Does Geothermal make sense?
I need to replace my oil furnace this year. I have a relatively small, 1500 sq ft cape style house, originally built in about 1960 but extensively remodeled in about 1995 after a fire and before I purchased it. I currently have a 3 zone oil fired Weil Mclaine boiler with tankless coil hot water that must be replaced. I was given an off the cuff estimate of about 6800.00 from the person cleaning the furnace from a local company that does a lot of furnace intalls. I have no central air, an older through the wall AC in the kitchen and a few window units for other rooms. I am trying to research the feasibility of switching to a geothermal unit instead. I was given a ball park estimate of 25,000.00 to install geothermal. This is just another "off the cuff" estimate at a local home show based on the size, location and style of house I have. They estimated 60-80% savings over the cost of oil heat. That seems a little high, but I don't really know.
I currently use about 600 gallons of oil a year and the local cost of oil is almost 4.00/gallon. I have really not kept good track of my oil usage, and use mulitple oil delivery companies so it not an easy thing to calculate accurately. I have been going through about 100-125 gallons/mth in Dec, Jan, and feb, and use less in Oct, Nov, March and April. During the summer months I use very little, just for hot water. However, my electric bill rises from about 100.00 mth to about 250.00 per month due to ac costs.
I plan to have an energy audit with a blower test in the near future.
I plan to be in this house for at least 20 years. If the install does cost $25000.00 and I get a 30% tax credit, that brings the cost down to $17,500.00. (I think there is also a 1500.00 incentive from the local utility but I am not counting that right now, as well as very low interest loans to cover the cost) How do I figure it from there? If I assume I need to spend approx. 7000.00 anyway, the additional expenditure will be a little over $10,000.00. For that I will get the decreased fuel costs and a forced hot air system with central AC, and what I suspect is a much more cost effective cooling system as well.
My electrical costs depend on how you figure out the cost per KW. If I take my total bill and divide by the KW used that month it is $00.1766/KW. If I add up all the generation and delivery per kw charges it is 00.15865/Kw. The extra must be in taxes or other fees.
What else do I need to figure in? Can you heat and get HW solely with geothermal? When do you have to have an additional heating system? That might make it unfeasible.
I think this is probably my one chance to make this change since I need the furnace any way. It would not really make sense any other time due to the costs involved. I just want to be sure If I do go with such an expensive system that I am happy with it later. I had been under the impression that geothermal made the most sense with a new build. This contractor, however, estimates that 70% of their installs are retrofits. Natural Gas is not available on my street and I contacted the local gas company and found out there are no current plans to make it available here in the future.