Posted by Maria Dimitrova

Read this if: You are considering buying an electric car

Gain: A hype-free perspective on the efficiency of electric cars in terms of being eco-friendly

Ecologists have been warning us about global warming for decades but not many people paid attention to this issue as in the beginning the impact of climate change on our daily lives wasn’t so noticeable. However in recent years we have witnessed severe weather conditions and an unusually high number of natural disasters. This has resulted in a knee-jerk interest in environmentally-friendly solutions in all spheres of life.

One of the main pollutants is considered to be the CO2 emissions from vehicles. Polls have shown that 62% of car buyers are concerned about climate change. This number indicates a willingness to give up gas-powered cars for new electric ones. Some states in the USA are trying to encourage people to take this decision by offering cash incentives and extra privileges (like using the high-occupancy vehicle lane on highways even with only one driver). For example, the state of California is offering numerous rebates including a $3,000 to $5,000 tax credit in addition to the $7,500 federal tax credit.

Furthermore, makers of traditional cars are being pushed to improve emission levels and fuel efficiency. The Corporate Average Fuel Economy (CAFE) regulations require that the average mileage of a fleet of cars sold by an automaker should be 27.5 mpg. This means that if an automaker sells one hybrid car ( an electric car powered by a gasoline generator) that gets 60 mpg, it can then sell four less efficient cars – like SUVs and trucks – that only get 20 mpg. This is one reason why Chevy, Nissan, Ford, Toyota, etc. are launching new models of electric vehicles and trying to raise their popularity.

But are electric cars as “green” and efficient as they are said to be?

The electricity costs

A widespread use of electric cars will lead to increased electricity consumption. If most of the electricity supply came from renewable energy power plants (wind, solar, hydroelectric) there would be no problem. But currently the world is still to a large extent dependent on coal and nuclear power for electricity production. For example, see the chart below. In the USA the sources of electricity generation in 2009 were:

In this regard, detractors of electric cars say that this type of vehicles don’t eliminate pollution – they just “move” it from the place where the cars are used to the location of the power plants.

There is an option to recharge the batteries of electric cars utilizing the excess electrical power generated at night when the consumption is much less than during the day. This can be applied if all electric car users have the special chargers at home and use them after 10 pm which is highly unlikely. There is a significant limitation that occurs if people can only charge electric cars at night – the range of these vehicles would be 100 miles (160 km) per day, or only half of that when the cars are driven at high speed. There are some electric cars that have better mileage: 220 miles for the Tesla Roadster and 150 for the Mini E model – but both have no back seat since that space is taken by the larger battery.

No matter how small the amount of cars that needs charging during the day, a sprawling infrastructure of charging spots has to be built throughout cities and towns. But what will happen in the worst scenario when all plug-in vehicles are charged at 5 pm instead of after 10 pm ? A study from Oak Ridge National Laboratory calculated that in such case the US would need to build 160 “large” power plants and the related distribution infrastructure!  Plus, this concerns plug-in hybrids, not fully electric cars which need more charge, and a penetration of only 25 percent, not 100 percent. A complete conversion to plug-in hybrids would thus require 640 extra large power plants.

One of the main disadvantages of electric cars is the long time they require to recharge. On average it is between 6 and 8 hours. Manufacturers and researchers are striving to overcome this drawback and some auto makers have already announced recharging times of 30 minutes or less. Unfortunately, this is only possible through a high-voltage current outlet. Fast recharging can lead to a giant amount of peak power. If you charge an electric car in just 20 minutes, you need a power output of 75,000 watts (75 kilowatts x 0.33 hours = 25 kWh).This corresponds to the energy output of 220 plasma televisions of 340 watts each. Charging just 6,500 of these vehicles simultaneously in 10 minutes will require an energy output comparable to that of one large power plant. This amount of energy is required over a shorter period, but it has to be available.

Another possible solution is to use swappable batteries. This means that when drivers go to a charging station, they don’t wait for their battery to charge but instead replace the battery in their car with a newly recharged one from the station. In this scenario all batteries should be the same. But is achieving a universal standard technically and commercially likely? Different batteries in laptops and mobile phones contradicts this idea. Technology improves and the old standard (and investment in battery infrastructure) would quickly become redundant.

Production of the batteries

The concerns regarding the materials used for batteries are that they cause pollution. Many hybrids use NiMH cells – Nickel-metal hydride. Nickel is one of the world’s nastiest pollutants. The process of refining it requires much heavy diesel machinery and caustic chemicals.  Large areas within a mile of the mine are turned into a “dead zone” where it’s hard for living creatures to survive.

The production process of the batteries isn’t eco-friendly either: There is a large quantity of carbon emissions during their manufacture.

Since battery life is limited, owners of electric cars will need to replace the batteries periodically. The rate at which they expire depends on the type of battery technology and how they are used – many types of batteries are damaged by depleting them beyond a certain level. Lithium-ion batteries degrade faster when stored at higher temperatures. The limitation of battery lifespan means a bigger demand for batteries and this in turn means more pollution during the production.

The safety issues

Electric cars will not be safe in hot areas like Arizona, Mexico and southern California because the intense heat can cause the battery to go up in chemical flames, especially in cars in which the battery is placed inside the vehicle.

Other possible dangers include overcharging the battery at night and and lightning which again may cause an explosion of the battery.

In the case of road accidents, the battery can be split and go up in chemical flames. But even if this doesn’t happen, many electric cars have a small, light and fragile body which means inadequate safety protection.

In addition, pedestrians, especially the hard of hearing will have difficulty detecting any noise coming from the vehicle when it is operating below 20 mph (30 km/h).

Electric cars are one step further in the direction of attempting to replace cars emitting greenhouse gases but there are still many issues to be solved before we can be sure that it’s an efficient solution. Hopefully, in the near future scientists will create much more eco-friendly vehicles. A good example of their constant efforts to achieve this goal is Jaguar’s concept of a car with the smallest twin turbojet electric engines. The car will produce just 29g/km of CO2 and with a 60 litre fuel tank will have a range of 600miles. It’s considered to be faster, cleaner, and with greater range than petrol cars. But it’s still a concept and it will probably be unaffordable for most people.

In the meantime, those wanting to adopt a “green” lifestyle should use public transport, ride a bike or walk whenever possible. The 80-20 Pareto principle suggests this one is not ready for prime time and your conservation efforts are better directed elsewhere.