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Honda Neo electric scooter
Harry Valentine envisions a fast charging, low maintenance carbon capacitor powering fleets of delivery scooters like this Honda Neo prototype.

Powering Scooters with Carbon Flowerpots

Harry Valentine offers yet another 'out of the box' idea to create in EV world.

By Harry Valentine

The ongoing search for electrical storage technologies that can offer long service life over a wide range of temperature has focused on high-tech energy storage devices. Many eminent researchers have secured funding from government and other sources to investigate the potential to store a massive static electrical charge using carbon nanotubes. One research group claimed to be working on a storage device that could propel an electrically powered car for up to 500-miles (800-km). Except that as of late, nobody seems to have heard from them.

Given all the hype about state-of-the-art concepts such as nanotubes and carbon graphene, perhaps there may actually be a market for a low-tech, low-cost super capacitor that could propel an electric scooter for up to 25-miles at speeds of up to 30-mi/hr or 50-km/hr. The storage material for the super capacity would be the kinds of carbon deposits that form on the valves and other components of automotive engines. Carbon deposits are made of carbon and can stick to metal. The fact that the atoms of carbon deposits stick to metal and to each other suggest that carbon deposits could carry an electrical charge and store static electricity.

Carbon deposits have a density of over 130-lb/cu.ft and may be able to store up to 10 Watt-hours per kilogram (W-h/kg) of energy. Given that most medium size motorcycles weight some 500-lbs (226-kg), it may be possible to build a scooter that can carry some 200-lb or 90-kg of carbon deposit. A storage capacity of 900-Watt-hours would mean that a scooter powered by an electric motor of 0.75-kW (1-Hp) could operate for up to 1-hour. It could serve as a delivery scooter that will recharge upon its return of each delivery, where in heavy traffic conditions in a large city or in a small town.

The basis of a carbon-deposit super capacity would be 3-concentric metal containers that have the conical shape of a flowerpot. The carbon deposits would be formed on the inside surface of the largest container, on the outside surface of the smallest container and on both surfaces of the middle size container that would carry the positive charge. The largest and the smallest of the containers would carry the negative charge after the flowerpot super capacity is assembled along with electrolyte and separators.

The inner and other containers would be clamped to each other at the top, using a metal crossbar and contain the interior concentric conical shapes. The concentric conical pot concept may be expanded to 5 or 7-concentric metal shapes, with all inner containers and all that carry the positive charge being coated with carbon deposits on both sides. While coating the metallic shapes with carbon deposits may be economical, it may be possible to coat them with graphene at some time in the future, to increase energy storage capacity.

On a scooter with wheels of 14-inches, the flowerpot shaped super capacity of about 15-inches diameter would be installed ahead of the rear driving wheel and below the driver’s seat. The scooter may also be built as a tricycle carrying a super capacitor of some 24-inches diameter located between the rear wheels and below the luggage container. Several companies are in the business of carbon and offer carbon products as filter material. They could supply the carbon needed to develop a low-tech, carbon deposit super capacitor that may be able to store enough energy to propel an electric scooter for up to 1-hour at speeds of up to 40-miles/hour or 60-Km/hr.

Many of the rural roads across Asia have posted speed limits of 50-Km/hr and 60-Km/hr. In India where posted speed limits of 70-Km/hr are common, traffic congestion conditions restrict maximum speeds to within the top speed of the present generation of electrically assisted bicycles and scooters. While many of these vehicles are offered with lithium batteries in the North American market, they are offered with lead-acid batteries in the Asian market. Lead-acid batteries require a slow recharge, rendering them unsuitable for many commercial applications that would benefit from rapid-recharge capability.

For commercial operation in Asian cities and towns, a deliver scooter powered a carbon-deposit super capacitor may be rapidly recharged up to 30-times per day or some 10,000-times per annum. Each recharge may take about 3-minutes, allowing a delivery driver to be underway on the next delivery in less than 5-minutes following the return from the previous delivery. The types of delivery service for super capacitor scooters may include fast food, pharmacy, local-courier service, post office and possible non-delivery services including municipal police patrol.

While Asian cities and towns may constitute the main intensive-service market for super capacitor scooters, similar markets may develop in cities across Europe and the America’s. The low-storage density of 10-Watt-hours/kilogram may be sufficient to sustain the operation of such vehicles. It may be many years before a competitively priced ultra capacity of over 100 W-h/kg becomes commercially available, increasing the possible storage capacity of a flowerpot super capacitor to 9kW/hr, allowing a scooter with a 3kW electric motor scooter to travel at a speed of 50-mi/hr or 80-Km/hr on a journey of up to 3-hours duration. There may be a worldwide market for such a vehicle.

A more advanced concept of ultra-capacitor powered scooter may utilize flexible carbon material capable of being rolled into a spiral. If sheets of carbon fiber material can hold electrostatic charge, it may be a candidate material. The spiral roll would include 3-layers of metallic foil (inner and outer layer carry the negative charge), 4-layers of flexible carbon, 2-separation layers and 4-layers of electrolyte. Its outer dimensions would be of equivalent size as the muffler or silencer of a large truck (18-inches diameter x 72-inches length) and would form the backbone of a scooter tricycle.

Conclusions:

While there is much research underway in university laboratories worldwide, there is market potential for low-powered, low-speed electrically powered vehicles that could benefit from low-tech super capacitor technology.

illustration of cross section of flowerpat capacitor

Times Article Viewed: 9533
Published: 07-Feb-2011

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