You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an alternative browser.
You should upgrade or use an alternative browser.
Adhesive advice for Solar panels
- Thread starter Aurelia
- Start date
Greg,
Well, you've had a summer with your solar panels.
How did they work out?
I am considering a couple Ganz semi-flexible panels (55W to 80W)
and have a few questions:
1. Did you wire your 2 panels in parallel or keep them separate?
(Reports say a parallel connection will draw down the non-shaded
panel output as well as the shaded panel; series wiring is worse)
2. What charge controller(s) did you use (PWM or MPPT)?
3. Are you distributing the solar charging to one or two batteries
or battery banks?
(If two, how unless your charge controller is capable of 2 banks?)
4. Did you wire directly to the battery(ies) or to another battery input?
5. What average daily amperage output are you getting from your 2
100W panels?
Aye.
Well, you've had a summer with your solar panels.
How did they work out?
I am considering a couple Ganz semi-flexible panels (55W to 80W)
and have a few questions:
1. Did you wire your 2 panels in parallel or keep them separate?
(Reports say a parallel connection will draw down the non-shaded
panel output as well as the shaded panel; series wiring is worse)
2. What charge controller(s) did you use (PWM or MPPT)?
3. Are you distributing the solar charging to one or two batteries
or battery banks?
(If two, how unless your charge controller is capable of 2 banks?)
4. Did you wire directly to the battery(ies) or to another battery input?
5. What average daily amperage output are you getting from your 2
100W panels?
Aye.
First, it looks like I never say Pats question so here is that one...
I ran the wiring along the back of the roof and into the corner of our canvas with a drip loop like the RADAR cable. The wires then follow the RADAR cable through a rubber grommet in Joes custom Bulkhead and into the cabin and forward to behind the helm. That part was easy and is hidden from view inside the boat.
Pic of wiring on roof here:
http://www.c-brats.com/modules.php?set_ ... _photo.php
Greg
I ran the wiring along the back of the roof and into the corner of our canvas with a drip loop like the RADAR cable. The wires then follow the RADAR cable through a rubber grommet in Joes custom Bulkhead and into the cabin and forward to behind the helm. That part was easy and is hidden from view inside the boat.
Pic of wiring on roof here:
http://www.c-brats.com/modules.php?set_ ... _photo.php
Greg
I was working on them and teaching a class at the same time so it took a bit. Here they are.
1. Did you wire your 2 panels in parallel or keep them separate?
(Reports say a parallel connection will draw down the non-shaded
panel output as well as the shaded panel; series wiring is worse)
I had to wire them in series in this case because I used 6v panels. They were the only model of the type I could find that were sized perfectly for the short roof of the 19. There are impacts from shading of course but with total actual panel output near 19 volts, they can stand minor shading from my roof rails and still push a charge well enough.
2. What charge controller(s) did you use (PWM or MPPT)?
Because I already have a monitor, I choose to use a very simple PWM charge controller. Our setup is so small in Volts that the possible gains from a MPPT type don't exist. If you are using multiple panels and pushing well over 24v into a 12v system through a controller, the MPPT has advantages. I also liked the small size of this one for easy mounting in a tight location with only double stick tape.
http://www.campingworld.com/shopping/it ... -amp/56011
3. Are you distributing the solar charging to one or two batteries
or battery banks?
(If two, how unless your charge controller is capable of 2 banks?)
I have the controller wired directly to a buss bar connected to our house bank (two batteries in parallel) and that bank is linked to the start bank using a combiner that allows for two-way power flow. (http://www.yandina.com/c100InfoR3.htm) I have the start battery isolated from house loads so I don't really worry about pushing power back that way. I also carry a booster battery pack in case I/anyone needed a quick jump.
4. Did you wire directly to the battery(ies) or to another battery input?
The controller goes basically to the house batteries using a primary buss bar distribution point behind the helm (our house batteries are under the berth area)
5. What average daily amperage output are you getting from your 2
100W panels?
I have just the two 50w, 6v panels for a total of 50 watts for 12v charging. We seem to pull in 12-15AH of power for us in mixed summer weather and will charge at well over 4 amps when the actual sun comes out and just less than 1 amp in full cloudy conditions. We basically have a trickle charger on steroids connected all the time and that allows us to run the freezer and other accessories for up to 5 days without other charge sources before needing to move or plug in. This was our hope and is working great for our little boat.
