Postal Service looks to improve on 9 miles per gallon in mail trucks

March 17, 2015 by Alvin Powell, Harvard University
With the U.S. Postal Service poised to replace its mail trucks, which get 9 mpg, with more fuel-efficient models, the options can get complicated. For the biggest impact, improving the efficiency of truck engines, particularly small trucks, is the answer, contends Henry Lee, an authority on electric cars and the Jassim M. Jaidah Family Director of the Environment and Natural Resources Program at the Belfer Center. Credit: Jon Chase/Harvard Staff Photographer

The boxy mail truck familiar on American roads for more than two decades soon may be a thing of the past. The Postal Service is beginning the process of replacing some 180,000 of the trucks, a significant portion of its total fleet.

The request for proposals sent to automakers in January carried several design considerations, including enhanced fuel efficiency, lower emissions, and enough space to allow workers to stand up in the back as they grab letters and boxes for delivery.

The Harvard Gazette asked Henry Lee, an authority on and the Jassim M. Jaidah Family Director of the Environment and Natural Resources Program at the Belfer Center, about the opportunity for the Postal Service to improve its environmental footprint—and perhaps spark broader automotive changes—through a more fuel-efficient replacement for the current model, which gets roughly 9 miles per gallon.

GAZETTE: How important should fuel efficiency be to the Postal Service's consideration of a new vehicle?

LEE: That's a tough question to answer. From the perspective of someone concerned about the environment, they should be quite concerned. But if I was [head] of the Postal Service, I might say, "If society cares about this issue, they'll put a price on carbon and that will change my thinking about what I'm going to buy. But if they won't do it, why should the people who buy mail services and a company that's multiple billions of dollars in the red pay more for something that government hasn't told us it cares about?"

GAZETTE: Would that higher initial cost be offset by lower operating cost? You take something that gets nine miles a gallon and get something that gets 25?

LEE: I haven't done the numbers, but you have to ask how many miles postal workers travel in a day. Not many, though they travel a long time and they keep the engine idling. They probably travel more in a day than they would be able to if this was an electric car. They'd probably run out of electricity. I haven't done the analysis, but what if you went to natural gas? Or hydrogen? Certainly natural gas would be an option.

GAZETTE: Not electricity, though, because of the number of hours they're on the road?

LEE: Well, you have to have a lot of batteries to move something that heavy. So if you need 30 to 34 batteries—lithium batteries—the cost of the vehicle would be $20,000 more, times 180,000, which is a pretty big number.

The good news for is that they would all go back to the same garage in the evening, and you could put charging facilities in the garage quite easily. So charging won't be a problem, which it might be if you or I bought the car. But you'd have to figure that it needs more batteries than a normal car. You really don't want the vehicle to have to come back at noon to be recharged.

So you're going to need more batteries in each vehicle so you have longer range. A Tesla has a phenomenal number of batteries. But it can go for 240 miles.

GAZETTE: Do you have a sense of what an ideal mail vehicle would look like?

LEE: No. It's an interesting problem. If I had two weeks free, I bet I could come up with some ideas. I can tell you what won't work, but I can't tell you what the answer is. I can certainly beat 9 miles per gallon, though. The question is: Do I want to beat it by a factor of two or a factor of three?

GAZETTE: If the media coverage is correct and the Postal Service is going to replace 180,000 vehicles, is that big enough to make an impact on the tailpipe pollution that the country emits?

LEE: Yes and no. The no is because you have these vehicles dispersed across the entire country, so that's not going to make a big dent [in local air quality]. Where it can make a dent is if you are now manufacturing engines that are a lot more efficient for midsize and small-size trucks—small trucks and SUVs are what Americans buy these days. And if you can improve the efficiency of truck engines, particularly small trucks, that would have a major impact.

If I build an engine that is more efficient and I have to buy equipment and parts, somebody has to manufacture all those parts. They would probably like to sell some parts to customers beyond the U.S. Postal Service, so the impact of the improvement becomes wider. It's like when an elite car model has some [advanced] device, and the next two years more cars have it and, after 10 years, all cars have it. So the more we can build more efficient vehicles, the better off we're going to be and the better off the world's going to be.

GAZETTE: Where do vehicle emissions rank in the list of climate change challenges?

LEE: Again, a simple answer is hard here. If you forget climate for one second, smog is a huge problem in cities like New Delhi and many others in China. Smog is a chemical soup that consists of a number of chemicals, including small particles. A lot of these particles and a lot of the NOX [nitrogen oxides] are emitted by vehicles, particularly older trucks.

