Sunday, November 11, 2012

The Mystery of Miles per Gallon Electric MPGe

What does gasoline, Kilowatts, and British thermal units have in common?   They all are used to determine miles per gallon electric (MPGe)--whatever that means.

MPGe was devised by the EPA to explain the level of efficiency electric cars have to the motoring public.   We have become accustomed to miles per gallon (MPG) being the universal standard of efficiency as listed on the window of every new car. But the efficiency rating of EV's doesn't naturally translate into MPG because there are no gallons of anything being consumed per mile.

Once you drive an EV, you get used to the term of miles per kilowatt hour (Mls/kWh).  For example, in my ActiveE I commonly achieve 3.2 Mls/kWh.  Whereas someone else may achieve 4.0 Mls/kWh, which tells me they're a far more efficient driver.

But Mls/kWh doesn't have a universal meaning outside the EV world, so MPGe was invented instead.  I find MPGe to be a confusing standard, but here goes with an explanation: it starts with a gallon of gasoline, which when burned generates 115,000 British thermal units of heat.  If using electricity, it would take 34 kWh to produce the same amount of heat.  So one gallon of gas equals 34 kWh in terms of the energy generated.  The EPA then determines how far an EV can travel on 34 kWh under differing conditions and that distance is reported as MPGe.

The problem with this conversion is that not every EV has a 34 kWh battery.  The ActiveE has a 32 kWh battery and an MPGe of 102, but its range isn't always 102 miles on a single charge (although the BMW is probably closest to the 34 kWh mark).  Other EV's (aside from Tesla) range from a low of 16 kWh in the Volt to around 24 kWh in the Leaf.  So the MPGe reported for those cars is not the distance they can travel on a single charge, but rather the distance they could travel over multiple charges until using 34 kWh.  The Chevy volt for example is reported at 98 MPGe, but it can only travel about 35 to 38 miles on pure electric on a single charge.  The Honda Fit EV has an MPGe of 118, but has a range of 80 miles or less on pure electric.

Also, while a gallon of gas may cost less than a "gallon" (or 34 kWh) of electricity--it doesn't last nearly as long.  A gallon of gas in Southern California may cost $4.00 to $4.50 on any given day, whereas a typical kWh when purchased through Southern California Edison costs between 16 to 25 cents, making a "gallon" of electricity (34 kWh) cost $5.44 to $8.50.  It sounds higher, but not when you consider how far each gallon will take you.

Since EV's are far more efficient with the energy they use, a "gallon" of electricity goes a long way.  In a gas-powered car, a single gallon will allow you to travel about 25 miles.  In contrast, a "gallon" of electricity will take you 100 miles or more.  So $5.44 in electricity is roughly the same as four gallons of gas, or $16.00 in gas costs.  Why aren't they the same?  Because MPGe only measures the amount of energy generated by gas versus electricity.  It does not measure the cost of each energy source when put into practical use driving down the road.

Is MPGe a helpful measure?  Not entirely once you know the right questions to ask about EV's.  But it does look impressive to have 100 or more MPGe on the window of every new EV and hopefully it helps the gas-driving public understand just how powerfully efficient EV's can be.

Saturday, November 3, 2012

Pure Energy--The First 6 Months of EV Bliss

November marks my six-month anniversary with my Active E.  I love this car!  And I have learned how to drive electric--really not that hard.  Best of all, I think BMW is doing EV's the right way.

Love at first sight!
The Right Stuff

For example I drove the Ford Focus EV and found it to be a nice EV, but not great. Unlike my ActiveE there was no regenerative breaking engaged when releasing the accelerator.  Why not?  I was told by the Ford representative that they want the Focus EV to drive like a "regular" car.  Bad answer.  EV’s are NOT regular cars. They are way better than gas powered jalopies, and EV’s should be considered the new “regular.”  When a car offers something better, use it.  Don't do away with it. 

This is where BMW has gotten it right.  By using the characteristics of electric driving to the best advantage possible, the car is a joy to drive.  It can literally be controlled with just one pedal most of the time.  It has the strongest regenerative breaking that I have experienced so far and it’s a great attribute when driving.