Greg
1. Did you wire your 2 panels in parallel or keep them separate?
(Reports say a parallel connection will draw down the non-shaded
panel output as well as the shaded panel; series wiring is worse)
I had to wire them in series in this case because I used 6v panels. They were the only model of the type I could find that were sized perfectly for the short roof of the 19. There are impacts from shading of course but with total actual panel output near 19 volts, they can stand minor shading from my roof rails and still push a charge well enough.
2. What charge controller(s) did you use (PWM or MPPT)?
Because I already have a monitor, I choose to use a very simple PWM charge controller. Our setup is so small in Volts that the possible gains from a MPPT type don't exist. If you are using multiple panels and pushing well over 24v into a 12v system through a controller, the MPPT has advantages. I also liked the small size of this one for easy mounting in a tight location with only double stick tape.
http://www.campingworld.com/shopping/it ... -amp/56011
3. Are you distributing the solar charging to one or two batteries
or battery banks?
(If two, how unless your charge controller is capable of 2 banks?)
I have the controller wired directly to a buss bar connected to our house bank (two batteries in parallel) and that bank is linked to the start bank using a combiner that allows for two-way power flow. (http://www.yandina.com/c100InfoR3.htm) I have the start battery isolated from house loads so I don't really worry about pushing power back that way. I also carry a booster battery pack in case I/anyone needed a quick jump.
4. Did you wire directly to the battery(ies) or to another battery input?
The controller goes basically to the house batteries using a primary buss bar distribution point behind the helm (our house batteries are under the berth area)
5. What average daily amperage output are you getting from your 2
100W panels?
I have just the two 50w, 6v panels for a total of 50 watts for 12v charging. We seem to pull in 12-15AH of power for us in mixed summer weather and will charge at well over 4 amps when the actual sun comes out and just less than 1 amp in full cloudy conditions. We basically have a trickle charger on steroids connected all the time and that allows us to run the freezer and other accessories for up to 5 days without other charge sources before needing to move or plug in. This was our hope and is working great for our little boat.
Greg
For installing a rigid panel I was referred to this company.
http://amsolar.com/
They have a mounting system they developed for RVs.
See the mounts here http://amsolar.com/rv-solar-panel-kit/mounting-accessories
For mounting instructions and YouTube video instructions, see here http://amsolar.com/diy-rv-solar-instructions/edmounts/
This looks like a good solution for mounting rigid panels. If it works on RV roofs, it should work on a C-Dory.
I have not tried this and I have not purchased anything from this company, but I like their ideas.
http://amsolar.com/
They have a mounting system they developed for RVs.
See the mounts here http://amsolar.com/rv-solar-panel-kit/mounting-accessories
For mounting instructions and YouTube video instructions, see here http://amsolar.com/diy-rv-solar-instructions/edmounts/
This looks like a good solution for mounting rigid panels. If it works on RV roofs, it should work on a C-Dory.
I have not tried this and I have not purchased anything from this company, but I like their ideas.
I am using the "Z" mounts which Larry linked to on my RV. They seem to work fine--keep the panels off the surface of the roof to allow cooling.
One of the issues in any set of solar panels is tracking. You can get considerably more, power out, even if you manually turn the panels every 2 hours vs laying the panel flat on the roof. I have seen some C Dorys which have had 2 axis tracking. Folks who are living off the grid, have a timer, which will turn the panels continuously during the day--about once a week they change the Azimuth, as the sun declination changes with the season.
Studies show that 2 axis tracking will give about 35% more power output vs panels laid flat. Just raising the panels in the N/S plane to give the max azimuth, will increase the output about 15%. Considering the cost of panels that seems a reasonable thing to do. For trickle charging--not so important, as when trying to keep up with refrigation demands
One of the issues in any set of solar panels is tracking. You can get considerably more, power out, even if you manually turn the panels every 2 hours vs laying the panel flat on the roof. I have seen some C Dorys which have had 2 axis tracking. Folks who are living off the grid, have a timer, which will turn the panels continuously during the day--about once a week they change the Azimuth, as the sun declination changes with the season.
