[SGVLUG] Off-topic - solar power - city of pasadena

[Michael Proctor-Smith]

On 3/9/07, Jeremy Leader <jleader at alumni.caltech.edu> wrote:
> on 03/09/2007 11:24 AM Emerson, Tom (*IC)  wrote:
> >> -----Original Message----- Of Robert Leyva
> >> The city of Pasadena has a URL about their policy on home
> >> solar grid intertie systems and how to go about it.
> >>
> >> http://www.ci.pasadena.ca.us/waterandpower/program_solar.asp
> >
> > In the "it always pays to read the fine print" section, I noticed a
> > brief paragraph entitled "Interconnection" that states:
> >
> >      "... National Electric Code (NEC) standards may prohibit operation
> > of the customer's system when PWP power is interrupted."
> >
> > So, I take it that if there is a power failure in the middle of a hot
> > sunny day ('cause too many A/C units are online), your solar system
> > would shut down too...
>
> I suspect that just means that when PWP goes down, you're probably not allowed
> to send power from your system out into the (otherwise dead) grid.  So you can
> keep your power on, you just can't try to power the whole neighborhood.

The problem is how the system is wired into your electrical system.
You probably have to wire the system with more then on circuit breaker
panel so that only some of the circuits in the house are wired to run
off solar but not all so that when the grid power fails your system
disconnects from the grid but is not overloaded by things inside your
house. If only I was good at asci diagrams but the cheap way to add a
grid tie system would lead to all power shutting off when the grid
did.

> Jeremy Leader
> jleader at alumni.caltech.edu
> leaderj at yahoo-inc.com (work)
>