Digital dimming

[BRIGHT SPARK]

What would be the % cost saving if I used digital dimming ballasts to dim ambient fluorescent lighting to 50% of normal? We need to replace 130 70w units. T.I.A.

[Hymie]

130 units each drawing 70W = 9.1kW.
50% of this = 4.55kW.
I assume that you are an industrial user with this many lights.
To work out your saving, you need to know how much you are playing per kWh.

For purposes of a calculation, let say you are paying 10p per kWh � this would result in a monetary saving of 45.5pence per hour that the lights are on.

However things are further complicated since industrial users are charged a significant amount based of their peak hourly usage (actually measured over � an hour). If the lights would have been on during your peak hourly usage, this figure would be reduced by 4.55kWh, which may result in a significant reduction in charges from your supplier.

[BRIGHT SPARK]

Thanks Hymie, however I need to know whether a 50%reduction in lighting levels achieved via digital dimming would result in a 50% cost saving.T.I.A.