Studies show that 2 axis tracking will give about 35% more power output vs panels laid flat. Just raising the panels in the N/S plane to give the max azimuth, will increase the output about 15%. Considering the cost of panels that seems a reasonable thing to do. For trickle charging--not so important, as when trying to keep up with refrigation demands
The appeal solar panels have for me is they're quiet, out of the way and once
set up, hooked up and working no fussing and adjusting is 'necessary' (albeit
sacrificing some amperage output). There are plenty of others things to mess
around with.
C-Dory pilothouse roofing is not flat but bowed slightly port and starboard.
Considering my preference for fixing and forgetting about them, I'm going with
semi-flexible aluminum backed Ganz eco-energy, probably 2 55W panels with
a max output of 3.2 amps each. Easy to thru-bolt thru the roof decking with four
3/4" - 1 " small blocks of PVC or starboard and they bend to conform to the
curved pilothouse roof.
This set up puts each slightly curved panel central azimuth off vertical by
several degrees meaning to me one panel may have better alignment hence
better output than the other during the optimal daylight hours. It also
presents a dilemma as to having them connect
A) in parallel to one charge controller
or
B) separately with each panel having its own charge controller.
I've read with panels in parallel, the one panel with shade or less optimal solar
alignment will adversely affect the output of both panels WORSE than having
separate panels each doing their own thing as best they can.
Any informed opinions here with suggestions? I'm all ears.
Aye.
set up, hooked up and working no fussing and adjusting is 'necessary' (albeit
sacrificing some amperage output). There are plenty of others things to mess
around with.
C-Dory pilothouse roofing is not flat but bowed slightly port and starboard.
Considering my preference for fixing and forgetting about them, I'm going with
semi-flexible aluminum backed Ganz eco-energy, probably 2 55W panels with
a max output of 3.2 amps each. Easy to thru-bolt thru the roof decking with four
3/4" - 1 " small blocks of PVC or starboard and they bend to conform to the
curved pilothouse roof.
This set up puts each slightly curved panel central azimuth off vertical by
several degrees meaning to me one panel may have better alignment hence
better output than the other during the optimal daylight hours. It also
presents a dilemma as to having them connect
A) in parallel to one charge controller
or
B) separately with each panel having its own charge controller.
I've read with panels in parallel, the one panel with shade or less optimal solar
alignment will adversely affect the output of both panels WORSE than having
separate panels each doing their own thing as best they can.
Any informed opinions here with suggestions? I'm all ears.
Aye.
With just those two panels, I would wire each to a small and simple charge controller so they can work as well as possible when sun is on them. When you have one side shaded or angled away from the sun, the other panel will not be compromised by it. With only two panels, you only have a max of 2 times 12v for charging and that means the benefit of a combined MPPT unit over two simple PMW units is debatable. You don't have the volts to divide and charge very far (enough multiples of 12+ volts).
If you had three fixed panels of 12v, I would likely go with MPPT because it could better manage a steady 2x12 out of a partially shaded 36v. Anything less than 24v is still just 12v for charging, and positions of the panels will compromise them anyway. The added cost is not worth it for just two but that is my opinion.
Greg
If you had three fixed panels of 12v, I would likely go with MPPT because it could better manage a steady 2x12 out of a partially shaded 36v. Anything less than 24v is still just 12v for charging, and positions of the panels will compromise them anyway. The added cost is not worth it for just two but that is my opinion.
Greg
Marco Flamingo
Active member
I've been happy with my SNAD fasteners. No drilling through the cabin top, the panels are removable, and the panels are set off the cabin top surface. Mine have now been tested to 70 mph in high desert crosswinds, so I don't remove them for trailer travel. But if the panel is removed, the SNAD fitting is a good match to the gel coat and doesn't get in the way.
My procedure: attach female snap fittings to the back side of the panel. I used tiny stainless bolts with nylock washers, but pop rivets would work. Attach male SNADs to the snap fittings. Peel the paper off the adhesive and stick in place. I only used 4 SNAD fasteners, but more could be used, including one or two in the center to keep the flexible panel evenly offset from the curved roof. It takes a little fussing, but not as much as preparing to drill through your cabin top and then getting the holes sealed.
I thought I had a closeup picture in my folder, but I can't find it now.
