I've been watching this debate with interest. In some ways it shows that Tesla is achieving it's mission: to disrupt and move electrification along at a faster pace. The fact that it's generated more interest than any related topic I can think of in our field is testament to that, the debate is the first step on the way to changing the direction of travel.

I'm a naturally cynical person, but I cant help thinking that what Tesla and Elon Musk have achieved, for all the flaws, debatable whole vehicle life climate change benefits etc, is impressive. Tesla has become, in the space of a few years, the most valuable car company in the US, and has made electric cars attractive. You could argue they have pushed too hard, too fast, especially on autonomy, but that is how they have achieved disruption.

On the 'Semi', the diesel price in the UK is around US$4.60 per US gallon, one of the highest in Europe. Our trucks typically each consume US$60k per year in diesel, and that's pretty normal. We make them last around 7 years, so there could be a business case there for a very high capital cost truck with very low fuel cost. We, like many companies, are generally volume constrained, so could take a hit on payload if a fuel saving was there. In reality, it is the business case, not environmental factors, that will drive adoption

Automomous trucks would offer a massive labour cost saving, and companies that are building us huge databases of autonomous driving data will have a commercial advantage. Autonomy and electrification also go very well together, so Tesla are well placed there. 

For me, the interesting questions are :-

• What are the real, whole life environmental and business cases for electric heavy trucks. That includes the infrastructure costs.
• If the case is attractive, how do we solve the considerable challenges
• Are there better alternatives to diesel or electricity for heavy trucks that are suitable for wide scale roll-out in the future. The SRF Future Fuels project addresses this.

These are great times to be involved in road freight !

On 28 November 2017 at 21:16, David Cebon <[log in to unmask]> wrote:

Thanks Chris

 

Here is another view of the same problem:  If these trucks are to be charged in 30 mins as Tesla claims, the power required for each vehicle is about 3MW.  Each medium sized distribution centre (DC) /warehouse would have to charge about 20-30 vehicles at a time (while they are loading). This means that each would require a substation able to deliver 60-90MW.  That is sufficient capacity to power a city of 100,000-160,000 people (using Chris’ number of 0.5625 kW/capita).  ie each DC would need a substation able to power a city about the size of Cambridge.

 

…And don’t forget the dedicated fire crew that would be needed to put out all the battery fires!

 

But… one word of caution here.  Tesla is clearly wrong about the battery, but they are not necessarily wrong to look into the possibility of electric trucks. An electric truck that is charged while in motion is reasonably doable.  Siemens have developed and trialled quite a nice overhead pantograph system which achieves this with a relatively low infrastructure cost.  See https://www.siemens.com/global/en/home/products/mobility/road-solutions/electromobility/ehighway.html  Such a system could power a truck like the Tesla with a smart pantograph on the roof.  As long as DCs are close to the interstate/motorway network (which they often are), then only a modest battery (less than 100kWh) would be needed to get the vehicle from the interstate to the DC at either end*.  This would be a feasible way to electrify long-haul road freight in some locations – eg in the UK, or along the eastern seaboard of the USA.

I don’t agree with John Lambert’s analysis of the CO2 emissions due to electricity generation: 100% generation by coal is simply not the case anymore - anywhere.  The power grids in most countries are being decarbonised fairly quickly through increasing use of low carbon power generation – particularly gas, wind, solar, hydro and nuclear.  Our calculations for the UK show that today, a small electric truck (as might be used for urban delivery) generates about the same well-to-wheel (WTW) CO2 as its diesel counterpart. (This takes account of the CO2 emitted in generation and transmission of the electricity.)  If the UK Government’s projections for the carbon content of the electricity grid are correct, then by 2030, that EV will emit 70% less WTW CO2 than the diesel.  70% is worth having.  So electrification of urban delivery vehicles is worth considering now.  And as a community, we should be debating whether countries should invest in infrastructure for charging long-haul vehicles on the move - in the not too distant future.

David

 

* Nicolaides, D, Cebon, D and Miles J.  ‘Prospects for electrification of road freight’, accepted for publication in IEEE Systems.  Published online 21 April 2017. DOI: http://dx.doi.org/10.1109/JSYST.2017.2691408

 

 

From: Chris Winkler [mailto:[log in to unmask]]
Sent: 28 November 2017 19:21
To: [log in to unmask]
Subject: Re: Tesla electric truck: too good to be true?

