Watts is watts regardless of voltage. Just add the wattage of all your
bulbs and calculate as you would in the house. The reason fancified outdoor
lighting is lo voltage and not 'line' voltage is because it's safer since
the lines are rarely buried very deep and there's also a much wider variety
of fixtures and bulbs in lo voltage.

s


wrote in message
...
I use three, 300 watt 12 volt Maulibu type transformers to light my
yard and walkway lights around my home.

I was under the impression the reason one would use 12volt instead of
line voltage was the 12v was less costly to run.

How do I determine how much power each of these is drawing (per hr?)
so I calculate my cost per month. I don't think it will matter, but
one of them is only drawing about 160 watts. Each of the others is
near their 300 watt limit.

Thx