Mark
My procedure: attach female snap fittings to the back side of the panel. I used tiny stainless bolts with nylock washers, but pop rivets would work. Attach male SNADs to the snap fittings. Peel the paper off the adhesive and stick in place. I only used 4 SNAD fasteners, but more could be used, including one or two in the center to keep the flexible panel evenly offset from the curved roof. It takes a little fussing, but not as much as preparing to drill through your cabin top and then getting the holes sealed.
I thought I had a closeup picture in my folder, but I can't find it now.
Mark
Pat Anderson
New member
Lots to think about here! I need to investigate SNAD and 1"x1" aluminum tubing with double stick tape to move my panels off the "wings" up to the roof so they can be flat to the sky. Now we do not have the Alaska Series, the panels need to move to the roof!
The charge controller monitors the existing battery charge and delivers the
appropriate amps to charge the battery without over charging it. I get that.
When the battery is fully charged and the charge controller stops delivering
amps, save a few milliamps, what happens to the unused amps the solar panel
may be putting out at that time? Heat? Swelling? Explosion? Meltdown?
Ex: panel output is 3 amps, battery needs only 0.025 amp. Maybe there is a
market for a "save-your-amps" device?
Aye.
Grandma used to say, "It's possible to have too much of a good thing."
appropriate amps to charge the battery without over charging it. I get that.
When the battery is fully charged and the charge controller stops delivering
amps, save a few milliamps, what happens to the unused amps the solar panel
may be putting out at that time? Heat? Swelling? Explosion? Meltdown?
Ex: panel output is 3 amps, battery needs only 0.025 amp. Maybe there is a
market for a "save-your-amps" device?
Aye.
Grandma used to say, "It's possible to have too much of a good thing."
I believe the oldest of shunt controller designs did produce some heat to effectively burn off in certain overpower conditions but more modern PWM and MPPT types actually interrupt the circuit, allowing the panels to go to full open circuit voltage, and no amps are produced by the panels.
The only heat to worry about would be at the panels themselves in warmer climates, direct sun, and poor venting installations. Performance goes way down and the health of the panel is also at risk to some degree depending on type and construction.
A "save your amps" device would simply be a storage method for the power such as added battery capacity to charge, or it could be put to use more directly by consuming the incoming power for something useful so the cutoff voltage is not quite attained. When we are running the boat and I can see us nearing our peak charge, I am plugging in everything rechargeable we have to put that juice to use.
Phones, tablets, wireless speaker, hand vacuum using little inverter.... Those items will collectively pull over 8 amps if they are discharged significantly.
Greg
The only heat to worry about would be at the panels themselves in warmer climates, direct sun, and poor venting installations. Performance goes way down and the health of the panel is also at risk to some degree depending on type and construction.
A "save your amps" device would simply be a storage method for the power such as added battery capacity to charge, or it could be put to use more directly by consuming the incoming power for something useful so the cutoff voltage is not quite attained. When we are running the boat and I can see us nearing our peak charge, I am plugging in everything rechargeable we have to put that juice to use.
Phones, tablets, wireless speaker, hand vacuum using little inverter.... Those items will collectively pull over 8 amps if they are discharged significantly.
Greg
When the battery is fully charged and the charge controller stops delivering
amps, save a few milliamps, what happens to the unused amps the solar panel
may be putting out at that time? Heat? Swelling? Explosion? Meltdown?
To put what Greg said, in a different term: it is like a water faucet. It is closed (electronically)--no water is wasted when the faucet is closed. If the circuit is not complete, there is no electricity/heat etc which is surplus. There is the potential to have flow of electricity if the valve is opened.
In the example by Greg, that is adding more items which consume power as they charge other batteries.
For years I maintained the batteries (two group 27's) on my Road Trek, and C Dory 22, I left in Las Vegas with 5 watt solar panels. (No controller needed). I went as long as 9 months between times I ran them, and the batteries were always fully charged.
Thanks, I got (part of) it. '' Open circuit voltage" = no amps flow to the battery
since the circuit is open (or in the water hose analogy, the nozzle is shut off and
no water comes out of the hose).
Still, the "open circuit" is located in the charge controller, right? But, in a small
panel without a charge controller, where is the open circuit located?
What is happening in the solar panel? How do the cells in the solar panel get
the message to stop making energy in sunlight when the voltage circuit is open
(the water pump should still be working creating increased pressure in the hose;
hence, swelling, explosion, etc)?
