Declining power from PVs?

[Scott Loupin]

I just had a solar system installed last Fall. THis Spring, on bright,
sunny days, we'd store up to 7kWh/day.

Now we're only getting 4.4 to 5 kWh/day.

The panels aren't shaded, so why would the power output drop? How can I
test the panels?

Thanks for you help.

 

[William P. N. Smith]

The panels aren't shaded, so why would the power output drop? How can I
test the panels?

Could be dirt buildup, so you could try cleaning them. Physical
inspection would be important, to detect broken wires, cracked glass,
etc. You can test them by measuring open circuit voltage and short
circuit current on individual (disconnnected) panels on a sunny day
and see if there's any difference between them.

 

[Scott Loupin]

Hi William, thanks for the ideas. They get rain-washed often, but it might
not take much dirt to cut back power....

No cracks, and the wires aboveground look OK. I did have a dumptruck drive
over the buried wires, but that was last Fall.

How would I measure short circuit current? Use a shunt block, or a clamp
meter?

Thanks,
Scott

 

[daestrom]

I just had a solar system installed last Fall. THis Spring, on bright,
sunny days, we'd store up to 7kWh/day.

Now we're only getting 4.4 to 5 kWh/day.

The panels aren't shaded, so why would the power output drop? How can I
test the panels?

Thanks for you help.

Well, since nobody else asked, "How are they oriented?" What angles (tilt
and azimuth) and what latitude?

Could it be in the spring/fall they get a better angle to the midday sun
than now near the summer solstice? If the sun is higher in the sky, at
noon, you could be losing some to reflection off the unit. With fixed
mounts, the angle chosen is a bit of compromise between the seasons.

daestrom

 

[Scott Loupin]

daestrom;
The panels are set at 45 degrees (we're about on the 45th parallel), and are
oriented toward solar 1PM.

 

[George Ghio]

I just had a solar system installed last Fall. THis Spring, on bright,
sunny days, we'd store up to 7kWh/day.

Now we're only getting 4.4 to 5 kWh/day.

The panels aren't shaded, so why would the power output drop? How can I
test the panels?

Thanks for you help.

Cold, clear mornings/days and your panels will produce their max.

Hot panels produce less. Summer.

Spring is cooler than summer.

Thin layer of dust will affect your output.

Wrong angle will produce less at cretain times of the year

On a clear day check your output, then wash the panels, clean water,
brush, rinse with clean water check output again.

At noon adjust your panels, small block of wood on frame of panel,
adjust amgle until there is no shadow above or below block and the angle
will be right, at least for a few of months.

Log your system. After a year you will know what to expect from your
system for time of year.

 

[daestrom]

daestrom;
The panels are set at 45 degrees (we're about on the 45th parallel), and
are
oriented toward solar 1PM.

So, about 11 days ago, at the summer solstice, the sun was 23.5 degrees
higher in the sky than your panels were tilted for at solar noon. The
cosine of 23.5 is about 0.92. So that alone would be an 8% reduction in
peak output. Depending on just how much of your total energy production is
at/near the peak time versus the rest of the day, this could be a part of
it.

The gain in the number of hours of daylight is interesting. The sun is 'up'
for longer time, but if the system only generates from say 9AM to 3PM solar,
the extra hours don't contribute a lot more energy with fixed mounts.
(you're far enough north, you probably see the sun on the *backside* of the
collectors at sunrise/sunset this time of year).

I guess keep monitoring the situation. If production increases again in the
fall, then it was probably a combination of angle and ambient temperature.

daestrom

 

[Glenn jacobs]

I just had a solar system installed last Fall. THis Spring, on bright,
sunny days, we'd store up to 7kWh/day.

Now we're only getting 4.4 to 5 kWh/day.

The panels aren't shaded, so why would the power output drop? How can I
test the panels?

Thanks for you help.

Two Things. Are you anywhere near the fires in the west, smoke seems to be
very effective in blocking UV. I live in Colorado and on days that we have
a haze from the current fires, my charge current drops 25 to 30%. These
are days that appear to be clear, with just a bit of haze on the horizon.
Back when Colorado had big fires three years ago I found my charging to be
reduced over 50% even when the sun didn¢t seem to be obscured.

Also check your battery connections for corrosion, and clean them if they
need it. I rinse my batteries off at least once a year and still find
that I will have several connections that need cleaning in the battery room
every couple of years.

