Autumn for the Leaf? Part Two
Posted by Jeff Id on June 14, 2011
by Robert Allaband
According to the Bureau of Transportaion their was 255,917,664 total registered vehicles in the United States as of 2008. Of that total 137,079,843 were passenger cars and 101,234,849 were classified as other 2-axle 4-tire vehicle (SUV’s, Pickups and such).
Now the goal is not to replace a small fraction of those numbers with Electric Vehicles (EV’s), it is to replace all or the vast majority of them if you want to cut the strings of dependency to the internal combustion engine. Now you might want to reach that goal for the reason of GHG’s emission cuts or for energy independence from Middle East tyrants. No matter the reason for the switch lets look at what happens if or once it does occur.
First lets look at what happens if the EV’s that replace the Internal Combustion Engine (ICE ) vehicles use a plug in system such as what is used for the Nissan Leaf. When you do this you have to ask yourself a couple of simple questions:
Where is the electricity going to come from?
Right now the US is suffering a supply problem, and some places experience brown outs and rolling balck outs during the summer months. We have what is called “peak” hours where the demand for electricity is just about to, is at or has surpassed the supply in some areas. We get told to turn things off and to turn up the thermostat on the AC until the “peak” passes. Depending on your electric utility and where you live you can be “in peak” for as long as 12 hours as seen by one provider charging “peak rates” between 9am and 9pm. So this begs the question what happens when you replace just 137,000,000 passenger cars that ran on gas with EV’s and they all come home after rush hour and plug in?
Lets use the Leaf as an example.
According to Nissan (http://www.nissanusa.com/leaf-electric-car/index#/leaf-electric-car/faq/list/charging ) you can program your car to charge during off peak hours so lets say that most people do this trying to save money (this is a best case scenerio). Also according to Nissan it takes approxiamtely 7 hours to charge a dead battery back to full using the 240v charging dock. There is a 480v option that works in 30 minutes, but very few people already have 480v service and very few of those that don’t are going to pay to have 480v service set up, and it takes 20 hours for a 110/120v line. This is why Nissan recommends the 240v charging dock. So you end up over a four hour period every week day with a large percentage of those 137,000,000+ vehicles being plugged in and starting to charge. This in turn means that you must keep more generating capacity up and running for longer periods of time if there is no increase in overall capacity to meet this new demand. This in turn leads to increased costs for the utilities as they must shoe horn more maintainence in during early morning hours where pay scales increase for not working 9 to 5. Also this means line maintainence is going to become more problematic as there will be more demand during what is now “off peak” hours. This in turn means rising costs to the consumer. However lets say the generating capacity is overcome which at leads us to other questions.
How do you charge your car when you are out of power for a day or more?
Lets face it folks, for some places in the US that is not a rare occurance. Places such as known hurricane landing areas, Tornado Alley or where servere ice storms occur people lose power and most do not own emergency back up generators. Even if you did most residential back up generators are not going to allow you to power the necessities of your home and charge an EV. You come home from work one evening with a very low battery, you plug it in, set to charge off peak. You sit down for the evening and catch the news that the hurricane you been following for the last few days is going to come ashore within 50 miles of your home that night. You go to bed, the hurricane comes ashore and the power goes out at 2 am and stays out for the next two days. Yes there is local damage but not that extensive, yes your car got a partial charge and yes you still have to go to work. A day later the power is still out and your car’s battery is dead and so is everyone else’s and you still have to get to work. With an ICE powered vehicle you could have stored gas in a gas can for just such an emergency or more then likely if you live outside of an urban area the gas for you lawn mower. That ability to store the energy in a portable form to be used later is the one area a plug in type EV is hard pressed to meet.
Where exactly are we going to put charging stations besides in our homes?
Does anyone really think that major companies that have 1,000+ workers in one facility are going to install enough charging systems to charge up their employees cars. Or how much they are going to charge their employees for the priviledge if they do? Or how about retail stores and restraunts are they going to try to put in charging stations for all their customers? The cost to install and use all these charging systems have to come from somewhere and guess who that is going to be: You the taxpayer, worker and consumer.
Where are we going to make all these multiple charging stations at?
Remember we are not talking about a couple hundred or thousand charging stations but millions. Then there is the cost of maintaince and replacement. More then likely those charging stations will be made in China or India and shipped to the US, so on the manufacturing side we do not see a jobs increase. At the same time you have to train a large enough group of Electrcians or Electronics Techs to maintain/repair those systems.
