How to compare electric vs natural gas heating costs

with supplmental

The Portland General Electric residential tariff is available at

As I said in another post, it is byzantne at best.

I am a residential customer, single phase power, no renewable energy "blocks"; no "conservaton" blocks, just straight power.

While this is the mst recent (Feb. 2007) tariff on the web site, I think that this tariff schedule from the PGE website is not what is currrently in effect. PGE had huge (like 25%) rate icreases in June - July 2007 when the 9th Circuit invalidated all the BPA offset payments / sales of cheap hydro to the ivestor ulitiies in the NW. Oregon PUC approved an emergency rate increase for PGE (and others - Pacific Power and Light, for example) effective early summer 2007.

I'm going to look atthe Oregon Public Utility Commission (PUC) site to see if there is anything more transparent as to PGE rates.

Hi Jim,

Thanks for the additional info. In my original analysis, I had used $0.09246 as PGE's standard domestic rate, but if this rate has since changed and the schedule shown on PGE's website is out-of-date, please let me know.

Again, an air-source heat pump with a HSPF of 8.5 will provide, on average, 2.5 kWh of heat for every kWh consumed, so your effective cost of electric heat is 3.7 cents per kWh(e). At $1.22449 per therm and assuming an AFUE of 90 per cent, your cost per kWh of natural gas heat works out to be 4.64 cents. In this case, natural gas must fall below $0.98/therm before it breaks even.

For argument sake, we'll assume a typical new home in your climate requires 50 million BTUs/year for space heating purposes. At current rates, if it were heated with electric baseboard units, the cost would be just under $1,355.00, whereas that same home heated with an air-source heat pump would come in at $542.00. Equipped with a high efficiency natural gas furnace (90% AFUE) and at $1.22449 per therm, a homeowner could expect to pay something in the order of $680.00/year.

Natural gas is a terrific fuel but we're quickly running out of it and over the long term, not withstanding any temporary price fluctuations, it's going to get increasingly more expensive. For anyone building a new home or replacing their current heating system, I hope you consider either an air or ground source heat pump as one more option.

Cheers, Paul