|A Green Ride|
Greenhouse gas emission is inversely proportional to thermal energetic efficiency. Electric bicycles provide the most efficient personal transportation possible without slowing below urban commuter speeds, or using a totally enclosed fairing. An electric bicycle will operate very efficiently at average urban transportation speeds of 25 miles per hour. When compared to automobile use, the systemic reduction in greenhouse gas emission is about twenty-five fold. Indirect benefits to electric bicycle use include reducing urban footprint on street infrastructure and parking facilities to a sliver of personal automobile footprint. The Neodymics Cyclemotor can enhance performance and utility of existing bicycles, thereby increasing opportunities for bicycle use.
"Green" is quantified below by systemically evaluating alternatives. Specific pollution reductions, scalability, relative costs and benefits are compared to other transport means.
The transportation matrix above indicates thermal efficiency, greenhouse gas emissive efficiency, and energetic performance for various modes at typical usage speeds. Vertical position in the graph indicates thermal efficiency in payload kilogram meters per thermal Joule, or 70 kg passenger miles per gallon of gasoline. Thermal efficiency is proportional to greenhouse gas emissive efficiency, as denoted on the right vertical axis. Horizontal position in the graph indicates speed. Horizontal position of the intersection of the diagonal lines with the horizontal blue line indicates energetic performance, which is the product of thermal efficiency and speed. Various conditions are differentiated by the data point icons. Effective values for mass transit take wait time into account are strongly influenced by utilization, delays and terminal pedestrian flow. Steady state cruising conditions are denoted, along with average conditions which include velocity changes in crowded environments. Payload mass is indicated by diagonal line color. Hairline diagonals indicate personal vehicles, in which the driver is also the payload. The price for convenience of personal transit is evident when compared to mass transit. For human powered transportation, the thermal energy content of food was used to measure efficiency and performance. Energy used to obtain food varies widely, and was not included.
Vehicles with the highest level of energetic performance have efficient powerplants, high payload to gross mass ratios, or reduced friction with the surrounding environment. For practical personal transport at urban commuting speeds of 25 MPH or 11 m/s, as exemplified by the Neodymics Cyclemotor, the electric bicycle has the highest thermal efficiency (0.3 kg-m/Jth), GHG emissive efficiency (4.2 kg-km/gCO2e) and energetic performance (3.4 seconds).
It is ironic how efficiently petroleum (crude) is transported. If a person were to be transported around the world with the same efficiency as can be realized in the shipment of petroleum, it would only require two-thirds of a gallon of gasoline! Oil companies are very efficient in delivering their product before it is squandered as gasoline. About 95% of our petroleum is transported by ship or pipeline.
In evaluating transportation choices, efficiency is an important and well characterized consideration. Average speed is also important, since people are paid by the hour and "time is money." Multiplying thermal efficiency by speed, a quantity is obtained that we define as Energetic Performance. Using standard SI units, it expressed in seconds. By evaluating performance with respect to thermal instead of electrical energy, we are comparing apples to apples. The table below gives efficiency, speed and energetic performance for various modes of human transportation. Efficiency is determined by estimating the number of passenger-kilometers obtained per unit of thermal energy present in the fuel consumed. For electrically powered mopeds, the net powerplant efficiency, electrical transmission loss, charger efficiency, and battery discharge loss are all accounted for. Thermal efficiency non gasoline fueled vehicles was used to determine an equivalent fuel economy in person-miles per gallon of gasoline.
For more complete, referenced descriptions of Energetic Performance, click below:
The prototype device uses stored electrochemical energy to provide propulsion. This does not directly produce any air pollution. A vast worldwide fleet of electric mopeds and small streamlined vehicles could meet most human desires for personal transportation, without greenhouse gas emission. At the societal level, electric propulsion allows a great deal of choice in energy feedstock. Alternative sources such as solar, wind, nuclear and hydroelectric can provide electrical energy without atmospheric emissions.
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