Thursday, October 24, 2013

Just Take The Prius!

After 3+ years of development of the public charging system, we still have very little insight as to what the future holds. I thought by now a somewhat predictable roadmap would have emerged that would have made a buying decision a bit easier for someone thinking about a shorter range EV like the LEAF.  But that has not happened. If anything, the future has become cloudier.

Ecotality is no more, bought up by another company called "Car Charging" (  so the "voting" for various billing options on the Blink fast chargers is probably going away which is a disappointment.  With the large disparity in electrical rates thru-out the country, a single rate structure means some benefit and some get screwed. With the low rates in the Pacific Northwest, I am definitely part of the latter group so "voting" for the rates I thought was a great compromise from a company that has done very little right the first time but they are no longer... *sigh*

 Now, Car Charging has posted that they will address any issues with current Blink customers for their home chargers and so far their ownership on the public chargers has been relatively transparent with the exception of splitting the billing cycle for the month of October.

But changes in the rates are sure to come. They have existing chargers and the rates for those are higher which makes the calculation for LEAF verses Prius much harder especially when we really dont know what the price will be. Its like 2010 all over again except that we dont get any free charging while Car Charging figures it out.

Also; Yesterday, CBS News announced that gas prices are dropping and are expected to continue to do so for the rest of the year. This is not really news as most of the time gas prices spiral downwards from their bloated Summer Vacation season levels. Analysts expect the national average to settle to about $3.15 gallon from its current $3.35.  ($3.54 in the Seattle Area)

So does this make the "Just drive the Prius" crowd stronger or more justified?

Well, that question can't really be answered directly because there is no right or easy way to answer the question. It also depends on how you determine the costs of the car.  Now, the best and easiest way is to simply have two cars. So for people in the buying market. If one can afford a LEAF and keep their gasser, that is the way to go.

The one rule that does apply is that a Prius will cost roughly 6-15 cents a mile in fuel costs. That is a pretty big range but that is how the math works when you only have a small percentage of the energy available to apply to the distance traveled. So to get a real good handle on the cost factor, we need to look at all the driving each car would do. Now we could do what EVERYONE else does and only look at the driving that the Prius does best in and the LEAF does worst in and then justify the Prius right?? WRONG!  After all, this is an EV blog and despite my having owned 3 Priuses of which I still have a strong fondness for, I do know when its time to move on! Actually just kidding on that last part and remember I did say the best option was to have two cars right?

Now, I normally would not be writing this but I am seeing way too many people (actually one is too many!) abandoning EVs and going back to gas based on the one-sided "JTTP" argument so the wrong must be righted! Now to elaborate on my statement above; the only justification I see is the limited range argument against the LEAF and the high cost of public charging and that could be a valid argument when time to charge is added in but its being unfairly presented.

So we first need to start off with a fair representation of the Prius.  Now everyone's driving needs are different so each of you must start out collecting data to see what your specific needs are.  This is something I started doing 15 months ago and this is what I have come up with divided by trip distances and frequencies. To make it a bit more fair to gassers, trips made within 30 mins of each other were counted as one. I did this because the large usually unconsidered factor is ICE warm up times and the penalties involved concerning performance. This time limit is valid during Summer but not so during Winter which means I am somewhat penalizing EVs by making gas cars slightly more efficient.

The other problem is that the Prius was wrecked (not by me!) Dec 30th but still had the car long enough during the record gathering to get a good idea of how well it does during all seasons.

A; 0-3 miles;  17%
B; 3.1-15 miles; 35%
C; 15.1-30 miles; 35%
D; 30.1- 60 miles; 11%
E; 60.1 miles +; 2%

In the breakdown above, I can safely say my LEAF covers 87% of my trips without public charging support (Actually by driving slower, colder, etc. Its more like 95% but also not what I would consider "mainstream acceptable") since many of these trip lengths need to be doubled as most are "there and back" types.  Of the trips more than 30 miles in length, 80% was because of work. Considering the office (a prime destination) is 23 miles away that also accounts for 60% of the "C" trips but many times, the office was a brief stopover to pick up co-workers, equipment or paperwork, etc only to go onward so the distance moved into the "D" category. Now most people would probably have much more in "B" or the lower end of "C" but once again, the variety of need is great and each of you should create your own mileage breakdowns.

Winter is coming and due to the short lengths of  Trips A and B, the Prius will not come close to its advertised 50 MPG. In all my Priuses, my overall average was in the 50 mpg range but there was always a 5-7 mpg difference from Winter to Summer in the 04, 06, and 2010 with the 2010 exhibiting the largest discrepancy and this discrepancy is magnified during colder weather.  Typical performances run 20-25 mpg for A trips and 25-40 mpg for B trips. Each trip performance was calculated by resetting the trip meters at the beginning of the trip and then deducting 8.35% from the dash results. The 8.35% figure was the lifetime medium variance from the dash display and the calculated fuel economy. My 2010 was from the first batch built in April 2009 and had a much larger discrepancy than ones built later that year.

