FABRICATION OF SOLAR BICYCLE

Guide: Submitted ByMr. Sunil Kumar Sumit Shahi Aviral Sharma

Bhuvnesh VarshneyAnkur Rajput Vipin Shahi

Kushagra Srivastava

Content• Introduction• Objectives• Methodology• Details of Component

a)DC Gear Motorb)Solar Panelsc)Sealed Lead Acid Battery(SMFB)d) Throttle

• Assembly of Component• Connection of Components• Problem aroused and their solutions• Analysis• Life of Set-Up• Future Aspects• Advantages• Conclusion

Introduction•The depleting reserves of fossil fuels made the engineers and scientists to look for renewable energy sources. India is spending large amount of foreign exchange to import crude oil even though we have abundant resource of solar energy. If we utilize solar power for local conveyance, a large amount of currency can be saved and we can also ensure pollution free environment and contribute to nation’s economy.•The general mode of transportation for local trip (with in a range of 5 km) is a bicycle, motor cycle or electrical bicycle. Bicycles are the cheapest healthiest and eco-friendly but poses problem in climbing slopes. Motor cycles are not affordable to poor people and with the rising fuel prices and pollutions; it does not seem a suitable option.•Hence a bicycle which can be peddled as well as run on solar powered battery seems to be suitable option to solve the issues.

Objectives• In human transportation as a personalized vehicle.• For inter departmental transportation in huge campuses.• In industries for different level personnel to move around to inspect the

work progress.• In hospitals, Airports, Shopping malls, IT campuses, Hotels &resorts, Power

stations, manufacturing units, etc.• Light weight & easy to control, makes convenient for use by anyone.• Controlled speed ensures rider’s safety.• Can be used by old aged demography.• On site charging facility. No need to visit fuel station.

Methodology• Firstly the DC Gear motor was connected to rear wheel through chain

drive, which is fitted on seatstay through nut and bolts on iron strips welded to seatstay.

• The fabrication was carried out keeping in mind the maximum load the motor will be able to withstand.

• Edge grinding was done to provide smoother surface finishing on freewheel and iron strips.

• Welding to join the freewheel to DC motor shaft.• All the fabricated parts were assembled.• The throttle is powered by batteries which are fitted on the handle.• The throttle gets powered through battery and sends signal/ output to the

DC Gear motor.

A. DC Gear Motor• Geared DC motors can be defined as an extension of DC motor which already had

its Insight details. A geared DC Motor has a gear assembly attached to the motor. The speed of motor is counted in terms of rotations of the shaft per minute and is termed as RPM .The gear assembly helps in increasing the torque and reducing the speed. Using the correct combination of gears in a gear motor, its speed can be reduced to any desirable figure. This concept where gears reduce the speed of the vehicle but increase its torque is known as gear reduction.

• gear motor adds mechanical gears to alter the speed/torque of the motor for an application. Usually such an addition is to reduce speed and increase torque. A DC motor without gears is useful in many applications, for example the simple fan. Contrast that with the motor that operates the turntable in your microwave, a gearbox there reduces the speed so your food isn't thrown against the interior wall.

Table 1: Specifications of Gear Motor

S.No

Details

1. Length 160mm

2. Shaft Diameter 6mm

3. Voltage 24V

4. Weight 2.5 Kg

5. RPM 72 RPM

B. Solar Panels

• Light striking a silicon semiconductor causes electrons to flow, creating electricity. Solar power generating systems take advantage of this property to convert sunlight directly into electrical energy.Solar cells convert the energy of sunlight directly into electricity through the use of the photovoltaic effect. The photovoltaic effect involves the creation of a voltage into an electro-magnetic radiation.

• There are two types of solar power generating systems: grid-connected systems, which are connected to the commercial power infrastructure; and stand-alone systems, which feed electricity to a facility for immediate use, or to a battery for storage.

• Grid-connected systems are used for homes, public facilities such as schools and hospitals, and commercial facilities such as offices and shopping centers.

• Stand-alone systems are used in a variety of applications, including emergency power supply and remote power where traditional infrastructure is unavailable.

Table 2: Specifications of Solar Panel

Fig : Solar panel

S. No

1 Maximum Power(Pmax) 20W

2 Voltage at Pmax 17V

3 O.C Voltage 12V

4 S.C Voltage 1.2A

5 NOCT 45

C. Sealed Maintenance Free Battery(SMFB)• Sealed Maintenance Free Battery is a type of lead acid

rechargeable battery. They are widely used in large portable electrical devices Batteries are used for storage of electrical energy. Since the batteries are high in Capital cost it is necessary that overall system be optimized to be economically attractive, the storage Batteries with particular combination of properties:

Fast and Efficient Charging. Very Little Wasted Energy. Long Life, Improved Safety,High Reliability, High Efficiency.• It demands for a battery with longer running hours. Among all

the existing rechargeable battery systems, the lead acid cell technology is the most efficient and practical choice for the desired application. Plastic casing is provided to house the internal components of the battery.

Fig 5:Lead Acid Battery

S. No

1 Type of Battery SMFB

2 Size(lxbxh) 150x60x90

3 No of Batteries 2 batteries connected in series

4 Voltage 12V (each)

5 Amp Hr 7.2 Ah(each)

SMFB

D. Throttle

• The maximum speed of a bicycle will be 10 km/h. It is required to vary the speed depending upon the road conditions & traffic. Therefore an accelerator or a throttle is necessary. Throttle allows us to drive the motor from zero speed to full speed..

• The throttle is fitted on right side of the handle bar and is connected to controller. The throttle converts DC voltage from battery to an alternating voltage with variable amplitude and frequency that drives the hub motor at different speeds.

