On May 17, 11:54*am, Andy wrote:
On May 16, 8:02 pm, JimT wrote:



I think it's viable here (Austin) if you take advantage of the $2.50/kw
rebate but you have to use one of the city approved installers. A PV
certificate isn't going to do much good in that case so that's why I
dropped the course. My wife is calling me a college drop-out.

I'm looking into one of the "plug-in" systems but it seems like they are
still in the development stage.

Jim

Andy comments:
* I guessing that the requirement for a "licensed installer" is more
for
the safety angle of the panels blowing off your roof and damaging
property or persons than whether a "proper" electrical installation
is
involved. *The city of Austin probably doesn't care whether it works
or
not, just whether it is safe ---- as most building codes are designed
to do...

* *One further safety issue is whether the installation will feed
electricity
back into the power line. *If a lineman has to "disconnect" power to
do
repairs a couple streets over, and PV installations are keeping the
power line energized and he doesn't know about it, it will be a safety
hazard....

* *But, mostly, I think it is all the wind,hurricanes, and tornadoes
making loose
shingles, tiles, signs, panels fly about decapitating people..... and
ruining their flower beds.

* * * * * * * * * * * * Andy in Eureka, Texas (south of Dallas)

This is all taken care of by the inverter. Known as "Anti-islanding"
Bit on the topic here.
http://en.wikipedia.org/wiki/Anti-islanding
If the grid supply fails, the inverter shuts down. ie it won't run in
stand alone mode.

There are many other aspects such as excess grid voltage etc.
These new inverters do lots of things. Mine gathers all manner of
statistics, It can be linked to a computer so they can be continually
monitored. Not that I've bothered. I just keep a daily record of Kwh
produced.

I have to produce 10kwh/day over a year to make 11% return on money
invested.
So far I've averaged 18.8 but it's early days yet.. It will be a lot
less in Winter.
Max.has been nearly 30, min has been 9.6

We don't have extreme climatic events in the UK. Or very rarely.

If you are retired you can make vast savings in electric bills by
doing major electricity using activities in the middle of the day.
I have a 3.88Kw array, it often hits that. This is enough to run any
appliance we have.
Surplus is exported. We are paid for all electricity generated to a
total worth of about $0,70/Kwh whether we use it or export it...