Creepy EV’s

And BMW did NOT build in any creep into their vehicle.  Creep is what an automatic gas car does when in drive, slowly moving forward on its own volition.  EVs don't creep by nature because when the car is stopped nothing's moving.  Unlike a gas car where the engine keeps whirling around when stopped.  

So if an EV doesn’t creep why add it artificially?  Because it makes it feel more like a "regular" car?  Bad answer. Don't do that.  Let EVs be great for all the right reasons, there's no need to dumb down these cars to make them feel “regular.”  Especially since the motoring public is not stupid (hear that car manufacturers), we get when something is new, different and better.  Just drive the Active E once and you'll get it instantly, it's better to drive.

Efficient and Rage Anxiety

Charging Not a Problem
Range anxiety has largely left my conscious mind.  After driving for just 6 months I have gotten accustomed to how far I can go and how I need to drive to get there.  And I know that I can squeeze a little distance just by changing my driving habits. I've learned how to change too. It's really not that hard.  I have never ran out of juice or been stranded anywhere.

Yet, range is the number one reason why people say they are reluctant to try an EV.  Range is a false concern because it can be easily managed--especially with the installation of new charging units all over town.  Although, most of the time, I don’t need to charge away from home.  But when I do, chargers are widely available. 
Charging still not a problem

I like that BMW went with a range of between 80 to 100 miles.  It is just right for me.  Of course, 200 miles would be nice, but it’s rarely necessary.  In talking to a few Nissan Leaf owners, their range of about 75 miles (or a little less) is hard to live with.  The extra 20 to 25 miles that I get in my E makes a big difference and allows me to travel even beyond 100 miles when I charge during stops in my day. 

Charging some more

Too Sexy for my Circuit Graphics

Plug me in!!
BMW built a good looking EV.  Whether you like or hate the funky circuit graphics on the side (I’ve grown to like it), the car looks unlike an other EV out there!  And when I have had the opportunity to show it off at the National Plug-in Day event in Temecula, CA or the Alternative Fuels Expo in Riverside, CA, people stop and take notice of a good looking EV.  I like that I don’t have to drive a car that looks like an egg, or a shoe, or a dinner roll.  This looks like a sporty BMW.  EV’s can be great to drive and great to look at too.

No Gas, Mo Money

In six months I have a little over 8,000 miles on the E’s odometer.  In my gas guzzling GMC Yukon (that gets 15 MPG—or maybe less when I’m driving it) that would translate into 533 gallons of liquid gold in six months.  At an average of $4.25 per gallon (which again is being generous) that equals $2,265.25, or $377.54 per month in wasted money.

Driving the ActiveE for 8,000 miles I spent…let’s see…carry the one…NOTHING.  Since I have a home solar array I generate far more power than the E can consume.  However, even if I was sipping electrons from Southern California Edison, it would average somewhere between $50 to $75 per month—far lower than $377.54.  

Considering the E’s monthly lease payment is $499, I’m getting $377.54 of that back in gas savings, for a net monthly cost of $121.46.  Cheapest BMW I’ve ever owned!

Not to mention I have yet to do an oil change, injector flush, use a fuel additive, replace spark plugs, you get the idea.  The maintenance is far less cumbersome than an ICE’d vehicle.  In fact, it’s largely nonexistent. 

That brings me to my final topic: why are you waiting?

Why Are You Waiting???????

I know the ActiveE is not generally available to the public yet, but when BMW does release its full production BMW i3, why wait to get one?  The benefits of driving electric outweigh a gas car in every way.  Wait did I say every way?  Yes I did, and I mean it wholeheartedly.  EV’s drive better, feel better, have more power, are more confortable and take less gas…as in NO GAS.  I never have to stop at a crowded, noisy, dirty, expensive gas station.  My “refueling” occurs in the comfort and quiet of my own garage.

I can safely say that I will never drive an ICE’d vehicle again, if I can help it.  And the costs of owning an EV reduces the overall cost of ownership so drastically that it actually pays to drive electric.  It’s a “no-brainer” all the way around—a better car that costs less overall! 

What are you waiting for; it’s time to charge up!!