Solar panel controller
 

So here you are cruising along with more wind then needed for hull
speed, why not drag a surfboard with an alternator with big paddle
wheels on each side to make electricity?
Gordon

(As you can see, this hasn't been quite thought out completely yet!)

Solar panel controller
 

Goofball_star_dot_etal wrote:
On Fri, 09 Feb 2007 17:45:41 +0000, Ian Malcolm
wrote:


Geoff Schultz wrote:

You can't produce more power
than the panels are generating.


Larry wrote:

Ok, here's a little electricity for everyone....

Geoff Schultz wrote:

Thank you Professor Larry for the edification. I always enjoy it when
this forum is used to exchange information instead of throwing barbs at
one another.

Goofball_star_dot_etal wrote:

Unfortunately the information is wrong.

Well without any references or explanation and as an anonymous poster,
your word isnt worth anything near as much as if it was printed out on
used toilet paper . .



You mean you would like me to post references to the equivalent
circuit AGAIN?

http://groups.google.co.uk/group/rec...13bf8612?hl=en

If people did some homework instead of making wrong assumptions before
posting them as fact, there would be less BS.

Didnt show up here, first I saw was you saying 'assume what you like'.
Obviously Google has it so I suspect its a USENET propagation issue at
the european end. Anyway the problem with quoting Wikis is some @sshole
usually vandelises them mid discussion, Its always advisable to go back
to original sources or Wikipedia gets further damaged :-(

I do see where you are coming from, as both myself and Larry made the
obvious but incorrect assumption that a PV panel could be modelled
adequately as a controlled voltage source. It was labelled as an
assumption and an approximation, i.e. a simplification, NOT A FACT. As
it happens, the only effect that correcting that has is to move the
modelled MPP for the better panels above the charging voltage of a Lead
acid battery. This means a small simplification in the topology of the
switching converter. A closed loop converter based on the simplistic
analysis would soon settle within a few percent of the MPP anyway so the
results would be almost identical. You get what you pay for on USENET,
and neither of us were being offered any beer coupons :-) Now what
point were you trying to make?

Tying to stomp BS offseason just gets you covered in sh!t and sprays it
all over the place. ;-) Lighten up. At least this isnt a political thread.

Here is a new link for you:
http://patft.uspto.gov/netacgi/nph-P...391&RS=6111391
or http://tinyurl.com/yobfz3

And of what use is that link? If you can muster the patience to wade
through their claims, you find there is nothing new under the sun there.
They've tried to claim a unique application to gasoline powered
motorhomes. The Saudis were installing MPPT panel arrays on a large
scale back in the early 80's (lots of cash, lots of sun) so there is a
hell of a lot of 'prior art'
That patent *might* be usefull as toilet paper . . .

The link I found has usable Spice models so if one grabs a copy of
SwitcherCad (google it) the rest is just tedious engeneering . . .

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.

Solar panel controller
 

On Fri, 09 Feb 2007 20:32:54 +0000, Ian Malcolm
wrote:

Goofball_star_dot_etal wrote:
On Fri, 09 Feb 2007 17:45:41 +0000, Ian Malcolm
wrote:


Geoff Schultz wrote:

You can't produce more power
than the panels are generating.


Larry wrote:

Ok, here's a little electricity for everyone....

Geoff Schultz wrote:

Thank you Professor Larry for the edification. I always enjoy it when
this forum is used to exchange information instead of throwing barbs at
one another.

Goofball_star_dot_etal wrote:

Unfortunately the information is wrong.

Well without any references or explanation and as an anonymous poster,
your word isnt worth anything near as much as if it was printed out on
used toilet paper . .



You mean you would like me to post references to the equivalent
circuit AGAIN?

http://groups.google.co.uk/group/rec...13bf8612?hl=en

If people did some homework instead of making wrong assumptions before
posting them as fact, there would be less BS.

Didnt show up here, first I saw was you saying 'assume what you like'.
Obviously Google has it so I suspect its a USENET propagation issue at
the european end. Anyway the problem with quoting Wikis is some @sshole
usually vandelises them mid discussion, Its always advisable to go back
to original sources or Wikipedia gets further damaged :-(

Never mind the "problem with Wikis" or that my "word isnt worth
anything near as much as if it was printed out on used toilet paper"
or that I am a Goofball, Wikipedia® and I are correct and the rest of
you were wrong. Does it matter? No, although anybody in The World(tm)
can read Usenet, nobody does.. Just fun to observe people twist and
turn.


