Some homes don't have Gas Service. "Tru-Tankless" Electric Water Heaters are the best in the industry.
-They are the most efficient, using less electricity than the competition yet producing more hot water.
-They last the longest. LIFETIME warranty on the Heat Exchanger, the longest in the business. LIFE, as in, forever.
-5 year warranty on all other parts
-requires only 2 breakers from the panel, most of the others require 3. This saves you on your Electrician installation fees.
-LCD Screen, Wifi, can be controlled from your Cell Phone
-they can really make a lot of hot water - up to 7.5 gallons per minute in Arizona in the Summer (about 4.4 gpm in the Winter)
Check out this Video - designed for Homeowners:
And here's a video designed more for Pro's: