Off-Grid Cabin Renewable Energy Systems
Commercial power was not available to serve this cabin in the Boise Front Foothills. In order to provide the cabin with a source of power for comfort features including a refrigerator, lighting, computer, ceiling fans, and small appliances, the Owner employed an off-grid renewable energy system.
The Owner realized the benefit of renewable energy, and the available incentives, and called on Matrix Renewable Energy to provide a system which would provide electrical energy to this mountain cabin. A small wind turbine was desired for aesthetic purposes, and to take advantage of the wind resource which is intermittently present through the ravine. This same land form affected the amount of solar resource which was available to produce power for the cabin. The renewable energy system implemented includes a 900 watt, 24 volt wind turbine, and a 3,000 watt photovoltaic (PV) solar system (12 PV panels). A four (4) bank array of deep cycle batteries, configured for 24 volts @ 456 amp-hours, charged by the combination of the wind turbine and PV systems, provides power to the cabin.
The 900 watt wind turbine was surprisingly low cost, well-constructed, and presents well (a nice touch for the rustic cabin). Full power production from the turbine does not result until the wind speed approaches 32 mph. Due to the geometry of the cabin roofs, the 12 PV panels were clustered in three locations and interconnected using a combiner box. Both energy producing systems are connected to specific charge controllers, and an off-grid inverter which produces 120 VAC power for the cabin from the 24 VDC batteries.
Monitoring features provide data associated with the state of charge in the batteries, voltage and current produced from the PV panels, voltage and current consumed from the batteries, and charge history. Two means are provided to charge the batteries during non-solar periods. The Magnum inverter is equipped with an AC input for auxiliary generator power. An Iota regulated power supply & battery charger was also installed for connection to the Owner’s 2,000 watt Honda generator. System operation protocol requires the auxiliary generator to be connected to the system when the state of charge in the batteries is in a 40% to 50% range.
Even though this cabin is not the Owner’s primary residence the renewable energy improvements still qualify for a federal 30% renewable energy tax credit (dollar for dollar) and a State of Idaho 40% tax deduction.