How do you work out how much power your lighting is costing you. Is there some sort of formula, thanks.

Working out the power comsumption of lights and filters etc is easy.. Just read the wattage of it for fluoro's add up the wattage of each tube to find the total..

Once you have a total times that by the number of hours the light is on..

Say you have a 30W bulb and its on for 10 hours a day it will consume 300W of power in a day. 1 unit of power is 1kW (1000W) running for an hour and costs around 20-30cents (read your power bill).

One or 2 lights running wont make much difference it should only cost a few $ a month, however once you get a few going it can add up.

If your trying to do this with heaters remember they're not on all the time so you will get a stupidly high cost for them unless you assume they're on half the time or something like that.

Or if it is really important, Dick Smith no sell a plug in power meter, so you can plug in inline with any device to see what the actual power consumption is.

I believe it works much the same way as your house power meter giving you an actual consumption over a period of time.

The Warehouse has them too.

Most fluro's are only about 90% efficient so you need to divide the calculated watts by about 0.9 to get the actual input power. In the example about, the 300Wh becomes 333.33Wh. At about 19-20c a kWh this equates to approx 6.7c a day or about $1.00 per month for a 30W tube running 10 hours a day.

Wh = Watt Hours

kWh = Kilowatt Hour (this is the unit power companies charge in)

Thanks guys, was just wondering how much my halides where going to cost to run