Another solar panel query!

[number four]

No I am saying that its not often that I have spare. Its also hard to tell if you have spare as the stats on the FM80 will only show what power has been put into the bank not what could have been used but was not gathered. Yes I know about the "cream off" option on the outback & I also have a similar setting on the inverter. The thing is what will I use it for? If its a good sunny day the water will be hot from the solar array any way.

 

Just been going over the june & july stats & there was only a few time that the bat got up to full & then we had a run of good days after, mostly they good runs followed a bad run to was just going into the bank.

 

i was thinking about running a seprate creem of for charging all mu rechargable small batteries etc. per haps that will work for you. the trick is to get it to bypas automaticaly i wonder if one of the smart gage gizmos will do it?

i to am looking at hot water solar but far from easy on a boat!

[Justme]

Oh yeh I forgot I can also do it with the SG unit as well as it has a programable relay. So thats 3 options I have for automating it. That said I tend to manually put things on charge when its sunny (or use a timer) plus I will put the freezer on "fast freeze" to store more energy. I also tend to be doing more power tool stuff on the best days.

 

I think the total amount of power that could be saved per day during daylight hours into small AAA, AA, A, B, C, D & 9v batts is so small compared to the amount stored in my bat bank its not worth doing.

[hillbilly]

I have a 85w panel from china £195, which I cannot distinguish from a lot of the UK offerings. I think that they must also get chinese units and sell them on!

I was a little concerned at first but as I got mine on E-Bay, I checked the feedback system which was 100% so decided to go ahead. Arrived well packed after about 4 weeks. I am contemplating about getting another so that I can twin them up. I think this seller's ebay name was 'Tiffanywatch' if my memory serves me correctly. Roll on the day when we can get a new memory from china as well!

Can I ask what you got with this solar panel? Did you get wiring kit etc?

[steviehat]

Sorry 'bout this. I have trawled several threads on this but cannot find the answer i need, so here goes:

 

We want to get solar power to assist keeping the batteries topped up, but not sure how much wattage we would need. We have a widebeam so roof space not a problem, so is it better to get more than one panel or just get the biggest single panel we can get?

We are guessing at about 200w, but that's exactly it - a guess. We have 6 batteries powering all the normal stuff (lights, radio, fridge). Does this sound about right? I don't want to get too anal about power consumption - just laymans terms would be great!

We are looking at panels on ebay, direct from China - does anyone have an opinion on these? Anything to watch out for?Do we need a charge controller? Again,we have seen digital ones on ebay.

 

Any help and advice from the elecy gurus much appreciated!

[steviehat]

I've just bought a 120w chinese panel from sunrise energy on ebay. It cost £299 delivered and is exactly the same as my other three(which were £650 each) just without the fancy logo.In summer time we have power galore. In winter we switch off the fridge and use a homemade cold box. The panels still chuck out enough to get us through the day. Every few days we might run the generator fort 20 mins or so. .We try to moor out in the open to try n grab a bit more light and try to remember to tip em up at night for the morning but i'm often too drunk to do that.

Good luck!

[wirren]

I've just bought a 120w chinese panel from sunrise energy on ebay. It cost £299 delivered and is exactly the same as my other three(which were £650 each) just without the fancy logo.In summer time we have power galore. In winter we switch off the fridge and use a homemade cold box. The panels still chuck out enough to get us through the day. Every few days we might run the generator fort 20 mins or so. .We try to moor out in the open to try n grab a bit more light and try to remember to tip em up at night for the morning but i'm often too drunk to do that.

Good luck!

 

Hi Steve, I've been watching these panels, they get good feedback. I am tempted but may wait till next spring. What regulator did you get ?

Just noticed some have gone up a £ tenner !

[Bones]

I have a Kyovera 85w solar panel and am thinking of upping that by either 100w or another 85, but not Kyocera - probably just with what is described as a HIGH EFFICIENCY SILICON CRYSTALLINE PHOTOVOLTAIC PANELS

 

Can I mix 85 and 100w and can I mix the kyocera which is multicrystal wtih non-Kyocera monocystal? My charger controller is sufficient for more wattage.

[Justme]

I have a Kyovera 85w solar panel and am thinking of upping that by either 100w or another 85, but not Kyocera - probably just with what is described as a HIGH EFFICIENCY SILICON CRYSTALLINE PHOTOVOLTAIC PANELS

 

Can I mix 85 and 100w and can I mix the kyocera which is multicrystal wtih non-Kyocera monocystal? My charger controller is sufficient for more wattage.