Trying to create a visual here... (maybe the analogy sucks).
Aye.
since the circuit is open (or in the water hose analogy, the nozzle is shut off and
no water comes out of the hose).
Still, the "open circuit" is located in the charge controller, right? But, in a small
panel without a charge controller, where is the open circuit located?
What is happening in the solar panel? How do the cells in the solar panel get
the message to stop making energy in sunlight when the voltage circuit is open
(the water pump should still be working creating increased pressure in the hose;
hence, swelling, explosion, etc)?
Trying to create a visual here... (maybe the analogy sucks).
Aye.
You need a closed path, or closed circuit, to get electric current to flow. If there’s a break anywhere in the path, you have an open circuit, and the current stops flowing — and the metal atoms in the wire quickly settle down to a peaceful, electrically neutral existence.
Within a charge controller, there is effectively a type of switch that opens the circuit, disconnecting the power from the boat loads. Without a load to consume it, power will not flow and nothing happens. The open circuit turns electrical power into only electrical potential which does nothing without a something consuming it.
A battery stores power while a solar panel produces it but they both have the same open circuit behavior. If there is no load on either, they do not transfer any power, anywhere. Literally nothing happens because they only have potential so long as the circuit is open.
Close the circuit with a switch, and power flows. A solar panel without any loads still has an open circuit voltage that you can measure with a voltmeter, but no load means no heat or action of any sort.
A solar panel without a load, is just a modest source of shade.
Greg
Within a charge controller, there is effectively a type of switch that opens the circuit, disconnecting the power from the boat loads. Without a load to consume it, power will not flow and nothing happens. The open circuit turns electrical power into only electrical potential which does nothing without a something consuming it.
A battery stores power while a solar panel produces it but they both have the same open circuit behavior. If there is no load on either, they do not transfer any power, anywhere. Literally nothing happens because they only have potential so long as the circuit is open.
Close the circuit with a switch, and power flows. A solar panel without any loads still has an open circuit voltage that you can measure with a voltmeter, but no load means no heat or action of any sort.
A solar panel without a load, is just a modest source of shade.
Greg
One other thing to remember about the trickle charge and topped off battery. With the small panels and no controller, there will be a diode to keep the battery from putting current back into the solar cells at night. This diode does drop the voltage by about half a volt. When the battery is fully charged, and there is essentially no current flowing--there will be an equilibrium between the battery voltage and the solar panel output. Since there is no voltage differential, no current flows. (Sort of "self regulates" This works fine if the solar panel is small. Lets say 2 watts for a typical group 27, 75 amp hour battery. If you have two of the 75 amp hour batteries, and it is hot (100* = 10% loss a month)--then 5 watts will be OK. If it is cold 40* to 50*, then you may only have 1.5% loss, a month, then 2 watts may be for for two batteries.
Now if Foggy has just two group 27 batteries--and a 80 watt panel, that is far more than needed for trickle charging, and a controller (best to have the MPPT) is essential.
On the other hand, 80 watts may not be enough to keep up with demands (depending on what he is running). Lets say that there is a refrigerator, and Foggy likes to anchor for several days, and not run his engines, or a generator to charge the batteries. He would be best served by the very least 100 watts, and probably best 200 watts. (The determining factors, assuming that it was only refrigeration and a few LED lights at night, would be both ambient temperature (how much run time for the refer, vs how much direct solar radiation hitting the panels.
Type of controller depends on temp: From Solarcraft site:
"An MPPT controller is better suited for colder conditions. As solar module operating temperature goes down, the Vmp1 increases. That’s because the voltage of the solar panels operating at their peak power point at Standard Testing Conditions (STC is 25C°) is about 17V while the battery voltage is about 13.5V. The MPPT controller is able to capture the excess module voltage to charge the batteries. As a result, a MPPT controller in cool conditions can produce up to 20 – 25% more charging than a PWM controller."
Now if Foggy has just two group 27 batteries--and a 80 watt panel, that is far more than needed for trickle charging, and a controller (best to have the MPPT) is essential.
On the other hand, 80 watts may not be enough to keep up with demands (depending on what he is running). Lets say that there is a refrigerator, and Foggy likes to anchor for several days, and not run his engines, or a generator to charge the batteries. He would be best served by the very least 100 watts, and probably best 200 watts. (The determining factors, assuming that it was only refrigeration and a few LED lights at night, would be both ambient temperature (how much run time for the refer, vs how much direct solar radiation hitting the panels.
