itheheartofthecity2

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.

Update: 2012

Gas prices are relatively lower. Electric cost has continued to rise. I believe electric heating costs are about 250% higher than natural gas.