Switching to Solar
Whether you use passive or photovoltaic solar power,
the basic principles of harnessing the sun remain the
same. To capture the maximum amount of light, you
will need your capture medium, in as exposed a site as
possible—often a house or shed roof, or the roof or sides
of a greenhouse. You can also buy free-standing solar
panels to put in an unobtrusive spot in the garden, or on
a flat roof. These have the added advantage of needing
no special equipment to install, so you don’t need to call
the electrician in.
Choose a site that faces more or less due south: anything
from south-southeast to south-southwest is ideal. The
further you stray from this arc, the less effective your solar
collection will be. Check that the site is not overshadowed
at any point during the day, including during the winter,
when the sun can drop low in the sky. Again, the more
exposure to sunlight, the better your energy efficiency.
It’s important to angle the panels so they face the sun.
In practice, this means sloping them back at an angle of
40-60 degrees from vertical. This holds true for passive
solar energy collection, too: lean-to greenhouses made
with a sloping wall from ground to wall, exposing the
maximum area of glass to the sun, make the most of
every scrap of
winter sunshine.
If you have
a greenhouse, you already own a
giant solar panel. Just putting it up
increases temperatures
inside about 3-5 degrees
above ambient air
temperature outside.”
Maximum Yield USA | January 2015
77