• It consists of MOSFET transistors and a small microprocessor. This throttle is technically referred to as a Hall Effect type.

• The throttle has three wires contains a black, red, and green. The supply voltage is via red and black wires and is usually around 4 volts. Green wire voltage increases as the throttle is turned.

Table 4: Specifications of a Bicycle

Drive Dual Powered ( Motor and Pedal)

Weight 30 Kg

Riders Weight

80 Kg

Load Capacity

110 Kg

Assembly of Components• We installed the motor on the rear wheel of the bicycle by chain. The

bicycle rim diameter 0.52m. For connecting the motor to the hub of wheel, we had to make some adjustments of motor to fit on bicycle through chain.

Motor Assembly

Battery Assembly• The batteries have to fit them in way that balancing doesn’t get

disturbed, so we decided to put them in the frame of the bicycle as low as possible. We made a stand for carrying the batteries and for providing side support we made side covers.

Connection of Components

Problems Aroused And SolutionsMOTOR AXIS ALLIGNMENT

• The axis of motor’s freewheel and freewheel of rear wheel was difficult to make on a straight line. For that we have fitted washers on rear wheel axle before the joining of seat stay end to the axle so that there should be minimum gap for rotation of chain. Also the motor is bolted to two strips of flat plate of iron which is welded to seat stay such that the axis of both the freewheel should lie in a straight line.

MATERIAL SELECTION FOR LINKS• The material selection for the linkages for assembly of the battery was

very important as the weight of bicycle was a main concern for us. Therefore, we selected Iron strips (width: 2cm, height: 0.6 cm) for the linkages. Iron pipes were best suited for us because strength, weight and cost were our concern.

AnalysisMAXIMUM SPEED

• For determining the speed of our cycle we used a speedometer. We took the reading in mps (meter per second) in no load condition, which came out 2.77 mps, which is equal to 10km/hr.

RANGE• For determining the range of the cycle we have tested the cycle on the college

ground with the load of 110kg. The bicycle gave a test performance for 2 hours with 2 fully charged batteries.

• The bicycle covered a distance of 30km with a speed of 10 km/hr.CHARGING TIME

• The batteries are of 12V, 7.2Ah and the current supply for charging them is about thus the time required to charge a fully discharged battery will be 4 hrs.

BATTERY LIFE• The batteries are 2-3 years or 300 to 500 charge cycles maintenance free

whichever occurs first. One charge cycle is a period of use from fully charged, to fully discharged, and fully recharged again

MAXIMUM CARRYING CAPACITY• We assumed in the calculation that the weight of the cycle with the rider is110kg.

The total weight of the cycle is 30kg. Weight of the cycle (without any assembly) = 20kgWeight of the battery=2.5 kgWeight of motor= 2.5 kgWeight of all linkages= 5 kg

• Total weight of the cycle (20+5+2.5+2.5) kg= 30 kgMaximum Speed : 10 km/hrRange : 30 kmCharging Time : 4 hoursBattery Life : 2 yearsRunning Cost : NilMax. Carrying Capacity : 80 kg

COST ANALYSISMAINTENANCE COST

• The only maintenance in the bicycle is of the batteries and the life of batteries is 2-3 years, they can be replaced with new ones.The cost of batteries after 2 years = Rs 500 The cost of new batteries = Rs 1800Thus the effective cost of new batteries will be Rs (1800-500) = Rs 1300Thus the maintenance cost =Rs 1300/ (2x365) =Rs 1.7/day

Cost AnalysisS. No Item Description Amount(Rs.)

1 Solar panel 20 W 2500/-

2 Motor 24V 2000/-

3 Sealed lead acid batteries 2x12V, 7.2Ah each 1800/-

4 Cycle 3000/-

5 Manufacturing of Links 1000/-

6 Wires, Capacitor, Throttle 100/-

7 Soldering 100/-

8 Chain Drive 200/-

9 Transportation 2000/-

Total 12700/-

Life of Set-Up

• The majority of manufacturers offer the 25-year standard solar panel warranty, which means that power output should not be less than 80% of rated power after 25 year.

• The rated power output of solar panels typically degrades at about 0.5%/year.

• The Maintenance of SMFB is after 3 years.

Future AspectsUSE OF FLEXIBLE SOLAR PANEL

• The flexible e solar panels are also available in the market. Flexible solar panels can be very suitable for the project as these can be used as a solar coat for the driver.

SOLAR PANEL ON THE WHEEL RIM• If the solar panel gets fitted onto the wheel rim then it will be helpful for

our project because of their ease in balancing and good looking design. As shown in the figure the solar panel can be fitted onto the rim without using extra space for the solar panels.

Advantages• More economical than fuel-powered cars and motorcycles, and cheaper

than buying an electrical vehicle for the city.• No contamination, forget about CO2 emissions!• The type of terrain or the distance, the electrical bike can be more

comfortable since it allows the rider to cover more distance or climb hills when more moderate physical exercise is required.

CONCLUSION

• It’s going to be a cheap alternative for the commuter. Most people, on their drive to work, go less than 40km. Its cleaner and you never have to buy gas or change the oil. Thus leading to a pollution free environment.

• This bicycle is cheaper, simpler in construction & can be widely used for short distance travelling especially by school children,college students, office goers, villagers, postmen etc. It is very much suitable for young, aged, handicap people and caters the need of economically poor class of society.

• The most important feature of this bicycle is that it does not consume valuable fossil fuels thereby saving crores of foreign currencies.

• It is eco-friendly & pollution free, as it does not have any emissions.