For those in touch with the auto world, electric cars are all the rage for development. Even those not directly interested in cars know about the energy friendly, environment caring cars that drive on electricity.
This topic surely isn’t as exciting as self driving cars, but the essence is more or less the same. Electric cars are meant to reduce hassle: they don’t emit greenhouse gases, don’t waste a expendable fuel source, and effectively lower our carbon footprint.
Electric cars are different from hybrid cars. Hybrid cars are those that use gasoline as a primary fuel source and use electric motors to improve efficiency. These just aren’t the same as electric cars, cars driven solely on electricity.
The image shown below is a comparison between electric and gasoline cars.
The major downfalls of electric cars are that they can’t drive for more than a hundred miles, and take a lot longer to recharge than gasoline-driven cars.
EV (electric vehicle) advocates claim that a hundred miles are already a decent amount, saying that the normal travels of most people rarely exceed the total.
As another counter to this statement, newer cars have mile ranges up to 200 miles. Even though the cost of the car goes up by increasing the range, the price of cents per mile will steadily go down: as battery prices are dropping.
Due to the fact that only thirty or so electric cars exist in the market currently, another issue is the lack of customer choice: but this is a hurdle that will soon be overcome by the market.
Demand for these cars are going up as well: as shown in figure 2, the projections for sales go up exponentially.
The main part to these cars is their battery. Electric cars have a rechargeable battery inside, that can be charged at home or at a dock. There are two parts to this: the type of battery and the type of charger.
According to the White House in a post, “The lack of affordable, highly functional batteries has been a particularly high barrier to the widespread adoption of electric vehicles.” Most agree with this statement, and development is under way for a better battery.
The precursor of modern car batteries came from Alessandro Volta in 1800. This was a container filled alternately with copper and zinc plates, separated by cardboard plates dipped in salt water. This battery ensured a steady flow of electrical current, by creating a chemical reaction, forcing the zinc plates, negative anodes, to release an electron for the copper disk, a positive cathode, to catch.
After two centuries, it is no wonder the battery hasn’t remained the same. With modern technology, the battery has been upgraded, but the basic principle has stayed the same. Now, batteries use lithium ions. The ion is shuttled back and forth from the anode and cathode, and is called a lithium ion battery.
The lithium ion battery provides a higher energy density than previous batteries. Compared with the nickel-metal hydride battery used in the Toyota Prius, for example, a lithium-ion battery of the same weight and volume would increase energy density two to three times, says Dr. Srinivasan.
Dr. Venkat Srinivasan is the manager of the Battery for Automotive Transportation Technologies Program, an Energy Department-supported program managed by Lawrence Berkeley National Laboratory at the University of California, Berkeley.
Jeffrey P. Chamberlain, head of the Electrochemical Energy Storage group at the Argonne National Laboratory, a lab near Chicago sponsored by the Energy Department, says that all vehicles available with electricity as a primary power source use some form of lithium-ion battery, and that these types of battery will be prevalent for at least the next two decades.
Researchers are experimenting with bonding lithium with other materials in the battery cathode. The materials used dictate the voltage and amount of lithium the cell can hold, and as both increase so does the energy efficiency for the overall cell, according to Dr. Srinivasan.
At Argonne National Laboratory, people are working with newer mixes of nickel, manganese, and cobalt for the cathode, as blending in different amounts and forming different structures has shown to double the efficiency, and, in turn, Argonne is offering patents for the material to various battery makers. According to Mr. Chamberlain, the result would be batteries “that squeeze more energy into a smaller package, are less expensive to make and last longer.”
Similar to changing the cathode, researchers at Argonne and other places are contemplating swapping the cathode for silicon, replacing the current carbon anode, as silicon will theoretically increase the amount of energy holdable tenfold.
This was as of 2011, and even as recently as 2015, these batteries have major limitations: scientists haven’t found an efficient way to get over the expanding properties of silicon: it can expand up to 300%.
According to Mr Chamberlain, to get over this hurdle, researchers are experimenting with blending silicon with other materials like graphite to try to find a balance to prevent expansion while increasing energy density.
These batteries, or rather, electric car batteries are the most expensive part of a car, easily racking up into the thousands. Due to this, manufacturers deem it competitive information: but, according to a study by the Frankfurt School of Finance & Management, the prices for batteries have gone down by about 35% between 2014 and 15.
Looking at the graph (figure 3) the decrease in price is drastic.
According to a study by McKinsey & Company, “Despite that drop, battery costs continue to make EVs more costly than comparable ICE-powered variants. Current projections put EV battery pack prices below $190/kWh by the end of the decade, and suggest the potential for pack prices to fall below $100/kWh by 2030.”
The drop in mention is battery costs falling from ~1,000 per kWh in 2010 to ~$227 per kWh in 2016, according to McKinsey.
Basically, McKinsey doesn’t expect a real drop in prices, or at least no ~$100 per kWh battery to occur soon, even though Tesla has hinted at this possibility.
Now, these prices mentioned are for the entire package: both the battery pack and cells.
Batteries must also be charged for the car to actually drive. The battery is charged differently than most expect: the port is actually on the car itself. The appliance known as a ‘charger’ is in reality just a converter for AC to DC, allowing your electricity to feed a car. Its real name is an Electric Vehicle Service Equipment, or an EVSE, and all EV owners should own one. Like, seriously.
A general consensus between EV drivers is that chargers cost around 6-7 hundred dollars. Each EVSE can handle a specific amount of amps. The suggested amperage is 30, allowing approximately 30 miles from an hour of charge. This is like 15 amps will charge about 15 miles in an hour. There are two things to note from this, however, that 30 amp EVSEs need a circuit breaker of at least 40 amps, and that not all EVs will benefit from the faster charge, notable ones including the Nissan LEAF before the 2013 model.
It is essential that chargers are mobile, or rather movable, so that if needed, the car can be charged from somewhere else, as it decreases the cost of buying another one. The car should ideally be reached by the charger with some length of cord left over as well.
Most cords are at lengths of 15 to 25 feet in length, and increasing the amount of wire will also increase the cost.
Despite some minor setbacks, EVs have proven to be developing fast: they may be the tech breaking dependence ties on fossil fuels. They will continue to develop, and till then, the world will wait.
References used in the making of this article:
http://www.plugincars.com/ basic info, the various guides give great info.
http://www.nytimes.com/2011/03/31/business/energy-environment/31BATTERIES.html On lithium ion batteries
Figure 1: http://www.plugincars.com/electric-cars
No comments:
Post a Comment