The Solar Resource
Not all roofs are created equal.
A successful Solar installation needs great access to the sun. For most home and business owners in urban areas, this means a Southern-facing roof, minimal shading, and about a 30 degree tilt of the array. Rural areas and owners with excess land can erect ground-mounts for their arrays on nearby property, while options also exist for awning and carport-style Solar canopies.
Solar irradiance on the Earth’s surface averages around 1000 Watts per square meter, meaning an owner’s access to solar power is dependent on how much area they can devote to the project. The more space available for an array, the more access to power for heat and electrical generation. This ‘resource’ must sometimes be protected from shading and adjacent contstruction projects, and many municipalities have enacted ‘Solar Rights’ laws to ensure reasonable access to sunlight for all properties.
Although an array facing due South is ideal, East and West facing roofs are also acceptable for most installations. The South-facing orientation gives panels optimum exposure to sunlight year-round, averaged through all seasons and times of day. When a different orientation is used, the expected system production will be lower by 5-25% for all Solar technologies.
Solar Alternatives uses specialized software simulation to predict average annual Solar Energy System production very accurately for Solar PV, Solar Water Heat, Solar Pool Heat, and Solar Process Heat projects. These production values are used to provide each client with expected performance and investment figures for their particular system configuration.
