Hybridcar

In 1998, Daimler announced that they will start selling fuel cell automobile within 5 years. This announcement was failed and now hybridcar seems most successful. Mr. Greenwood continued discussion about hybridcar with Mr. Cooper living in Manhattan Beach, and found many interesting points.

Tank-to-wheel efficiency of conventional gasoline driven car is only 16% as illustrated fellow. Here, accessories loss, such as air conditioning unit consumes 2% but for comparison purposes, it was assumed 0%.

Tank-to-Wheel Efficiency of Conventional Car

Whereas, tank-to-wheel efficiency of hybridcar reaches 37% by eliminating standby and idle operation loses and recovering power during braking. as shown below. Following mechanism of Prius was prepared after reviewing the Toyota site  http://www.toyota.com/planetkaizen/ which Mr. Cooper found. If you wish to know in more detail, go to the "Explore" section and type "Hybrid" into the search bar.

Tank-to-Wheel Efficiency of Hybridcar

Mr. Cooper founds different figure of tank-to-wheel efficiency of 32%. But if hybrid runs 60MPG in urban area, and if mileage of conventional gasoline car is 26MPG which correspond to tank-to-wheel efficiency of 16%, tank-to-wheel efficiency of hybrid car becomes 37%.

If it is assumed that well-to-tank efficiency of gasoline is 88% and that of hydrogen from natural gas is 58%, well-to-wheel efficiency of gasoline car becomes 14% and that of hybridcar becomes 32% as shown in the following table.

In case of FCV (Fuel Cell Vehicle), well-to-wheel efficiency becomes 22% which is inferior to hybrid car.

In case of FCHV (Fuel Cell Hybrid Vehicle), well-to-wheel efficiency improves up to 29% which is still inferior to hybrid car.

Vehicle Type	Well-to Tank Efficiency	Tank-to-Wheel Efficiency	Well-to-Wheel Efficiency
Gasoline (town mode)	88	16	14
Gasoline (highway mode)	88	38	33
Diesel (town mode)	90	20	18
Diesel (highway mode)	90	47	42
Gasoline Hybrid (town mode)	88	37	32
Diesel Hybrid (town mode)	90	46	41
Fuel Cell Vehicle（FCV）(town & highway mode)	58	38	22
Fuel Cell Hybrid（FCHV）(town & highway mode)	58	50	29
Target  of  FCHV (town mode)	70	60?	42?
Compressed Natural Gas（CNG）(town mode)	90	16	15
CNG Hybrid (town mode)	90	37	33
DME Diesel (town mode)	70	22	15
DME Diesel Hybrid (town mode)	70	46	32
Electric Car (town & highway mode)	40	80	32

Bush administration launched a new energy policy placing hydrogen fuel from oil and gas. This is idea is based on utilization of fuel cell. But it is unlikely as shown above table. Such scheme may increase carbon emission. According to Mr. Cooper, not only Sierra Club but Cato Institute started criticizing Bush administration.

Rather than converting fuel, direct combustion in engine can achieve higher efficiency. Diesel engine can achieve higher thermal efficiency than gasoline engine. Therefore Diesel Hybrid car can achieve 41-42% Well-to-Wheel Efficiency for highway mode and for town mode. Fuel cell technology might be obsolete as Daimler presented prototype Diesel Hybrid car in Tokyo Motor Show in 2005 and French company, Peugeot announced commercialization of Diesel Hybrid car by 2006.

Mr. Morinaga who was a professor of Nuclear Physics in Univ. of Munich for over 25 years told me a story about Prius. When his wife visited hair dresser in Germany a month ago, she heard a chat among men client about buying Prius for their private use. One of them asked "What if all of us buy Prius, who buys Daimler". Another man replied "Japanese may wish to buy those cars".

November 13, 2003

Latest 10・15mode Well-to-Wheel Efficiency data by Prof. Ishitani are; (Chemical Engineering Vol.71 No.2 2007) .

Vehicle Type	Energy Input	Carbon Dioxide Emission
Unit	MJ/km	g-CO2/km
Electric Car	0.94	49
Fuel Cell Hybrid	1.5	86.8
Diesel Hybrid	1.2	89.4
Gasoline Hybrid	1.7	123
Diesel	2.0	146
CNG car	2.7	148
Gasoline	2.7	193

Rev. April 1, 2007

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منبع:http://www.asahi-net.or.jp/~pu4i-aok/cooldata2/hybridcar/hybridcare.htm