Solar Panel Power and Sizes Solar panels come in various size but are usually about a square yard or square meter in area. This calculation is used to compute your solar panel efficiency and the total area that will be consumed on your roof. Depending on which panels your provider offers, the number you enter here will vary accordingly. Here are a few common solar panels, their sizes and power generation capacity. There are 2.54 centimeters (cm) in an inch. One centimeter is about 0.394 inches. Prices listed here are the lowest retail one's I have seen, uninstalled. Panel model Width (cm) Height (cm) Peak power (watts) Watts per square meter Approximate cost ($) BP Solar BP3150 79 159.3 150 119 xx BP Solar BP3160 79 159.3 160 127 xx BP Solar BP4160 79 159.3 160 127 xx BP Solar BP4170 79 159.5 170 135 xx Kyocera KC120-1 65.2 142.5 120 129 420.00 Kyocera KC158G 99 129 158 123 xx Kyocera KC167G 99 129 167 130 576.00 Sharp ND-123U1 66.2 150 123 124 444.00 Sharp NE-165U1 82.6 157.5 165 127 634.00 Sharp ND-167U1 100.4 132.8 167 125 xx Sharp NT-175U1 82.6 157.5 175 134 682.00 Sharp NT-185U1 82.6 157.5 185 142 xx Shell PowerMax Plus 150 81.4 162.2 150 113 xx Shell PowerMax Plus 160 81.4 162.2 160 121 xx Shell PowerMax Ultra 165 81.4 162.2 165 125 xx Shell PowerMax Ultra 175 81.4 162.2 175 132 xx There are other ways to put photovoltaic cells on your roof. Kyocera offers UniSolar shingles, for example, but these are not covered here because they are considerably more expensive at this time. Complicating matters more is the temporary shortage of solar panels due to generous rebate programs in Germany and Japan, where electricity costs substantially more than in Texas.