I do see where you are coming from, as both myself and Larry made the
obvious but incorrect assumption that a PV panel could be modelled
adequately as a controlled voltage source. It was labelled as an
assumption and an approximation, i.e. a simplification, NOT A FACT.

Yes but it is not an approximation, it was totally wrong and useless
not "useful" at all.


As
it happens, the only effect that correcting that has is to move the
modelled MPP for the better panels above the charging voltage of a Lead
acid battery. This means a small simplification in the topology of the
switching converter. A closed loop converter based on the simplistic
analysis would soon settle within a few percent of the MPP anyway so the
results would be almost identical.

The MPP is light and temperature sensitive. The quoted patent states
that they sample the open circuit volage and apply an offset to arrive
at the (instantaneous MPP)

You get what you pay for on USENET,
and neither of us were being offered any beer coupons :-) Now what
point were you trying to make?

"Shut up if you don't know the answer" ?

Tying to stomp BS offseason just gets you covered in sh!t and sprays it
all over the place. ;-) Lighten up. At least this isnt a political thread.

Here is a new link for you:
http://patft.uspto.gov/netacgi/nph-P...391&RS=6111391
or http://tinyurl.com/yobfz3

And of what use is that link?

Well the OP wrote:
"I am considering purchasing a Blue Sky Energy Solar Boost 2000E
controller (regulator) to use with my solar panels. The manufacturer
claims an increase in current power of 30%"

Larry inferred that the claims were close to perpetual motion.

Oh, the link is a link to a patent for that particular product which
explains its operation and shows it is not pure snake oil or perpetual
motion.

See: http://www.blueskyenergyinc.com/pdf/...Ldatasheet.pdf


If you can muster the patience to wade
through their claims, you find there is nothing new under the sun there.
They've tried to claim a unique application to gasoline powered
motorhomes. The Saudis were installing MPPT panel arrays on a large
scale back in the early 80's (lots of cash, lots of sun) so there is a
hell of a lot of 'prior art'
That patent *might* be usefull as toilet paper . . .

The link I found has usable Spice models so if one grabs a copy of
SwitcherCad (google it) the rest is just tedious engeneering . . .

A diode is a diode.

Solar panel controller
 

On Feb 9, 8:33 am, Jeff wrote:
Geoff Schultz wrote:
Jeff wrote in
:

Geoff Schultz wrote:
Get a controller that diverts voltage above the maximum charging
voltage of the battery to a resistive load. In my case this is the
water heater with 12V and 120V heater elements. 100% of the power of
the solar panels will go to charging the panels up to that point.
You can't produce more power than the panels are generating.

I personally use a Morning Star TriStar controller to control both my
wind generator and solar panels and it works great.

-- Geoff
So, are you saying that if the panels are putting out 17 volts and the
battery is only taking 14, then 3 volts are applied to the heater? I
don't think that's the way it works.

That's exactly what I'm saying. It's called Diversion Mode and on the
controller you set the maximum voltage which is allowed to be applied to
the batteries. Anything above that is diverted to the load.

The only time that this occurs is when the batteries are fully charged.
The vast majority of the time the charging load of the batteries drops the
output of the solar cells to a voltage less than the maximum allowable
voltage and thus nothing is diverted.

For details please see the manual:
http://www.mrsolar.com/pdf/morningstar/TS_Manual.pdf

Yes, this is how the tristar works. And for some people, it works
fine. However, for those of us whose power usage far exceeds the
charging ability, the diversion mode would rarely be turned on. In my
case, it would only happen if I had just run the engine, and at that
time the water tank is fully heated.

The diversion mode is suited to boats with excess generating
capability, such as trade wind passagemakers with wind or hydro
generation.

For systems where the solar panels will fall behind the load, the new
MPPT (Maximum Power Point Tracking) systems will generate more power
at the battery. Many panels will put out up to 17 Volts, and their
Wattage will be rated at this level. A normal regulator will reduce
this to an appropriate charging Voltage, perhaps 13.5 Volts if the
battery is discharged. However, the current is not increased so the
net Wattage will be reduced.

A MPPT controller is a DC-DC converter that will drop the Voltage down
without reducing the Wattage. An 85 Watt panel that can put out 5
Amps at 17V will put out 6.3 Amps at 13.5 and stay up at 85 Watts. A
normal controller would only allow 67 Watts.

