For the first six or seven years we lived here we only had four 150 watt panels on the roof, I forget the brand. There is a charge controller, I forget the brand. It feeds into a battery bank of twelve deep cycle 6 volt batteries wired series to get the voltage up to 24volts and then in parallel banks to add up the amp hours. I think they are golf cart batteries we got from Costco. The battery bank feeds a Trace DR1524 inverter which is old school now. It does have a really nice charging system built into it, apparently the "DR" on the model name meant "Dominican Republic" where they only had several hours of grid power a day so during those hours the inverter would be charging up the battery bank. It is only a modified sine wave, though instead of a pure sine wave but it's been running just about everything in the house. There is a back up generator in case the sun doesn't shine for several days or if we want to use a lot of power for something.
When we only had four solar panels, we had a propane refrigerator. It was using a five gallon tank of propane about every seven to ten days so that was getting expensive when the price of propane went up. No natural gas in Hawaii, so we didn't have that option for the refrigerator. The stove is gas as well as the water heater. It would take a HUGE photovoltaic system to run a water heater or electric stove. We were running lights, power tools, computers, radios, TVs, VCRs, table top incubators, washing machine with a gas dryer although we mostly hang the clothes out on a line to dry, an electric blanket, etc. although all the lights were fluorescent or CFLs and we keep a real tight watch on energy use. All power outlets have a switch to turn them off so no ghost loads are possible. Most of the system was powered by solar although we still ran the generator during the winter for several hours a day. We got four more solar panels and we had to upgrade the controller when we did that. We've switched over to an electric refrigerator and have a small freezer now, too. We rarely run the generator now.
If we were to get a new system, we would look at an Outback system, they make good stuff. We'd also get a pure sinewave instead of modified if we could and probably add in a small wind generator, too. One of those Airex types. We are completely off the grid even though there is an electric pole for our neighbor up back more or less in our front yard so it at least looks like we are connected to the grid. The electric folks even give us notice when they are working on the power in the neighborhood.
Oh, if we move, we are taking the photovoltaic system with us! From the main circuit breaker on, the house is wired just like any other house (well, except for those walls switches above the outlets which the electronics are hooked into. Basically our photovoltaic system replaces the electric companies meter, everything else wiring and appliances wise is the same as all the other houses around. We do have a meter to look at to see if we have enough power for whatever we want to do. If the power is low, there's a switch to turn the generator on and off. So far, we don't have that automated. If we were getting a new generator, we'd probably opt for a propane one - natural gas if we were somewhere that it was available.
