Bangladesh Power System Peak Demand Shaving through Demand Side Management of the Battery Operated Easy Bike Load

Abstract

Electric vehicle (EV) charging is an important contributor to the peak load of a power system. A survey carried out by the author shows addition of significant load to the grid during peak hour due to the plugging in of battery operated three-wheel ‘easy-bike’ for their charging. Demand side management involves changing energy use habits of
consumers, and this can be adopted to shift pattern of connecting EVs to the grid so that no vehicle is connected and charged during peak hours. The other way to solve the issue is to use technology to compel the EVs to be charged during off peak hours. In this paper a suitable technique of Demand Side Management has been proposed to mitigate the problem.

Full text

4th International Conference on Electrical Information and Communication Technology (EICT), 20-22 December 2019, Khulna,
Bangladesh
Bangladesh Power System Peak Demand Shaving
through Demand Side Management of the Battery
Operated Easy Bike Load
Md Rezaul Awal,a,* A K M Nazrul Islam,a and Md. Ziaur Rahman Khanb
a Department of Electrical Electronic and Communication Engineering, Military Institute of Science and Technology, Dhaka-
1216, Bangladesh
b Department of Electrical and Electronic Engineering, Bangladesh University of Engineering and Technology, Dhaka-1205,
Bangladesh
*rezaul_awal_maj@yahoo.com
Abstract— Electric vehicle (EV) charging is an important
contributor to the peak load of a power system. A survey
carried out by the author shows addition of significant load to
the grid during peak hour due to the plugging in of battery-
operated three-wheel ‘easy-bike’ for their charging. Demand-
side management involves changing energy use habits of
consumers, and this can be adopted to shift pattern of
connecting EVs to the grid so that no vehicle is connected and
charged during peak hours. The other way to solve the issue is
to use technology to compel the EVs to be charged during off-
peak hours. In this paper a suitable technique of Demand Side
Management has been proposed to mitigate the problem.
Keywords—Bangladesh National Grid, Daily Load Curve,
Demand Side Management, Easy Bikes, Electric Vehicles, Timer
Control
I. INTRODUCTION
Electric vehicles (EV) such as motorized three-wheelers
vehicles and rickshaws, commonly known as Easy Bikes
(EB), have started to dominate the transportation sector of
Bangladesh in recent past. These vehicles were first
introduced in 2004 and were fully marketed by 2008. Most
of these vehicles are either locally assembled or bought from
china. In many major cities, they are serving as the major
intra-city transport system. These vehicles are rapidly
increasing in number, starting from a few and now there are
about 1 million [1]–[3]
Electric vehicles are equipped with five batteries of
different sizes depending on the type of the vehicle, which
needs to be connected to the grid for charging. Lead-acid
batteries are used as the energy storage device and over 1.9
million batteries are used all over the country every year [4].
Easy Bikes are usually connected overnight and require a
large amount of electrical power to charge, thereby is likely
to have a negative impact on the grid due to its high demand.
Average power consumption of a battery-operated auto-
rickshaw is about 8 - 11 kWh per day [5]–[7]. These vehicles
are interfaced to the grid as active loads in an uncontrolled
way. No specific measures are taken to ensure the vehicles to
be appropriately connected to the electric grid.
Due to the rapid economic growth the electricity demand
has increased significantly in recent time. This has put
pressure on the distribution network which has been the
major contributor in load shedding [8], [9]. The Government
has taken massive plan to expand the distribution network.
The demand for electricity in the system varies throughout
the day and night with maximum demand occurring from 5
pm to 11 pm as `peak load`. The Easy-bike charging
generally starts during peak hour, thus it affects the peak
demand significantly. The amount of peak load can be
shaved up through demand side management for better
capacity utilization of the power grid [10], [11].
A survey on Easy Bikes has been carried out by the
authors in different cities of Bangladesh to investigate
various technical and economic facts. The impact on
Bangladesh national grid due to energy requirements of an
increased number of unexpected and unaware load of Easy
Bike and its Demand Side Management has been studied.