Thus, the controller is not "creating more power than the panel
outputs," its adjusting the Voltage so that 30% of the power isn't
thrown away. As I've said, I've watched the current go from 8 to 10
Amps when the MPPT is turned on.- Hide quoted text -

- Show quoted text -

Yes, i agree. I want to add my support again for this explination and
any negative comments (except maybe those negative comments against
practical sailor's reliability) that followed my post early in this
thread are unjustified. Let's face it, the affordable controllers that
have historically been available are simple an did little more than
keep the voltage at 12.6 volts, and if the voltage of the batteries
exceed the voltage of the panels, the controller will prevent the
batteries from draining. In this arrangement, the panels were setup
with enough cells to insure that 12.6 volts would be reached in
overcast days (or they would be useless), which means on sunny days
you end up with 18 even 19v. New controllers can match the panels to
the batteries better ... and without any snake oil, you get more bang
out of your solar cells.

In regards to practical sailor, they have demonstrated their
independence and willingness to tell it like it is, perhaps that is a
better description than reliable. If they measure a 25% increased
output in AMPS with the new technology controllers, I can take that to
the bank. However I will concede there are problems with some
articles. When it comes to bottom paints, I realize as I read the
articles the limits to their testing. To be really scientific and
valid the tests would be repeated on a second set of samples by a
different organization or employees, but it's amazing what they do for
limited $. The article on winches was just way off the mark. Also
they recently had an article on 2006 editions of two books in regards
to 12V boat systems, that was extremely poor, one of the books in fact
does not have such an edition. I could not get a response back from
them when I pointed it out. Perhaps the loss of their star editor has
a big influence, I don't think he would have let that article on
Winches fly. But .. it is real refreshing to read their articles,
especially boat reviews. I am getting tired of reading boat reviews in
sail magazine that are absolutly meaningless, and really hate to read
words such as "we only had light winds today, but judging from this
boats design it will be a real performer" ... do meaningful
journalism, go out and sail the boat again on a windy day would
you ? In that light, Practical Sailor looks reliable to me, just not
scientifically so.

Solar panel controller
 

Goofball_star_dot_etal wrote:

I do see where you are coming from, as both myself and Larry made the
obvious but incorrect assumption that a PV panel could be modelled
adequately as a controlled voltage source. It was labelled as an
assumption and an approximation, i.e. a simplification, NOT A FACT.


Yes but it is not an approximation, it was totally wrong and useless
not "useful" at all.


As

it happens, the only effect that correcting that has is to move the
modelled MPP for the better panels above the charging voltage of a Lead
acid battery. This means a small simplification in the topology of the
switching converter. A closed loop converter based on the simplistic
analysis would soon settle within a few percent of the MPP anyway so the
results would be almost identical.


The MPP is light and temperature sensitive. The quoted patent states
that they sample the open circuit volage and apply an offset to arrive
at the (instantaneous MPP)

Leaving out any personal attacks *this* time, Mr Ball,
Their approach is actually questionable *FOR A MARINE APPLICATION* as
they make no provision for extracting power if the panel voltage is
below that of the battery. This frequently happens if the panel is
partially shaded and some cells bypass diodes are conducting. This
wouuld be a not uncommon situation aboard an yacht at anchor, on a
swinging mooring or underway. The panel has to deliver over 140ma at
over 14V before *any* power is transferred. Elsewhere they say it is
stable down to 0.8A and as it seems to be designed for 10A nominal
output, what proportion of the time will it not operate? They seem to be
excessively concerned about keeping the converter in continuous
operation mode, *Probably* to avoid violating a competitor's patent.
It looks like it would be advisable to disable their regulator and run a
float regulator if layed up for the winter as the trickle charging
capabilities are suspect to say the least.


I suspect that the manufacturer the OP was considering were rather
optimistic in their test conditions for a 30% efficiency boost, they
probably tested it normal to the sun, totally clear sky and at 10
degrees C ambient temperatue into a very flat battery. At more normal
insolation levels and temperatures, averaged over a normal battery
charging cycle, the 10% to 15% improvement that most other sources claim
is more plausible. After all, you CANNOT get more out than you can get
at the MPP.