The LEAF does appear to have somewhat of a warm up cycle as well but much shorter. I spent a lot of time experimenting with how well the LEAF does in the first few miles after a full charge was completed and found the first 5 or so GIDs dont seem to provide the same amount of driving distance. I even went so far as to drive ultra-conservatively try to bolster the numbers to no avail having to drop to roughly 15 mph before seeing any real repeatable results.  But what is there to warm up? Since getting access to the ELM app (now more commonly known as "LEAF Spy" at the Android Marketplace) I now can track battery temps and have determined their role to be small if any here. But whatever it may be, I mention it only in the interest of full disclosure of my observations.  But my LEAF essentially uses 225 to 265 watt hours per mile and this figure applies to a fairly wide range of driving conditions and speeds. 40 watt hours is not a whole lot so if using a widely accepted value of 4 miles/kwh (250 watt hours per mile) and my actual electrical cost of 10.4 cents per Kwh the value of 2.6 cents per mile comes real close to my real figure of 2.42 cents per mile (my real figure does take into account, free AV station charging and public charging costs by SemaConnect, Blink, etc) and that figure only seems to vary by no more than +/- .3 cents per mile from Summer to Winter. I will admit to using A/C liberally in Summer and very little if any heat in Winter.  Warmblooded I am, I am!

So to summarize what we have to this point; The Prius true cost for fuel can be hard to predict and very much tied to the personal driving needs of its owners and the seasons and the peculiarities of the Oil Markets.  The LEAF's cost varies little and is easily predictable weeks or months in advance.

Now if we look at the typical "JTTP" argument, it is centered on the only real thing a gasser can attack and that is public charging costs and the time it takes to rack up those charges. Right now, SemaConnect provides the worst deal in my neighborhood charging .49 cents per kwh. Now, I use them due to convenience of locations and the fact that I have a $20 credit on my account so might as well get that out of the way right? But unlike other companies; I pay for EXACTLY what I get to the penny! None of this rounding up to the next hour if I miss it by 5 minutes or whatever, so Kudo's to Sema for at least having an effective and FAIR billing system!  But at 49 cents a kwh and 4 miles/kwh times a 85% efficiency is 14.4 cents per mile (which is what my Yaris got last Winter when it replaced the Prius) and that is not good. The Prius can easily beat that right??

The above is how the typical argument goes and we have to assume this is for a trip of 60 plus miles or maybe even 50 miles in Winter right? Ok, but what about the other half of the trips made that fall into categories A and B?  Remember, in the LEAF it does not matter the length of the trip. The cost per mile is relatively static and predictable. In the Prius our 45 mpg winter average (actually 45.4 Winter, 52.3 Summer,  49.8 overall) at 7 cents a mile (when gas gets to $3.15 a gallon) is really as high as 15.8 cents a mile for A trips to 10 cents a mile on average for B trips.

So when I am categorizing my planned trips into EV or "JTTP" I compute my costs using the 2.6 cents for the first 60 miles then incorporating whatever charging cost that may arise.  Now, not all charging options are as expensive as Sema. Blink although much maligned for their one size fits all $5 flat fee fast charge (now to be known as "5F". I mention this so we all know that the "5F" is not a grade but an acronym, right??) actually provides a bargain for L2 charging at a buck an hour for members (there is no cost for membership and as I predicted, will never least as a Blink company) so now for my dollar we are getting (at my 2011 lame-o 3.8 kwh rate) about 13 miles (at 85% efficiency) or 7.8 cents a mile which just about matches the Prius on a good winter day. (provided it has driven far enough...)  So on a 100 mile trip, the LEAF would have 60 miles at 2.6 cents or a buck fifty plus 3 hours of charging for a total of $4.50 roughly or the Prius at 45 mpg and $3.15 gas at 7 cents a mile or $7 so the Prius loses by a few bucks but add in the time to charge and that is a problem convenience wise right?

So lets look at the Blink $5 fast charge. Now we all know that the higher the SOC of the LEAF, the slower it takes a charge. So for convenience sakes and the consideration of time, lets do an 80% charge for 30 minutes.

So, now we drive the same 60 miles for $1.50, pay our $5 and get enough to complete our 100 mile trip and its $6.50 so we still beat the Prius  but only by 50 cents. We can almost call that a wash right? (remember, we are not only dreaming of a White Christmas but also $3.15 gas for this to work...)

So on long trips, Prius is good but even with public charging costs, the LEAF is still cheaper, but that is not where most people live.  Now if you are like Steve Marsh (who has a 130 mile round trip work commute) then maybe a re-evaluation of the car you drive is in order (unless you are lucky enough to have your boss install your very own charger at work!) but most of us put most of our miles on driving locally. Short trips.

Its short trips and the lack of  "warm up penalty" where EVs excel. So the small savings seen on longer trips becomes a significant amount of  "cash back" with shorter trips due to their being a lot more short trips and the gas cost being much higher while "EV" cost goes down as the percentage of "home juice" increases over "public (make sure that "L" gets in there!) juice."  Short trips is also what prematurely ages a gasser. So, if for no other reason; get a LEAF because you love your Prius!

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