How to save energy in street lighting with staggering ?

Generally there is no or less traffic on the roads after mid night and before early morning. At that time we can save a lot energy by switching off one or two phase.
Hear is a simple calculation for understanding monitory benefits of staggering.
Or See the presentation "How Technology saves Energy."

For calculating the payback time period of the system described, we can go through the following calculations. Say considering 10 KW load Total Investment of Unit cost will be Rs.30,000/-

Total unit consumption
@ 12 hours/day will be 10 x 12 = 120 Units a day
@ 365 Days will be 365 x 120 units = 43800 Units/annum
@ Rs. 4 per Unit rate total billing will be 4 x 43800 = Rs. 175200/- annum.

Staggering One phase.

If we switch OFF only one phase @ 12 AM say for 6 hours a day then total working hours of three phase are 36 hours out of we can save 6 hours will be around 16 % + minimum longitude can save 4 % Total 20 % saving can be achieve entire operation.
@ 20 % of 175200 will be Rs.35040/-
@ Max the unit cost will be recovered in 11 months.

Staggering two phase.

If we switch OFF only one phase @ 12 AM and another phase @ 2AM say for 4 hours a day then total working hours of three phase are 36 hours out of we can save 10 hours will be around 27 % + minimum longitude can save 4 % Total 31 % saving can be achieve entire operation.
@ 31 % of 175200 will be Rs.54312/-
@ Max the unit cost will be recovered in 7 months.

Staggering alternate phase.

If we operate on only two phase and used alternate systems then switch OFF only one phase @ 12 AM for 6 hours a day then total working hours of two phase are 24 hours out of we can save 6 hours will be around 25 % + minimum longitude can save 4 % Total 29 % saving can be achieve of entire operation.
@ 29 % of 175200 will be Rs.50808/-
@ Max the unit cost will be recovered in 8 months.

Advantages

1) No frequent time to be change according to season.
2) Redundant Power supply to controller. Any phase up to 150 Volt controller will work and contactor will be operated up to 170 VAC
3) Real-Time Clock with very high life of more then 5 years. No Battery.
4) Individual phase output with MCB for protection.
5) Input out put terminal of 35 MM sq.
6) Power wiring of feeder pillar with ISI mark fire retardant cable.