This paper presents the analysis of the survey, the results of
the study of the effects of EV on national grid and the
technique to manage these load with the timer control
system.
II. FIELD SURVEY ON EASY BIKES
A field survey on Easy Bikes has been carried out by the
authors physically in different cities of Bangladesh to get
proper view of its impact on the daily load curve of national
grid. More than 200 Easy Bike was surveyed. Most of the
vehicles surveyed belong to the first owner, i.e. they are
procured as new vehicles. About one-fourth of the samples
were second-hand vehicles.
The life of a flooded Lead Acid battery depends on the
depth of discharge (DoD) of the battery. As the easy bike
batteries generally has a very high DoD value the cycle life is
considerably lower. The survey shows that majority battery
banks have a life less than 9 months as shown in fig.1.
Fig. 1. Life of Easy Bike Battery.

Fig. 2. Warranty of Easy Bike Battery.
Most of the local battery manufacturer do not offer any
warranty for their battery if used for easy bikes. This may be
due to the inefficient charger and high DoD of the system.
According to the dealers outside Dhaka, some Chinese
manufacturer offers warranty. The survey results show that
majority of the vehicles have battery warranty in the range
of 4 to 8 months as shown in fig. 2. About 55% of the
sample does not have warranty for their battery bank.
Though the dealers offer a warranty, the users also
expressed that it is very difficult to get replacement during
warranty period. The dealers try to repair the used battery
instead of replacing it. Because of the large number of
vehicles, there is a huge demand for battery in the market.
The batteries are of 180AH in capacity according to the
nameplate data and each Easy Bike has five of them. The
cost of five batteries is around BDT 40,000.00 to 60,000.00.
There is a value of the old or damaged battery and generally
the value of such battery bank ranges from BDT 15,000.00 to
20,000.00 and they can be sold directly to the battery seller.
In this section, a detailed analysis of the field survey is given.
A. Battery charging and Charger Analysis
Most of the vehicles are charged in the garage. This may
be because of the convenience of the whole system. The
garage does not only provide the charging connection but
also ensure the security of the vehicles. Most of the home in
the rural area does not have sufficient space to store the
vehicles securely. Additionally the guard/caretaker of the
garages also can attend the vehicle in case of some
emergency. The excessive gassing of the battery during
overcharging also makes it inconvenient for charging at
home. The charging cost of the vehicles varies from garage
to garage. Most of the user need to pay BDT 100.00 to
125.00. But the charging rate can be higher than BDT 150.00
as shown in fig. 3.
Fig. 3. Charging Cost of Easy Bikes.
Fig. 4. Easy Bike plug-in time.
The cost is not only for charging the vehicles but also for
ensuring security. The easy bike has a range of more than
100 km in single charging. There are two types of charger
available in the market, one with copper transformer and
another with aluminium transformer. The copper one costs
more. The chargers sometimes get damaged due to
overheating caused by overcharging. The survey data also
shows that a substantial amount of the vehicles need to
procure the chargers separately from the market. Depending
on the quality of the system, the cost of a battery charger
varies from BDT 2500 to 5000.
The current three-wheeler charger technology is very
simple consisting of few power-electronic components. The
charger should be most reliable and long-lasting for them. In
the field of power electronics simplicity begets reliability.
This charger is very simple and reliable, though it suffers
from few problems like overcharging, wastage of energy,
environmental hazard etc. One of the major difficulties of
this charger is that it takes 8 to 10 hours to charge the battery
fully which affects the plug-in and plug-out time.
B. Existing Connecting Pattern (Plug in and Plug out Time)
of Easy Bike
The vehicles are charged overnight, starting to get
connected to the grid by 7 pm and all vehicles connected by
11 pm. From 7 pm to 6 am the next morning a high load is
observed in recent years due to easy bike charging. Most of
the vehicles are plugged out from the grid between 6 am to 7
am. Whereas almost all the vehicles are disconnected by 8
am. Fig. 4 and fig. 5 shows the plug-in and plug-out time of
easy bikes respectively. Table I shows the percentage of
vehicles plugged in to and plugged out from the grid for
charging purpose.
