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wstewart

I agree that a weight requirement would at some point be arbitrary - the actual objection is about safety, which is not measured directly by weight. And since 2-wheelers and 3-wheelers are considered motorcycles, they are under far less stringent safety requirements anyway. At some point, we have to get away from assuming SUV impact resistance, as impending higher oil prices will soon remove most of them from the road anyway;

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Thomas

The requirement for a minimum weight is somewhat arbitrary but not without merit. The drive cycles utilized in testing could be argued to be both arbitrary and not indicative of real world driving (especially when applied to a banked oval NASCAR track). The weight issues expressed by many engineers and teams were based on the fact that cars were not equally required to have the same modern conveniences and safety features. Edison 2 did not have HVAC, interior finishes, full airbags and other standard features of other mainstream entrants. In fact, not to pick on E2, but the cars most technically qualified to be categorized in the "mainstream" class were the modified production cars. However these cars were required to make substantial modifications to make them non-standard production, essentially prototype cars in order to comply with X Prize rules. To suggest that the rules "allowed for" some of the cutting edge innovations is preposterous. There were many long nights of deliberations and considerations by technical staff to consider waivers to a number of the rules. This is not speculation but fact. I know, we requested and were granted some waivers so our mainstream, production car could meet the requirements. Strange, but true.

John Shore

While it's true that it's difficult to design a drive cycle that is indicative of real-world driving, we did base it on DOT statistics and also on standard EPA drive cycles.

Also, I wanted to correct a couple of misunderstandings. We did require heaters in all vehicles, and - while we did not require air conditioning per se - we did put a limit on the temperature in the passenger compartment. In fact, Edison2 had means to heat and air condition their vehicles. As the rules did not specify a conventional heating system and a compressor/condenser AC system, many teams got creative and came up with alternate, efficient solutions.

Also, if a vehicle did not have air bags and/or interior trim that was deemed sufficient to address occupant protection, we required the vehicle to carry additional ballast weight. In this case, Edison2 and one other team carried the most ballast for required items that were not included in their competition vehicles.

Jim Bullis, Miastrada Company

Edison2 showed that in order to beat the advantage given to electric cars in the Mpge rating system, it was necessary to achieve great aerodynamics and to greatly limit weitht, but also to jack up the internal combustion engines to a performance level that clearly was not sustainable; as evidenced by all four engines having blown out before getting to the official dynamometer testing. The excuse that the fault was in the professional drivers is weak.

Simple observation shows that it was easy for electric vehicles with regenerative braking to achieve very high 'mpge' results that made the Edison2 numbers look like very poor performance.

I was watching for the dyno test results of the engines to see if the modifications to the engines, that were done to achieve the 100 mpge requirements in the track finals, stayed within the NOx limitations. As I recall, the earlier results did not make it.

The efficiency of a heat engine is very dependent on maximum temperature, but high temperatures create excessive NOx. Hence the dilemma of the engine designer, but also the opportunity to squeak up performance if the final configuration is not verified.

Jim Bullis, Miastrada Company

I add to my last that the entire developed world seems to concur with your position on MPGE. Thus, the US DOE, EPA, Argonne, Consumer Reports, the UK DOE (Dr. Prof. David MacKay, oft referenced (-- Without Hot Air).

Does that cause me to waver in my position? Not for a moment.

It does validate my original statement that the Automotive Xprize was doing great harm with this system of rating vehicle efficiency.

The key question is: How much heat energy does it take to produce one kWhr of electricity?

Answers:
1.0 kWhr -- Wrong, this violates both First and Second laws of thermodynamics.

.8 kWhr, or something somewhat less than 1.0 --- Wrong, but at least this appreciates the First Law.

It depends on the process, but for an electric energy grid where market economics determines the choice of power sources in response to new loads, and this is certainly coal fired equipment, it will take about 3 kWhr of heat to produce that 1.0 kWhr of electricity.

If one has a government that forces other outcomes, and the existing rate paying public is willing to pay for others to drive electric cars, then the answer might be about 2 kWhr of heat.

Electric car MPGE results should thus be divided by 3 or 2 to get a fair result.

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