The Earthship Electrical System

This is a quick overview of the Earthship electrical system, which is completely off grid.

 

A PV system is used to provide electrical power to the Earthship.  Typically there is no connection to the power grid.   Some Earthships use wind as well as PV power.

 

The Earthship design minimizes electrical power loads by:

  • Using DC pumps and appliances where possible

  • Using efficient appliances (e.g. Sunfrost refrigerators)

  • Using solar water heating with natural gas backup

  • Using propane dryer (if so equipped)

  • Using propane for cooking

  • Using wood or propane for backup heating

  • Minimizing pumping loads locating the cistern so that the pump can be gravity fed.

 

The PV system in the Hut consisted of 4 PV panels at 125 watts each, a Trace 2500 watt inverter, and 8 batteries.   This is a pretty small system, and just looking around the Earthship Community, it was apparent that many homes had larger systems.  During our short stay, the system did (barely) provide sufficient power without ever running the batteries out of the "green" zone.

 

Earthship offers a systems module that has all of the components packaged as a unit, and pre-wired.  This module can be put in at the beginning of the construction process to provide power during construction.  This also makes it easier for an electrician not familiar with PV systems to wire the rest of the Earthship (which is conventional).

 

An article from Homepower Magazine on planning and living with the PV system in an Earthship:

HP article on Earthship PV

 

Some pictures below of the electrical system on the Hut Earthship:

 

 

The power module as installed in the Hut Earthship.

 

 

 

 

 

DC and AC panels

 

 

Distribution and charge controller.

 

Batteries for the PV system are located in this box -- this is on the roof.  The top of the thermosyphon solar water heater is to the right.

 

The backup power source -- only 100 gallons of propane

 

Gary

3/15/06