Wire For Solar Panels
choose and use the right
wires with your solar system.
Solar wire types (also known as solar panel wire and pv
wire) refers to the type of wires used to connect your solar panels with the rest of your
Choosing the right wire for your solar energy system is critical to it's functioning
properly and remaining undamaged. If you get this wrong and choose a pv wire too small for
your pv system, your battery bank may not charge fully and as a result your appliances might not
work as well or at full power.
Solar Wire Types
Electrical wire (which is the same exact thing as
solar panel wire) is categorized mainly based on it's conductor type. If it has a single metal
wire core, it's a single stranded conductor and if it has a multiple wire core, it's a multi
stranded conductor. These are the two basic wire types.
The difference between a single stranded conductor and a multi stranded conductor is that the
multi stranded performs better in continuous vibration environments such as mobile applications in
cars, boats, planes and trains.
The one strand conductor type wire
is most commonly used in domestic wiring and should be okay for your solar system, however if your
area is prone to consistent and extremely high winds, you may
want to consider wire types with a multi stranded conductor as it is more flexible thus more
The wires used in solar systems are rated by their Amps. This is
the maximum amount of amps that can travel through that wire and this rating must not be
Basically, the higher the current (amps) your solar system
is rated at, the thicker the pv wire has to be. If your system produces 7 amps, you
will need 7 amp wire (actually it's better to go a little higher like 9 or 10 amp wire,
just to make sure you can handle the current).
If you mess up and use wire rated at less amps than your solar
system produces, the voltage will drop, your solar panel wire
will most likely heat up
and eventually may even catch fire
causing damage to your solar energy
system and your home. You can learn more about staying safe while
working with solar power by clicking here to go to the Solar Safety section of our
Think of your electrical wire like a plumbing pipe. If there is too
much water pressure (amps) flowing through it, it will burst.
Therefore you would need to get a bigger pipe (wire) that can
handle the pressure (amps) produced by your system.
Thicker pv wire costs more than thinner pv wire because
it can handle more amps. When choosing the thickness of your wire, you can go one of two ways. A little thicker
for safety or just thick enough but vulnerable to sudden power surge.
A great way to go about choosing the wire thickness for your solar system is to buy solar panel
wire big enough to cope with the biggest current (amp) drawing appliance you have and using that
wire for all the other runs to the AC breaker panel. Here's a handy wire sizing calculator for solar arrays that will figure out the
size of wire you need for you.
PV Wire Length
Along with having to use pv wire rated at the right amps, you must also take into account the
length of your solar wire. By this we mean that if your pv wire is longer than average and
connected to a high current appliance, you will need wire with more (higher) amps. Otherwise, there
may be a voltage drop and a fire.
For example: If you had a 20 amp appliance and you used a 20 amp wire of considerable length,
you would be at risk of a voltage drop. To prevent this from happening increase the size of the pv
wire to at least a 35% margin, so for the above example, use 27-30 amp wire to be safe.
The longer your wire is, the higher the amp rating on your wire needs to be, so don't be shy to
go a little thicker in the name of safety.
Also, using thicker wire can insure that potentially high current (amp) appliances bought in the
future will be more likely to handle the current. There is no harm in preparing for the future now,
especially if it's going to save you having to upgrade to thicker wires later.
Here's an example to illustrate how length affects
Let's say your solar panels / battery bank produced 7 amps and
you were using a wire length of 4.6m. This is starting to get lengthy, so add a
35% safety margin which is:
7 + (35% of 7) = 9.45
Therefore, you would need 10 amp
If you run pv wire that's even longer, you can use the chart below to determine the necessary
wire thickness based on amp rating and wire length.
PV Wire Gauge
Here is a guide to choosing the right wire gauge
(thickness) for your amp rating plus your wire length.
To determine the size of solar wire needed, just look at the AMPS in the left column and select
the amp rating of your solar system. Next follow the same row over to the approximate length of pv
wire you will be using. Then, follow the column up to the yellow box at the top which will be the
AWG number wire you'll need. AWG is a system of labeling wires that has been used for many years in
the USA. AWG numbers get smaller, as the wire length increases.
One important thing to note is that, while all wire used for individual runs from the breaker
panel to the appliances must be able to handle the amps of that appliance, the wire from the
battery to the rest of your photovoltaic components must be able to handle the total amps of all
the individual runs, plus at least 35% more. You can learn more about the various
photovoltaic components needed in a solar energy system by clicking here to go to the
Photovoltaic Components section of our website.
Also, keep in mind that it's better and much more
affordable to try and use solar wires that are shorter in length rather than to have to buy
very thick (and expensive) wire to compensate for unnecessary length.
Please consult with a certified electrician to verify that you have chosen the right
solar wire types for your entire solar power system before connecting any
If you stick to these rules and basic safety pre-cautions to choosing the right solar wire type
and thickness, you will definitely improve your effectiveness and efficiency as well as reduce your
chances of causing damage to your solar energy system.
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