Page 86 - GRIHA Manual Volume II - Introduction to National Rating System
P. 86
78 GrIha Manual: Volume 2
Step 2
lighting controls: Ensure that all outdoor lights are fitted with automatic ‘on’ ‘off’ controls.
Step 3
Solar-powered light: List all the outdoor lamps and using detailed lamp specifications; add up
loads of all the lamps. This will be the total connected load of all outdoor lighting. Calculate 15% of
this total load. From the list of all exterior lamps calculate 25% of the total number and add up the
load of this number of lamps.
Compare the two values calculated above and ensure that the higher load value (15% of total
connected load of outdoor lighting or 25% of the total number of outdoor lights) is powered by
solar energy.
Note While calculating the load of 25% of the total number of lamps, which all lamps to be included in the calculation, is at the discretion
of the project team. There may be lamps with different wattages and depending on which types of lamps are considered for calculation,
the load value will vary.
example
Table 3 Format for solar lighting load calculation
S No. Lighting Type Number of ixtures Wattage of lamp (W) Ballast power losses (W) Total wattage (kW)
A-1 Gate light 9 70 15 0.765
A-2 Street light 103 150 21 17.613
A-3 Landscape light 30 70 15 2.55
A-4 In ground tree uplighter 64 70 15 5.44
A-5 Parking post top 41 70 15 3.485
A-6 Tube lights in parking 23 28 2 0.69
Total 270 30.543
Calculations for outdoor lighting to be powered by solar energy.
15% of 30.543= 4.58 kW (load)
25% of 270 = 68 (number of fixtures)
In the example given above load of 25% of the fixtures can be calculated in many different ways.
Given below are a few examples.
Option 1
Lighting type Number of ixtures Wattage of lamp (W) Ballast power losses (W) Total wattage (kW)
Inground tree uplighter 4 70 15 0.34
Parking post top 41 70 15 3.485
Tubelights in parking 23 28 2 0.69
Total 4.515
Option 2
Lighting Type Number of ixtures Wattage of lamp (W) Ballast power losses (W) Total wattage (kW)
Landscape light 30 70 15 2.55
Street light 38 150 21 6.498
Total 9.05
Step 2
lighting controls: Ensure that all outdoor lights are fitted with automatic ‘on’ ‘off’ controls.
Step 3
Solar-powered light: List all the outdoor lamps and using detailed lamp specifications; add up
loads of all the lamps. This will be the total connected load of all outdoor lighting. Calculate 15% of
this total load. From the list of all exterior lamps calculate 25% of the total number and add up the
load of this number of lamps.
Compare the two values calculated above and ensure that the higher load value (15% of total
connected load of outdoor lighting or 25% of the total number of outdoor lights) is powered by
solar energy.
Note While calculating the load of 25% of the total number of lamps, which all lamps to be included in the calculation, is at the discretion
of the project team. There may be lamps with different wattages and depending on which types of lamps are considered for calculation,
the load value will vary.
example
Table 3 Format for solar lighting load calculation
S No. Lighting Type Number of ixtures Wattage of lamp (W) Ballast power losses (W) Total wattage (kW)
A-1 Gate light 9 70 15 0.765
A-2 Street light 103 150 21 17.613
A-3 Landscape light 30 70 15 2.55
A-4 In ground tree uplighter 64 70 15 5.44
A-5 Parking post top 41 70 15 3.485
A-6 Tube lights in parking 23 28 2 0.69
Total 270 30.543
Calculations for outdoor lighting to be powered by solar energy.
15% of 30.543= 4.58 kW (load)
25% of 270 = 68 (number of fixtures)
In the example given above load of 25% of the fixtures can be calculated in many different ways.
Given below are a few examples.
Option 1
Lighting type Number of ixtures Wattage of lamp (W) Ballast power losses (W) Total wattage (kW)
Inground tree uplighter 4 70 15 0.34
Parking post top 41 70 15 3.485
Tubelights in parking 23 28 2 0.69
Total 4.515
Option 2
Lighting Type Number of ixtures Wattage of lamp (W) Ballast power losses (W) Total wattage (kW)
Landscape light 30 70 15 2.55
Street light 38 150 21 6.498
Total 9.05
