Living off-grid with a reliable generator is not all that difficult; but if you want to minimise your fossil fuel use, and on top of that have a spouse who insists on a modern home, things get a little more complicated! At PhotonPharms near Fairbanks, Alaska, we are not connected to the electricity grid, yet we have a home with all the comforts to rival any house ‘in town’. Thanks to efficient design, the home runs quite comfortably on an average of around 10 kWh per day; from mid-February to mid-November, 8 kW of solar panels and a 40 kWh 48-volt battery bank feed the home system without any trouble (we also have a 1 kW wind turbine, but the Fairbanks wind is often not steady enough to make an appreciable difference).
December and January are another story: at 65 degrees north latitude, for most of December the sun stays above the horizon for less than 4 hours a day (maximum elevation 4 degrees). The solar panels produce roughly 30 kWh over the whole month. The difference is made up by a 6 kW diesel generator controlled by a DSE402 Mk II Auto Start Module. For two years, we relied on a Magnum inverter/charger that could charge the batteries at around 3 kW (about half of what the generator can produce).
The DSE9450 was added to the system; one reason was that it can be programmed up to a full 2.5 kW and its flexible charge curves can be easily adapted to a lithium battery system. Afterwards, I discovered that the programmable fault detection feature could be used to detect conditions before the generator becomes overloaded (for example when the water pumps kick in). Now the generator runs at around 90% capacity instead of operating at a low load of 50-60%. This has led to a significant reduction in generator run time (early indications suggest that this winter the generator will run for less than 200 hours, compared with around 350 hours in the past); although hourly fuel consumption has increased slightly, total fuel use has decreased markedly. I am grateful to Richard Ridley (DSE Technical Support Engineer), who helped me with the installation, particularly in working out that we could use the charger at 240 V AC with a neutral in the middle.