--
Ian Malcolm. London, ENGLAND. (NEWSGROUP REPLY PREFERRED)
ianm[at]the[dash]malcolms[dot]freeserve[dot]co[dot]uk
[at]=@, [dash]=- & [dot]=. *Warning* HTML & 32K emails -- NUL:
'Stingo' Albacore #1554 - 15' Early 60's, Uffa Fox designed,
All varnished hot moulded wooden racing dinghy.

Solar panel controller
 

On Fri, 09 Feb 2007 23:09:58 +0000, Ian Malcolm
wrote:

Goofball_star_dot_etal wrote:

I do see where you are coming from, as both myself and Larry made the
obvious but incorrect assumption that a PV panel could be modelled
adequately as a controlled voltage source. It was labelled as an
assumption and an approximation, i.e. a simplification, NOT A FACT.


Yes but it is not an approximation, it was totally wrong and useless
not "useful" at all.


As

it happens, the only effect that correcting that has is to move the
modelled MPP for the better panels above the charging voltage of a Lead
acid battery. This means a small simplification in the topology of the
switching converter. A closed loop converter based on the simplistic
analysis would soon settle within a few percent of the MPP anyway so the
results would be almost identical.


The MPP is light and temperature sensitive. The quoted patent states
that they sample the open circuit volage and apply an offset to arrive
at the (instantaneous MPP)

Leaving out any personal attacks *this* time, Mr Ball,
Their approach is actually questionable *FOR A MARINE APPLICATION* as
they make no provision for extracting power if the panel voltage is
below that of the battery. This frequently happens if the panel is
partially shaded and some cells bypass diodes are conducting. This
wouuld be a not uncommon situation aboard an yacht at anchor, on a
swinging mooring or underway. The panel has to deliver over 140ma at
over 14V before *any* power is transferred. Elsewhere they say it is
stable down to 0.8A and as it seems to be designed for 10A nominal
output, what proportion of the time will it not operate? They seem to be
excessively concerned about keeping the converter in continuous
operation mode, *Probably* to avoid violating a competitor's patent.
It looks like it would be advisable to disable their regulator and run a
float regulator if layed up for the winter as the trickle charging
capabilities are suspect to say the least.


I suspect that the manufacturer the OP was considering were rather
optimistic in their test conditions for a 30% efficiency boost, they
probably tested it normal to the sun, totally clear sky and at 10
degrees C ambient temperatue into a very flat battery. At more normal
insolation levels and temperatures, averaged over a normal battery
charging cycle, the 10% to 15% improvement that most other sources claim
is more plausible. After all, you CANNOT get more out than you can get
at the MPP.

Yes.
http://www.blueskyenergyinc.com/pdf/...PSB2KErevE.pdf page 8
table 2

Solar panel controller
 

Ian Malcolm wrote:
....

Leaving out any personal attacks *this* time, Mr Ball,
Their approach is actually questionable *FOR A MARINE APPLICATION* as
they make no provision for extracting power if the panel voltage is
below that of the battery. This frequently happens if the panel is
partially shaded and some cells bypass diodes are conducting. This
wouuld be a not uncommon situation aboard an yacht at anchor, on a
swinging mooring or underway. The panel has to deliver over 140ma at
over 14V before *any* power is transferred. Elsewhere they say it is
stable down to 0.8A and as it seems to be designed for 10A nominal
output, what proportion of the time will it not operate? They seem to be
excessively concerned about keeping the converter in continuous
operation mode, *Probably* to avoid violating a competitor's patent.
It looks like it would be advisable to disable their regulator and run a
float regulator if layed up for the winter as the trickle charging
capabilities are suspect to say the least.


I couldn't find anything on the Blue Sky or Outback sites that address
the issue of raising the voltage from a partially shaded panel so the
it is at the charging point for the battery. In theory, there's
nothing to prevent this. But the situation is complicated because
many installations have several panels in parallel (I have three) the
shading would not be even.


I suspect that the manufacturer the OP was considering were rather
optimistic in their test conditions for a 30% efficiency boost, they
probably tested it normal to the sun, totally clear sky and at 10
degrees C ambient temperatue into a very flat battery. At more normal
insolation levels and temperatures, averaged over a normal battery
charging cycle, the 10% to 15% improvement that most other sources claim
is more plausible. After all, you CANNOT get more out than you can get
at the MPP.

