Each homesteader reaches a point
in his research where it is decided that an alternate energy source is
necessary due to location, thrift, or the need to get off the grid. However choosing between the available options can be a daunting
challenge, especially when tens of thousands of dollars may be spent. Our
two major options are solar power in the form of photovoltaics, and wind power.
Solar power, also known as photovoltaics (PV), is one of the most prevalent forms of alternate
energy. Photovoltaic panels can be installed relatively easily, are
non-polluting (at least in use), quiet, and most importantly, very
reliable if the weather cooperates. However they require
controllers, batteries, inverters, or specialized appliances, and for the
price, they don’t generate nearly as much power as wind.
Wind power is also a very common
form today. Wind generators generally produce more power for the
price, a higher level of power, day and night, even in inclement weather,
and generally produce four times as much power as PV - but it must be
windy. If you live in an area where a light breeze only pops in once
a month, it will not be your best choice. Most wind turbines achieve
maximum power at around 24 - 28 miles per hour of wind. They also
require a tower that can be quite high, depending on local ordinances and
propeller diameter.
Before we go any further, let’s
explore the technologies and manufacture of both options that may be of
interest to the environmentally-conscious homesteader. Solar cells
can be produced in a rather nasty manner. Semiconductors are made of
extremely exotic blends of elements to achieve maximum efficiency and even
more exotic elements in the future. These can include heavy metals
and polluting plastics (used during manufacture). However the fine
folks that put these together understand the need to lessen the impact on
the environment, and take great steps to minimize any danger.
Wind power, on the other hand,
uses some very conventional materials in construction. Imagine the same
generator that is inside your gas or diesel gen-set, placed on top of a
tall pole with propellers mounted to it. Copper, steel and aluminum
will make up the motor. Many blades are carbon-fiber these days,
and some are even made of wood. You will need a large tower on your
property, anywhere from 20 or so feet to upwards of 100 feet for some
large units. Taller or shorter towers are in use depending on the
need of the turbine. There is also the factor that some birds, for
some unknown reason, fly into the propellers of the spinning turbine and
are killed or maimed. This doesn’t seem to occur often, but it does
happen infrequently.
Batteries: when you want to think
of a nasty way to store electricity, this is it. The most common
battery in use has lead plates inside a plastic shell filled with acid.
They don’t last all that long and must be replaced once the life of the
battery has passed. On the upside, batteries are always recycled
when you bring a batch in to exchange for new ones. Other batteries
include some more exotic types such as gel cell, calcium lead, and lead
antimony to name a few. Also, you may need a lot of batteries, big
batteries, with prices ranging from $80 or so to upwards of a thousand
dollars. The more you pay, the more power it can store, and the
longer it will last.
Now that we understand what goes
into the bits and pieces that will make up our systems, it is time to look
a bit further into the systems themselves. Each system requires some
of the same elements. The source (PV or wind turbine), charge
controller, batteries, DC appliances or inverters, wiring and supporting
hardware such as battery racks, fuse systems and wiring. In the case
of solar you will need racks to hold the cells; with wind you will need
the tower.
To setup a solar system you will
need the cells themselves which can range in price from $80 or so, all the
way to several thousand for the big boys. On the plus side, they
will require little maintenance and last for 20 years or so. A
secure and sun-drenched locale is also needed with sufficient support
structure. (A few 2X2 pine strips nailed to keep them down isn’t
sufficient.) Then you will need a charge controller, the batteries,
wiring, and either DC appliances or an inverter.