Most existing homes and buildings are not designed to be powered by the
sun. However, retrofitting solar power
may be an option for some homeowners who are interested in harnessing the
free energy of the sun. Before you start any installation, check to see
how best to integrate solar power into
your home or yard.
How Much Available Space Do You Have?
The amount of space needed for solar panels depends on how much
energy you need. A good location for producing solar power should
be easily accessible and have unobstructed access to sunlight. For
established homes and yards, such a premium area may or may not be
available.
The amount of open space will determine the maximum number of
solar panels that you can install. For most dwellings, the roof
or a south or west facing wall of a home, garage or shed is the
best places for unobstructed access to the afternoon sun (peak
energy production occurs when the sun is highest in the sky).
Try to avoid locations where shadows from trees or fences will
block the sun during parts of the day when peak power will be
generated. A shadow cast upon only a portion of a solar panel
will drastically reduce the efficiency of the unit.
In most cases, roofs are the ideal location for solar panels
as they are unhindered by trees and not easily damaged by children’s
toys and soccer balls. But even if the roof is a candidate, the
pitch may not be ideal to align the panels directly with the sun.
Solar panels work most efficiently when positioned perpendicular
to the incoming sunlight. Unlike large solar power generating
stations which automatically rotate panels to follow the sun,
these aligning mechanisms are too costly for residential use.
An ideal roof pitch for stationary solar
roof tiles depends on where you’re located in relation to the equator
and the time of year that you want to produce maximum power. As a rule of
thumb, a good pitch would be your latitude + 10 degrees.
If your roof pitch is not ideal, then you can build a wood frame
to correct the angle. This may be difficult and awkward on a roof
but easier for a ground installation. Since you’ll be enjoying solar
power for years to come, ensure the supporting structure fits with
the aesthetics of your yard and neighborhood.
How Much Power Do You Need?
The maximum available area of your roof or yard will
limit the amount of solar energy produced. If this isn't
enough power, then first try to implement some energy-conserving
techniques such as new energy-efficient appliances. If your energy
needs still exceed this capacity, then your other option is to find
more area for additional solar panels.
Required Equipment
You can power your equipment directly from the solar panels, as
long as it can use 12 V direct current (DC). DC electricity will be
produced only during daylight hours and whenever the skies are clear.
Use a charge controller to maximize current output and check to see
if your equipment can tolerate unfiltered DC current that has variable
current and voltage output (10V 18V).
If you need uninterrupted power, then you’ll also need a battery
bank, inverter and possibly a transfer switch. This equipment can be
located outside but should not be exposed to severe cold temperatures
(batteries hold less charge when cold). The battery banks require
good ventilation as deep-cycle batteries release small amounts of
hydrogen gas when recharging.
Plan for the Future
It’s best not to install more solar panels than needed. Additional
panels will produce more electricity and charge the battery bank faster,
but once the batteries are fully charged, the charge controller will
electrically disconnect the load to ensure they will not be damaged
from overcharging. The extra current will be wasted.
Use your system for a complete season to determine how it performs
through the different seasons. Keep the panels clean of accumulated
dust and debris to ensure it operates at peak power production. If
your power needs grow, you’ll still have the option of retrofitting
solar power into the remaining space.