Fig. 5. Easy Bike plug-out time.

TABLE I. PERCENTAGES OF VEHICLES PLUGGED IN AND PLUGGED
OUT FROM THE GRID
Status Time Percentage of
Vehicles
Plug-in EVs
7 pm to 8 pm 20
8 pm to 9 pm 20
9 pm to 10 pm 50
All connected 10 pm to 6 am 100
Plug-out EVs 6 am to 7 am 60
7 am to 8 am 30
Not connected 8 am to 7 pm 100
III. LOAD CURVE AND DEMAND SIDE MANAGEMENT
ANALYSIS
A. Electric Grid Scenario of Bangladesh
Electricity plays a vital role in the economic growth
through sustainable structure as well as poverty eradication
and security of any country. Future economic growth
crucially depends on the long-term availability of electricity,
which is affordable, available and environmentally friendly.
In line with this, Bangladesh is moving ahead extensively to
create sustainable growth of power sector for overall
development of the country economy. Present installed
generation capacity in public, private & import sector is
15,953 MW [12], [13]. Up to date, maximum generation
achieved is 10,958 MW on May 28, 2018 [12]. At present,
90% of the total population has access to electricity and per
capita generation has increased to 464 kWh (including
captive).
The change in the vital parameters of the electrical grid -
installed capacity, maximum demand, maximum peak
generation and maximum load shedding from 2005 to 2018
have been pictured in fig. 6. It is observed that over the last
ten years installed capacity and generation has been
increased. At the same time demand has been increased
significantly. As such, load shedding has never been reduced.
B. Load Curve Analysis
A load curve shows the variation of load on the electrical
power station with respect to time. The generation (in MW)
at every hour can be extracted from the load curve.
Fig. 6. Power and energy generation scenario of the Bangladesh electrical
grid from 2005 to 2018.
Fig. 7. Daily load curve of a day in August 2018.
Important parameters such as average load, maximum
demand, size and the number of generating unit and
operating schedule can be determined from the curve.
Fluctuations in load curves are observed during holidays or
certain circumstances like change in weather or natural
disasters. Fig. 7 shows a daily load curve of a day in 2018.
The daily load curve of a day in 2018 has been plotted for
study and analysis where the peak generation load is 10,862
MW. It is observed that the difference between peak and off-
peak load is almost 3500 MW, which is a large variation.
The load curves are available in Bangladesh Power
Development Board (BPDB) website [14].
There are many reasons for the increase of peak load but
an increase of easy-bikes and motorized rickshaws connected
to the grid for charging is one of the main reasons for raising
peak load. These loads in the system during peak hour can be
avoided or minimized by the consumers if the demand Side
Management is exercised by the authority. In order to shift
these kinds of loads from peak hour to off-peak hour
appropriate authority can motivate, formulate and apply
regulation and introduce mechanism.
C. Load Factor and Load Management
The demand for electricity in the system varies
throughout the day and night. The maximum demand occurs
from 5 pm to 11 pm which is termed as ‘peak hour’ and
another part of the time is termed as off-peak hour. The
extent of this variation is measured in terms of Load Factor,
which is the ratio of average and maximum demand. For
economic reasons, it is desirable to have a higher Load
Factor, as this would permit better utilization of plant
capacity. Moreover, the cost of energy supply during peak
hour is higher, because some relatively more utility appliance
is required to put in operation during the peak hour. For these
reasons, load management is essential throughout the year
for better capacity utilization of power plants and minimum
generation cost.
There are some loads in the system which can be avoided
or minimized by consumers during peak hour. In order to
shift these kinds of loads from peak hour to off-peak hour by
introducing some mechanism is termed as load management.

