Living Off Grid – Operating Our Solar Power System – Part 1

Reader Contribution by Ed Essex
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Part 1 – System Overview

As most of
you know, we get all of our electrical power from our solar power system. In
the blog Our Solar Power I describe a system that is
completely “hands off’ automatic if
you want to use it that way. I choose not to.

I’ve never
had any experience with solar energy before now. When the system was installed
I received a pile of literature, user manuals, and an hour of instruction. For
me the instructions when right in one ear and out the other. It takes me a
while to absorb information that is so unfamiliar.

As you
gradually get used to working with solar power you become more familiar with
how each component works. The components for us are broken down into the
following categories: solar panels, battery charger, inverter, batteries and
Trimetric monitor.

There isn’t
much to do with the panels. Keep them clean and free of snow in the winter.
Adjust the tilt twice a year for maximum exposure to the sun. The sun is high
in the sky in the summer and low towards the horizon in the winter. The sun
stirs up the little electrons in the panels which creates electricity which is
then sent to the charger.

The charger
receives electricity from the panels and maximizes that power in terms of
efficiency to charge the batteries. Once it is set up it is virtually hands
free.


The panels
make electricity which then goes to a charger which maximizes the power and
sends it to the batteries where it is stored for future use. The larger the
battery bank, the more storage capacity you have. This is where our power comes
from when the sun is gone at night or on a cloudy day. We have enough storage
capacity for about three days. Once my batteries get down to about 60% capacity
the generator will come on to charge them back up if the sun isn’t shining.

Batteries need to be maintained at all times. I keep the terminals clean, the
water filled up in the cells and the batteries equalized once a month. There
are a lot of opinions on how often to equalize batteries. My warranty requires
that you do it once a month. Equalizing batteries is a controlled overcharge
for a given length of time to desulphate or kind of like a self cleansing. It
also causes all of the cells to become equal. For instance if you have one weak
cell it will cause the whole system to be less powerful than it should be. By
“equalizing” that weak cell will be brought up to the same level as the other
cells and your system will be as strong as it can be.


The inverter
is programmed to do a lot of things. It is talking to the charge controller,
the batteries, and the AC panel all of the time. It coordinates all of those
along with your backup generator when necessary. It is the Manager of the whole
solar power system. One of the most important jobs an inverter does is to
convert the battery DC (direct current) to AC (alternating current). Solar
panel and battery power are DC.
Most homes are wired for AC. Ours is too. The inverter sends the converted DC power
to our AC panel. From that point on our house operates just like yours for
electricity. We use the same appliances and light bulbs as everyone else. Once
an inverter is programmed to do what you want it to, it is also hands free. 


Inside our
house we have a Monitor of what our system is doing all of the time. It tells
us how much power there is to use, how much we are using, and how much is left.
It is only a monitor. It doesn’t manage or operate anything but is a necessary
source of information you can use to manage your system if you choose to.

Part 2 next week – Managing the System.

Ed and Laurie Essex live in the Okanogan Highlands in Eastern Washington State where they operate their websites goodideasforlife.com and offgridworks.com.