Structural Design of the mCCHP-RES System - Design for Micro-Combined Cooling, Heating and Power Systems - page 185

Table 18 Standard values for battery sizing [ 18 ]
Battery
voltage

Battery
capacity (A h)

Average
consumption (kW)

Estimated time
for recharging (h)

Duration of the energy
delivering for a fully
charged battery (h)

48 V 600 0.5 9.5 35

1 5.5 19

2 3 10

4 1.5 4

6 1 2

48 V 800 0.5 13 48

1 7 26

2 4 14

4 2 6

6 1.2 3.5

48 V 1000 0.5 16 57

1 9 29

2 5 16

4 2.5 8

6 1.5 4.5

where:
E is the total annual energy used for lighting, (kWh/year);

floor area of the building, (m 2 ).

A is the total

Determination of dependency factors

constant illuminance factor F C . The constant illuminance factor is the ratio of
the average input power over a given time to the initial installed input power to
the luminaire. Normally, the time is taken to be the period of one complete
maintenance cycle. Therefore:

￿

Fc ¼ ð 1 þ MF Þ= 2 ð 44 Þ

where
MF is the maintenance factor for the scheme.
All lighting installations, from the instant they are installed, start to decay and
reduce their output. In the design of the lighting scheme the decay rate is
estimated and applied in the calculations known as the Maintenance Factor
(MF). The maintenance factor is the ratio between maintained illuminance and
initial illuminance. Its value is dependent value by time in use (hours) having
0.9 value for 3,000 h of the time use and 0.8 value for 6,000 h of time use. In
installations where a dimmable lighting system is provided, it is possible to
automatically control and reduce the initial luminaire output to just provide the