Showing posts with label kWh. Show all posts
Showing posts with label kWh. Show all posts

Wednesday, April 30, 2014

How Much Does it Cost to Charge an Electric Car?




There are many reasons for considering making an electric car the next car you buy or lease. Besides the many environmental benefits, the promise of energy security, the silky-smooth driving experience with instant torque available without delay and low maintenance, one of the best characteristics of electric vehicles is how little they cost to operate. I've covered this topic here before, but this is something that really needs to be driven home. While Electric cars are currently more expensive than their conventionally-powered counterparts, the total cost of ownership over time can certainly be less, and in some cases much less.

Just as with gasoline cars some EV's are more efficient than others, but the average EV needs about 30 kWh’s of electricity to power the vehicle for 100 miles. For example, the EPA rating for the Nissan LEAF is exactly 30 kWh’s per 100 miles. A Tesla Model S 60 is rated at a combined 35 kWh’s per 100 miles and uses a little more energy since it’s heavier and more powerful than a LEAF, while the Chevy Spark EV has a combined consumption rating of 28 kWh’s per 100 miles. The BMW i3’s EPA consumption ratings haven’t been announced yet, but since the i3 is likely to be wear the “most efficient EV” crown, I expect it to be rated somewhere around 26kWh’s per 100 miles. The consumption for all electric vehicles can be viewed at the US Department of Energy’s website: www.fueleconomy.gov

According to Researchers at the University of Michigan Transportation Research Institute, the sales-weighted average fuel economy of all new vehicles sold in the United States in 2013 was 24.8 mpg. The average cost for a gallon of regular gasoline in the US over the past three years was $3.53/gallon. By using 15,000 miles as the average amount of miles a person will drive in a year, the annual cost of gasoline for the average car will be $2,135 per year, using the average cost of gasoline from 2011 through 2013.

Electricity rates vary much more than gasoline across the country, but the cost is much more stable. Unlike with gasoline, there aren’t huge spikes in electricity rates if a refinery has a problem, and neither does the price skyrocket when there is political instability in one of the large oil producing countries as we have seen lately, since all of the electricity we use in America is domestically produced. The average cost of electricity in the US is 12 cents per kWh. Therefore the average person driving an average EV 15,000 miles per year pay about $540.00 per year to charge it. As mentioned, the cost of electricity can vary greatly depending on where you live, but in order to equal the price of the average gasoline car’s fuel costs, the price of electricity would have to be four times the national average, and cost 48 cents per kWh. Nowhere in the US does electricity cost even close to that much. So the average American would save roughly $1,600 per year in fuel alone, and that's if gasoline prices remain around $3.53 per gallon. Gasoline prices do frequently spike up and down, but in the long run they always goes up. Electricity costs do eventually increase also, but not nearly at the pace of gasoline. Plus with fewer moving parts, EV's cost much less to maintain. If you combine the fuel savings with the reduced maintenance costs, it's clear to see an EV will cost you much less in the long run, even if the vehicle costs a little more up front.

Another great thing about electric cars is that you can easily reduce your electric bill by $40 to $50 per month just by being more efficient, and therefore completely eliminate your transportation fuel cost! You really can't use less gasoline unless you drive less or buy a more efficient car, but you can reduce your electricity usage at home and still drive as much as you always have. Simple measures like a programmable thermostat and the use of compact florescent or LED light bulbs can make a big difference. In fact, five 100 watt light bulbs left on continuously for a year use nearly the same amount of energy as it takes to power an electric car 15,000 miles! Here's how: five 100 watt light bulbs use 500 watts per hour. In 24 hours they use 12,000 watts or 12kWh. In 365 days they use 4,380kWh’s. A typical EV that uses 30 kWh’s for every 100 miles will use 4,500 kWh’s to drive 15,000 miles. Simply by turning unnecessary lighting off at your home, you can drastically reduce or completely eliminate your annual transportation fuel cost. Try doing that with a gasser!

Tuesday, November 5, 2013

How Long Will it Take To Charge an i3?

The i3 will charge in about 3 hours on a standard level 2 supply.
Since installing public charging stations at my restaurant in Montclair NJ, I have conversations with EV-interested folks nearly every day. One of the most popular questions they seem to always ask is how long does an electric car take to charge?

I wish I could just give a quick answer, but it's just not that easy. Nearly every EV takes a different amount of time to charge since they have different size batteries and the also have different charging rates. Then you throw in three different levels of charging (120V, 240V & 480V DC quick charge) and there isn't even a single answer for every car. For instance if I said the i3 takes about 3 hours to charge I'd be correct. However I could also say it will charge to 80% in under a half hour (DC QC) as I could say it takes about 15 hours (simple 120V household outlet) to charge and I'd still be correct. So I try to quickly explain the different methods of charging and the fact that every car is different without totally confusing the person or making it sound so complicated that they are are turned off by it all. After all, getting gas may be expensive but let's face it, it's very easy to understand!

The size of the battery, the onboard charger and the supply provided will all work together to determine how long your EV will take to charge. The vast majority of the time most EV owners will charge their car they will do so on a 240V electric supply, so I'll focus on that here. One advantage "little battery" EV's like the i3 have is since they have a small battery, they will charge relatively quickly, provided they have robust onboard charging capabilities. The i3's standard 7.7kW charger will fully charge the battery in under three hours which is pretty good compared to the other EV's on the market. Only Tesla (9.6kW charging standard) and Renault (43kW Chameleon charger) offer an EV with a faster level 2 charging rate than the i3.

Miles Per Hour:

One way to condense the conversation about charging time is to simply say how many miles of range per hour of charging you get. The i3's small battery (18.8kWh usable) combined with its relatively fast onboard charger will allow you to gain about 30 miles of range for every hour you are plugged into a 240v 32 amp supply. This will be something I really welcome. My MINI-E could accept up to 12kW's and I would get about 30 miles per hour of charging. However after a recent BMW software tweak my ActiveE only gets about 15 miles of range per hour and it feels painfully slow, especially when I need to charge to get somewhere. I am
so looking forward to getting back to charging at 30 miles per hour when I get my i3. Being able to charge quickly on a standard level 2 supply is really helpful and once you've been able to do so you don't want to go to a slower charging rate. The car becomes imminently more usable when you can charge it quickly so I'm glad BMW is offering a pretty robust onboard charger. Now of course I wish it was a 9.6kW charger like Tesla uses, but that's just the part of me that is never satisfied speaking. In reality 7.7kW's is fine for a car with a 22kWh battery. It will charge twice as fast as my ActiveE and deliver about the same range, and that will really make the car much more versatile.

Saturday, October 5, 2013

DC Quick Charge: Better Than a Bigger Battery

A BMW i3 charges at the first public SAE CCS quick charge station open in the US. 



The first public DC quick charger in the US that uses the SAE-endorsed Combined Charging System (CCS) opened this week in San Diego, CA. It's located at the Fashion Valley Mall and uses a dual connector quick charger called a "Freedom Station" by EVgo.

The i3 will have a DC quick charge option that the customer can elect or pass on. The price has not been set yet but the speculation is it will cost somewhere between $750 and $1,000 extra. Having the option will allow you to recharge the car to 80% in about 20 minutes. This is an incredible advantage to have in an EV, since charging times are really what limit EVs like the i3 from being able to cover hundreds of miles without much inconvenience. Of course you can get an EV with a huge battery like the Tesla Model S which will allow you to drive a couple hundred miles between charges, but to be able to really cover long distances without much inconvenience, DC quick charge (or battery swap ability) is really needed. 

Standards War

SAE & CHAdeMO side by side
Tesla understands the absolute need for quick charging on pure electric vehicles and is rolling out their own network of DC quick chargers they call Superchargers. Since Tesla uses a proprietary connector nobody other than Tesla customers will be able to use their network. Nissan uses a different connector called CHAdeMO (short for CHArge de MOve or charge for moving) which was developed by Tempco (yeah, the power utility that runs the Fukushima nuclear power plant) for quick charging electric vehicles in Japan. When Nissan came out with the LEAF, the SAE hadn't yet endorsed a DC quick charge connector for the US so Nissan had no other option but to use the CHadeMO connector on the LEAF for quick charging, not that they wouldn't have anyway. Then, once the SAE endorsed the CCS connector, BMW, along with Audi, Chrysler, Daimler, Ford, GM, Porsche all agreed to use it on their plug in vehicles, when they eventually make them. I'm not going to go into why one is better than the other, or why some manufacturers chose one over the other here. There are plenty of articles on the internet that discuss this at nauseam; just do a simple search and you'll find them. I will say that I've talked with a few BMW engineers about this and they all basically told me there was no decision to be made. That the SAE CCS system is so technically superior to CHAdeMO, especially for future applications, that they wouldn't have even considered it. 

