Diesel saving calculation:Average per day grid power
availability at different regions of India is shown in the figure
below:
Figure 1: Average per day Grid Power availability by regions in
IndiaFrom the figure shown above, we can conclude that on an
average, grid power is available for 16 hours/ day in a rural
telecom center in the form of single-phase, two-phase, and
three-phase. Therefore power outage per day is approx. (24-16) = 8
hours in rural areas of India.In a day, if 100 faults occur in a
power system, a three-phase fault(total outage) is expected to be 5
times, a two-phase fault is expected to be for 25 times and a
single phase fault is expected to be for 70 times. Therefore, in a
given day, single-phase input is expected for 25% of the time and
two-phase input is expected for 70% of time. Based on these fault
patterns a very conservative estimation of diesel saving is given
below: Grid power is available for 16 hours /day in rural telecom
centre in the form of three-phase, two-phase and single phase From
a 16 hours/day supply, let us assume that that all three phases are
available for 10 hours/day. That means, for the rest 6 hours either
single-phase or two-phase power is available. So any saving of
diesel will be in these 6 hours. Power Supply De-rating: Under
two-phase condition the power rating is (0.8*Full Load) and under
single-phase condition the power rating is (0.5*Full Load). Present
Diesel Requirement for a exchange with three phase power supply: DG
set requires Z liters/hour for a full load operation of the
exchange (24-10)=14 hours DG set has to work that demands (14*Z)
liters of diesel New Power supply Technology Diesel Requirement:
Diesel Requirement with two-phase power
available=(0.736*6*0.2*Z)=(0.884*Z) liters Diesel requirement with
single-phase power available=(0.264*6*0.5*Z)=(0.79*Z) liters Total
Diesel Requirement with the new power supply=(8*Z+0.884*Z+0.79*Z)
=9.674*Z liters Total % Diesel Saving: Total % Diesel saving =
*100%=30.9%
Figure 2: Grid availability in a rural plant based on assumption
that 16 hours/day power is availableSo, percentage diesel saving is
a function of per day power outage, per day three-phase, two-phase
and single-phase power availability. Following graphs illustrate
the effect of variation of these parameters on diesel saving:
Figure 3: Variation of percentage diesel saving with three-phase
power availability at constant power outage of 8 hours
Figure 4: Variation of Percentage Diesel Saving with Power
Outage at constant three-phase power availability of 10 hoursEffect
of Diesel Saving:
