EA was contacted in 2004 by a developer who was building a luxury vacation home in an off-grid location. The client had no previous experience with off-grid and had no experience with energy efficiency. These buildings were constructed as if they were tapped into an unlimited energy supply with all the conventional appliances - and then some. With two homes, many appliances were duplicated.
A partial list of loads:
- Two propane furnaces.
- Three dishwashers.
- Two washer/dryers.
- Three refrigerators, two full, one bar.
- One deep freeze.
- Every electrical kitchen gadget that exists and then some.
- Significant quantity of lighting, indoor and outdoor.
- Satellite Internet & wireless computer network.
- 2 HP effluent pump.
- Well pump.
- Security system.
This was a significant project which has evolved over time. Here's a summary of the system as it stands today:
Inverter: 4 x 5.5 kW inverters give 22 kW continuous inverter power, loads split into two power panels. Original inverters Xantrex SWII5548. Expanded inverter capacity with SWPlus5548 panel.
Batteries: 24 x Global Yuasa 85T21's give 70 kWh of total storage. A battery watering system facilitates refilling of battery.
Charge Controllers: Morningstar TriStar 60's regulate the PV array.
PV array: 8 x Sharp 185 modules (1.5 kW) on first array and 12 x Sharp 175 modules (2.1 kW) provide the bulk of summer power needed.
Generator: Dual onan RS12000 propane generators, for redundancy.
Monitoring System: This site has an extensive remote monitoring system. The client or EA techs can remotely monitor system performance (PV1, PV2, Gen1, Gen2, demand), can modify inverter programming as needed, start/stop generator, restart satellite internet, restart router.