Personally, I really don't care which "standard" my EV has, as long as there are chargers out there for me to use. I've held both and even plugged both into cars and the SAE is a little lighter and less bulky and you only need a single charge port on the car so I tend to favor it, but honestly, I would be fine using CHAdeMO if there were chargers installed in my area and there aren't. At the i3 premier in July a BMW program manager asked me how much would I be willing to pay for the DC quick charge option. I suspect the price for the US market hadn't been finalized yet. My response was, "That depends" eliciting his curiosity. I followed it up by saying right now I won't pay a penny for a DC quick charge option because there are no chargers within driving distance of my home. However let's say there were a couple here and there in my general area, then I'd pay about $500 for it. And if there were a couple dozen of them in northern New Jersey I'd be willing to pay $1,000 for it. 

 
I know we are many years from having DC quick chargers in accessible, convenient locations like gas stations but I also believe that day will eventually come. The West Coast has a huge head start over the rest of the country and probably has as much as 70% of the Superchargers, ChadeMO and now CCS stations installed in the entire country. Plus, with the recent NRG settlement California will get 200 more DC quick charge stations, most being dual connector (CHAdeMO and CCS) units. Tesla currently has 24 Superchargers installed and an aggressive plan to cover the rest of the US in a few years. Nissan meanwhile has committed to installing hundreds of CHAdeMO stations in the US although they haven't delivered much on that promise yet. Outside of California's NRG settlement the future is unclear how and when we'll get the SAE CCS stations installed. Without any clear plan for the area you live in, I think it would be foolish to pay up to $1,000 for the option if you don't even know if you'll ever be able to use it. I have a friend that bought a LEAF in 2011 here in New Jersey and paid for the CHAdeMO option but nearly three years later he has never been able to use a CHAdeMO station because there are none within his range. 


I had the opportunity to talk with a BMW manager at the i3 premier about DC Quick charge infrastructure and one of the questions I asked was will the BMW i dealerships be required to install a DC quick charge station. I thought that would be a great way to at least begin the roll out of compatible DC quick chargers for the i3 so customers will at least have their local dealerships to fill up quickly at. They could also look for BMW i dealerships along the route of their long trips and since most dealerships are on highways, the locations would probably be good ones. Unfortunately that isn't going to happen. The dealers will not be required to install DC quick charge stations, but they will be "encouraged to." Personally I'd like to see BMW "encourage" them by offering to supply them with the DC charging station for free, as long as they pay to install, maintain it and have it available for use even when the dealership is closed. The dealerships will however be required to install multiple level 2 charging stations though which is a start, but really doesn't help out with longer road trips.

"Quick" Level 2 Charging

Is there such a thing as quick level 2 charging? While level 2 charging (240v) isn't necessarily quick, some cars do charge quicker than others. The Model S is the king (in the US at least) of L2 charging as it can charge at a rate of up to 20kW with optional dual onboard 10kW chargers. However the real L2 charging champ is only available in Europe. The Renault ZOE's onboard "Chameleon charger" can charge at up to 43kWs! On the other end of the spectrum is the Chevy Volt that is restricted to 3.3kW charging. However since the Volt has a much smaller battery than a Model S, it can actually fully charge in about the same time as a Model S can with it's massive 85kWh battery. The i3 will be able to charge at up to 7.4kW, and since it has only a 22kWh battery, it can fully charge in under 3 hours. This delivers a rate of about 30 miles of range per hour when charging from a 240v 30 amp level 2 charging station. That's a good improvement from my ActiveE, which returns only 15-18 miles of charge per hour. BMW is quick to point out how fast the i3's battery can be replenished while charging on L2, and while it is better than any non-Tesla EV here in the US, it still pales compared to the 80 miles of range you can get in 20 minutes on a DC quick charger.

