Report 5 (of 6): Safa Tempos
- Nepal
The Kathmandu Valley is surrounded by hills on all
sides and because of its bowl like topography it is
very susceptible to air pollution. Increasing urbanisation,
industrial activities and automobile traffic all contribute
to air pollution in the valley.
The population of Kathmandu Valley was 577,246 in
1971 and has now increased to approximately one million.
By 2015 it is expected to rise up to levels around
1,800,000 and therefore, the population is increasing
at an annual rate of about 5.7 per cent. As the urban
population grows, it is inevitable that the number
of vehicles will increase to meet the demands of
the people.
In Kathmandu, pollution is most noticeable in the
late spring and early summer months, at which time
haze forms through a combination of dust, household
smoke and automobile exhaust fumes. Increased emission
of automobile exhaust fumes and other urban activities
directly effect the mortality rates in a locality,
at least among the high risk road side residents,
shopkeepers and pedestrians. Petroleum based fuels
mainly generate hydro-carbon, carbon-monoxide, carbon-
dioxide, oxides of nitrogen, lead, sulpur-dioxide
and other suspended particles which are hazardous
to health and can cause chronic lung diseases such
as bronchitis and asthma, as well as irritation of
the respiratory tract, throat and eyes.
Simple observation reveals that much urban air pollution
in Nepal, particularly in the Kathmandu Valley, is
caused by vehicular emissions. The age and condition
of vehicles appears to be a key factor to the contribution
of exhaust emission problems and the quality of fuel
is also significant.
More than 38 per cent of the entire Nepalese transport
fleet consists of three wheelers, i.e. tempos, and
motor cycles, both of which are mainly used in the
commercial or public transport sector. These vehicles
tend to be badly maintained and often use adulterated
fuels. The use of low quality fuel coupled with poor
maintenance habits, which are partly attributed to
the sparse availability and high cost of spare parts,
results in the incomplete combustion of fuel. The
excessive exhaust emissions which are produced contribute
to a substantial increase in air pollution and consequently,
the deterioration of the atmosphere. Electric vehicles
In order to try and reduce the problem of air pollution
from vehicle exhaust emissions, two companies in
Nepal have developed environmentally sound tempos
which operate on batteries. The electric tempos cost
the same to produce as the diesel or petrol ones.
Electric tempos use three batteries as their source
of power which need recharging every sixty kilometres.
Each battery takes six hours to recharge and therefore
almost twenty four hours is needed before the electric
tempo can operate again after its batteries have
run down. Despite this, an electric tempo has the
advantage of having very few moving parts and an
electric motor can last several years without any
maintenance.
NEVI
Nepal Electric Vehicle Industry, NEVI, which was
established in March 1996, manufactures and operates
electric vehicles (figure 1). It aims to promote
electric vehicles based on clean, renewable hydro-electric
power, as the appropriate means of transportation
for Nepal and thereby reduce the country's atmospheric
pollution as well as its dependence on imported fossil
fuel.
Figure 1: NEVI's Safa Tempo - a non-polluting electric
vehicle
EVCO
The Electrical Vehicle Company, EVCO, manufactures
three wheeler electric vehicles (figure 2). The chassis
of the electric vehicles are manufactured by Scooter
India Limited, Luckhnow and are claimed to be amongst
the toughest ever made in India. All the electrical
components used are manufactured in the UK or USA
and the motor specifically designed to carry heavy
loads is manufactured by the Prestolite Company.
Electrical Equipment
The battery used is the Trojan T 105 which is made
in the USA and is of the deep cycle lead/acid type.
Ordinary vehicle batteries are quickly damaged if
they are fully discharged very often but the deep
cycle type is designed to withstand regular discharge.
They have a life span of about 700 to 750 complete
charge and discharge cycles. Each battery produces
6 volts so that the twelve batteries provide a total
of 72 volts. A fully charged set of batteries will
drive the electric vehicle for a maximum of sixty
kilometres.
In order to provide an operating voltage of 12 volts
and, at the same time, provide the fairly high (15
amp) current needed by the motor, a DC to DC converter
is used to reduce the storage voltage from 72 volts.
The converter results in lower losses than would
be experienced of resistors were used. A transistorised
speed controller system is employed in order to minimise
losses in this area and to extend the running time,
therefore, reducing operating costs.
An indicator lamp keeps the operator informed of
the state of charge of the batteries as it is important
that the batteries are recharged before they are
more than 80 per cent discharged. The indicator lamp
flashes when 70 per cent discharge is reached and
then remains on when the battery level falls to the
danger level.
All the lighting - front head lights, parking lights,
front indicators, side indicators, brake lights and
tail lights - run on the 12 volt circuit.
Specifications of Electrical Vehicles
Overall length 3200mm
Overall height 1600mm
Overall width 1430mm
Minimum turning radius 7000mm
Ground clearance 140mm
Seating capacity Unloaded weight 650kg
Pay load 1000kg
Rear wheel track 1250mm
RAW 700kg
FAW 300kg
Mechanical Equipment
The electric vehicle only needs one gear because
the maximum speed it can travel at is between 30
to 35 kilometres per hour. It has two braking devices.
The hand brake which only operates the rear wheels
and the foot brake which controls all three wheels
when the foot pedal is pressed.
The front suspension consists of a rocker arm which
is assisted by two helical springs and telescopic
hydraulic shock absorbers. The rear suspension works
by using longitudinal springs which are assisted
by two telescopic shock absorbers.
The drive is to the rear wheels through the the
differential unit.
Servicing Electric Vehicles
Although the maintenance cost of electric vehicles
is relatively low, the battery, used as a substitute
for fuel, has to be replaced after 750 cycles of
its charging and discharging process. This means
that an electric vehicle can run for up to 45,000
kilometres before the battery needs to be renewed.
Every 1500 kilometres: *check gear box oil *check
differential oil *check brake fluid level in the
reservoir *check and if necessary, adjust brake *grease
the brake and the joints *check steering box *clean
springs and grease all nipples using multi-purpose
grease and suitable grease gun Every 2000 kilometres,
the oil in the sump of the gear box and the differential
oil should be completely drained and replaced with
new oil. The level of the oil can be checked with
a dip stick and should be maintained to the volume
of approximately one litre.
The reservoir for the brake fluid is located on
the front right side of the cabin and the fluid level
should be at the mark shown on the reservoir. If
any part of the system is disconnected, the brake
fluid should be completely drained and replaced.
For further information on the electrical tempos
please contact:
PO Box 9219 Bhat Bhateni Kathmandu Nepal
Tel/Fax: 977-1-420 670
E-mail: EVCO
|
Related
Links 
