they have a built-in ballast and require a grounded outlet (those 3-prong outlets on your wall) at most. but most come in kit form (easy to put together) and will probably also need a pig tail and wire nuts...so ask before you take it home. plan on a minimum of 40W/sq ft...double that for better results...and no, the lights for a small grow will not produce enough heat to worry about. you can easily figure the costs of electricity by looking at your elec bill and doing a little basic math. cost/KW x total wattage will get you real close...