~ Auto Buzz ~: mi/kWh
Showing posts with label mi/kWh. Show all posts
Showing posts with label mi/kWh. Show all posts

Wednesday, 3 September 2014

The Norby's "Driving to Net Zero Energy Challenge" Starts off Strong!



My i3 is powered by electricity generated by my home solar array. EV+PV is really a fantastic combination and one that I believe will be fairly common in the near future.  So how can you possibly top that? How about by getting two i3s and powering both of them plus your entire household's energy use by your  solar array! That's exactly what the Norby's are attempting to do.
I have frequently written on my blogs how one of the best part of being in BMW's e-mobility test program for the past five years has been meeting and interacting with many of the other people in the program. Together we learned how to live with the issues that test cars frequently have, we built up our own support network and we simultaneously realized how fantastic driving electric was. It was a really a great experience and one that was nothing short of life changing for many of us. 

While I've literally made hundreds of acquaintances in the program, there are a few people who I've really connected with and now consider friends, and one of them is Peder Norby. Peder and his wife Julie live in Carlsbad, California and went from MINI-E to ActiveE to BMW i3, just like I did, only they went one step further and got two i3s! Like me, the Norby's power their electric cars with clean energy from their rooftop solar array. However even though our systems are about the same size, their array provides about 1/3 more energy than mine does because of the location (sunny Southern California) and orientation of the arrays. 

This year, Peder and Julie began a year-long net-zero energy challenge. They are attempting to live the entire year with their solar array providing all the energy they need to power their home and both of their cars. I believe this is a fantastic story and a glimpse into what the future has in store. Peder has been updating the progress on his i3 blog but now that he is one quarter of the way through the year, I asked him for permission to post his progress here and he happily agreed.  Below is a little introduction to what the Norby's are doing followed by the three month update. 

It’s hard to get this down to a sentence or two, but when we built our home in 2005,  our ethos was to partner with nature, harvesting the gifts of nature, building the most efficient home possible.

In doing this, we wanted to elevate, we refused to compromise or lower the enjoyment of our life and the caliber of our dwelling, we refused to reduce our life to living in a small cave with one solitary light bulb, solely for the sake of efficiency.

Our desire was to express ourselves artistically, with the highest quality materials, design and comfort in the size home needed to accommodate our family and friends, while partnering with nature, being as efficient as possible. We wanted to live in a net zero energy home, harvesting food and drink from our land. Not big or small, not right or wrong,  just our home.

The idea is a simple one: Harvest sunshine from the roof of your home to provide 100% of the power needed for your home and the two cars in the garage. That is our goal in this "Driving to Net Zero Challenge.
 
The 12 month documented journey began May 15, 2014. Three months in, things are looking pretty good:

Update Month Three. We're killing it!

The idea is a simple one, harvest endless sunshine from a small portion of a roof to provide 100% of the energy needed to power a home and two cars with zero utility cost, and zero gasoline cost.

Summary:
  • 1/4 of the way through the year,  -167 kWh and a $468 credit.
  • Stats, Stats, Graphs, Graphs. 
  • We're killing it! Ready to make a projection!
  • Our French import.
We estimate that we will be -$800 by Oct/Nov
Solar PV production holding steady at 1326 kWh

Electricity use for the two BMW i3's rose to 478 kWh for the month
We have a credit of $315 for the first seven months of the year

1/4 of the way into our "Driving to Net Zero Energy" challenge and as they say in political election coverage:
"I am ready to make a projection and call this race"
We will be below zero in utility cost and gasoline cost providing the energy for our home and guest house, and the two cars in the garage driven a total of 24,000 miles a year.  In fact we are so far ahead we will accomplish this goal four months earlier than planed with the January 2015 true-up bill from our utility. 
Our natural gas cost for a year is $301.27
We estimate at the true-up bill that we will have a credit of $400 to $450 for our electrical use and a cost of natural gas of $301 for the year thus  -$100 to -$150 in total energy cost for the year.

