There are many ways to mount solar panels. Some of these methods may include fixed on your roof, fixed on the ground, fixed on pole mounts, or pole mounted tracking arrays. Mounting your panels on the roof makes sense from a security, stealth and convenience standpoint, and can lower roof temperatures in hot climates, but is inconvenient in snow country. Panel angle should be adjusted seasonally for best collection.

The size of a 200 watt panel is approximately 60" x 40" x 1.5", and weighs about 40 lbs, so keep that in mind when thinking about mounting methods and location.

The solar panels are wired to a charge controller. This unit makes sure that the batteries get fed the proper amount of electricity, at a rate they can handle, and will help ensure longer life from the batteries. The traditional method is to have a 12v solar panel, a 12v charge controller, and a 12v battery. The newer and more efficient method is a series string of panels running at a higher voltage (100v or less, but at least 20v higher than battery voltage), a special MPPT controller, and the 12v battery pack. The MPPT controller matches the best performance curve of the panels to the batteries, allowing up to a 30% increase in power, without needing more panels.

The typical battery in an off grid system is a flooded lead acid battery. This unit has vented caps, discharges hydrogen during charging, and needs to be vented, as well as rewatered fairly often. Another solution is the AGM battery. This unit does not need venting, and is sealed, eliminating watering. It also won't leak acid in the case of physical damage. It is more expensive, so there is a trade off. Deep cycle (do not get starting batteries) come in 6v and 12v. Consider two 6v in series to be a 12v, four in series for a 24v system, or eight in series for a 48v system. You can parallel multiple 12v batteries (or 6v pairs) to increase Amp Hour storage (two 100ah batteries in parallel = 200ah). Batteries in series add voltage, batteries in parallel add amp hours.

An inverter changes low voltage dc (Direct Current) into 120v ac (Alternating Current) for regular household appliances. Inverters can range from the cheap $60 750 watt Black and Decker from Walmart, to a $2500 Xantrex or Outback with integrated battery charger and transfer switch for connecting to the grid or a generator. Cheap inverters have to be connected directly to an appliance, while the larger, more expensive units can be connected directly to your existing breaker panel.

For safety, and convenience, we install fused disconnects between the solar panels and the charge controller, between the charge controller and the batteries, and between the batteries and the inverter. This allows us to safely isolate the components for maintenance (or panel deployment), or automatic disconnect in case of a short or equipment malfunction.

Running a system without a battery monitor is like using a bank account without a check register. You have no idea how much energy you have until it runs out and you are in trouble. The simplest, and least effective is a volt meter. It will tell you the voltage of the battery pack, but that reading is highly affected by charging and discharging, making the reading basically useless. The best method is an amp hour meter on your battery pack, that indicates amp hours deposited, and amp hours withdrawn. These units commonly also include a amp and volt meter function. There are standalone units like the Bogart Trimetric, and integrated units like the Outback Flexnet DC. A standard multimeter ($15 at Radio Shack) is useful for detecting power, polarity, and continuity, but not as a system monitor.

Wire size is a function of amps being carried, and the distance they need to move. If you have 40 amps (480 watts) of PV on your roof, and it's 8' to the charge controller and batteries, then you should use 8 AWG wire between the PV panels and the charge controller (and from the charge controller to the batteries). The wires between your battery(s) and inverter should be short and large. A 2000 watt inverter, 6' from the battery bank, needs 1 AWG battery cables. The smaller the AWG, the larger the cable. If your cables are too small, they will generate heat, and possibly a fire, as well as dropping the voltage to less than useful levels.

I know I said we wanted to avoid these things, but sometimes you can't. If you live in 100 degree weather, you are going to want an air conditioner, and that means a outlandishly large PV system, grid connection, or a generator. Many northern climates have a large number of sunless days. We like the Honda EU series generators. They are small, quiet, and scalable (can run one for small loads, and slave a second for heavy loads). Yamaha makes a similar series. Both can be modified to run on gasoline and/or propane. This is where you'll want the better inverter/charger/transfer units as mentioned in the inverter section, as there just one cable to connect to the generator, and switching/charging is automatic. A wired or wireless remote is available for remote start and shutdown, and the more expensive inverters can handle this procedure automatically based on battery needs.