These are just a few of the infrastructure and economic problems to switching to vehicles based on the current plug in battery technology. There is a Scientific American article on the problems of EV infrastructure that lays out proposed solutions to them: http://www.scientificamerican.com/article.cfm?id=electric-car-quandary
In my humble opinion some of the solutions are pie in the sky fantasy like the robotic battery replacement on the go solution. Really? You think every car maker is going to use the same battery and place them in the same position or make their own unique version and place them where they can? History goes for the latter not the former. Others, such as building the charging station version of gas stations, will take too long to get in place before technology changes in some way, such as Semi Solid Flow Cell (SSFC) technology, renders that solution obsolete. Also as pointed out in the SciAm article you have be careful with this technology because support might go “poof” fast.
So lets look at what the infrastructure for a system that uses a SSFC type of technology.
Since the hardware part of the battery system is part of the car and not a subcomponent of the battery we just need to worry about the liquid medium that stores the charge. We need to replace spent liquid for fresh and the paper points out two methods. The first is a whole tank replacement method, basically think of your gas grill but with your car. On paper it sounds nice, but what about in practice? You have to take things into account such as how easy it would be to reach the unit, how big the unit was and how much it would weight. If the unit was about the size of todays gas tanks then a tank replacement method would not work, it would be just too big and heavy for easy replacement.
The second system is IMHO the best way to go and that is a pump system. Basically it would work just like it does with gas. You have a local station with tanks holding the charged fluid and a collection tank that the spent medium goes into for recycling/recharging. The tank and pump system is already in place and the technology is proven, you just convert existing gas stations to handle this new energy medium. People are already familiar with how the system works and they are everywhere. The only new aspect would be connecting on outlet to a vacuum system to remove the spent medium first. This woud be a much faster and lower cost way of getting the needed infrastructure in place before demand rises ahead of supply.
As to conversion from gas to SSFC liquid it is basically nothing more then a new twist on something gas stations already do. Gas stations replace tanks and pumps as needed and it doesn’t require a massive new assembly plant somewhere to make them or massive training or retraining to find people to make or maintain them. Existing storage tanks could be refurbed/recycled for the new medium and the same with pumps. The only thing added is the vacuum system to collect the spent medium from the EV’s fuel tank (again something that is already used in ICE vehicles that can be tweaked to work with the new fuel).
Now this new battery system does have one thing in common with the system now in use: Where is the extra electricity going to come from? Lets assume that just like before that question gets answered. So that leads to how do we charge or recharge the SSFC storage medium?
In the system that EV’s use now it is a diffuse system of individual charging systems straining the exisiting and aging grid. With the new system you can do it by mass production by setting up charging/recharging facilities near power generation plants. This does two things that in the long run reduces cost. The first being it reduces the amount and distance of power lines needed to charge the medium, the second is the economy of scale. If you have a few big recharging facilities they are able to run higher power lines to them and this reduces how much they are charged. Also it would be cheaper to recharge thousands of gallons of medium at one time in one large vat, then it would be at the indiviual fueling stations. That in turn means you need a distrubtion system for the fuel and there is already one in place: tanker trucks and rail cars. The tankers that now bring gas to your local station would now bring the fuel needed for the new SSFC batteries.
This in turn leads to another factor, people do not want to buy a second car that can only be used near their homes. That is a big drawback to EV’s for most people, they can’t drive them to the beach unless the live close enough, they can’t drive them on vacation unless they are not going far. Even when you extend the range of todays Lithium Ion batteries and put in more charging stations, there is still the time to charge if you try to use it on an extended trip. With this type of system that problem goes away, since operationally to the owner there would be no difference between an SSFC powered EV and a gas powered ICE vehicle. The owner/operator just pulls into a refueling station and replaces his spent fuel.
Right now the MIT team believes they will have a working prototype in about 3 years, ready to mass produce:
The target of the team’s ongoing work, under a three-year ARPA-E grant awarded in September 2010, is to have, by the end of the grant period, “a fully-functioning, reduced-scale prototype system,” Chiang says, ready to be engineered for production as a replacement for existing electric-car batteries.
Even if that turns out to be an overly optomistic timeline and it takes 6 years, SSFC technology could be making EV’s that are able to compete both operationally and economically with ICE vehicles well before the plug in EV’s are projected to reach a 2% to 5% market share. So it might be autumn for the Nissan Leaf and its brethern before they ever got out of spring.