 

 

Mixing panels is not simple.

 

You have to choose to either wire then in series or parallel.

 

In series they need to have the same specs & your controller be able to convert the increased voltage to the bank voltage (IE a MPPT).

In parallel they still need the same specs but your controller needs to be able to handle double the amps.

 

The important spec is the V IMP I think its called.

 

If you dont you could damage the panels or if lucky just get poor output.

[Bones]

Mixing panels is not simple.

 

You have to choose to either wire then in series or parallel.

 

In series they need to have the same specs & your controller be able to convert the increased voltage to the bank voltage (IE a MPPT).

In parallel they still need the same specs but your controller needs to be able to handle double the amps.

 

The important spec is the V IMP I think its called.

 

If you dont you could damage the panels or if lucky just get poor output.

 

by same specs do you mean the same panel or do you mean both 85w?

[Smelly]

I've just bought a 120w chinese panel from sunrise energy on ebay. It cost £299 delivered and is exactly the same as my other three(which were £650 each) just without the fancy logo.In summer time we have power galore. In winter we switch off the fridge and use a homemade cold box. The panels still chuck out enough to get us through the day. Every few days we might run the generator fort 20 mins or so. .We try to moor out in the open to try n grab a bit more light and try to remember to tip em up at night for the morning but i'm often too drunk to do that.

Good luck!

 

I don't suppose you'd give us a linky?

[Justme]

by same specs do you mean the same panel or do you mean both 85w?

 

No I mean the specs.

 

You can have dif wattages but you do have to look at how they are wired so that you dont get one panel passing more power than it can.

 

This is the specs of my panels.

 

 

Electrical Specs:

Max Power: 80WP

Open Circuit Voltage (V): 21.88 + 2

Short Circuit Current (A): 4.98 + 0.4

Max. Power voltage (V): 17.64 + 2 (also known as V IMP)

Max. Power Current (A): 4.54

 

The important one is the V IMP. The peak point on the voltage scale where the panel produces the most current. You also need to make sure the max V the panel can take is not exceeded (but most are higher than the controller will take anyway)

[Bones]

No I mean the specs.

 

You can have dif wattages but you do have to look at how they are wired so that you dont get one panel passing more power than it can.

 

This is the specs of my panels.

 

 

Electrical Specs:

Max Power: 80WP

Open Circuit Voltage (V): 21.88 + 2

Short Circuit Current (A): 4.98 + 0.4

Max. Power voltage (V): 17.64 + 2 (also known as V IMP)

Max. Power Current (A): 4.54

 

The important one is the V IMP. The peak point on the voltage scale where the panel produces the most current. You also need to make sure the max V the panel can take is not exceeded (but most are higher than the controller will take anyway)

 

Ah haha! Ok. I understand.. I think. So the spec have to be exactly the same. My kyocera is

 

Max Power: 85WP

Open Circuit Voltage (V): 21.7

Short Circuit Current (A): 5.34

Max. Power voltage (V): 17.4 (also known as V IMP)

Max. Power Current (A): 5.02

 

I didn't find any +'s as you did. So i need something the same, or is a little deviation allowed? The panel I was looking at is not a kyocera and much cheaper!

 

Max Power: 85WP

Open Circuit Voltage (V): 22.1

Short Circuit Current (A): 5.41

Max. Power voltage (V): 17.6 (also known as V IMP)

Max. Power Current (A): 4.63

 

Is that the same enough?

 

The 100w panel is

Max Power: 100WP

Open Circuit Voltage (V): 21.63

Short Circuit Current (A): 6.48

Max. Power voltage (V): 17.3 (also known as V IMP)

Max. Power Current (A): 5.78

 

 

How they are wired - do you mean in the controller or the actual panel itself? My current panel has a thing on the back where you can add another panel to it.

Edited February 18, 2010 by Bones

[Justme]

Close enough is close enough. The most important one is the V IMP (peak power volts IE 17.4 & 17.2v in your case). That would be fine.

 

The +'s on mine are the variations that can be expected in normal use. All electronics have a "range" of expected performance.

 

I could have gone on to show the temp adjustment stats as well but for this its not needed.

