What types of electrical panels are good candidates for solar? And what are bad candidates for solar? Is a
question I asked John Shaw project engineer for
John Shaw: Long story short there are panels out
there through grand father clause, if any
contractor came in and did any type of electrical
work, that electrical work could not pass because
of the fact that there is a panel there for a
particular brand because of law suits and stuff like
that, but that is a bit too nit picky.
The things I look for when doing a site visit are
100 amp main service limit the size of the back
feed breaker that we use to feed the house there are other ways
to integrate a system into the house with line
side taps which can be done in a couple of
We are looking for 150 plus amp service with empty breaker spaces at least two that is going to be the best scenario. We can certainly get around
anything and everything we run into but it is a
question of how much addition time and weather or not we are service
upgrade or we might need to ask Xcel for a service
upgrade or stuff like that.
The easiest way to integrate a system into your
home which is what is called a backfeed service
breaker onto your service
panel some people call a breaker box. If there are
a couple of empty spaces we take a special breaker
instead of drawing power and sending it to your
living room actually takes power from the PV system and
puts it on to the bus bar which then is just
another source of electrons on those bus bars for all of the other
breakers to pull from.
But we are limited in the size of the breaker we can put in there, by the overall service. So for example lets say
you have 100 amp service, the biggest breaker we
can use to back feed the system is 20 amp breaker?
That would mean that you could only do about a 2.5 to 3 kilo watt system.
If I am not mistaken.
3 sounds about right I would have to do the math
to figure it out,
I dont have it in my head there are some other
ways to get around it too. What the code actually
says is that if it is a 100 service that usually
means you have a 100 amp bus bar in your service
panel and 100 amp main disconnect that means you can
only feed the bus bar with 120% of its rating, so it is feed by the main breaker usually
100 percent of its main rating you can have 20%
but if the main breaker happens to be an 80 amp
breaker on a 100 amp bus bar
that is another 40 amps you could add or
you could sometimes change out that main breaker
but it is easier to go to a line side tap then
involving to changing out main breakers but you
know there are many ways you can do it.