JakeInHartsel

 

[wmbjk]

I just had a solar system installed last Fall. THis Spring, on bright,
sunny days, we'd store up to 7kWh/day.

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)

Now we're only getting 4.4 to 5 kWh/day.

Much better, but you still have a way to go.

Is this a grid-tied system? Or by "storing", do you mean in batteries?
If so,then you might describe the normal charge/discharge day, if the
system has MPPT, etc. Dramatic reductions in system production can be
expected if a charge controller is throttling input for hours each
day.

Wayne

 

[George Ghio]

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)




Much better, but you still have a way to go.

Is this a grid-tied system? Or by "storing", do you mean in batteries?
If so,then you might describe the normal charge/discharge day, if the
system has MPPT, etc. Dramatic reductions in system production can be
expected if a charge controller is throttling input for hours each
day.

Wayne

Ah Wayne is back, Funny how, when it comes to real numbers you duck for
cover then return some days later and hope no one will remember that you
failed to answer a fair question.

The question remains; Can you make a coherent accounting of your energy
use/input.

The answer appears to be a resounding NO

 

[Roland Mösl]

I just had a solar system installed last Fall. THis Spring, on bright,
sunny days, we'd store up to 7kWh/day.

Where on this planet are You?
What weather conditions?
Whet PV?
What orientation?

 

[George Ghio]

Ah Wayne is back, Funny how, when it comes to real numbers you duck for
cover then return some days later and hope no one will remember that you
failed to answer a fair question.

[snip]

George, do you think out of courtesy to the rest of the news readers
that you could keep your attacks on Wayne to a distinct thread? It's
really bad manners to keep trying to hijack every discussion to renew
your battles.

What is this?

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)

 

[John P Bengi]

Rinsing your panels in cold water in the heat of summer makes them jump up
10% but it returns to normal in a few minuted again.

 

[John P Bengi]

Ditto George. You appear to have a lot of knowledge in this field but if we
all killfilter you because of your Obsessive Compulsive Disorder with the
Wayne troll nobody will see your posts either.

The group thanks you for your co-operation.

Ah Wayne is back, Funny how, when it comes to real numbers you duck for
cover then return some days later and hope no one will remember that you
failed to answer a fair question.

[snip]

George, do you think out of courtesy to the rest of the news readers
that you could keep your attacks on Wayne to a distinct thread? It's
really bad manners to keep trying to hijack every discussion to renew
your battles.

What is this?

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)

 

[Steve Spence]

You have it backwards, George is the troll who is envious of Wayne,
hence the constant attacks for attention.


Steve Spence
Dir., Green Trust
http://www.green-trust.org

Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Ditto George. You appear to have a lot of knowledge in this field but if we
all killfilter you because of your Obsessive Compulsive Disorder with the
Wayne troll nobody will see your posts either.

The group thanks you for your co-operation.

George Ghio wrote:


Ah Wayne is back, Funny how, when it comes to real numbers you duck for
cover then return some days later and hope no one will remember that you
failed to answer a fair question.


[snip]

George, do you think out of courtesy to the rest of the news readers
that you could keep your attacks on Wayne to a distinct thread? It's
really bad manners to keep trying to hijack every discussion to renew
your battles.

What is this?

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)

 

[George Ghio]

John, what you say is true. But has nothing to do with the dust that can
reduce efficiency. Removing the dust will increase output.

 

[John P Bengi]

George has never attacked me more than minor stuff. However I have seen
Wayne continuosly troll many here as a child would do bored for attention.

Need I display examples?

You have it backwards, George is the troll who is envious of Wayne,
hence the constant attacks for attention.


Steve Spence
Dir., Green Trust
http://www.green-trust.org

Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Ditto George. You appear to have a lot of knowledge in this field but if we
all killfilter you because of your Obsessive Compulsive Disorder with the
Wayne troll nobody will see your posts either.

The group thanks you for your co-operation.

Tony Wesley wrote:

George Ghio wrote:


Ah Wayne is back, Funny how, when it comes to real numbers you duck for
cover then return some days later and hope no one will remember that you
failed to answer a fair question.


[snip]

George, do you think out of courtesy to the rest of the news readers
that you could keep your attacks on Wayne to a distinct thread? It's
really bad manners to keep trying to hijack every discussion to renew
your battles.


What is this?