From the viewpoint of load management, (i) Two-part tariff
is introduced for 3-phase consumers (LT & HT) where peak
hour price is much higher than the off-peak hour that
motivates consumers to avoid or use less in the peak hour;
(ii) Market & Shopping malls are kept close after 8.00 PM;
(iii) Holiday staggering is implemented to keep industries,
markets & shopping malls close on area basis holiday
marked day; (iv) Consumers are encouraged to use energy-
efficient bulb, electric appliances, pumps etc; (v) Consumers
are encouraged to keep their air-conditioners temperature at
25 degrees and so on. These measures also minimize load-
shedding across the country.
D. Demand Side Management
Demand-side management (DSM) modifies energy use to
maximize energy efficiency. DSM tries to get the maximum
benefit out of existing energy generation. DSM involves
changing energy use habits of consumers and encouraging
them for using energy-efficient appliances, equipment etc. at
their premises. To keep load shedding at a minimum level,
BPDB has taken a number of steps for demand-side
management, which are as follows:
 To shift irrigation load from peak hour to off-peak
hour, BPDB has started a campaign through
electronic and print media. In the last few years, it is
estimated that about 500 MW irrigation load was
shifted from peak hour to off-peak hour.
 BPDB has taken motivational programs to enhance
awareness of the consumers during peak hours.
Consumers are being urged through electronic and
print media to be rational and economical in
electricity use during peak hour by switching off
unnecessary loads like extra lighting, ironing, pumps,
air conditioners, welding machines etc. As part of the
demand-side management program, BPDB has taken
steps to use CFL in BPDB's offices and also trying to
motivate consumers to use Energy efficient lamps.
 Industries operating in two shifts are being requested
not to operate during peak hours. Holiday staggering
for industries has been implemented, which
contributes about 200 MW load shifting.
 Load Management Committee has been formed in
every distribution zone/circle/division to monitor the
proper load distribution during irrigation. As part of
DSM, BPDB is monitoring shop/market closure time
at 8 p.m. It is estimated that this measure contributes
about 400 MW [12], [13]. Load shifting from peak
hour thereby reduces load shedding. Table II shows
total load shift from peak to off-peak hour by the
process of DSM.
TABLE II. LOAD SHIFTED USING DSM METHOD
Item Irrigation
(MW)
Industry
(MW)
Shops
(MW)
Total
Load
Shifted
(MW)
Load
Shifted 500 200 400 1100
BPDP is unaware of a load of approximately 700 MW
which is connected to the grid during peak hour due to the
charging of EVs mostly by Easy Bike. If this load is shifted
from peak to off-peak period than peak load period will be
considerably relaxed.
IV. SUGGESTED SOLUTION
Due to the addition of unplanned low priority load, the
peak load has become unmanageable. Demand-side
management is one of the important tools to manage energy
during peak and off-peak hour. If 70% Easy Bike is
connected at a time to the grid out of one million it will add
more than 700 MW of load to the system. It remains unaware
of the authority and needs proper management. As a part of
motivation or regulations BPDB can take a step to shift
pattern of connecting EV to the grid so that no vehicle is
connected and charged during peak hour. The other way to
solve the issue is to compel the vehicles to be charged with
control using technology. Both the solutions are discussed in
this section.
A. Suggested Pattern of Connectivity of EV to the Grid
Most of the vehicles are plying in urban areas and most
of the drivers complete their trips by 7 pm. Thus vehicles are
connected to the grid for charging as soon as they return to
the garage. The government may formulate regulation to
restrict connecting this EV to the national grid during peak
hour. Table III suggests percentage of vehicle to be
connected to the grid to eradicate the problem. In this process
it is assumed that 90% vehicles will be connected by 10:30
pm. Since charging period is almost 8 to 10 hours and due to
the habit of the driver it is expected that 60% vehicles will be
plugged out from charging by 7 am. 30% vehicle may be
plugged out by 8 am. There are some Auto drivers who come
for charging or topping up even in day time, thus provision
to be kept to connect during off-peak hour till 5 pm.
