Power Consume and Electricity Bill for Dimming and Non-Dimming Ballast for Street Lighting System

In one of my projects which due to the cost saving, the Owner having an intention to use the dimming ballast for their street lighting system.

I've been asked to come-up with a report on the cost saving that the Owner will get also to calculate the payback time using the dimming ballast system.

Below is my report;

Objective

The objective of this report is to tabulate the total power consumes and the electricity bill for dimming and non-dimming ballast for the Street Lighting System.

The calculation of the electricity bill will be divided into two segments, which is;

a) Calculation based on non-dimming ballast

b) Calculation based on dimming ballast

The parameters that being used in calculating the estimated MD will be as follows:

a)    Total power consume for street lighting system.

The total power consumed will be divided into two, which is non-dimming and

dimming system.

Total Power For Non-Dimming Ballast

i) (Operating Hour: 7pm-7am)

ID	DESCRIPTION	QTY	WATTAGE	TOTAL
1	250W & 150W (8m&6m Pole)	20	400	8,000.00
2	150W (8m Pole)	46	150	6,900.00
3	70W (4m Pole)	26	70	1,820.00
TOTAL WATTAGE				16,720.00

Total Power For Dimming Ballast

ii) (Operating Hour: 7pm-12m/night)

ID	DESCRIPTION	QTY	WATTAGE	TOTAL
1	250W & 150W (8m&6m Pole)	20	400	8,000.00
2	150W (8m Pole)	46	150	6,900.00
3	70W (4m Pole)	26	70	1,820.00
TOTAL WATTAGE				16,720.00

iii) (Operating Hour: 12m/night-7am)

ID	DESCRIPTION	QTY	WATTAGE	TOTAL
1	250W & 150W (8m&6m Pole)	20	200	8,000.00
2	150W (8m Pole)	46	75	3,450.00
3	70W (4m Pole)	26	70	1,820.00
TOTAL WATTAGE				9,270.00

Note:

1) Dimming ballast only apply for lantern which more than 150Watts.

2) Lantern will be dimmed to 50% of its rated wattage. This perecentage will subject to Owner's preference since the dimming ballast is a pre-set dimming ballast.

Power Consume and Electricity Bill for Dimming and Non-Dimming Ballast for Street Lighting

System

b) Operating hour

The operating hour for non-dimming and dimming system will be as per figure

below;

c) Unit rate based on tariff C1

The unit rate is based on latest TNB’s unit rate of RM0.288/kW.

Electricity Tariff Calculation

The whole development will be billed as per tariff C1. Based on tariff C1, the monthly

bill will be as per formula below:

Monthly Bill (RM) = MD/Month + Monthly kWh

Since the street lighting is only a small part from the total maximum demand consumed therefore, the MD/Month can be assumed constant and not into consideration for this calculation.

a) Calculation based on non-dimming ballast

Monthly kWh will be as per below:

Monthly kWh = Total Power (kW) X Working Hour X Load Factor X Days X Unit Rate (RM)

= 16.72kW X 12 Hr X 1 X 30 days X RM0.288

= RM 1,733.53

b) Calculation based on dimming ballast

Monthly kWh will be as per below:

Operating hour (7pm – 12m/night)

Monthly kWh = Total Power (kW) X Working Hour X Load Factor X Days X Unit Rate (RM)

= 16.72kW X 5 Hr X 1 X 30 days X RM0.288

= RM 722.30

Operating hour (12m/night – 7am)

Monthly kWh = Total Power (kW) X Working Hour X Load Factor X Days

X Unit Rate (RM)

= 9.27kW X 7 Hr X 1 X 30 days X RM0.288

= RM 560.65

Monthly Bill (RM) = Operating hour (7pm – 12m/night) + (12m/night – 7am)

= 722.30 + 560.65

= RM 1,282.95

Difference (RM) = non-dimming - dimming

= RM1,733.53 – RM1,282.95

= RM 450.58

Based on the calculation above, it can be concluded that by using the dimming ballast the monthly electricity bill can be reduce up to RM 450.58/month.

The budgetary cost for dimming ballast to be installed is RM 10.920.00. Therefore, the

Return on Investment for this dimming ballast system is within 24 months.