 

If you wire a 100w panel in series with a 50w panel then the power through the 50w one is in excess of what it prob can take (plus your controller needs to be able to take the increase in volts). If you wire it in parallel the controller needs to be able to take the increased amps. There is also a prob in parallel with the dif flows but I cant remember what & why.

 

Best to try to get panels of the same watts or very close with the same or close specs & then wire to suit the battery voltage & controller type. With a MPPT go for high V (so in series) low amps on the array side. If its a non MPPT then you have to match the array voltage to the bat bank voltage so prob in parallel.

 

In both cases the controller needs to be able to handle the amps to the battery not the array amps.

 

On mine the array amps are about 12 amps yet the amps to the bank are up to 80amps.

 

The controller is an 80amp one.

Edited February 18, 2010 by Justme

[magnetman]

Close enough is close enough. The most important one is the V IMP (peak power volts IE 17.4 & 17.2v in your case). That would be fine.

 

The +'s on mine are the variations that can be expected in normal use. All electronics have a "range" of expected performance.

 

I could have gone on to show the temp adjustment stats as well but for this its not needed.

 

If you wire a 100w panel in series with a 50w panel then the power through the 50w one is in excess of what it prob can take (plus your controller needs to be able to take the increase in volts). If you wire it in parallel the controller needs to be able to take the increased amps. There is also a prob in parallel with the dif flows but I cant remember what & why.

 

Best to try to get panels of the same watts or very close with the same or close specs & then wire to suit the battery voltage & controller type. With a MPPT go for high V (so in series) low amps on the array side. If its a non MPPT then you have to match the array voltage to the bat bank voltage so prob in parallel.

 

In both cases the controller needs to be able to handle the amps to the battery not the array amps.

 

On mine the array amps are about 12 amps yet the amps to the bank are up to 80amps.

 

The controller is an 80amp one.

 

I would suggest if you have an 85w panel giving around 5.5 amps max and a 100w panel giving around 6.5 amps max then you need a controller capable of handling over 12 amps. This assumes that the panels are wired in parallel to retain the 12vdc nominal output.

 

I think your "amps to the bank are up to 80 amps" is an irrelevant comment in a 12v system involving two panels rated at 85 and 100 watts.

[Justme]

I would suggest if you have an 85w panel giving around 5.5 amps max and a 100w panel giving around 6.5 amps max then you need a controller capable of handling over 12 amps. This assumes that the panels are wired in parallel to retain the 12vdc nominal output.

 

I think your "amps to the bank are up to 80 amps" is an irrelevant comment in a 12v system involving two panels rated at 85 and 100 watts.

 

You have failed to see that the max amps from the panel is not at the banks voltage but at about 17v. Once the V its actually running at is accounted for its a dif picture.

 

I would say over 16amps as at some point the bank could be as low as 12v & if its very cold that 185 watts could be more like 200 watts.

 

As I was explaining that the controller needed to handle the banks charging amps & not the arrays output amps it was not irrelevant at all. It was showing that the two can be very different when using a MPPT controller.

 

 

 

Oh & since when has any thing on here be relevant?

[magnetman]

You have failed to see that the max amps from the panel is not at the banks voltage but at about 17v. Once the V its actually running at is accounted for its a dif picture.

 

I would say over 16amps as at some point the bank could be as low as 12v & if its very cold that 185 watts could be more like 200 watts.

 

As I was explaining that the controller needed to handle the banks charging amps & not the arrays output amps it was not irrelevant at all. It was showing that the two can be very different when using a MPPT controller.

 

 

 

Oh & since when has any thing on here be relevant?

 

 

Going back to your explanation of array amps versus charging amps surely this would be the same if the panels are in parallel?

 

I still think that if you have an 85w pv module on a narrowboat with a 12vdc domestic system and you want to add a 100w pv module to that you will need to have a controller capable of handling 12 amps.

 

for the purposes of argument reduction I agree that a 15A controller would be the best option.

 

but for the purposes of argument enhancement I do not agree that array amps and bank amps will differ if modules are mounted in parallel in a simple two module 12v system.

 

or maybe I've had too much beer

[Bones]

i have a 15amp, maybe even 20amp charger controller

[Justme]

 

Going back to your explanation of array amps versus charging amps surely this would be the same if the panels are in parallel?

