PLEASE NOTE: These bulletins, published since 1997, are historical. The content is not updated.
King County is purchasing hybrid electric vehicles that increase fuel-efficiency and reduce greenhouse gas emissions. Growing scientific evidence suggests that greenhouse gases contribute to a change in the earth's climate, and transportation, specifically the combustion of fossil fuels in vehicles, accounts for a large portion of greenhouse gases.
What is a hybrid electric vehicle?
Hybrid electric vehicles (HEVs) combine the internal combustion engine of a conventional vehicle with the battery and electric motor of an electric vehicle, and attain twice the fuel economy of conventional vehicles. This combination offers the extended range and rapid refueling of a conventional vehicle, with a significant portion of the energy and environmental benefits of an electric vehicle. The practical benefits of HEVs include improved fuel economy and lower emissions compared to conventional vehicles.
How does a hybrid vehicle work?
A hybrid propulsion system has five major components: engine, generator, electric motor, battery energy storage and energy control system.
The gasoline or diesel engine spins the generator to produce electricity. Most of the energy produced goes into the electric motor to move the vehicle. Excess energy goes into storage. When more energy is needed than can be produced by the generator (such as climbing a hill), the batteries supplement the generator. All this is managed by the computerized energy control system. When less energy is needed, the computer directs it back into the batteries.
The energy-management activity is not noticeable to the driver. Since it only spins a generator, the engine can be much smaller than what is used today, and its fuel economy is greater. Also, emissions are greatly reduced since the engine typically operates in a small horsepower range.
Currently, two mass produced hybrid gasoline-electric vehicles are sold in the United States, the Toyota Prius and the Honda Insight. These new cars are energy-efficient, attaining gas-mileage of 50 miles per gallon or more. Many more are on the drawing board.
DOT purchases 20 hybrid cars (gas/electric)
King County's Department of Transportation (DOT) has purchased 20 Toyota Prius cars. They are being delivered now, at a total cost of $375,000, which is comparable to the price of the cars that we typically buy. These cars will be assimilated into King County's vehicle fleet.
For more information, please see the press release: "King County cleans up air quality with purchase of new hybrid cars"
DOT gets grant to buy hybrids for car sharing program (Flexcar)
In addition to the purchase of hybrid vehicles for its own fleet, King County DOT received a grant to purchase hybrid cars for the local Flexcar program, a county-supported car-sharing program.
The $150,000 grant from the EPA is part of a new national transportation partnership. These are the first grants to be awarded under the Clear Air Transportation Communities program.
For more information, please see the press release: "King County cleans up air quality with purchase of new hybrid cars"
DOT testing hybrid buses (diesel/electric)
King County Metro Transit will
be the first in-service demonstration site in the nation for an articulated hybrid bus. The demonstration unit is scheduled for delivery in April 2002.According to the King County press release:
Vehicle Maintenance Manager Jim Boon said, "Hybrid buses fit perfectly into our existing maintenance infrastructure while complementing our basic objectives of cost-efficiency and ultra-low emissions. Furthermore, our existing maintenance technicians have maintained the Breda fleet for almost 12 years. That experience makes us the only transit system in the country with a knowledgeable workforce that is ready to transition to hybrid drive."
For more information, please see the press release "Metro first in nation to test articulated hybrid diesel-electric bus."
King County Department of Transportation
Technology Snapshot - Featuring the Toyota Prius (U.S. Department of Energy):
Environmental Purchasing Program
The King County Environmental Purchasing Program assists County agencies in implementation of King County Executive Policy CON-7-1-2, which requires agencies to use recycled and other environmentally preferable products wherever practicable.
The program assembles information about these products and makes it available to specific agency users who can evaluate them and develop applications in County projects.
These environmental purchasing bulletins contain information about the results of product evaluations and other accomplishments of County agencies. We hope this information will help you find ways to use recycled materials in the work of your agency and that you will contact us if we can help you with further information or if you have suggestions.
Environmental Purchasing Program King County Procurement Services Division
Published: August 27, 2001
Return to Environmental Purchasing Menu |
Bulletin List
Updated: August 27, 2001
King County
| News | Services | Comments | Search Links to external sites do not constitute endorsements by King County.
By visiting this and other King County web pages,
you expressly agree to be bound by terms and conditions of the site.
The details.
E-mail