Designing A System
Whether you are planning or living in an existing home or building, the design and placement on a building or lot will allow your solar electric system to take advantage of the sun’s energy saving thousands of dollars in energy costs over the years. Key factors that will affect performance are:
ORIENTATION
A South or Southwest orientation is best to maximize
sun exposure. The closer a solar
photovoltaic system is oriented to solar south, the more solar electricity it
will generate, thereby increasing the financial return on the project.
TILT ANGLE
While the best annual performance generally
comes from a PV array that is mounted at a tilt equal to your location’s
latitude, your roof pitch may not match this parameter. No problem - an array
tilted 15 degrees off from your latitude will still produce 95% of the energy
from an array tilted at latitude.
AVOID SHADE
Small amounts of shade can significantly
reduce the output, which is like throwing kWh and money down the drain. Shading
is the number one system performance problem whether form overhangs, second
stories, trees, exhaust vents or chimneys.
ROOF AGE/SPACE
Solar panels will generate electricity for
more than 25 years. If your roof is more than 10 years old, it may be more cost
effective to install a new roof than remove and re-install the panels down the
road. Panels will preserve the roof’s longevity by blocking UV rays, keeping
most snow and ice off the roof and providing shelter to the roof. The amount of
space needed depends on the size of your system.
SOILING
Dirt, dust, bird droppings and snow can filter
out some sunlight affecting system performance. Periodic rainfall or light
hosing will take care of these.
TEMPERATURE
Like any material exposed to sunlight,
PV
modules heat up. Therefore, it is important to provide sufficient airflow with a
3-6” air gap between the roof and flat mounted panels to maximize performance.
