You also have to consider the amps used by the pumps, heater, chiller, skimmer, in addition to the lights. All in all not too bad unless you have a real big tank or a chiller.
When I had my 200g reef in Texas, in the hot summers the 1/2hp chiller added about $30 a month by itself. The tank was a comfortable 76 degrees but we were sweating our %$^@'s off in the house because the chiller dumped hot exhaust air into the house which in turn caused the house AC to run constantly. Since home AC's only do a 20 degree pull down, when it's 103 degrees outside, the best you can expect is 83 inside. Dump hot chiller exhaust and you get my picture. It added another extra $100 to my electric bill. If I ever have the need for a chiller again, I will locate or vent it outside.
R/Duke
When I had my 200g reef in Texas, in the hot summers the 1/2hp chiller added about $30 a month by itself. The tank was a comfortable 76 degrees but we were sweating our %$^@'s off in the house because the chiller dumped hot exhaust air into the house which in turn caused the house AC to run constantly. Since home AC's only do a 20 degree pull down, when it's 103 degrees outside, the best you can expect is 83 inside. Dump hot chiller exhaust and you get my picture. It added another extra $100 to my electric bill. If I ever have the need for a chiller again, I will locate or vent it outside.
R/Duke