Authority may motivate drivers and encourage them to plug
in their vehicle for charging at off-peak hours and facilitate
in terms of reduced charging cost.
TABLE III. PROPOSED PERCENTAGES OF VEHICLES PLUGGED IN AND
PLUGGED OUT FROM GRID
Status Time Percentage of
Vehicles
Plug-in EVs 10 pm to 10:30 pm 90
10:30 pm to 11 pm 10
All connected 11 pm to 6 am 100
Plug-out EVs
6 am to 7 am 60
7 am to 8 am 30
8 am to 5 pm 10
Not
connected 5 pm to 10 pm 100
B. Controlling the Charging System using Timer Circuit
The timer circuit can be incorporated into the Easy Bike
charging system to limit the charging start time. Easy Bike
drivers after completion of their duty can plug in the vehicle
in their respective garage as usual but timer circuit will
decide the start time of charging. Considering the off-peak
hour and charging period of the charger, start time of timer
circuit can be maintained from 10 pm. In this system there
will be a provision to allow the charging station to plug in
the vehicles during daytime till 5 pm. A restriction will be
imposed for charging between 5 pm to 10 pm.
The timer-circuit can be incorporated in three ways, (i)
Central system with one timer-circuit at the charging station,

Fig. 8. Controlling the Charging System using Timer Circuit.
(ii) Central system with one timer-circuit at the charging
station and individual relay coil at the charger (iii)
Staggered system with individual timer to the charger. There
are advantages and disadvantages of all the three systems. If
the system is centrally controlled all the vehicle will be
charged simultaneously creating huge imbalance in load. To
Fig. 9. Charging System Control Algorithm.
minimize this, individual relay coil may be introduced to the
chargers. In this case control is dependent on charging
station as well as individual charger. If the timer circuit is
set to individual charger with random generation number
then the load can be staggered and controlling will be easier.
It will be programmed to add all the vehicles to the charger
within 15 to 30 minutes from start time to facilitate
generating random number and connect the vehicle in
staggered time. In this case authority will have to ensure that
drivers purchase charger with timer circuit. Fig. 8 and fig. 9
shows the timer circuit and the algorithm of the timer circuit
for staggered connection respectively.
V. RESULTS AND DISCUSSIONS
The electrical grid of Bangladesh needs to adapt to
address the effect of electric vehicles. According to the
analysis of the pattern of connection, if all the EVs are
connected to the grid after 10 pm a significant reduction in
peak load can be ensured. It is expected that 70% of the total
Easy Bike is connected to the grid and with average
consumption of 1 KW by one Easy Bike highest 700 MW
load can be shifted from peak hour to off-peak hour in this
process. By controlling the charging system with the timer
control circuit the load shifting amount can be estimated
using the data in table I and table III. Table IV shows
percentage and total load shifted from peak to off-peak hour.
TABLE IV. PERCENTAGES OF LOAD SHIFTED FROM PEAK TO OFF-
PEAK HOUR
Time Load, % Total Load
(MW)
Load shifted from 7 to 8 pm 20 140
Load shifted from 8 to 9 pm 40 280
Load shifted from 9 to 10 pm 90 630
Load shifted from 10 to 11 pm 50 350
Load added from 6 to 7 am 20 140
Load added from 7 to 8 am 40 210
Load added from 8 to 9 am 40 210
The analysis shows that the peak load has been shifted
significantly from peak hour to off-peak hour. Fig. 10 shows
Fig. 10. Load shifted from peak to off-peak hour using Timer Circuit.

the graphical representation of load shifting due to timer
control management. It can be observed from table IV as
well as from the graph that maximum 630 MW of load has
been reduced in the time range of 9 pm to 10 pm due to the
shifting of the charging load using timer control system. It is
also observed from the graph that the peak load has been
reduced significantly using timer control system. The load,
which has been added to the off-peak hours due to the
shifting of charging load using timer control system, mostly
from 6 am to 9 am does not pose any negative effect to the
power grid.
