| Secluded Asheville area mountain vacation rental |
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Electrical Power
Here is your chance to try off-the-grid living without serious hardship. The home is completely off the commercial power grid; the power lines do not even come that far up the mountain. The system was professionally designed and installed and provides for complete hands-off operation. Standard 120 volt AC (VAC) is supplied via an inverter from a battery bank of 16 deep-cycle six volt batteries arrayed in series-parallel (2 x 8) into a 48 volt DC (VDC) system. (That is about 2,000 pounds of batteries.) Power to charge the batteries comes from three sources: solar, mini-hydro, and a backup generator. Primary power comes from two 1,200 watt solar panel arrays. Each array has eight 12 VDC panels in series-parallel (2 x 4) to produce 48 VDC system voltage, the same as the battery bank. Each array has a separate controller for charging the batteries. The secondary source is a mini-hydro unit which is installed at the home of our daughter a little way down the mountain. Water is taken via a two inch pipe from a catch basin installed in a small stream up the mountain on our property. The pipe runs down the mountain for about 1,000 feet with enough vertical fall to generate the pressure needed to power a small turbine before it is returned to the stream from which it was taken. The hydro unit runs 24/7 and when the stream has enough water it usually produces more power than is needed for our daughter's home for at least some portion of the day. When that happens the excess is sent up the mountain to our system as 120 VAC, where it is stepped down and rectified to 48 VDC and charges our batteries. The third (backup) source is a quiet, highly reliable, propane-powered, 15 kilowatt, water-cooled, low (1,800) rpm, Kohler/Generac generator purchased new in 2007. If the battery voltage falls below a predetermined level then the generator self-starts, checks itself for voltage, frequency, and other operating parameters, and then automatically begins charging the batteries. It automatically shuts down when the batteries are fully charged. The system has proven to be much more reliable than commercial power usually is this far out in the mountains, since it is unaffected by the weather conditions that interrupt commercial power; i.e., thunderstorms in the summer and ice storms in the winter. We have never been without power due to weather. The only disadvantage of this system is that the primary and secondary power sources can generate only a limited amount of power for continuous use; i.e., 2,400 watt theoretical maximum on a sunny day with the solar arrays perfectly angled to the sun. The use of electric stoves, ovens, and air conditioners is not feasible at all. For example, a 3.5 ton air conditioner uses about 6,500 watts, over two and a half times the theoretical maximum for the solar arrays. Prolonged use of smaller heat-producing appliances like toasters and hair dryers will cause the generator to kick on because, when added to the normal load for things like lights and refrigerator, they exceed the output of the solar panels. We make a kind of game of it. We are always careful with electricity, but we watch the battery voltage on the meter beside the wall oven and conserve even more carefully if it is getting below 48 volts. If the backup generator comes on, we've lost the game. It's not a big deal, though. If you really need to dry your hair then go ahead and do so. We use LP gas to cook, dry clothes, and heat water for household use and for the radiant-heat floors in the winter.
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