Page 247 - Shaping A Sustainable Future

Savings Due to LED Lightings

Items Savings
1 SP group with GST included Electricity 20.97 cents/kWh (w GST)
2 Water $1.29 or $1.63/m³ (w GST) based on < 40 m³ or > 40 m³
3 ef, emission factor in Singapore 0.4188kg
4 CO (kg) kWh x ef
2

Table 13: Reference factors for calculating savings.

Power Per month: = 9.516 kW x 12 x30 = 3,426 kWh
Carbon emission: = 0.4188 x 3,426 = 1,435 kg CO
2
Cost per month = 3,426 x $0.2097
= $718.4
Brightness per Tungsten Halogen lighting 4,000 lumens
Total Brightness for 38 pieces of Tungsten Halogen lightings 152,000 lumens

Table 14: Energy usage of 38 Tungsten Halogen Lights.
Replacement LED lightings

Brightness per LED lighting 12,000 lumens. Hence, need about 13 LED lightings (152,000 / 12,000 ≈ 13).
LED lightings at 150W (x13) 1.950 kW
LED Power per month = 1.95 x 12 x 30 = 702 kWh
LED Carbon emission = 0.4188 x 702 = 294 kg CO
2
LED Power Cost per month = 702 x $0.2097
= $147.2

Table 15: Energy usage of proposed LED lights.

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