On Sat, 3 May 2008 14:10:57 -0700 (PDT), "
wrote:

http://www.aceee.org/consumerguide/waterheating.htm

best comparison I have seen, compares electric, gas, oil, standard vs
tankless yearly water heating costs.

Even has install costs, expected lifetimes of units etc.

good reading for anyone considering a new hot water unit

It's a good resource, but I'd caution that some of the assumptions
need updating. For example, the cost of fuel oil in the price
comparison table is listed as $2.40 a gallon and, today, that number
would be closer to $4.00 (I'm currently paying $4.17 a gallon). On
that basis, the annual energy cost of a conventional oil-fired water
heater would fall in the range of $1,100.00, as opposed to the $650.00
shown here.

Cheers,
Paul