Our 2400 square foot home and office is located on 5 acres East of Seattle and North of Redmond (home of Microsoft) in the suburban/rural transition area of Washington State’s most populous county.

The "farm" includes 4 acres of 80 year old evergreens, a chicken coop with 2 dozen laying hens, a 600 square foot garden and a wood shed.

We have a deep water well with an 800 gallon reservoir and a septic system because these county services are not in our area. We do have underground grid connection but the slightest wind often knocks this out because the community feed is on poles surrounded by trees. This fact prompted us to purchase a 10KW generator when we first moved in because living without running water was not attractive. However, the noise and hassle of the generator quickly got us thinking of alternatives.

With recommendations from a friend and co-worker, Darren Emmons (well known among RE enthusiasts in our area), I designed a code-compliant back-up power system around the Xantrex Trace SW4024 Sine-wave Inverter.

The DC side contains 660 AH of Trojan T105 batteries in a 24-volt configuration with DC distribution to a few "outlets" to support lighting in the event of grid and inverter failure. DC is also fed to the HAM station in the office where a 24-to-12 volt converter powers the equipment. The DC side is monitored by a Cruising Equipment E-Meter.

The inverter AC output powers 10 circuits through a GenTran transfer switch which allows us to select the feed to each of the circuits; either grid or inverter. This makes it convenient to ensure that when we are away from home, the backup system only powers the bare essentials so that the batteries last as long as possible. We also use this for manual load shedding when we are at home during power outages.

The output feeds the deep well pump, the pressure pump, the gas furnace fan, fridge, freezer, washer, microwave, computer, TV/stereo and most lights. It does not power the outdoor circuits, dryer, cook-top, range or electric base-board heaters in the two rooms without furnace heating.

The 10KW generator 240 volt output feeds a step down transformer which then feeds the inverter at 120 volts. This ensures that the generator is equally loaded on both sets of 120 volt windings. The generator is wired to the Trace Inverter for automatic start.

After the initial installation, photo voltaic (PV) panels were added. The first panels were a set of 4 donated 1984-vintage 40-watt panels decommissioned from one of my father’s mountain-top commercial radio sites. Next a set of 4 UniSolar 64 watt panels were added (these were chosen because of their good performance in partial shading). Lastly a set of 4 BP 75 watt panels were added. The PV panels are located on top of a 16 foot platform erected on the North side of the property. This was necessary to catch the sun’s rays above the 120 foot evergreens in the dead of Winter (even so, partial shading occurs for two months).

Of course, it goes without saying that we use the products that we develop and sell, and we try them out first on our system before we give them to our “beta” testers who evaluate them before we ship them to paying customers.