Solar Power Assisted Electric Scooter

INTRODUCTION

“Because we are now running out of gas and oil, we must prepare quickly for a third change, to strict conservation and to the use of coal and permanent renewable energy sources, like solar power.” – JIMMY CARTER, televised speech, Apr. 18, 1977

In times such as today, cumulative solar energy production accounts for less than 0.01% of total Global Primary Energy demand. And the Solar Energy demand has grown at about 30% per annum over the past 15 years.

In 1985, annual solar installation demand was only 21 Megawatts.

Whereas the worldwide photovoltaic installations increased to 5,948 MW in 2008, up from 2,826 MW installed during the previous year.

Solar Energy (photovoltaic) prices have also declined on average 4% per annum over the past 15 years. Progressive increase in conversion efficiencies and manufacturing economies of scale are the underlying drivers.

Approximately 45% of the cost of a silicon cell solar module is driven by the cost of the silicon wafer, a further 35% is driven by the materials required to assemble the solar module.

State of the art versions have electronically controlled power assistance via sensors in the cranks linked to a computer chip, which automatically fade out power assistance at 25 km per hour. (2) The E-Bike is around 10 kg heavier and has around twice the power output and only needs to be pedaled on hills and against strong headwinds. It is used mostly in China but in 2003 was classified as a bicycle in US and Canadian traffic law.

Both types can enhance the mobility of the elderly, and when used by the able bodied are practical substitutes for many car trips of less than 10 km. This paper describes their development and their use.

2. Why Solar Powered Mobility?
Roland Reichel, Bundesverband Solarmobil e.V. (German Solar Car Federation)

Abstract

The emission due to traffic causes considerable problems mainly in urban areas. Here “zero emission vehicles” could be a solution by avoiding any direct pollution. The German Solar Car Federation demands “Real Zero Emission Vehicles” and defines this as vehicles with a clean energy supply from solar, wind, water or similar sustainable and clean power sources. The solar power supply is feasible for so-called “LEMs” (light electric mobile) with low power requirements. LEMs require typically less than 10 kWh per 100 km. Some models are available in the market, and the energy can be supplied by the so-called “solar-net”. The solar-net consists of solar power stations feeding the energy into the grid and charging stations for recharging the vehicles batteries. This idea or model is the basis for the “Park & Charge®” system of public charging stations for electric vehicles, which at present exists in Switzerland, Germany, Austria, France and Italy.

3. How to convert an electric scooter to a solar scooter?
From ecoGizmo by Donald Dunklee

The basic bike is a stock EVT 4000E available from various dealers around the U.S. The rest of the system consists of a Xantrex (formerly Trace) C-40 charge controller, and 4 Atlantic Solar 30 watts, 16 X 25 inch panels mounted two to a side. The panels fold open while in charging mode and are closed while driving. Mounting hardware is basic off the shelf parts available from any hardware store. The design criteria were simple. The bike needed to be able to be self contained, that is all charging from the sun, but still allow the factory charger to be used if needed.

Any modifications needed to fit within the capacities listed and approved by D.O.T. and should be safe as well as functional. The panels needed to be foldable so they are out of the way of lighting, seating, and protected from road hazards. The panels needed to be clear of shadowing obstructions from the bike when folded out into the charging position and at a good angle for the three seasons a bike can be ridden in Michigan. All parts needed to be “off the shelf” to keep this D.I.Y. user friendly. The system operates at 48 volts.

4. AltCar 2008: Prometheus’ solar-powered electric motorcycle by Jim Corning

This model is called the Prometheus and it was sent to us by the guys at Ecoblog.it. Designed by Prometheus Solar LLC and shown at the Alt Car Expo in Santa Monica (alternative cars show), this motorcycle runs off four big solar panels, strategically placed. The Prometheus adopts lithium phosphate batteries of 4.6 kWh and is connected to an electric Perm PMG 132 engine from Thunderstruck Motors.

5. The SunRed Solar-powered motorcycle

The recipient of the Best Innovative Technology award at the Barcelona Int’l Auto Show, this does look pretty cool and anything that is good to the environment and can be classed as gadget or latest technology is good in my books. This SunRed project in the near future will result in a life-size prototype of the solar-powered motorcycle, the prototype will be able to store electrical power from captured sunlight and power the motorcycle in the most environmentally-friendly way.

The clamshell looking motorcycle is built that way to optimize the panel’s surface and to make the vehicle not too bulky. The SunRed solar-powered motorcycle is not moving it can store energy for up to 20km (13 miles) and travel at around 50km/h (30 mph). Most modern electric bikes are designed in the same way as the motor on this solar-powered motorcycle; it is placed right in the axle of the wheel and brushless.

6. Determining the Optimum Tilt Angle and Orientation for Solar Energy Collection Based on Measured Solar Radiance Data Danny H.W. Li and Tony N. T. Lam Building Energy Research Group, Department of Building and Construction, City University of Hong Kong

Abstract

A prior requirement to the design of any solar-based conversion systems is the knowledge of optimum orientation and tilt surface at which peak solar energy can be collected. In many parts of the world, however, the solar radiation data for the surfaces of interest are not always available. This paper presents a numerical approach to calculate the solar radiation on sloped planes by integrating the measured sky radiance distributions.

The annual total solar yield at different sloped surfaces facing various orientations and monthly solar radiations at the optimal tilt surface and three vertical planes facing east, south, and west were determined. The energy outputs and efficiencies were simulated using a computer package. The environmental benefits in terms of greenhouse gases reductions and cost implications were also considered. The findings provide technical information for engineers to design and evaluate photovoltaic (PV) systems which could contribute to the environmental, energy, and economic aspects.

PROJECT DESCRIPTION

The SOLAR POWER ASSISTED ELECTRIC SCOOTER consists of mainly a solar power harnessing system, a set of batteries and an electric hub motor. The solar power harnessing system uses 4 solar panels of 20W, 1.35A and 12V rating. The panels used are of the polycrystalline silicon based type. This is positioned at an inclined angle at the front and the rear of the scooter with the aid of a metal frame such that it is exposed to sunlight. This system is coupled with 4 Standard Sealed Lead Acid Batteries each of 12 V rating which acts as the main power source.

The scooter does not have a gear system and the speed control is carried out with the aid of a throttle connected to a controller circuit. We have used to a 48V, 250W Electric Drive Hub motor from the Hero Maxi. The chassis was modified to incorporate the added weight of the solar panel frame and the necessary modifications to the drive system were carried out. The vehicle was then put through a series of tests to observe the variations in mileage. These results were then recorded and the conclusions were drawn.