Comparison: Electric costs 147% of gas cost for equivilent water heating in Seattle.
Electric 50 gallon Water Heater Cost per 30 day month
4500 watt running for 1.5 hrs/day = 5.85 KWH per day
Cost of Electricity per month Feb 2008 @$.471 per KWR = $28.26 or $339.12 per year
Natural gas 50 gallon water heater Cost per 30 day month
40,000 BTU/hr running 1.5 hrs/day = 60,000 BTU /day
Cost of gas (PSE Feb 2007) $1.07 per therm
Gas cost $19.20 per month or $230.40 per year
Comparison: Electric costs 147% of gas cost for equivilent water heating in Seattle.
Notes: 1 therm = 100000 btu's
a typical pilot light burns .0075 therms per hour
1000 cu ft of gas = 10.31 therms
Gas cost is the sum of gas cost plus delivery cost (I know - it is stupid. You have to add the two charges together - see your utility bill.