How about total cost?

As I mentioned in my first post in May, an asterisk is required regarding the cost of energy as our utility does not let us carry over our electricity credit to our natural gas cost.  Essentially our valuable peak hour electricity that we do not consume will be a gift to our utility.  As the years go by we will most likely convert one or two of the natural gas appliances at the end of their useful life to electric in order to reduce the natural gas bill by using our excess electricity credit.

Where are we with energy usage and gasoline cost now compared to 2007 when we began this path to energy independence?

In 2007 our energy cost were:

$3,800 a year in electricity
$   300 a year in natural gas
$2,800 a year for Julie's Infinity G35 gasoline
$2,400 a year for my Volvo S60R gasoline

Total:    $9300 a year in energy cost.  ($792 per month)

This is not far off the statistical norm for a US family which uses an average of 11,000 kWh per year ($3,060 at SDG&E rates) and $2912 for gasoline according to the 2012 EPA statistics.
In 2014 our energy cost are:

$      0 a year in electricity*
$  300 a year in natural gas
$      0 a year in fuel cost for Julie's BMW i3
$      0 a year in fuel cost for my BMW i3
Total $300 a year in energy cost. ($25 per month) 
* we donate $450 worth of electricity back to SDG&E.

You can see how quickly that $9000 a year in energy cost savings will pay off a $30K Solar PV system, $15k in extra construction cost for a thick well insulated home, efficient appliances and led lights and $1000 for a EV charging station in the garage.  We have calculated from the installation in January of 2007 we reached the payoff point in April of 2012.

From April 2012 and for the next few decades, we will have essentially zero or de minimus cost for energy saving us $200k to 300K in energy cost with escalating utility and gasoline cost.

How about total usage?

Julie and I live normal lives, things come up and situations change. The interesting part of our Drive To Net Zero Energy challenge is that we are real people with a real life and not some demonstration house with nobody living in it.

We have been doing really great using a net total of -167 kWh of electricity (generation vs consumption) for the first three months of the challenge. We can extrapolate the prior four months of usage pre i'3s, assuming we had the efficient BMW i3's and the extra 1kw of solar pv production which would have saved us 225 kWh per month. We estimate that by May of next year we will be very close to a net of 0 total kWh used, +- 250 kWh per year which is a normal usage and weather variable.

The French Import.

I bet you thought it was a car :)

Julie and I have decided to make an impact on two young adults lives.  We are hosting through Rotary Youth Exchange, a 17 year old French student named Peroline for a one year exchange. By doing so, an American young man is traveling to France to begin his year as an exchange student in France living with Peroline's family.

Our household has now risen to four and the extra electricity that our 17 year old exchange student will use will most likely push us into the positive use territory.

Hosting a 17 year old young lady French exchange student for a year was not contemplated and is not a very good idea for the Drive To Net Zero Energy Challenge!

But life is life, unpredictable, wonderful and real.  We are very happy to have Peroline as part of our family for the next year and we're looking forward to driving her everywhere, using lots of electrons, to see the sights of our great nation.

Our goal remains Net Zero Energy usage as well as Net Zero Energy cost.
We'll see how the the next 3/4 of the year goes.

Imagine a better future and your participation in it.

Next Month:

  • Charging stations and what's on the horizon.
  • Our CHG emissions 
  • Our version of GHG offsets
Thanks for reading and commenting.

(Past "Driving To Net Zero" articles on Peder's blog)

Energy Challenge Introductory Article

Bonus video:
Below is one part of a series of videos that Peder and I participated in. The video series is called "Wherever You Want to Go" and was produced by BMW back in 2011. BMW recruited Buzz Aldrin, Marissa Meyer, Robin Chase, Syd Mead, and many others to participate and Peder, Todd Crook and I were also chosen to because of our high level of participation in BMW's e-mobility program. The four-part series is available online and did a good job of opening the up a conversation about where we are going with regards to personal mobility. Take a look and see if you can spot Peder and me.  :)
 


Friday, 22 August 2014

BMW i3 REx vs Chevy Volt: My Take



The Challenge

Last week I was contacted by High Gear Media Senior Editor, John Voelcker and asked if I had interest in doing a head to head comparison piece between my i3 REx and a Chevy Volt. Green Car Reports contributor David Noland (who happens to own a Volt and a Model S) wanted to pit the Volt against an i3 REx and asked John to reach out to me and find out if I was up for it.

