Performance and Operating Cost
of the Geothermal System, 68 South St.
Extra electric cost to run Geo Heat Pump at 68 South St.
|Month||2006 Avg. KwHr./day||2009 '10 Avg. KwHr./day||Difference|
Heating Season +75 Cooling Season -30 Difference = 45 / 12 months
= 3.75 Kw Hrs / Day x $0.194 per KwHr = $0.7275 x 365 = $265.50 per year more.
So payback at these rates = $1182.00 (savings on $2.75 oil ) - $265.50 (extra electric at $0.20) = $916.50 per year.
Investment of $11,000 for R-22 single stage - $1500 CL&P rebate = $9500 cost (CCEF and 30% tax credit not taken back then)
10.3 year payback.
Note also that 2006 was a much warmer winter than 2009/2010.
If as fuel man said, it is true that he was delivering twice as much this year as in past years, then payback would be 5.15 years.
And if fuel oil costs rise above $2.75 per gal. payback also accelerates.
Here is a similar testimonial from a colleague George Hu, PE in New Hampshire:
Back in January, I wrote you about a geothermal heating and cooling project we engineered recently:
~15,000 sf house in Rye, NH, completed by 12/31/2009. Since we installed a dedicated electricity meter
for the geothermal system, I have obtained some measured data for the two-month period of 1/2010 and
2/2010 (peaking heating season), I thought you might be interested in knowing the energy cost savings this
geothermal system has given the owner. Compared with the propane-fired boiler heating system for the same
period of 2009, the new geothermal system saved the owner 60% energy bill for this 2-month period.
This was based on the propane price of $2.11 / gallon the owner was paying in 2009.
Besides the impressive energy savings, I wanted to point out that the savings we are seeing, are “true” savings,
in the following senses:
1. There is no sacrifice in comfort in the whole house – the owner has been very happy with the performance of the system;
2. Everything else has stayed the same, there was no change to the building envelope;
3. The system did not take any more space than the replaced system;
4. Plus, the house no longer has half a dozen condensing units sitting outside. 6/10/1
has good performance info in real time as does www.Ourcoolhouse.com
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