So if I can either substitute much more efficient models or get those trucks off the road, I'm going to make a dent in conventional pollution. I was just amazed at the number of trucks I've seen in China. I haven't spent time in India, but I would suspect it's not much different.

Second, as I ratchet down emissions of power plants—there's the new Obama [power plant] rule and I suspect the Chinese are going to do the same thing when they come up with their cap-and-trade program—then those sources I'm not ratcheting down will contribute a higher percentage of the total CO2 emissions. People may say that we can get everything we need [in emissions reductions] now from power plants, but that's not going to be the case 10 years from now, or 20 years from now, or 30 years from now. So if you want to make a difference in the out years, if you want to meet the 50 percent, 60 percent, 70-80 percent goals that the politicians are talking about, you have to address transportation.

I've done a lot of work on electric cars, and I've done some work on Chinese electric cars and at first blush they look like a monumental failure. They were trying to build cars to compete with Toyota and Tesla, but there are a couple of small, private entrepreneurs who are saying, "We have a pretty good monopoly on electric bikes, why don't we produce small electric cars that cost $5,000 and go 35 miles an hour and maybe can't even be used on the highway?"

So they started making them and, lo and behold, they sold 400,000 of them last year. In fact, they sold 200,000 in one province. That's five times what they sold in [larger] electric cars, so maybe they're onto something here. These cars' costs are at most $5,000 to $10,000. And somebody's going to come along and say maybe there's a niche here at $20,000 or $15,000 or $18,000 for a better electric car. That doesn't solve the transportation emission problem, but with 800 million households in China, it can really make a dent. And these cheap electric vehicles might just be what India needs.

Our focus is on the Tesla and these fancy $75,000-$80,000 cars, which are great cars. But maybe the answer for the world is these small and slow electric vehicles.

Explore further: More electric car charging points in Japan than gas stations

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26 comments

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stpruemper
5 / 5 (2) Mar 17, 2015
Since mail trucks are happily idling away for quite some time every day, top speed shouldn't be a factor, range should be manageable, why look for a more fuel efficient vehicle? I would think, this should be a perfect application for an all electric vehicle.
Cave_Man
5 / 5 (2) Mar 17, 2015
Seriously do they think idling an electric engine uses electricity? It shouldn't, stick solar panels on the top of the cars and make their charging port compatible with ones that are in most cities. They will still use jeeps and trucks for rural mail delivery anyways so we are talking about an urban delivery vehicle. Doesn't seem so hard to me, why does this article remind me of sitting in a long post office line then getting to the counter only to find they have so many rules about how to pack a box or affix a label that I end up leaving and using fedex!
PeterPiker
5 / 5 (1) Mar 17, 2015
Actually it was a hot topic (again?) in 2006.

"Electrification of Delivery Vehicles", August 28, 2009
http://postalmuse...-001.pdf

From the feasibility study, the average driving distance was estimated at 18 miles per day and the battery size at 1 kWh for every 2 miles of range for an average of 9 kWh per vehicle.

Miles ***Delivery Vehicle ***Percent of
/ Day ******* Count *********** Count
0-4 ********** 1,733 *********** 1.18%
5-9 ********* 22,379 ********** 15.27%
10-14 ****** 40,920 ********** 27.92%
15-19 ****** 36,232 ********** 24.72%
20-24 ****** 21,977 ********** 14.99%
25-29 ****** 10,486 *********** 7.15%
30-34 ******* 4,909 *********** 3.35%
35-39 ******* 2,429 *********** 1.66%
40-44 ******* 1,461 ************ 1.00%
45-50 ********* 892 ************ 0.61%
>50 ********* 2,442 ************ 1.6
PeterPiker
not rated yet Mar 17, 2015
It was a hot topic in 2006

U. S. Postal Service, "Electrification of Delivery Vehicles", August 28, 2009, DA-WP-09-001
saw
4 / 5 (1) Mar 18, 2015
A few KW of batteries-some supercapacitors--and, a range extender. Polaris has a good one-the Erdgan-Lotus would work--the Ecomotors OPOC counter rotating genset would work A small genset based on the Achates OPOC engine would offer the best fuel economy.
Eikka
3 / 5 (2) Mar 18, 2015
Actually it was a hot topic (again?) in 2006.