I liked the idea of swapping cars and driving side by side for a few hours and that met David's needs as well. David wanted to do an efficiency test and measure the miles per kWh's used driving 15 to 20 miles in a city environment, and then do the same thing at highway speeds of 65 to 75mph. Going in, David expected the i3 to be more efficient in the city driving test, but the Volt to be more efficient on the highway test where weight plays a lesser role and aerodynamics are more important. The i3 is tall, has a large front area and is a bit boxy compared to the Volt. This creates a much higher CdA which will lower the i3's efficiency at high speeds. Having driven my i3 for a while now, I knew it would be more efficient in the city cycle, but I figured it would probably tie the Volt on the highway leg of the test. My i3's life time efficiency so far is 4.5 miles per kWh and I do at least 50% of my driving at highway speeds.
David averaged 4.1 miles per kWh over a 46 mile drive at highway speeds. This was driving about 15 miles in charge depleting mode and another 31 miles with the range extender running.  The display only shows an average speed of 56.7mph, but much of the trip was done at 70+ mph
David was also very interested to find out how the range extender performed. In my opinion, the i3's range extender is largely misunderstood. Even months after the launch, few people really understand how it works, what it can and cannot do. It has been called everything from a "limp mode" to an "emergency use only" option, and quite honestly BMW hasn't done itself any favors by not fully explaining how it works and how to use it properly. I promised David he could drive it as he wished, and even purposefully overwhelm the REx by driving fast enough to use more energy than the range extender could produce, should he desire to do so. At one point he even asked if I minded if he did just that, but due to the other traffic we couldn't really sustain a speed much over 70mph for long and we were not going up and long, steep inclines so the REx was able to put out enough power to maintain the SOC between about 4% and 6%. In short, we couldn't overwhelm it without driving in a an unsafe manner.
Getting ready to take off from Nauna's Bella Casa in Montclair

There aren't many long climbs in my area and I've driven with the range extender on quite a bit. I haven't found any condition where it isn't perfectly capable of allowing me to drive as long as I needed to, including hundreds of miles if I really wanted. However I know the REx has its limits, unlike the Volt. I have heard stories of people not being able to maintain highway speeds as the car drops to 45 mph suddenly. That's a problem that BMW needs to address. I think they need to make a better effort to communicate to the customers what the limits are, and I also believe the customer needs to be cognizant of the limits and keep an eye on the SOC under high speed driving up long inclines. It's not a do-all-under-any-condition vehicle. The range extender has limits but I definitely believe that for the vast majority of people it will do just about anything they need. Also, since the i3's electric range is double that of the Volt, the range extender will be used much less, so it's reasonable to understand why it is less robust.

People are surprised when they see the i3 next to other EVs. It is larger than I believe many people think it is.
On the Road
 
