrogen based fuel cell electric vehicles a commercial viability. Batteries if you take a recent battery example, let's say lithium ion battery, the lithium ion battery has specific energy and energy density very low around 75 times low and 25 times low compared to petrol which means that for the same energy content, the mass of lithium ion battery will be 75 times more compared to a petrol and it requires 25 times more volume compared to petrol. This is a serious limitation of batteries compared to liquid fuels. Ultra capacitors provides very high specific power. But it can store very limited energy. As we know ultra-flywheel stores energy in mechanical form at very high speeds but it has drawbacks such as it is less reliable and there is a safety concern around it when it is used inside the electric vehicle.
