Our Journey into Going Green:

Geothermal HVAC and Solar PV System

By: Dale Binkley

Geothermal HVAC system

As we approached the end of the annual heating season in March, 2006, Linda (my wife) and I had a long discussion about the condition of our HVAC system. Our oil burner (29 years old) was the original unit installed in the house when it was built in 1977. It still performed well but had begun to require some type of repair each year over the past 4 or 5 years. All the other homes built around the same time in our end of the subdivision had already replaced their oil burners years ago. The central AC unit (16 years old) that we added to our system in 1990 still worked well and had never given us any trouble.

We had supplemented heating our house for 8 years with a coal fired fireplace insert. After refinishing the basement where the fireplace is located, we switched to a pellet stove for 6 years. This kept the lower level of our house warmer when our kids were still living at home. Now they had all grown and left home and we were looking for a less labor intensive system (no more carrying buckets of coal, bags of pellets or cans of ash).

I had read about geothermal heating and cooling and was familiar with the concept. I also knew it would be a big upfront cash outlay. I started researching local geothermal installers and found Sinton Air Conditioning and Heating in Kennett Square, PA. We scheduled an initial appointment to discuss the feasibility of having a geothermal system installed in our house. Bill Sinton came out and spent about 2 hours giving us a very good overview of how the geothermal system would work and the cost savings we could expect on our heating bills in the future. We arranged for Bill to come back and do a detailed analysis of our home so that he could give us a better estimate of the cost of the project. At this point, we knew that we were looking at spending around $20,000 for a geothermal HVAC system compared to about $10,000 for a replacement of the type we already had. The estimate was about a 7 year payback for the premium of installing the geothermal system compared to a standard replacement oil burner/ central AC system.

While we were trying to make a final decision about spending the money to do this I came across an article in May/June 2006 Countryside & Small Stock Journal entitled "Home Heating from the good Earth" written by Rex Ewing. This article served to reassure us that there were long term savings using a geothermal system. It also served as the final nudge we need to go forward with the project. More on Geothermal Pennsylvania incentives. Cost: Our geothermal system was installed in late April, 2006. The total cost out of pocket for our system was $23,522.48. This was the price after a $500 rebate from PECO Energy and a $300 federal income tax credit. $17,256 was paid to Sinton Air (after deducting the PECO rebate) for installing the WaterFurnace high efficiency heating and cooling unit with a desuperheater to preheat our hot water. It also included a lot of ductwork replacement to increase the airflow throughout the house to improve our comfort. $6,566.48 was paid to the well driller for drilling (2) 250' bore holes, the trenching to the house and installing all the piping for the fluid transfer system.

Installing the entire system took close to 2 weeks. The crew kept us up to date with what they did each day and what to expect the following day. When the system was turned on and tested, the installers all signed their names on the heat pump.

Performance: Comfort wise, there is no comparison between the geothermal system and what we had before. The improved airflow through better ductwork and a multi speed air handling system eliminated the hot and cold spots in our home. The other added benefit is the elimination of the outside AC compressor unit and the noise it creates in the summertime. The new unit also gives us a more comfortable air conditioned house than our old unit. We are able to sit outside on our deck on a summer evening and enjoy the sounds of nature instead of the constant whine of the outside AC unit. Linda was a bit skeptical when I first brought up the idea of installing a geothermal HVAC system on our home. Since it is a heat pump, she remembered the performance of heat pumps years ago that provided "cool" feeling air when heating in the winter time. After feeling the "warm to the touch" air our unit produces she says that if we move in the future, and the house we buy does not have a geothermal HVAC system, it is one of the first improvements we should consider.

Cost wise, heating in the winter season is much more economical. The best cost comparison is the last season of oil burner and central AC unit to the first season of the geothermal system. Our electric bill for the last year of the old system was $1,660.05. The electric bill for the first year of our geothermal system was $1,692.93. While we had a slight increase of $32.87 in our electric bill, we eliminated the $902.58 that we spent on fuel oil and wood pellets to heat the house the previous year. While I do not have exact prices on fuel oil since our installation, they have gone up in general and our savings are at least as much every year as the first year. We feel that we are close to having recouped the "premium" we paid for our geothermal system instead of just replacing our former system with something similar. In the summer, the air conditioning is more efficient than the unit we had before. The first summer that we had the geothermal system we experienced a heat wave that coincided with our electric billing period. Our home is about 30% larger in square footage (2800 sq. feet) than most of our neighbors. Our bill to cool our home for the period was $175 compared to about $225 for most of our neighbors.

Solar PV System

I have been intrigued for many years about the possibility of generating our own electricity. Installing our geothermal system reduced the variety of utilities we consume in our home to electric only. If we are able to generate most of our own electricity, we are more in control of the resources we consume to run our household.

In 2007 I contacted Dale Davis of CMI Solar Electric in Newark, DE to get an estimate of how much it would cost us to have a solar PV system installed to generate a portion of our electricity. Dale reviewed our home and the feasibility of installing a system on it. While we were ideally situated to maximize the efficiency of a roof installed system, Dale suggested we wait until Pennsylvania approved an incentive program to subsidize the cost of an installed PV system.

In 2009 Pennsylvania initiated the PA Sunshine Rebate Program to reimburse homeowners 35% of the installed cost of a solar PV system. Once again I contacted Dale Davis and resumed the process of determining what size system we could afford to install at our home. We decided on a system that would cover the south facing roof of our detached garage. This 4.1 KW system would provide about 35% of our annual electric use.

The installation only took 3 days. The crew was efficient in their work and kept us informed of what was going on each step of the process.

Cost: The total cost of the system installed by CMI Electric was $33,622.00. After a PA Sunshine rebate of $9,225.00 and Federal Tax Credit of $10,087.00, our out of pocket cost was $14,310.00. Performance: The system has performed as designed. During the first year of operation, the PV system generated 35% of our electric used during that time. Our electric bill for the 14 month period ending Dec 31, 2010 was $1,504.99. The cost we avoided paying PECO by generating our own electric was $765.74. We also had Renewable Energy Credit (REC) income of $1,521.00 received from the sale of our green production. Based on the "avoided cost" of the electricity we generated and the return of our system cost through REC income, our projected payback is just a bit over 7 years.

Conclusion

We are very satisfied with the decisions we have made concerning our geothermal and solar PV systems. We desired to be more efficient in our use of energy in our home. The payback time required to recoup our upfront costs has been shorter than expected due to higher energy costs than predicted at the time of or system installation.

The geothermal system gives us economical heating and cooling and the comfort level in our home is much better than it was previously. During the 6 years prior to our geothermal installation we used an average of 375 gallons of fuel oil plus 1.5 tons of wood pellets annually to heat our home. Installing our geothermal system has allowed us to reduce our utility use for our home to electric only and substantially reduce our heating and cooling cost.

The solar PV system has performed as designed and has lowered the amount we pay out to buy electricity. We view the purchase of the solar PV system as a prepayment of our electric purchases. With electric deregulation coming to Pennsylvania, we anticipate that our payback time will become shorter with each future rate increase.

Installing the geothermal HVAC system first made the most sense for us. We were at the point that we had to replace our HVAC system and the geothermal system was the best choice for us. It allowed us to reduce the variety of utilities we previously used for heat (fuel oil, wood pellets) to just one (electricity). Cost wise, we feel that we have seen a slightly faster payback time on our geothermal HVAC system purchase than with our solar PV system.