I felt very comfortable behind the wheel of the Volt as I've driven many of them and have always liked the driving experience that they offer. However, this was the first time I've driven a Volt since getting my i3 REx three months and about 6,500 miles ago. The two cars definitely feel very different. The much heavier Volt absorbs road irregularities better and is quieter at high speeds, where the boxy i3 has noticeable wind noise. The i3 is much quicker, especially at higher speeds and has better braking and handling. The i3's steering is more direct and sensitive and the Volt's brakes seemed a little spongy or squishy compared to what I'm used to in the i3. The i3 is clearly more of a performance car, while the Volt offers a more supple, softer ride. The regenerative braking on the i3 is much stronger than the Volt's, even in Sport mode and low driving gear. I'm sure I would adjust to it if I had a Volt for awhile, but I just couldn't get myself to stop for traffic lights without needing to depress the friction brake pedal every time. I almost never use the friction brake pedal on my i3 unless it's an emergency situation where I need to slow down unexpectedly. I really love this on the i3, and haven't found any other EV to have a regen system that matches it. It's definitely one thing that BMW got right. I know the Volt blends regen with friction braking so I suspect most of the time I depressed the brake pedal I wasn't even using the friction brakes, but I've really grown fond of the one-pedal driving of my i3 that anything else now seems sub-standard.
The interior of the Volt
The interior of the i3









I found both cars comparable in seating comfort and room, with the Volt having a larger cargo area. Because the e-drive motor and range extender are under the deck behind the rear seats, the i3's cargo deck is higher, which cuts down on the cargo space, but it also doesn't have a tailgate lip so you can slide objects in and out without having to pick them up over the lip to remove them as is the case with the Volt, which my bad back appreciates. Personally I like the uncluttered, modern interior look of the i3 better, and the large center display probably is the nicest I've seen in any car besides the Model S. However the exterior styling of the i3 is definitely unconventional and I'm sure many people will say they like the look of the Volt better, but styling is subjective so I'm not really going to get too caught up appearance here. One thing I really do like in my i3 is how the absence of a center transmission tunnel (battery tunnel on the Volt) provides a much more open, spacious feel in the cockpit. In fact, this makes it quite easy to slide across from the drivers seat and exit from the passengers door if you want to.  
The Volt has a larger cargo capacity, but with the rear seats folded flat, the i3's cargo space is definitely adequate for my needs.
Efficiency

David really wanted to focus on the efficiency of the cars so we did roughly 15 miles of city driving, followed by 15 miles of highway driving at 60 -70 mph. There were a few occasions we got up to 75 or so to pass other vehicles but for the most part we drove in the middle lane and averaged a little under 70mph. In the city cycle the i3 averaged a 5 miles per kWh used compared to the Volts 4.5. The Volt did better than I expected in this part of the test though, which I am happy to report. On the highway test the i3 delivered  4 miles per kWh used and the Volt averaged 3.5 mi/kWh. David and I were both surprised that the i3 actually had a larger advantage on highway driving than it did in city driving, but was 14% on the highway. I suspect if we drove faster, and averaged over 70 mph, the Volt would have caught the i3 in efficiency. The test also isn't perfectly controlled, since David and I aren't the exact same drivers. However, we are both very experienced electric vehicle drivers, and understand perfectly well how to maximize efficiency with the use of regenerative braking and limiting jack-rabbit style take offs. We drove with the climate controls set to 72 degrees and the windows closed.

During the city driving test. I jumped out of the Volt at a red light to grab this picture.
Conclusions

Having had quite a bit of previous experience driving Volts, there were really no surprises for me. I have always liked the Volt, and nothing from this experience has changed that. It's a very capable extended range electric car that offers a good ride, decent performance and nice styling. It is a better choice for long range driving (over 200 miles) and definitely if you live in a mountainous area. I can't even count how many people I've recommended the Volt to; and many have stopped back to my restaurant weeks or months later to show me that they took my advice. With a starting price of $34,999 it's a really a great deal. The i3 REx on the other hand starts at $46,125 which is $11,000 more. Yes, you do get a more nicely optioned vehicle but it's very hard to ignore the $11,000 difference. If price is a big consideration then it's hard not to pocket the eleven grand and take home a Volt.

