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What are some payback times for systems currently installed? - Page 3

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Posted by stevey on November 7, 2011, 9:16 am
 
Hi Peter,

Thanks for sharing your experiment with us.
First of all, the Harbor Freight modules appear to be hobbyst quality,
not commercial
grade modules.  Nor is your Balance-of-System typical of commercial
installations.
Thus is is not fair to declare a general conclusion about a category
product and
practice.
Your experiment is rather interesting in that it reveals electrical
characteristics
where different subsystems are introduced.  Please keep us up with
updates
on your system.
I am quite curious about actual long-term performance of most solar
power sites.
In general, I can say from first hand observations, most systems are
delivering 65% to 95%
of 'promised' performance, if these are professionally designed,
constructed and maintained.
My data sources are mostly spotty and non-rigorous.  Thus I'd be
interested in large scale,
collection of performance data, which is not readily available.
-Steve
-



Posted by argusy on November 7, 2011, 12:15 pm
 
On 05/11/11 9:07 AM, Pete S wrote:

for

I've had a 1.5Kw solar array for over a year, (Adelaide, South Australia), but
with a 3Kw inverter. The feed-in tariff is 50c, and the system has reduced my
power bill by about 25% (comparing last year's bills with this year's). The Feds
have (sorry, had) a rebate scheme that took off several thousand dollars
as well

We get a lot of sunshine here

IT cost me $200, and if I toss in the cost of a "Cost Current" brand monitor
with two extra sensors (I have three phase power), I should get a return on my
investment in about 5 to six years. I'm just wondering if you've got the
expected life expectancy of solar arrays (25-30 years) mixed up with ROI.

Considering I was paying 23c/Kwh last year, now up to 29c/KwH, and is going up
to 34c/Kwh early next year (with who knows how many rises after that), I
consider I made the correct decision to install, and my effective ROI may be
sooner than I originally thought, based on my electricity utility's spiralling
rises in cost

I'm seriously considering spending some of my retirement money next year (I'm
64) and adding the extra panels to increase my output to 3Kw. (yeah - I know the
difference between 3Kw and 3 Kw/hour)

Like you, I like to know how, what and why, and because I'm just as much into
electronics as you are (I've been in electronics over 40 years), I wrote my own
program for the CC monitor, to track the three phases into my house. (two are
power in, and the third is dedicated to solar generation). I even built a
twilight sensor to cut the supply power, because when the inverter was "off", it
was drawing about 125w per hour!!

I've now got a mountain of info stored in an access database, and my program can
present graphs showing the data hourly, daily, weekly, monthly and yearly.
I threw out the .CSV data the monitor generates, as within a week, neither
notepad, wordpad, word or excel could take it in.

Well, it could, but I'd have to add some serious data stripping in my program to
chop up and store the CSV file as it comes through the comms port. As it is,
every six seconds it sends model, version, three phase info, date, time,
temperature, nine other (unused) AIM sensors and every two hours a big bunch of
historical info. Most of which is not needed when just the three phase info is
stripped out and stored in an .mdb file.

With that sort of info presented in the graphs, I tracked down just where I was
using power in the house and did some cost cutting (CFLs throughout, 1 watt LEDs
in the toilets, just how much power was used leaving the TV in standby ......
that sort of thing)

So, between the solar system, and purchasing a decent monitor, I've probably
answered your question about payback times. With changes in attitude on power
usage, installing just a 1500W system here in Adelaide, a ROI could be down to
about six-seven years.

Maybe less if the PV systems keep dropping in price, and they have - now I could
buy my system for about $700-1800, but the bastards in the government dropped
the FIT for new installations. (I'm OK - I'm locked in at 50c for the next 17
years!)

AND - electricity costs keep going up!!

I'm sorry, Pete, but I don't think a 45 Watt system, even connected to an
electricity utility would ever give you any idea as to what payback times are in
play. For all the effort you've put into it, and I give you a lot of kudos for
doing it (I took a look at your site), I think you've gone the wrong way to
estimate a return-of-investment on solar arrays.

er.. also sorry - you didn't pay any taxes on my system here in OZ!!

Graham AKA Argusy


Posted by Mho on November 7, 2011, 3:14 pm
 You must have some very cheap panels available there!

It would seem, as in the past, without subsidies, the system would still not
likely, ever "break even"

----------
I've had a 1.5Kw solar array for over a year, (Adelaide, South Australia),
but
with a 3Kw inverter. The feed-in tariff is 50c, and the system has reduced
my
power bill by about 25% (comparing last year's bills with this year's). The
Feds
have (sorry, had) a rebate scheme that took off several thousand dollars
as well

We get a lot of sunshine here

IT cost me $200, and if I toss in the cost of a "Cost Current" brand
monitor
with two extra sensors (I have three phase power), I should get a return on
my
investment in about 5 to six years. I'm just wondering if you've got the
expected life expectancy of solar arrays (25-30 years) mixed up with ROI.

Considering I was paying 23c/Kwh last year, now up to 29c/KwH, and is going
up
to 34c/Kwh early next year (with who knows how many rises after that), I
consider I made the correct decision to install, and my effective ROI may be
sooner than I originally thought, based on my electricity utility's
spiralling
rises in cost

I'm seriously considering spending some of my retirement money next year
(I'm
64) and adding the extra panels to increase my output to 3Kw. (yeah - I know
the
difference between 3Kw and 3 Kw/hour)

Like you, I like to know how, what and why, and because I'm just as much
into
electronics as you are (I've been in electronics over 40 years), I wrote my
own
program for the CC monitor, to track the three phases into my house. (two
are
power in, and the third is dedicated to solar generation). I even built a
twilight sensor to cut the supply power, because when the inverter was
"off", it
was drawing about 125w per hour!!