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)

 

[Steve Spence]

Wayne is just giving George just due. George has been posing here for
years. You need to know the background behind the controversy.


Steve Spence
Dir., Green Trust
http://www.green-trust.org

Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html

George has never attacked me more than minor stuff. However I have seen
Wayne continuosly troll many here as a child would do bored for attention.

Need I display examples?

You have it backwards, George is the troll who is envious of Wayne,
hence the constant attacks for attention.


Steve Spence
Dir., Green Trust
http://www.green-trust.org

Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Ditto George. You appear to have a lot of knowledge in this field but if

we

all killfilter you because of your Obsessive Compulsive Disorder with

the

Wayne troll nobody will see your posts either.

The group thanks you for your co-operation.



Tony Wesley wrote:


George Ghio wrote:



Ah Wayne is back, Funny how, when it comes to real numbers you duck

for

cover then return some days later and hope no one will remember that

you

failed to answer a fair question.


[snip]

George, do you think out of courtesy to the rest of the news readers
that you could keep your attacks on Wayne to a distinct thread? It's
really bad manners to keep trying to hijack every discussion to renew
your battles.


What is this?

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)

 

[John P Bengi]

I really don't care about their trolling conversation. I know Wayne has been
a complete asshole to me and others many times. I have observed his
childish attacks on what he doesn't understand too many times. George is
just very patient with an asshole like that and it makes them almost
indescernible.

He fits the troll label and I don't see his posts after a few chances. He
just needs to mature a lot.

Perhaps I should start posting some of Wayne's garbage here the way he likes
to behave?

Funny how I clean out my bozo bin every so often and the same ones end up
back in it... LOL

Wayne is just giving George just due. George has been posing here for
years. You need to know the background behind the controversy.


Steve Spence
Dir., Green Trust
http://www.green-trust.org

Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html

George has never attacked me more than minor stuff. However I have seen
Wayne continuosly troll many here as a child would do bored for attention.

Need I display examples?

You have it backwards, George is the troll who is envious of Wayne,
hence the constant attacks for attention.


Steve Spence
Dir., Green Trust
http://www.green-trust.org

Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html

John P Bengi wrote:

Ditto George. You appear to have a lot of knowledge in this field but

if

we

all killfilter you because of your Obsessive Compulsive Disorder with
the

Wayne troll nobody will see your posts either.

The group thanks you for your co-operation.



Tony Wesley wrote:


George Ghio wrote:



Ah Wayne is back, Funny how, when it comes to real numbers you duck
for

cover then return some days later and hope no one will remember that
you

failed to answer a fair question.


[snip]

George, do you think out of courtesy to the rest of the news readers
that you could keep your attacks on Wayne to a distinct thread? It's
really bad manners to keep trying to hijack every discussion to renew
your battles.


What is this?

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)

 

[George Ghio]

Steve, Wayne disappears every time the numbers get too hard for him.

His last cut and run was when he realised that he admitted that he used
500Ah to do 100 minutes of welding and a couple of hours AC.

He just disappeared. Again. The man is a buffoon. In the same post he
thought it impessive to state:

"I didn't check the current draw, but the
machine was set at 280 inches per second, 18 Volts, with .035" solid
wire."

Well, ya gotta laugh.

And then there is you, the great Steve Spence, the man who has,
apparently, run back to the big smoke after failing to cope with your
alternative lifestyle.

Yesiree, the pair of you are a circus beyond compare.

You have it backwards, George is the troll who is envious of Wayne,
hence the constant attacks for attention.


Steve Spence
Dir., Green Trust
http://www.green-trust.org

Contributing Editor
http://www.off-grid.net
http://www.rebelwolf.com/essn.html

Ditto George. You appear to have a lot of knowledge in this field but
if we
all killfilter you because of your Obsessive Compulsive Disorder with the
Wayne troll nobody will see your posts either.

The group thanks you for your co-operation.

Tony Wesley wrote:

George Ghio wrote:


Ah Wayne is back, Funny how, when it comes to real numbers you duck
for
cover then return some days later and hope no one will remember
that you
failed to answer a fair question.



[snip]

George, do you think out of courtesy to the rest of the news readers
that you could keep your attacks on Wayne to a distinct thread? It's
really bad manners to keep trying to hijack every discussion to renew
your battles.


What is this?

Well, there's your first problem right away: as I've been told many
times, everything above 1kWhr per day is the road to ruination. ;-)