The literature specifically says "up to 30%" gain; they certainly
don't claim that will always be possible. In particular, it depends a
lot on the temperature, since panels will put out a much higher
voltage when cold. Thus, the gains would be less in the tropics, more
in temperate zones in colder seasons. Also, gains are more with a
depleted battery, less as the battery is charged. The web sites are
pretty up front about these issues, admitting that gains might be only
10% in some scenarios. As I've said, the system I checked out had a
25% gain, which the owner said was typical.

Solar panel controller
 

A question about bypass diodes:

"Jeff" wrote in message
...
Ian Malcolm wrote:
...

Leaving out any personal attacks *this* time, Mr Ball,
Their approach is actually questionable *FOR A MARINE APPLICATION* as
they make no provision for extracting power if the panel voltage is below
that of the battery. This frequently happens if the panel is partially
shaded and some cells bypass diodes are conducting. This wouuld be a not
uncommon situation aboard an yacht at anchor, on a swinging mooring or
underway. The panel has to deliver over 140ma at over 14V before *any*
power is transferred. Elsewhere they say it is stable down to 0.8A and
as it seems to be designed for 10A nominal output, what proportion of the
time will it not operate? They seem to be excessively concerned about
keeping the converter in continuous operation mode, *Probably* to avoid
violating a competitor's patent.
It looks like it would be advisable to disable their regulator and run a
float regulator if layed up for the winter as the trickle charging
capabilities are suspect to say the least.


I couldn't find anything on the Blue Sky or Outback sites that address the
issue of raising the voltage from a partially shaded panel so the it is at
the charging point for the battery. In theory, there's nothing to prevent
this. But the situation is complicated because many installations have
several panels in parallel (I have three) the shading would not be even.


I suspect that the manufacturer the OP was considering were rather
optimistic in their test conditions for a 30% efficiency boost, they
probably tested it normal to the sun, totally clear sky and at 10 degrees
C ambient temperatue into a very flat battery. At more normal insolation
levels and temperatures, averaged over a normal battery charging cycle,
the 10% to 15% improvement that most other sources claim is more
plausible. After all, you CANNOT get more out than you can get at the
MPP.

The literature specifically says "up to 30%" gain; they certainly don't
claim that will always be possible. In particular, it depends a lot on
the temperature, since panels will put out a much higher voltage when
cold. Thus, the gains would be less in the tropics, more in temperate
zones in colder seasons. Also, gains are more with a depleted battery,
less as the battery is charged. The web sites are pretty up front about
these issues, admitting that gains might be only 10% in some scenarios.
As I've said, the system I checked out had a 25% gain, which the owner
said was typical.

Do most panels have the bypass diodes (to allow current flow through shaded
cells)? The specs for my Shell 100W panels do not mention them. I'm not
talking about the series reverse-current blocking diodes, but the per-cell
bypass. I am considering an MPPT controller, and if the panels have these
diodes, it should be better to connect the panels in series, rather than in
parallel. My installation has three panels, and does have issues with panel
shading. Currently I have the panels in parallel, and use a non-MPPT
controller.

I will probably do some V/I curves for the panels with varying types and
degrees of shading, which should answer the bypass diode question, but until
then any advice would be appreciated.

Thanks,
Paul

Solar panel controller
 

Wayne.B wrote in
:

So I guess you would disapprove of my 15 and 20kw generators?



Not me. Dan's Hatteras 56 had two Onans on it with two transfer panels at
the main helm. One was a two-cyl 8KW and the 4-cyl 20KW. You could shed
the load from one to the other very neatly or to shore power for the 5 zone
air conditioners under the galley deck, where I used to spend my weekends
in the heat sweating like a pig on my hands and knees...(c; Someone would
ask them where the hatch in the middle of the galley floor lead. They'd
tell them, "That's Larry's Stateroom."....(c;

Larry
--
VIRUS ALERT! VISTA has been released!
NOONE will be spared!

Solar panel controller
 

Gordon wrote in news:12spkq9in9jgh88
@corp.supernews.com:

So here you are cruising along with more wind then needed for hull
speed, why not drag a surfboard with an alternator with big paddle
wheels on each side to make electricity?
Gordon



Lionheart's free spinning shaft alternator produces over 20A at 6 knots.
Her Aux diesel is a Perkins 4-108 powering a hydraulic transmission made to
freewheel when off. The 3-bladed screw provides pretty nice power to the
slow-spinning shaft alternator to run my toys.

Larry
--
VIRUS ALERT! VISTA has been released!
NOONE will be spared!