Bigger battery vs DC quick charge 

The i3's 22kWh battery will allow for 80-100 miles or range in every day driving conditions, and up to 125 miles if the more efficient ECO-Pro+ driving mode is selected (Says BMW). So if range is so important, why not just slap a 40kWh battery in there and call it a day? The i3 would get about 200 miles of range and you wouldn't need quick charge, right? Wrong. Tesla uses enormous battery packs and they still realize they need a DC quick charge network to really make their electric cars viable to the broad public. Even with 200 to 300 mile range their customers want to be able to quickly recharge so they can drive long distances. The truth is, no matter how big your battery is and how far you can drive on a single charge, people will always want more range and quick charging. This is way BMW is offering the range extender on the i3. They know that it's going to take years for a comprehensive DC quick charge network to be built out, so until we have a robust infrastructure in place, the range extender will be a very popular option and will allow the owner to drive as far as they need on the few occasions they need to travel long distances. For daily use they won't use any gas, as the ~100 mile range should be more than enough for the vast majority of the time, yet they still have the flexibility of being able to cover hundreds of miles should the need arise. I believe the range extender becomes obsolete once we have adequate quick charge infrastructure in place. In fact, large Tesla-sized batteries won't be necessary either. Why carry the additional weight around and pay for a huge battery pack when you can use one half the size and just charge it quickly when the occasional need arises? The main reason EVs cost more than conventional powered vehicles is the cost of the battery pack. A smaller pack combined with readily available quick charge is clearly the way to go, however getting the infrastructure in place is the 800 lb gorilla in the room. It's not just going to happen without the support of the manufacturers. Tesla and Nissan seem to be doing their part, will BMW and the others that have signed up to use the SAE CCS standard do their part? Only time will tell.
 
The BMW EV infrastructure team was well represented at the grand opening event for the first public CCS quick charging station. Will they continue to be involved in assisting CCS station deployment, or wait by the sideline and watch?


Thursday, June 6, 2013

How Much Will It Cost To Fuel The i3?

The concept i3 coupe parked with a BMW i branded level 2 wall charger
I get asked all the time "How much does it cost to drive an electric car?" I've also had a fair share of people say " I like the car, but I wouldn't want to see your electric bill". Like gas cars, some electric cars are more efficient than others. The BMW i3 has been purpose built to not only offer the dynamic driving experience BMW customers have come to expect, but to also be a highly efficient car. But what is efficient for an electric car? Everybody understands MPG for gas cars but few really understand how electric cars are measured for efficiency, let alone how that will translate into the cost to operate it.

The ActiveE Monroney sticker
First off lets discuss how the EPA calculates the miles per gallon equivalent(MPGe) for electric cars. Gas cars have the official EPA miles per gallon listed on the window(Monroney) sticker and electric cars have a rating called MPGe. Since one gallon of gasoline creates the same energy as 33.7 kilowatt hours of electricity, electric cars are tested to see how far they can go on 33.7kWh's and that is the official MPGe which is listed on the window sticker of every new EV. The BMW ActiveE I drive has a rating of 107 MPGe. Not bad for a heavy converted gas car, but not especially good as far as electric vehicles go. The Chevy Spark EV, recently was rated at 119 MPGe making it the most efficient EV rated so far as it barely beat out the Honda Fit EV's 118 MPGe rating.

Neither The Fit EV or the Spark EV were purpose built as electric vehicles. They are converted gas cars like the ActiveE. Being purpose built as an EV with a lightweight CFRP body and aluminum frame, the i3 should easily top the Spark's 119 MPGe rating. I'm guessing the i3 may have an MPGe rating as high as 130, which will give it the "most efficient EV" crown, one that it may hold for quite some time as there is really no other EV coming out anytime soon that will challenge it in my opinion.

So lets say the i3 gets a 130MPGe rating for arguments sake. That means it will go 3.86 miles for every kilowatt hour of electricity you use to charge it or need about 26kWh's to drive 100 miles. The average price of electricity in the US is 11 cents per kWh, however that varies greatly from state to state. I pay 18 cents per kWh so for me it would cost $4.68 to drive an i3 100 miles. If I were to drive 15,000 miles per year my annual fuel cost would only be $702! How far can you currently drive on $702 in gas? If your car gets 25 miles per gallon and you pay on average $3.50 per gallon(which is lower than what we have averaged the past year) it would cost you $2,100 in gas to drive the same 15,000 miles! Plus, we all know gas prices will only climb over time. Electricity rates do go up occasionally but historically they are much more stable than gas prices. Plus, many people do have the option of installing a solar array which will guarantee a free supply of electricity for the next 25 to 30 years. There is nothing the gas and oil industry can offer to compete with solar, as the customer supplies, and has control over their own energy.

BMW will offer solar canopies to i3 customers

So whip out your electric bill and find out how much you pay per kWh for your electricity. Then divide the number of miles you drive per year by 3.86 and multiply that by your electricity rate and you'll know how much it would cost you to fuel an i3 for a year. I'm sure you already know how much you dump into the gas pump so calculating your savings won't be too hard. Of course if you want to save even more you can install a solar array at your home like I did and start making your own electricity. Sure there's an initial outlay of cash for the solar system and not everybody can afford it, but if you can it's a fantastic set up and you'll have it paid off in a few years of savings from driving your i3 on sunshine!