And from the paper we see that the conclusion was "Not Feasible" unless they also started a vehicle-to-grid power trading scheme and went to the government begging for money to make up for the difference.

Over 10 years they expected to be $16 million in the negative, but gain $76 million by trading battery power with the utilities. Problem is, they didn't include estimates on the cost of the additional wear on the batteries from the V2G scheme, which would show up in increased replacement rate/cost.

It's very hard to make any money out of V2G schemes because you need to sell power at 50 - 100 cents a kWh to make profit, but such peak demands aren't an everyday occurrence. So instead they simply assumed that utlities would agree to pay them a monthly fee for having their batteries "available".

MR166
not rated yet Mar 18, 2015
One would think that this would be an ideal use for an electric vehicle. If you cannot replace a 9 MPG (because of stop and go driving) vehicle that only drives a few miles each day with an all electric or electric/gas one and save money doing so there is a real problem with the whole idea of electric vehicles. This application is custom built for battery power. I live in a suburban/rural area and our mail carrier drives something the size of a small jeep.

shavera
5 / 5 (1) Mar 18, 2015
Eikka, et al. Considering that they are now looking to upgrade the fleet, such funds could exist for the upgrade. Plus there's been significant improvement, nationwide, in the electric vehicle market. Maybe with the battery "gigafactory" costs could be reduced even further in a few years?

Or perhaps a series hybrid (EV with a gasoline generator, not gasoline motor) may be a decent "best-of-both-worlds" balance for the fleet?
MR166
5 / 5 (1) Mar 18, 2015
"Or perhaps a series hybrid (EV with a gasoline generator, not gasoline motor) may be a decent "best-of-both-worlds" balance for the fleet?"

If they turned the Chevy Volt into a small truck that would do it. But, at $40K+ a pop, payback might never happen. It is a safe guess that if something costs more to own and run than the equivalent fossil only vehicle then there is no real savings in CO2 emissions since it implies that it took a lot of energy to produce the item.
gkam
2.3 / 5 (3) Mar 18, 2015
Why do some folk oppose alternative energy as if it were going to kill them? It is coal and nukes which are killing us.

Let's make a deal: I'll buy the fuel and take all the waste from wind and PV generation if you buy the fuel and take all the waste from coal and nuclear generation.

Got it?
MR166
3 / 5 (2) Mar 18, 2015
"Why do some folk oppose alternative energy as if it were going to kill them? It is coal and nukes which are killing us."

I beg to differ all of the energy sources mentioned are saving countless lives every day. When wind and solar solve all of their problems and provide reliable power that costs no more than the existing system there will be no argument and no need for government interference. Market forces will make sure that this happens.
MR166
not rated yet Mar 18, 2015
As far as living down wind from a coal generating plant goes, I would much rather live there than down wind from a wind farm.
gkam
3 / 5 (2) Mar 18, 2015
Do you have any idea how much noise coal plants make? Been in one?

Yuk.
MR166
not rated yet Mar 18, 2015
"Do you have any idea how much noise coal plants make? Been in one?"

What's the complaint gkam, did you have trouble sleeping at your desk? HeHe!
gkam
3 / 5 (2) Mar 18, 2015
Something like that. I had to teach a technical seminar for the utility engineers with the roar of the draft fans and noise of coal conveyors, . . not exactly in the background, . . more like the mid-ground.
TheGhostofOtto1923
1 / 5 (2) Mar 18, 2015
Something like that. I had to teach a technical seminar for the utility engineers with the roar of the draft fans and noise of coal conveyors, . . not exactly in the background, . . more like the mid-ground.
And did you prepare this presentation yourself or were you presenting something prepared by real engineers who knew what they were doing? Be honest now.
gkam
3 / 5 (2) Mar 18, 2015
Otto, I taught them how electricity and electrical systems really work, how to figure them out, how to read waveshapes of disturbances, and how to troubleshoot problems. We deal with customer loads and their effects on the types of distribution transformers.

You know that, it is on my web page. Did you see the distorted current waveshape your mommy's computer puts into the electrical system, generating voltage distortions through the impedances of the circuits?