Type of controller depends on temp: From Solarcraft site:
"An MPPT controller is better suited for colder conditions. As solar module operating temperature goes down, the Vmp1 increases. That’s because the voltage of the solar panels operating at their peak power point at Standard Testing Conditions (STC is 25C°) is about 17V while the battery voltage is about 13.5V. The MPPT controller is able to capture the excess module voltage to charge the batteries. As a result, a MPPT controller in cool conditions can produce up to 20 – 25% more charging than a PWM controller."
Thanks, Bob
My current :wink plan is an 80W (4.14 amps) and a 55W (3.2 amps) in parallel to
a PWM dual battery charge controller (10 amp max, automatic and smart)).
I'd like twin 80Ws but not space enough. More on controllers below.
Shading on solar panels is a power killer. Still have not determined whether a
small panel system (above) is better connected in parallel or kept separate for
the effects of shade (objects, clouds, etc). Greg thinks separate is the way to go
here. Also, apparently, shade on a single panel connected to others in series, is
a much worse draw down than if the panels were connected in parallel (?).
Below is my understanding level on PWM vs MPPT charge controllers.
SUMMARY (2 WEBSITES***) PWM v MPPT SOLAR CHARGE CONTROLLERS
PWM CHARGE CONTROLLER
* Smaller systems where MPPT benefits are minimal
* Requires heavier cable size for longer runs
* Solar array should match the battery voltages (12V for me)
* Solar array sized in amps (12 V panels in parallel)
* Better in warm solar cell temperatures (45* - 75*C = 113* - 167*F !!!)
[ Keep those panels cool? Why?]
* Less cost for small system
MPPT CHARGE CONTROLLER
* For higher power systems; 12V: few hundred Watts, 24V-48V: several hundreds of Watts
* Less efficient in low power applications (MPPT sweet spot = 170W or higher)
* Smaller cable sizes allowed in connections
* For full benefits, solar array voltage should exceed battery voltage
* Solar array sized in Watts (panels connected in series)
* Operates above battery voltage providing boost in cold temperatures when
battery is low (<45*C) or high temperatures (>75*C) or in low irradiance
*** www.victronenergy.com/blog/2014/07/21/w ... m-or-mppt/
*** www.solarcraft.net/articles/comparing-p ... ontrollers
Aye.
My current :wink plan is an 80W (4.14 amps) and a 55W (3.2 amps) in parallel to
a PWM dual battery charge controller (10 amp max, automatic and smart)).
I'd like twin 80Ws but not space enough. More on controllers below.
Shading on solar panels is a power killer. Still have not determined whether a
small panel system (above) is better connected in parallel or kept separate for
the effects of shade (objects, clouds, etc). Greg thinks separate is the way to go
here. Also, apparently, shade on a single panel connected to others in series, is
a much worse draw down than if the panels were connected in parallel (?).
Below is my understanding level on PWM vs MPPT charge controllers.
SUMMARY (2 WEBSITES***) PWM v MPPT SOLAR CHARGE CONTROLLERS
PWM CHARGE CONTROLLER
* Smaller systems where MPPT benefits are minimal
* Requires heavier cable size for longer runs
* Solar array should match the battery voltages (12V for me)
* Solar array sized in amps (12 V panels in parallel)
* Better in warm solar cell temperatures (45* - 75*C = 113* - 167*F !!!)
[ Keep those panels cool? Why?]
* Less cost for small system
MPPT CHARGE CONTROLLER
* For higher power systems; 12V: few hundred Watts, 24V-48V: several hundreds of Watts
* Less efficient in low power applications (MPPT sweet spot = 170W or higher)
* Smaller cable sizes allowed in connections
* For full benefits, solar array voltage should exceed battery voltage
* Solar array sized in Watts (panels connected in series)
* Operates above battery voltage providing boost in cold temperatures when
battery is low (<45*C) or high temperatures (>75*C) or in low irradiance
*** www.victronenergy.com/blog/2014/07/21/w ... m-or-mppt/
*** www.solarcraft.net/articles/comparing-p ... ontrollers
Aye.