Top 5 benefits of geothermal systems
This month's "Ask the Expert" column is about what to consider when installing geothermal. Since this topic is well covered by Ted Clifton's column, I thought I would add to the discussion by talking about the benefits of geothermal. Our recently LEED Certified home has geothermal heating and cooling, and we have lived in our new home for over 2 ½ years — so we have the experience too.
- There is no outdoor air conditioning compressor. For people that know how loud, big and ugly these are outside, this is a big deal. You also don't ever have to clean all that cotton wood pulp out of it, because the ground source heat pump is located inside.
- The system is super efficient. Utilizing the ground's year-round temperature of 50-55 degrees is a huge benefit, particularly in more extreme climates like Minnesota. Efficiency means lower utility bills and lower energy consumption.
- One of the criticisms I have heard about geothermal is that they require a great deal of electricity to run the pump. This is true — while our gas bill is miniscule, our electric bill is quite high. However, electricity can be cleaner than gas by using solar or wind, and solar photovoltaics are a nice complementary technology to a geothermal system. Additionally, our utility offers a dual-fuel rate for geothermal systems. This means that the electricity used in the winter for the system is half the rate they normally charge — further decreasing our utility bill.
- Because it is a hydronic system (made of tubes with water flowing through them), a geothermal system is particularly compatible with in-floor heating — also an efficient, quiet, comfortable way of heating a home.
- If equipped with a side arm tank or a "desuperheater" (and I highly recommend this), whenever the geothermal pump is running to heat or cool your home, it also preheats your domestic hot water with the compressor's waste heat. What does this do? Again, further reduces our utility bill and energy consumption.
While there is an incremental cost to these systems (which can vary greatly depending on the land you have to bury the loops), I have generally seen a four to six year payback for homeowners. If you can wrap up the cost in a mortgage, it is practically cash flow positive from day one. I would almost always recommend a geothermal system well before any renewable energy system is considered.
Melissa Rappaport Schifman Melissa provides sustainability consulting services for businesses in the Twin Cities metropolitan area. Melissa is also the founder of Green Intention LLC, where she writes and blogs about her experience in getting her own home LEED Gold certified--and then trying to live more sustainably in the home. She chairs her congregations Task Force for Sustainability, has her MBA, Master's in Public Policy, and is a LEED AP for Homes. www