However buying a car isn't always a rational decision, and there are indeed emotions involved. If that weren't the case we'd all be driving $15,000 Honda Fits. There are a lot of reasons why the i3 REx is a better EV for me than the Volt. First off, I drive about 33,000 per year, and the 38 mile AER of the Volt would mean I'd be driving on gas about as much as I drove on electric. The i3 REx will allow me to drive on electric over 90% of the time. For me to increase that 100% I'd need to jump up to Model S-type range because the times I have needed the REx were usually 150 to 200 driving mile days and there are no other current production electric vehicles capable of doing that without using a robust DCQC network which doesn't yet exist in the Northast. Another consideration is the 3.3kW onboard charger that the Volt has. I'd find it very hard to buy any EV that was limited to 3.3kW charging. My i3 can actually charge faster from zero to full an a level 2 EVSE than a Volt can, yet it has twice the electric range. GM absolutely needs to upgrade the onboard charger to a minimum of 6.6kW for the next generation Volt in my opinion.

I've read many comments on various online forums regarding the size of the i3's gas tank and I can say I categorically disagree with the notion that the car needs a larger gas tank. In fact, I'd be fine with a smaller one. If you think you need a bigger gas tank on the i3, then what you really need is a Volt because you're buying it for a use that it's not really intended for. The i3 REx is fine for driving in range extender mode for short distances, and I think it's really a great car for trips up to 150 miles or so, but if you really need to frequently drive more than that, it just may not be the best fit. If you need to go further once a month or so, then sure that shouldn't be a problem as long as you don't mind the 2-3 minute stop to refill the tiny tank, but frequent long distance driving just isn't the car's best use.

I also put a big emphasis on the driving experience and the i3 is really a blast to drive. The Volt is fun in its own right, and it is certainly no slouch by any means, but the i3 is noticeably faster and has a much more direct steering feel. I also love the fact that the i3 is all carbon fiber reinforced plastic and aluminum, the open cockpit and simple dashboard with the large center display. It was indeed the better choice for me, but honestly, I would be very happy driving a Volt also, especially if I drove less than the 90 miles a day that I do now. I don't think you can lose with either of these extended range EVs. Just pick the one that fits your budget, needs and desires and you'll be happy with whichever you choose.

You can read David's thoughts on his Green Car Reports article here.


Saturday, 5 July 2014

Independence Is Empowering. Go EV Now and Claim Yours!




Today's date is July 4th 2014, and here in the US the 4th of July is a national day of celebration. The 4th of July is "Independence Day" and is a federal holiday which commemorates the adoption of the Declaration of Independence on July 4, 1776, declaring our independence from the Kingdom of Great 
Britain. This was of course a great moment in America's history, and one worthy of celebration.

However for me, this date has had a dual meaning over the past five years. I too celebrate the birth of our great nation 238 years ago, but I also have a little extra to celebrate since 2009, because that's when I began driving electric.
My beloved MINI-E and me in 2009. You always remember your first...EV!
Merriam Webster defines independent as follows: "Not subject to control by others; Not requiring or relying on something else," so it's clear why this calendar day has been designated Independence Day in the US. 

I define my personal transportation energy independence as driving an electric car that is powered by sunlight which is captured on my rooftop solar array. Yes, I have a grid tied array and use net metering so I still rely on the utility to provide power when my array isn't producing. However the net benefit is I can drive as much as I want and I'm paying very little for the energy to power my home and drive my car. I am completely isolated from the extreme fluctuations of the cost of gasoline, and I'm not at the mercy of the supply chain of oil. Ask anyone who lives the EV + PV life and they'll tell you it's certainly an empowering feeling, and part of why electrics are indeed the vehicle of the future. 
Me and my second electric vehicle, the BMW ActiveE in 2012
So far I'm averaging a little over 4 miles per kWh in my i3. My solar array produces an average of about 30kWh's every day of the year. That's enough energy to power my i3 about 130 miles. Compare that to a gas car that gets 30mpg, (which is much higher than what the average car delivers) and it would need 4.3 gallons of gas to drive 120 miles. At today's gas prices that would cost about $16.00. Gas prices constantly fluctuate, and are very sensitive to any governmental instability in one of the main Oil Producing and Exporting Countries, but eventually they always go up. Conversely the sun will always be free, and electricity rates from the local utility are mostly stable. Sure, there was an initial investment for the solar array, but with my savings I'll be cash positive in about 8 years and the array's lifespan is about 30 years. 
In 2014 I'm now plugging my BMW i3 into the sun!
Plug into the sun!

