If you are in the market for photovoltaic (PV) solar panels that can supply some or all of your home's electrical power, you have no doubt discovered that are many diffferent types of these panels and they are all quite expensive. As discussed in Solar Panel Buying Tips, panels differ in many features, including output, dollars per watt, efficiency, and mounting. The main manufacturers of these products each have their strengths and weaknesses--sorting through the various models can be challenging.

One of the ways to measure the relative value of a solar panel is to figure its "dollars-per-watt" ratio. This figure will tell you how many watts per dollar of investment your solar panel will generate. For example, if a grid costs $800 and produces 170 watts, you divide $800 by 170 to determine that its dollar-to-watt ratio is $4.70.

Along with the dollars-per-watt ratio, the conversion efficiency ratio is a helpful measure of efficient output. The higher the conversion efficiency ratio, the better job the module does at converting solar radiation into electricity. Most modules on the market have a conversion efficiency ratio that ranges from 12% to 18%.