Something you can do is guarantee a kWh amount given a certain amount of
irradiance. Offer X annual kWh given 2000 sun-hours, perhaps. If you're
in a snowy area, just make sure the irradiance meter keeps snow on it as
long as the modules would.
Of course you wouldn't just take 0.8 into PVWatts and make that your
guarantee... a hot year could impact your production quite a bit so be
sure to include a cushion. Other things can still bite you here, like
the aforementioned example where there's a delay getting an inverter
tech to a remote area.
-------- Original Message --------
Subject: Re: [RE-wrenches] Volcanos, reduced solar production and kWh
performance warranties
From: Max Balchowsky <m...@seesolar.com>
To: RE-wrenches <re-wrenches@lists.re-wrenches.org>
Date: 2010/4/26 09:27
We've had a lot of people asking about "performance" warranties and I
stay very far away from any language that hints at a performance
guarantee. I think this especially important in the "PPA" I give them
all the product specifications, run the production charts and then
explain how little control I have over the things that affect output (to
the grid) which includes weather and the way they use electricity.
Max Balchowsky
SEE Systems
1048 Irvine Ave. Suite 217
Newport, Beach Ca. 92660
760-403-6810
------------------------------------------------------------------------
*From:* Marco Mangelsdorf <ma...@pvthawaii.com>
*To:* RE-wrenches <re-wrenches@lists.re-wrenches.org>
*Sent:* Sun, April 25, 2010 8:02:58 PM
*Subject:* [RE-wrenches] Volcanos, reduced solar production and kWh
performance
This thread brings up a very timely issue that I’m dealing with right
now with PV Power Purchase Providers. As an integrator providing turnkey
PV systems of X kW, I’m being asked to contractually agree to a minimum
performance warranty for said PV systems. I am EXTREMELY uncomfortable
to any such clause in any contract that I would sign. I have strong
confidence in my PV design capabilities and engineering support and in
my professional crew to install a top-quality PV system. I have a lot
less confidence in an inverter manufacturer being able to get to a site
on a Hawaiian island in the middle of the Pacific in a super timely
fashion as the lost PV kWhs rack up. And as I mentioned in a previous
post today, we have an active volcano here that’s been spewing since
1983, a volcano that could get a lot worse on any given day. I’m leaning
strongly against agreeing to any such clause. Way too bad a precedent to
set. Way too much of a liability.
Anyone else had to deal with this bugger of a performance warranty demand?
Thanks,
marco
ProVision Solar
Marco:
Our production /schedule/ has been in tatters - lowered by perhaps 30%
because of the rain.... can't plan, can't do. Then I pay overtime on
good days to (try to) catch up.
We have a number of systems online and I had not thought to actually
review and compare from this year to last. I'll let ya know.
We'll get a call like - "My bill is higher than last year (edison has a
bar graph of monthly consumption for the past 13 months) and I'd like
you to look at my system" or My meter is not going backwards, should I
call edison?" The weather is so consistently wet this winter (think
Hilo) that we usually just need to ask-
"Been outside lately?"
But everywhere is so green and the desert bloom is outrageous.........
http://www.desertusa.com/wildflo/ca.html
Pat Redgate
Ameco Solar
In a message dated 4/25/2010 12:24:53 P.M. Pacific Daylight Time,
ma...@pvthawaii.com writes:
Pat,
Kicked your butts as far as lower output? If so, by how much on a
percentage basis?
On the Big Island of Hawaii, we’ve had a very active volcano doing
its thing since 1983. With the normal trade winds, the vog (volcanic
smoke + fog) gets blown south past the volcano, around the south tip
of the island and */then back up/* along the west side of the
island. Which means that Kona-side residents can be in a yucky vog
zone for days and sometimes longer. Think L.A. on a smoggy summer
day. And as far as percentage decrease in solar output, I really
have little accurate clue.
Marco
ProVision Solar
Kicked out butts, in fact.
Pat Redgate
Ameco Solar
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