So come join me in the electric revolution! Declare your independence from oil and grab a plug instead! There are many ways to generate electricity; many are from clean, renewable sources and some you can even do yourself. You can never make your own gasoline, it will never be clean, and you'll always be dependent on others to provide it to you. There are many reasons to go electric, but energy independence may just be my personal favorite. Have a happy and safe Independence Day everyone!



Friday, 13 June 2014

BMW i3: The Emperor of Efficiency



After a recent 62 mile round trip I finished with a 5.0 mi/kWh consumption rating. I've never achieved such a low consumption rate on any other EV that I have driven. This translates to an astounding 200 Wh's per mile!
When the EPA range and efficiency figures were announced couple months ago, the i3 became the most efficient vehicle available in America. Here in the US, the EPA uses "MPGe" as its official efficiency metric to compare the energy consumption of alternative fuel vehicles. That stands for "miles per gallon equivalent", and unfortunately most people don't really understand what it means or how that really translates to what the vehicle will cost them to operate. The consumption rate, or how many miles the car will travel on one kilowatt of electricity, (mi/kWh) is a metric that I, and many other electric vehicle owners prefer to use.

i3 BEV EPA ratings
Wikipedia describes the MPGe rating as follows:
"The ratings are based on EPA's formula, in which 33.7 kilowatt hours of electricity is equivalent to one gallon of gasoline, and the energy consumption of each vehicle during EPA's five standard drive cycle tests simulating varying driving conditions."
The BEV i3 received a combined (city and highway) MPGe rating of 124 miles and the i3 REx (like I have) achieved a combined score of  117 miles. I'm not a huge fan of this rating system because all it really does is compare the efficiency of my car to the energy in a gallon of gas. One of the problems with that though, is gasoline engines are very inefficient, and only around 25% of that energy is harnessed to propel the vehicle. The rest is simply wasted. The MPGe metric isn't completely useless though. It does offer a standard rating system to compare all electric cars side by side, and it also calculates the energy use of the vehicle including the charging losses, meaning it is a true "wall to wheels" energy rating. So for a comparison tool, it has its merits.
Two days of combined driving with no real effort to drive efficiently at all. About 60% highway @ ~70mph and 40% secondary roads, with the air conditioning on the entire time and driving in comfort mode.

I've only driven about 1,500 miles so far, but I'm seeing energy consumption figures that I have never achieved on any other electric vehicle that I have driven (And I've pretty much driven them all by now!). Overall, I'm averaging about 4.5 miles per kWh and can easily attain 5 miles per kWh if I make an effort to. Five miles per kWh translates to an extremely low 200 Watt-hours per mile! For comparison, I averaged about 3.6 miles per kWh in my ActiveE under the same driving conditions and ambient temperatures under which I have been driving my i3. I had to really try hard to average 4 miles per kWh with the ActiveE, and with the i3 I would have to intentionally try hard not to do so. Based on the EPA figures I knew it was going to be a tremendously efficient car, but seeing it first hand has been an eye opening experience.

I'm sure I can push the consumption rate up to around 6 miles per kWh if I drive in Eco Pro+ mode, watch my speed and use the regenerative brakes to their full potential. But for now I'm having too much fun getting to know the car. Mashing the accelerator and feeling the instant torque every now and then is difficult to refrain from, but at some point I'll do a real efficiency test and see how low I can go. Now that I've had the car for about a month, I'm starting to get some followers message me ask what I like and don't like about it. I just want to say I have indeed been compiling a "likes and dislikes" list and I have just about enough info for a comprehensive initial review. That will most likely be the next post here so stay tuned. :)


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