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solar in CA? where to start? - Page 5

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Posted by Roderick on March 15, 2007, 7:20 pm
 
No, you don't need to demolish the old roof.  I did, because the roof
needed changing, anyway (25 year old shake).  How much it costs to
redo a roof varies widely.  I got quotes from $700 to $500 for the
same job.  But since your roof is relatively new, this should be
irrelevant.

You can absolutely install right onto a composition roof without
tearing up the existing roof.  What you need is "L-brackets,"
available from several solar rack vendors, or you can make your own.
The two tricks are finding the rafters, because you want to screw into
something solid, and sealing the hole, using a good amount of roofing
silicone.

As far as the electrical part, try Googline for "John Wiles NEC code",
and find the document that everyone uses.  That explains what you need
to know.  Generally, speaking, if you have a 100A panel, you can put
another 20A into it via solar.  As long as the subpanel is rated as
such, you could add the 20A to the subpanel.  The solar needs its own
breaker, of course.

If you're in PG&E territory, as of 2007, you are no longer required to
have an AC disconnect switch, I believe, but check with them.  I think
I would still put one in, anyway, to avoid having to flip a breaker
just to disconnect the inverter.

On Mar 15, 4:24 am, jeremy...@my-deja.com wrote:


Posted by dold on March 15, 2007, 8:49 pm
 


I found the requirement on the PG&E web site today.
Some of these things would be handy to discuss with a professional
installer.

I think I got decent pricing on the components from my installer, and I
don't begrudge the installation charge for the design, permitting and three
days labor for three guys.  They assigned the rebate to themselves, so I
didn't have to put that amount up and wait to get it back.

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA  GPS: 38.8,-122.5


Posted by Roderick on March 16, 2007, 12:20 am
 On Mar 15, 1:49 pm, d...@30.usenet.us.com wrote:

Here's what I was thinking of, regarding AC disconnect.  True, it
doesn't apply to every installation:

http://www.pge.com/suppliers_purchasing/new_generator/solar_wind_generators/disconnect_switches/

And for the record, I am not at all against professional installers.
For the amount of time it takes an individual to do it, including
research, hard labor, and risking life and limb if one isn't careful,
the payback is probably less than minimum wage for a self-installer.
I think of it as a fun project, kind of like a garden.  Home-grown
vegetables aren't worth it, compared to what you can buy at the
supermarket, but the gardening experience is satisfying for some.  For
folks that like that kind of thing, self-installing solar could have
value beyond dollars paid to the professionals.  If the install sounds
scary or boring to someone, by all means, I'd recommend going with a
turnkey installer.


Posted by jeremy_ho on March 16, 2007, 1:53 am
 So am I reading it correctly, it says you do not need any disconnect
switch at all, but recommended?   If they want to do work, they will
just remove your meter.

BTW, I am with PG&E and I live in Northern CA

My bill is not significant, electric portion is around $5 (about
400kW) but
I am being very frugal about it, I never used the air conditioning
unless, one of the occupants need it to avoid a fatal sitation. :)
We don't have much clouds and I get sun at 6am in the summer.   But it
is very hot where I am.   So I am thinking I can use air conditioning
more than I do now (practically none) if I have PV system.   I am
partly on tier 2 so if I use some Air conditioning I will be paying a
bigger bill once i reach tier 3.

Regards to the cost of PV system, I calculated many times for off-grid
simulation, it does not payback until after thousands of days at the
base rate.   Someone needs to check my math again... for example, 1
160W panel cost $00,  conservatively speaking, I get 5 hrs of sun
avg.   5x160W = 800W generated, lets just say it takes 800W of usage
of out my bill per day.   that maybe worth 11 cents a day.   Or 7272
days to payback for the panel.   Seems to scale similarly.   This is
for the cost of panel only, not counting batteries, replacement
batteries, inverter that fail along the way, although they don't cost
that much.

The only way I see it reach some sort of payback properly is with grid
tie system.. for a person with a daytime job and go home at night, is
to go with the E-6 or E-7 time of use plan and just use most of the
electricity at off peak hours.

Do they pay you 1:1 buy / sell ratio? at the peak hours and any time?

Yes, I realized there is a $ lease on the meter.  It seems
insignificant, although,  yes $4 a year.   So you cannot buy one?











Posted by dold on March 16, 2007, 12:21 pm
 jeremy_ho@my-deja.com wrote:

They are relying on your anti-islanding to shut down the inverter when AC
is lost.  The idea of the disconnect is for them to be able to visibly
prevent your generator from supplying power back to a grid that they have
turned off for maintenance.  The thought that they would actually flip
the switches on all of the associated PV systems (three on my block),
or remove the meters is not practical.


Compared to many places in the country, this is a financially favorable
location for grid-tied PV.  The PG&E guy that installed my meter has
had PV at two of his houses.  Where are you?  I am near Clear Lake.


My PGE 2005, 11255 kWh, $ 1,721.47, 0.153 per kWh
The rates are going up in the higher tiers.  My bill for 2006 would have
been $900 without PV, and my usage is down.


I had some tier 5 during the summer with A/C before PV.


http://rredc.nrel.gov/solar/codes_algs/PVWATTS/version1/
Predicted solar energy available, very accurate for me last year.
The predicted dollar amount is low, but the watts were right.


Batteries are expensive.  The inverters needed are more expensive.  For a
grid tied system, I wouldn't bother, unless you have frequent outages.  I
have a gasoline generator that I test occasionally for backup, but haven't
used in in five years.


E-7 provides better payback for solar, without paying any attention to the
usage pattern.


It is a net meter.  You send kWh to the grid, or draw kWh from the grid.
They don't know which, they only know your net consumption each month.
You pay at the same rate that you buy.

--
---
Clarence A Dold - Hidden Valley Lake, CA, USA  GPS: 38.8,-122.5


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