120V vs 240V

I heard recently that a 240V set up uses less power and is much more cost efficient than the 120V set up. I don't know if there is any truth to this, but I'd really like to know. My questions are:
1) How much less energy do they use
2) What is the cost difference, and
3) Does it have to be connected directly to a 240V outlet, or is a converter acceptable?

I'm only looking for factual information please.

all that I can tell you from my exp is that my ballasts when on 120 v run at 9.8 amps and when on 240 v run at 5.5 amps as far as power goes I dunno so hope it will help ya some

its cut in half we only run 240 out here

you do not use less over all elecricity, you use less amperage.If you are running 10,000 watts of lite at 120 v and switch {I would} to 240v you will still use 10,000 watts, just the amps are cut in half. This may save a little as the 240v is less restrictive. the room still needs 120v for fans,dehumidifiers and things that only run 120v, so there would be no change there. I am doing my aprentiship with an old man whose motto is perfect isnt good enough, and am still learning but I,m pretty certain this is what was meant by a reduction in power use.As far as the plugs and outlets go, 240v come in diferent amp ratings and each socket has a matching plug. 30 amps will run 3 1000 w lites with amps to spare ,you never want to use more than 75% of a circiuts capasity for a safty margin. so plan acordingly when you wire your 240 cicuits 1 for every 3 lites and your ballasts should be able to rewire to use 240v the hydro store can show u how or do it for u.

less draw = less money as far as fans a 10 inch elicent draws like 300 watts lol and fans like 100 so who cares its the big 1000w im worried about.

the answer to your first question is no..they both use 1000 watts of power..a 1000 watt light bulb powered by 110 volt or 220 volt still uses 1000 watts of power...the 220 is more efficient ...and there is a little savings from that...and your ballast will run a little cooler..my 1000 watt light...will pull aprox..8 amps at 110 volts....my 1000 watt light will pull aprox 4 amps at 220 volt...if you have 14 gauge wire..so long as the length isnt excessive that wire is rated for 15 amps....as you can see you can only run one 120 volt 1000 watt lamp on that circuit....the second lamp will have your ciruit over loaded at 16 amps..then it will kick breakers and maybe melt wires and cause a fire...now..if we change it to 220 volt on 14 gauge wire..it will only hold max 15 amps...minus around 25% for over current protection so your not kicking breakers all the time..dont want to get to close to the max of 15 amps..ok..now..instead of only being able to run one light ...at 8 amps..now we can run three lights at 4 amps each..for a total of twelve amps...on a fifteen amp circuit...i would only run two on the cicuit......12 gauge wire is rated for 20 amps,,,,if you had two 1000 watt at 110 volt you would have 16 amps on a 20 amp cicuit..that is all you could run..but you could run 4 1000 watt lights at 4 amps each at 220 volt's on 12 gauge wire...if anything else i would wire 220 to where i wanted it then step it down to 110 volts..no convertor needed..there are several books at home depot that will help some..but the basics are no more than being able to count your appliance amp number's match them to the wire and amp rating.and match that to the breaker...oh yea.and of course..use outlets rated for 220..if you would...and the proper amp draws..when you use 220 volt..you will have to have extra space in your breaker box for a additional breaker..a double breaker to run your 220..and be able to make space for it in the breaker box...your local electrical supply house can help you out alot too..one of the larger electrical supply houses in my area is a company called kirby risk..the guy's in there or some of the electricians in the lobby will be a wealth of knowledge..

very impressive responses think I even learned a little haha I was always overloading with 120 but now rum a 50 amp timer box and done have any probs but was wondering if I could take 4 of the 8 220 outlets on it and split to dual 120 each 4 are on a 20 amp breaker thanks in advance

Thanx soo much bro you rock!!

now have it converted over the way that I want it and I love it bump