The Next "Green Project"

Over the past several years we have taken many steps to go "green" and reduce energy consumption and increase efficiency of our home. With the exception of lights inside appliances, all lighting in the house is either compact fluorescent (CFL) or light emitting diode (LED). That was the first item to reduce electrical use and lessen the heat output from lighting in the summer.

Then we installed 7.5kW of grid-tied solar electric generation, and most months we generate several hundred kilowatt hours (kWh) of surplus electricity which goes back to the utility and is used by other customers. The typical electric bill is less than $10 and consists of administrative charges and taxes only.

Last summer we installed additional rain gutters and added 1,250 gallons of rainwater storage for use in irrigation and filling of the ponds and birdbaths. An inch of rain is about all it takes to fill everything up to capacity. In a pinch, the water can be filtered and used for drinking. The yard has been relandscaped to use native plants and function with little to no additional water (xeriscaped). Even the drip irrigation has been shut off for the last year.

We removed all the old blown in cellulose insulation from the attic last year. In its place we installed new sprayed on, semi-rigid insulation on the inside of the roof. The new insulation is about 9 inches deep and all openings to the attic have been sealed and foamed over. The foam starts at the top of the walls inside the attic and covers everything overhead. Gone are the little drafts we used to feel, and an infrared thermal scan shows no more hot or cold spots. The house stays at a pretty even temperature and even the garage is comfortable year round. The garage never had insulation overhead before, and could go to the high 90s in the summer and down to the 40s in winter. After insulation was added summer peaks at around 80 and winter went down to about 68. The attic used to go into the 120s and now stays below 86.

The improvement after re-insulating has been especially noticeable in the decreased costs for heating and cooling. In mid-summer we were able to lower the thermostat and still generate a surplus each day. Natural gas usage was down this winter even though our winter was far colder than usual. So now we move to the next step.

Geothermal Heating/Cooling

This will be the major project for this year. Our existing heating, cooling and water heating will be eliminated and replaced with a unified geothermal solution. This eliminates two furnaces, two air conditioning systems, two evaporative coolers and a gas fired water heater. The projected energy savings is about 70% of what we used before. And like the solar project, there are significant incentives to make the change. Based on the projected savings, our electric utility (APS) will offer a rebate of 50% of the project cost. The federal government has a 30% tax credit for the energy efficient project. There's really no good reason not to do it.

So watch the blog for updates. The project kicks off on Monday, May 9 when they begin drilling the 3 wells for the heat exchanger.

Want to know more about geothermal and how it works? Click here.