I've now got a mountain of info stored in an access database, and my program
can
present graphs showing the data hourly, daily, weekly, monthly and yearly.
I threw out the .CSV data the monitor generates, as within a week, neither
notepad, wordpad, word or excel could take it in.

Well, it could, but I'd have to add some serious data stripping in my
program to
chop up and store the CSV file as it comes through the comms port. As it is,
every six seconds it sends model, version, three phase info, date, time,
temperature, nine other (unused) AIM sensors and every two hours a big bunch
of
historical info. Most of which is not needed when just the three phase info
is
stripped out and stored in an .mdb file.

With that sort of info presented in the graphs, I tracked down just where I
was
using power in the house and did some cost cutting (CFLs throughout, 1 watt
LEDs
in the toilets, just how much power was used leaving the TV in standby
......
that sort of thing)

So, between the solar system, and purchasing a decent monitor, I've probably
answered your question about payback times. With changes in attitude on
power
usage, installing just a 1500W system here in Adelaide, a ROI could be down
to
about six-seven years.

Maybe less if the PV systems keep dropping in price, and they have - now I
could
buy my system for about $700-1800, but the bastards in the government
dropped
the FIT for new installations. (I'm OK - I'm locked in at 50c for the next
17
years!)

AND - electricity costs keep going up!!

I'm sorry, Pete, but I don't think a 45 Watt system, even connected to an
electricity utility would ever give you any idea as to what payback times
are in
play. For all the effort you've put into it, and I give you a lot of kudos
for
doing it (I took a look at your site), I think you've gone the wrong way to
estimate a return-of-investment on solar arrays.

er.. also sorry - you didn't pay any taxes on my system here in OZ!!

Graham AKA Argusy


Posted by argusy on November 8, 2011, 10:39 am
 On 08/11/11 1:44 AM, Mho wrote:

No, not really - the Government gave me $200 when they purchased the RECs off
me (something about carbon savings). Add $200 and that's $,400
That's eight 192W panels, a 3Kw inverter, plus labour and installation

<snip>.

Bullshit!!

You'd better go see you investment advisor about that statement. I'll bet you
he'd say "Crap. In any 7 year period since the first bank opened for business
two thousand years ago, ANY investment will DOUBLE in value").

Get off your butt and do some research on the internet about investments,
because that's exactly what a solar installation is.

My savings on the electricity bill would be more than double that $,200 in
seven years time. After that, the Solar system has been paid for in the savings,
and beyond that, my electricity bill will be a damn side lower BECAUSE OF THE
ORIGINAL INVESTMENT.

IF I didn't factor in rising electricity costs or the REC payout, I would break
even about 17-20 years time on $,400. Even at my age (64), I should still be
alive then. But life never stays stagnant. If I thought, for one moment, that
electricity prices would stay at todays' prices for 17 years (which you seem to
think) then I'd be living in Fairyland.

This is reality - prices WILL RISE - Guaranteed, fair dinkum, honest-to-God, I
kid you not.

Any reduction of that cost means it stays in my pocket, not the supplier's. And
remember, that savings increases every time the cost goes up.

It's not the initial capital expenditure, but the FUTURE INVESTMENT that pays
off (in this case, the savings I make in that period of time).








Posted by Mho on November 9, 2011, 2:57 am
 Yup you have some pretty rich subsidies there. Without them solar PV is no
investment unless you like negative gains.

You refer to a Kw/hour. I assume you mean kWh?

What is your insolation factor there?

Your double your investment value in 7 years hasn't applied in N.America
since about 1980 and it never has at 7% ROI. That would be more like 10.3
years. Your math seems to be out of date.

I agree with your 17-20 years without maintenance and no removal of the rate
subsidy or rise in cost to you per kWh. You need to include the reduction in
interest as you would pay the investment interest off (amortize the loan)
making the time even less.

You have done quite well with the subsidies being given to you. Most are not
that lucky. We have been handed 80.3 cents /kWh and no capitol subsidies.
That definitely  makes our PV industry work. The subsidies will not last
forever,  though.


----------
You'd better go see you investment advisor about that statement. I'll bet
you
he'd say "Crap. In any 7 year period since the first bank opened for
business
two thousand years ago, ANY investment will DOUBLE in value").

Get off your butt and do some research on the internet about investments,
because that's exactly what a solar installation is.

My savings on the electricity bill would be more than double that $,200 in
seven years time. After that, the Solar system has been paid for in the
savings,
and beyond that, my electricity bill will be a damn side lower BECAUSE OF
THE
ORIGINAL INVESTMENT.

IF I didn't factor in rising electricity costs or the REC payout, I would
break
even about 17-20 years time on $,400. Even at my age (64), I should still
be
alive then. But life never stays stagnant. If I thought, for one moment,
that
electricity prices would stay at todays' prices for 17 years (which you seem
to
think) then I'd be living in Fairyland.

This is reality - prices WILL RISE - Guaranteed, fair dinkum, honest-to-God,
I
kid you not.

Any reduction of that cost means it stays in my pocket, not the supplier's.
And
remember, that savings increases every time the cost goes up.

It's not the initial capital expenditure, but the FUTURE INVESTMENT that
pays
off (in this case, the savings I make in that period of time).








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