Since charging will start at 10 pm, as such, drivers can
plug out the vehicle in the morning in a convenient time,
thus overcharge will not create overheat and gassing of the
battery can be avoided. Again, due to the control charging
system, safety and security can be better maintained.
VI. CONCLUSIONS
In this paper, an inclusive study has been carried out on
the effect of EVs on the Bangladesh national power grid. A
huge load is consistently observed at night from 7 pm to 6
am the next day due to the integration of a dominant load
like EV charging, which is approximately 700 MW during
peak hours. A physical survey has been carried out for an in-
depth analysis of the effects of Easy Bikes. Various
important technical facts and problems were discussed,
especially on Easy Bike battery charger and charging system.
Demand-side management was addressed to find out the
peak demand shaving of the load. To reduce the impact of
the battery operated vehicle on power grid a timer control
mechanism has been developed. A substantial amount of
load was considered can be shifted from peak to off-peak
hour if the mechanism is executed.
REFERENCES
[1] Z. Rian and A. N. M. M. Rahman, “Study on Power
Consumption and Social Aspects of Battery Operated Auto-
rickshaw,” 2014.
[2] R. Planning, “Evaluating the Socio-Economic and Environmental
Impact of,” no. February, pp. 1–7, 2018.
[3] “Electricity-Run Vehicles: Govt to bring them under regulation.”
[Online]. Available:
https://www.thedailystar.net/backpage/news/electricity-run-
vehicles-govt-bring-them-under-regulation-1667641. [Accessed:
22-Sep-2019].
[4] M. Iqbal, “Study on Merits and Demerits of Two Transport
Systems: Battery Operated Easy Bike with CNG Operated Auto
Rickshaw at Sylhet City in Bangladesh,” IOSR J. Mech. Civ.
Eng., vol. 5, no. 5, pp. 25–32, 2013.
[5] “Govt To Set Up 6 Solar Charging Stations For Easy-Bikes -
Energy Bangla.” [Online]. Available:
http://energybangla.com/govt-to-set-up-6-solar-charging-stations-
for-aasy-bikes/. [Accessed: 20-Sep-2019].
[6] S. Mandal, S. Ahmed, and F. Rabbi, “Impact of battery driven
vehicle on the electricity of Rajshahi city, Bangladesh,” vol.
2015, pp. 11–13, 2015.
[7] S. Islam and M. Z. R. Khan, “A Review of Energy Sector of
Bangladesh,” Energy Procedia, vol. 110, no. December 2016, pp.
611–618, 2017.
[8] R. Kawamoto et al., “Estimation of CO2 Emissions of internal
combustion engine vehicle and battery electric vehicle using
LCA,” Sustain., vol. 11, no. 9, 2019.
[9] “PDB for bringing battery-run vehicles under tariff regulations |
Dhaka Tribune.” [Online]. Available:
https://www.dhakatribune.com/bangladesh/power-
energy/2017/09/27/pdb-bringing-battery-run-vehicles-tariff-
regulations/. [Accessed: 16-Sep-2019].
[10] J. Lubna, “Cohesive City and Urban Informality : Battery-bikes
in Khulna City,” pp. 1–6, 2014.
[11] M. A. Hil Baky, M. M. Rahman, and A. K. M. S. Islam,
“Development of renewable energy sector in Bangladesh: Current
status and future potentials,” Renew. Sustain. Energy Rev., vol.
73, no. January, pp. 1184–1197, 2017.
[12] D. Board, “2016-17 Bangladesh Power Development Board
Bangladesh Power Development Board,” 2016.
[13] D. Board, “2017-18 Bangladesh Power Development Board
Bangladesh Power Development Board,” 2017.
[14] “Bangladesh Power Development Board.” [Online]. Available:
http://www.bpdb.gov.bd/bpdb_new/index.php/site/daily_generati
on. [Accessed: 03-Sep-2019].