Re: Suggestions how to make use of solar panels

["Rob Iles" <rob.iles@xxxxxxxxx>]

only things that spring to mind (admittedly, no research on
effiiciency!) -
- use panels + battery bank to replace "wall warts" - should be
reasonably
efficient to step down to 9 / 6.5 / 5V (these seem to be the most common
requirements I have here). my laptops appear to run on 19.5 volt DC -
thoug=
h
I'm sure you could accommodate this without too much difficulty.  (I'm also
in rented property - with the added complication it's a listed building -
s=
o
I feel your pain!)

I *assume* that the most efficient way to use the panels will be to drive
low voltage DC loads, as described above - - do you have enough of these to
make it worthwhile? (ooh, add phone charges / battery chargers to the
list)=
.

any losses in inverters are likely to increase the already horrific ROI
Vargster mentions. :(


at the risk of completely hijacking another thread, does anyone have
"baseline" figures for electricity consumption? (based on #rrooms
/
#occupants etc etc)

(Can you tell I'm waiting for a really slow data transfer to complete
befor=
e
I can go to bed? :S)

Rob

2008/5/5 Vargster <vargster@xxxxxxx>:

>   Graeme,
>
> Like many others on this list, I looked into this a few of years ago,
and
> came to the conclusion that it was a complete waste of time, unless
you'r=
e
> remote or can get the hardware cheap or you're a real eco warrior, the
> return on investment is too low to make it a worth while exercise...
>
> I was looking at a proper mains linked system, but the costs were
massive=
,
> PV panels were about =A34 per watt, (i.e. a 100W panel cost around
=A3400=
), a
> grid tie inverter cost about =A3450 per 500W, plus the cost of making
a a=
li
> frame to mount the panels on and the hardware to mount the frame.
>
> The initial idea of just making 500W to cover the base load on the
house
> didn't leave much change from =A33,000...
>
> Given that my elecy bill is around =A340/month, that's about 6.25
years
> worth,
> BUT you have to remember, that you only get 500W for 7-9 hours a
day...
> when
> it gets dark the panels stop working... so that's about 25 years to
recou=
p
> the investment... I'm not sure the hardware will last that long...
>
> It seems that size gets around this, if you have say 4KW of panels
then,
> you
> can pump elecy back to the grid and go more than self sufficient, but
the=
n
> you're looking at =A320K... that's a pretty serious commitment... I
didn'=
t
> work out the payback time...
>
> My next plan was a wind turbine, but the returns are even worse
(unless
> you
> live in Scotland), then I looked at solar water heating, and that was
> almost
> as bad with ready made panels =A33000-=A36000 installed with payback
time=
s of
> 30
> years+...
>
> Utter nonsense... But with a lot of reading there are pretty simple
> versions
> about, so I'm planning on building my own flat panel solar water
heater
> over
> the summer, estimated cost about =A3300... payback in less than 3
years..=
.
> And a fun project to tinker with... :)
>
>
> On Thu, May 1, 2008 at 9:56 PM, gearboxgraeme
<gkjones@xxxxxxx<gkjone=
s%40gkjones.com>>
> wrote:
>
> > Ive been lurking on here for years and done various bits of home
> > automation ( x10, temp loggers, camera etc. ).
> >
> > I finally decided I want to get some solar PV panels.
> >
> > Problem is Im currently in a rented house so a bit limited on
what I
> > can do, therefore looking for advice.
> >
> > Im thinking of getting a couple of 40 watt solar panels - PV, not
> > solar water heating - rented house ;{
> >
> > These would get a good load of direct sunlight for most of the
day in
> > the back garden. I already have a charge controller and a 110AH
deep
> > cycle battery. ( extra ones arent too bad - 85ah ones make the
most
> > financial sense )
> >
> > I recently bought a 300watt maplin invertor ( which did my 32inch
CRT
> > TV for a while - battery voltage dropped too low after about 20
mins ).
> >
> > Im now after suggestions as to what other people do with their
solar
> > panels.
> >
> > eg. what can I effectively power using the panels - either 12v
stuff
> > connected directly to the battery, or else via the invertor.
> >
> > I did a quick try with the washing machine but that was a
complete
> no-go.
> >
> > My mains plug meter reckons it only uses 85watts and the invertor
is
> > rated 300 watts but the extra motor current was too much.
> >
> > I would like to replace the ceiling lights with 12v led bulbs and
then
> > run the lot directly from the battery but that will have to wait
until
> > I buy a place again.
> >
> > Any other ideas gratefully received as I cant really think of
anything
> > with low enough power to cope with the invertor but high enough
to be
> > worthwile.
> >
> > Is it possible to get PC PSU's that operate from 12vDC instead of
> > mains ? ( Yes, but the cost of ones Ive seen capable of driving
my
> > games/desktop PC would be prohibitive )
> >
> > Graeme
> >
> >
> >
>
> [Non-text portions of this message have been removed]
>
>=20=20
>


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