 

All:

 

I agree with David and the other responders: I don't believe the electric semi is viable, except, perhaps, for local delivery service. (Although, if you read some of the electric-truck hype closely, it seems that TESLA and the others in the effort more-or-less to agree with that.)

I will add three thoughts to the conversation:

(A) These discussions often concentrate on travel range, and hence on on-vehicle electric energy storage capacity. But, in regard to over-the-road trucking operations, it strikes me that energy recharge rate is at least, and probably more, important.

Consider a moderate sized interstate truck stop with, say, ten pumps. Each of those pumps can deliver about 10 US gal/minute. (That is typical of gasoline pumps at an in-town station. I imagine highway truck-stop pumps may well be faster.) With all 10 pumps going at once (not uncommon), that truck stop is delivering usable (i.e., after energy efficiency considerations) energy at a rate comparable to electric power usage of a city of 150,000 people. (See calculations below)    …and, in the US, we have a few thousand such truck stops.

So, if the magical Mister Musk were every able to accomplish the near impossible: namely, producing a battery/charging system that could recharge a class-8 truck at the near equivalent energy delivery rate of an ordinary truck-stop diesel fuel pump, he would only have taken the first step in the larger problem of delivering the electric power needed to the world’s truck stops.

(B) It also strikes me that, in general, people do not have a very good intuitive sense of the “really huge” (sorry) amount of energy in petroleum fuels in comparison to our typical consumption of electric energy. For example, if you will accept that a typical fuel capacity of a US over-the-road class 8 truck is about 200 gallons, then I would point out that one fill-up of that truck represents the equivalent usable energy of my own household electric power consumption for nearly 13 years. (Also, see calculations below.)

(C) It has been pointed out that to a large extent, electric vs diesel trucks relocate the environmental pollution problem rather than eliminating it. Similarly, while the efficiency of the modern diesel truck engine is about 37% (see note 2 below) in comparison to the near 100% efficiency of electric motors, the US government data indicates that over the years 2005-2015, US electric power generating plants range in efficiency from 33% (coal and nuclear) to 42% (natural gas). See https://www.eia.gov/electricity/annual/html/epa_08_01.html

Good luck, Elon.

Chris Winkler

(1) https://www.afdc.energy.gov/fuels/fuel_comparison_chart.pdf

(2) https://en.wikipedia.org/wiki/Diesel_engine#Fuel_economy

(3) https://www.quora.com/How-much-electricity-does-an-industrialized-city-of-1-million-people-consume

(4) (We heat with natural gas.)

-- 

C. B. Winkler, Research Scientist Emeritus
University of Michigan Transportation Research Institute 
2901 Baxter Rd, Ann Arbor, MI, USA 48109            
Tel:+1 734 936-1061; Fax:+1 734 936-1068

 

On Mon, Nov 27, 2017 at 5:29 PM, David Cebon <[log in to unmask]> wrote:

Tesla’s claims for its new electric truck require some scrutiny.  Tesla claims that the new truck will have a range of 800kms and an energy consumption of 1.25kWh/km.  Running 800km will therefore require 1000 kWh of energy: in practice a 1300 kWh battery.  Suitable lithium-ion batteries for electric vehicles cost $150/kWh today and are expected to fall to $100/kWh by 2021.  This suggests a 2021 battery cost of $130,000: approximately equal to the current average price of new heavy truck in the US (in the Class 8 category).

The specific energy of lithium-ion batteries is 0.1 kWh/kg – 0.25 kWh/kg.  So the weight of a 1300 kWh battery will be between 5.2 and 13 tonnes.  A US Class 8 truck has a maximum gross weight of 36 tonnes, 8 tonnes less than the equivalent UK lorry.   In weight terms, US trucks are relatively inefficient by international standards.  US carriers must therefore use their maximum payload of 21 tonnes very effectively.  The weight of the battery in an electric truck is likely to constitute 25% to 60% of this available payload. Even after allowing for the absence of a fuel tank and lighter electric engine this payload penalty will deter many potential users…  A fleet operator might require 4 electric trucks to carry the same load as 3 diesel-powered vehicles.

Elon Musk promises that his electric truck “will blow your mind clear out of your skull and into an alternate dimension”.  However, in the real world, a vehicle offering at most 3/4 of the payload for double the capital cost does not seem a very attractive proposition for the road freight industry.

David Cebon

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