 |
 |
Hi All
And there’s more.
Those pushing electric vehicles often use energy pollution saving as a strong positive. But is this actually so?
Yes emissions are reduced at the point of vehicle use. But they are not reduced overall emissions except in very limited circumstances. With an electrical supply system that is 100% derived from burning coal it is possible to work out how much CO2 is emitted at the power stations compared to a diesel car of the same size. Allowing for power station efficiencies, transmission line losses, charging and discharging losses, etc, electric cars generate around 3.8 times more CO2 than diesel cars! So until around 75% of electrical power used comes from renewable sources electric cars are a negative re environmental impacts.
And then there is the issue of powering them up. Really needs to be a manged situation where charging times are controlled to be outside the evening peak. Otherwise there will be a huge need for extra power supply sources.
Regards from
John Lambert
MIEAust, CPEng 180785, Member ASME, ACRS, SAE
Bachelor of Engineering (University of Melbourne, ARMIT (Mechanical)
Director and Company Secretary, John Lambert & Associates Pty Ltd, ACN 090 833 873 ABN 59 090 833 873
235 Wandana drive, Wandana Heights, Victoria Australia 3216
Phone: Intl +61 3 52491228 Local 03 52491228
Fax: Intl +61 3 52491146 Local 03 52491146
Mobile: Intl +61 4 17033258 Local 0417033258
From: Technical, operational and economic aspects of road freight transportation [mailto:ROAD-TRANSPORT-
[log in to unmask] ] On Behalf Of David Cebon
Sent: Tuesday, 28 November 2017 9:29 AM
To: ROAD-TRANSPORT-TECHNOLOGY@JISCMAIL.AC.UK
Subject: Tesla electric truck: too good to be true?
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
************************************************************ ***
The ROAD-TRANSPORT-TECHNOLOGY mailing list is published by
International Forum for Road Transport Technology
************************************************************ ***
************************************************************ ***
The ROAD-TRANSPORT-TECHNOLOGY mailing list is published by
International Forum for Road Transport Technology
************************************************************ ***