You remind me of the time I was expert witness, and the opposing attorney famous for destroying technical witness attacked me - and I was terrified until I saw he was carrying the book written by the inventor of the power quality analyzer they used. My name is on page 10, explaining how analyses of waveforms are dependent on location.
TheGhostofOtto1923
1 / 5 (2) Mar 18, 2015
Otto, I taught them how electricity and electrical systems really work
-And Im guessing that you learned a lot delivering presentations prepared by others. Because you have admitted that you yourself have no formal education as an engineer. And so I assume you just 'picked things up' as you went.
expert witness
???
he was carrying the book written by the inventor of the power quality analyzer they used. My name is on page 10
And what a colossal coincidence it must have been that your contribution to that book was exactly the subject matter that you were testifying on? As an 'expert witness'?

But who cares. Even if it were true 1) it would mean that you probably spent less than 6 mos at each job you ever had and 2) it has NO BEARING on the efficacy of the SHIT you post here. Its SHIT whether any of your experience was real or not.

Why dont you get this?

Your EXPERIENCE doesnt make the stuff you post any less WRONG.
gkam
3 / 5 (2) Mar 18, 2015
Should I show you how to look up my reviews on the sites of my customers?.

What did YOU do in life?

You just hide behind that pseudonym, like Dubya in his Command Bunker screaming "Bring 'em on!".

otto, I bring up my experience because of the lessons learned. No bragging intended or implied.
gkam
3 / 5 (2) Mar 18, 2015
"And what a colossal coincidence it must have been that your contribution to that book was exactly the subject matter that you were testifying on? As an 'expert witness'?"
------------------------------------------

No coincidence, that is why they hired me. I taught waveshape analysis for the manufacturer in their facilites and on the road, and that was the only power quality waveshape analysis book on Earth at the time.
TheGhostofOtto1923
1 / 5 (3) Mar 18, 2015
Should I show you how to look up my reviews on the sites of my customers?
WHY would I want to do that?? Do they read what you post here?

You STILL dont get it. You post shit.

"Plutonium raining down on idaho, fallout as the principal cause of lung cancer, H2 explosions throwing reactor parts 120km, complex systems being self-stabilizing, only 1 scientist realizing that the next ice age is just around the corner, that microwaves from orbital solar stations will cause cataracts, etcetcetc ad infinitum."
What did YOU do in life?
I LEARNED how to recognize SHIT like this when I see it.
I bring up my experience because of the lessons learned
Your experience is WORTHLESS because it makes you think you can post SHIT like this and get away with it. WHY is that???.

My god youre stupid.
gkam
4 / 5 (4) Mar 18, 2015
"My god youre stupid."

The correct word is "you're", a contraction of you and are.

You're welcome.
gkam
1 / 5 (2) Mar 18, 2015
otto bleats:

"You post shit."

"I LEARNED how to recognize SHIT like this when I see it."

"Your experience is WORTHLESS because it makes you think you can post SHIT like this and get away with it. WHY is that???".
-----------------------------------------

Otto, being short-sighted apparently means what you see depends on where you have your nose.

Let's get back to discussing postal service transportation, not your fixation on me.
howhot2
3 / 5 (4) Mar 18, 2015
"Why do some folk oppose alternative energy as if it were going to kill them? It is coal and nukes which are killing us."

I beg to differ all of the energy sources mentioned are saving countless lives every day. When wind and solar solve all of their problems and provide reliable power that costs no more than the existing system there will be no argument and no need for government interference. Market forces will make sure that this happens.


blah blah blah; where wind or solar is installed, it does very very good! Thank you! However, since the corporations are such cop-outs when it comes to investing in newer technology, it only makes since that government should spend some taxpayer funds to start the ball rolling. It benefits all of us, and it makes all of us an investor in the technology in spirit and commitment to greening the planet!
TheGhostofOtto1923
1 / 5 (3) Mar 19, 2015
Let's get back to discussing postal service transportation, not your fixation on me
Well I agree but I constantly have to tolerate youre bragging about TOTALLY UNRELATED life experiences (alleged), like
Something like that. I had to teach a technical seminar for the utility engineers with the roar of the draft fans and noise of coal conveyors, . . not exactly in the background, . . more like the mid-ground
-and again I have to ask - who fucking cares?? Nobody here, thats obvious. Why isnt it obvious to you? Is it because youre so completely self-absorbed?
gkam
4 / 5 (1) Mar 19, 2015
Ah, . . the ottoids are back, and unable to debate the issue resort to personal attacks.

My comments were enabled by my experience on EPRI electric vehicle committees, back when I was Senior Engineer for Pacific Gas & Electric. From where do you get your opinions?

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