Site number:

Dreese Residence

Although the Dreese home's roof faces southwest rather than the more ideal due south, production from the PV and solar hot water panels has been as much or more than projected. There is absolutely no shading, which is probably more important than the exact orientation. Electric production is higher in the late afternoon when the load on the grid peaks. The ground-source heat pump is quieter than most refrigerators.

Read more about the Dreese residence in the August 2008 issue of The Solar Flare.

System Components

3.9 kW solar PV system with 20 Sanyo HIT 195W solar PV panels
Fronius inverter
2 Alternative Energy Technologies (AET) AE32 4'x8' solar thermal panels with an 80-gallon solar-heated water storage tank and a tankless natural gas backup heater
4-ton geothermal heat pump (GHP) with four 185-foot-deep wells

Additional Measures

Energy-efficient appliances
Triple-pane windows
Rain barrel

System Designer: Innovative Power Systems and UMR Geothermal
System Engineer: Innovative Power Systems and UMR Geothermal
System Installer: Innovative Power Systems and UMR Geothermal

Date of Installation Completion: Ground-Source Heat: December 2006, Solar Hot Water: October 2007, Solar Electric: January 2008

System Cost, Payback, and Financial Incentives Utilized

Ground-Source Heat: $18,600 minus $500 federal tax credit = $18,100 net cost
Solar Hot Water: $9,600 minus $2,000 federal tax credit = $7,600 net cost
Solar Electric: $40,000 minus $7,800 state rebate and $2,000 federal tax credit = $30,200 net cost

Anticipated Energy Delivery When Purchased

Solar Hot Water: Replaces about 130 therms/year of natural gas
Solar Electric: Produces about 4,800 kWh/year
Ground-Source Heat: 7–8 kWh of electric energy will replace 1 therm of natural gas

Actual Energy Delivered When Installed

All 3 systems are meeting expectations

Percentage of Total Energy Needs Delivered:

Electricity: 50%
Natural Gas: 80%