Re: Solar PV ?

["severnsource" <groups@xxxxxxxxxxxxxxxxxxxx>]

Download the Sunny Design software http://www.sma.de/en/products/software/s=
unny-design.html. That will give cable losses, amongst other things. My
inv=
erter is in the garage with about 15M of DC cable (2 strings, 4mm cable
for=
each) and 15M AC (6mm cable). The cable losses are insignificant.

--- In ukha_d@xxxxxxx, Marcus Warrington <marcus.warrington@...> wr=
ote:
>
>=20
> Stewart,
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> I looked at the micro inverters but the cost (for me) was prohibitive.
21=
panels each with its own micro inverter worked out around =A34000 , the co=
st of a single 3 string, transformerless SMA inverter was more like
=A31600=
.  I was looking at the SolarPV as an investment so the bottom line was
not=
how efficient things would be but how much profit they would earn me over =
25 years. I don't believe the micro inverters could ever earn me back
enoug=
h in the 25 year period to pay for the cost differential. Of course if I
wa=
s only having a few panels then it may work out differentially, e.g a
1.2Kw=
h array of 240W panels would only need 5 micro inverters so may well even
h=
ave a smaller capital cost than buying a single central inverter.
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> Having said all that I guess it does depend a lot of the amount of
shadin=
g you have, I only have a small localised amount so can work around it by
h=
aving the potentially shaded panels on separate smaller string.
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> Regarging the noise issue, I belive (and hope!) that this is an issue
wit=
h the ones that have a transformer in them and that the transformerless
one=
s do not generate a noise (or at least nowhere near as loud) as well as
bei=
ng slightly more efficient.
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> Our fitting date is in two weeks, but I'm still undecided if I should
fit=
the inverter in the loft, where it will will get hot but have short DC cab=
le runs, or have it in cellar where it will be nice and cool (and easily
ac=
cessable) but have a longer (~15M) DC cable run. The installer seems
confid=
ent that running 10mm DC cables will limit any ineffeciencies upto around
2=
5M.
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> Marcus
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> From: ukha_d@xxxxxxx [mailto:ukha_d@xxxxxxx] On Behalf Of=
Stewart
> Sent: 11 July 2011 11:12
> To: ukha_d@xxxxxxx
> Subject: RE: [ukha_d] Solar PV ?
>=20
>=20
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> Kevin/Marcus,
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> Had the chap from Sun Renewable here last week (thanks for the
> recommendation Mark and, YES, we did mention your name to Tom) and
we're
> looking at using Sharp panels and micro-inverters (1 per panel) made
by
> Enecsys. These micro-inverters fit directly onto the back of each
panel a=
nd
> solve the problem of one shaded panel bringing down the output of the
arr=
ay
> and also, as we were worried about the noise generated by a loft
mounted
> inverter, these will be mounted outside so noise won't be a problem
(we
> hope!).
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> The micro-inverters are a recent development so there's no worthwhile
> reliability data yet, however, they do come with a 20 year warranty.
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> regards
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> Stewart
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> From: ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>
[mailto:ukh=
a_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>]
On Behalf Of
> Marcus Warrington
> Sent: 16 May 2011 15:36
> To: ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>
> Subject: RE: [ukha_d] Solar PV ?
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> Kevin,
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> I think in theory it still does, but you can get panels with built in
byp=
ass
> diodes that should mean only those cells (or possibly string of cells)
> within the panel that are shaded get affected. I have another
installer
> coming tonight so I'll be quizzing him a little more about this :)
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> Marcus
>=20
> From: ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>
<mailto:ukh=
a_d%40yahoogroups.com>
> [mailto:ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>
<mailto:u=
kha_d%40yahoogroups.com> ] On Behalf
> Of Kevin Hawkins
> Sent: 14 May 2011 14:15
> To: ukha_d@xxxxxxx<mailto:ukha_d%40yahoogroups.com>
<mailto:ukha_=
d%40yahoogroups.com>
> Subject: Re: [ukha_d] Solar PV ?
>=20
> If you had an array of panels but one of them was in shade , perhaps
> from a chimney stack , does this same situation occur ? I'm
> assuming not as it must be correctable via electronics but just
checking.=
..
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> K
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> On 13/05/2011 09:06, Marcus Warrington wrote:
> > Since I've now read that output of a string of panels is dictated
by th=
e
> lowest producing panel, that's means if I have a string of Sharp
panels a=
ll
> producing +10% but the last one produces -5% then its as though all
the
> panels are at -5%.
> > Marcus
> >
> >
> >
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> [Non-text portions of this message have been removed]
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> [Non-text portions of this message have been removed]
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> [Non-text portions of this message have been removed]
>




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