electrical system / solar panels

Green Building Systems

Before the building process began, we set up our solar panels and installed a temporary electrical system in a tipi; this allowed us to power our building tools and water pump entirely from renewable energy.

Our final off-the-grid energy system consisted of sixteen 64-watt Solarex solar panels mounted on 2 Zomeworks trackers, and a 1.5 kw wind turbine on a 100 foot tower.  In 2006 we moved and increased the size of our energy system in preparation for the new building, which started construction in 2008.  Our new system consists of  16 Evergreen 120 watt  photovoltaic panels and 16 Solarex 64 watt photovoltaic  panels mounted on 3 Zomeworks trackers.  We also have  a  Bergey 1KW ( 1000 watts)  wind turbine.  We are planning to upgrade to a larger wind turbine when finances permit.

The solar panels generate most of our power during the summer; the wind turbine produces most of our power in the winter. Our system provides enough power for us to run a dishwasher, a washing machine, a refrigerator, a freezer, multiple computers (three laptops), a 220v water pump, a TV/DVD player, and other modern appliances. A backup propane generator is used only during extremely long periods without sun or wind. We estimate that we run our generator for only about 100 hours/year.

The energy produced by our solar and wind systems is stored in a bank of deep-cycle batteries. Both AC and DC lines come into the house. It is preferable to use DC power in an off-the-grid system, because some energy is lost when the inverter converts from DC to AC; therefore, we chose DC appliances whenever we could find ones that were good quality and energy-efficient. Currently our Sunfrost refrigerator and deep-freezer, and our low-voltage halogen track lights are powered by DC.

Because electrical heat-producing appliances consume large amounts of electricity and are very inefficient, both our stove and our clothes dryer are fueled by propane.

After 11 years our batteries needed to be replaced and in 2007 we installed 36 new batteries.  In 2008, as part of the new construction we replaced our inverter and controllers.  We now have 36 Surrette 2 volt batteries. The entire system can be seen in the basement of the new addition and will be a useful and demystifying part of any tour.

  PROMOTING SUSTAINABLE DESIGN TECHNOLOGIES
  VERMONT, USA info (at) earthsweethome.com