 

I still think that if you have an 85w pv module on a narrowboat with a 12vdc domestic system and you want to add a 100w pv module to that you will need to have a controller capable of handling 12 amps.

 

for the purposes of argument reduction I agree that a 15A controller would be the best option.

 

but for the purposes of argument enhancement I do not agree that array amps and bank amps will differ if modules are mounted in parallel in a simple two module 12v system.

 

or maybe I've had too much beer

 

In this case possibly not as he has 12v suitable panels so the dif between spec & actual will be minimal apart from if you let the bank voltage fall to low a level then at the reduced V the amps will increase.

 

Dont forget that the power from an array can go up by 10% or more in sunny & cold conditions. You need to allow for that when sizing the controller.

 

If he had say 24v panels & a MPPT controller then the array amps will be half the bank amps. Where possible you should up the array V to lower the array amps & then use a MPPT controller to lower the V & increase the amps. Whilst that does have losses the gains are bigger.

 

This gives lots of benefits.

 

Less losses for the same cable size, or same losses for smaller cable

more choice on install site as longer cables wont break the £ bank.

better power capture (up to 30% is claimed)

more choice on panels

more choice on wiring system

 

If you add a 100w panel to a 85w in series you will get in effect the power from 2 x 85w as one will limit the amp flow of the other. If you wire them in parallel there is again some losses involved but I cant think what they are & which one will give the best results. Doing it in parallel is like having two bats that are not the same size.

[rgreg]

How easily are these panels installed and what connections are needed to get the power into the batteries?

[Bones]

In this case possibly not as he has 12v suitable panels so the dif between spec & actual will be minimal apart from if you let the bank voltage fall to low a level then at the reduced V the amps will increase.

 

Dont forget that the power from an array can go up by 10% or more in sunny & cold conditions. You need to allow for that when sizing the controller.

 

If he had say 24v panels & a MPPT controller then the array amps will be half the bank amps. Where possible you should up the array V to lower the array amps & then use a MPPT controller to lower the V & increase the amps. Whilst that does have losses the gains are bigger.

 

This gives lots of benefits.

 

Less losses for the same cable size, or same losses for smaller cable

more choice on install site as longer cables wont break the £ bank.

better power capture (up to 30% is claimed)

more choice on panels

more choice on wiring system

 

If you add a 100w panel to a 85w in series you will get in effect the power from 2 x 85w as one will limit the amp flow of the other. If you wire them in parallel there is again some losses involved but I cant think what they are & which one will give the best results. Doing it in parallel is like having two bats that are not the same size.

 

I have 12volt, and if I add the 85W to my current 85w with my charger controller (stecca) that is suitable for two, then I should be fine - the spec are close enough?

 

How easily are these panels installed and what connections are needed to get the power into the batteries?

 

 

very.

Solar panel - charger controller - batteries

[Justme]

I have 12volt, and if I add the 85W to my current 85w with my charger controller (stecca) that is suitable for two, then I should be fine - the spec are close enough?

 

 

YES

 

Just check the wire size that you have used for the one panel is capable of taking the power from two without having huge losses. Or run new wires direct to the controller.

[matty40s]

I currently have an 240v immersion which is only supposed to be used when connected to a landline.

 

Would it be possible to add a solar panel via inverter to power this for warm/hot water , thus freeing me up from using the eberspacher on a daily basis??

 

Obviously in Winter it would need a back up, but would it work in summer??

[Pretty Funked Up]

...check the wire size that you have used for the one panel is capable of taking the power from two...

 

 

the above is important.

 

Run some good/fat cable (able to carry the full power of the array) to first panel, then parallel the other panels onto the same connection (these cables only need rating to output of the individual panels).

 

Its been mentioned elsewhere you get better performance without a charge controller at all but you cant leave boat unattended for any length of time like that, nor can you set it up to heat the water after batteries are full. Swings n roundabouts, Swings n roundabouts.

[Justme]

Would it be possible to add a solar panel via inverter to power this for warm/hot water , thus freeing me up from using the eberspacher on a daily basis??

 

Obviously in Winter it would need a back up, but would it work in summer??

 

 

Yes IF you have enough money to buy enough PV panels to provide the amount of power needed by the heater.

 

Very roughly if you use the immersion for 2 hours per day (so 2 x 2kw = 4kwh per day) in the height of summer you would need about 800w to 1kw of solar panels. Or to put it another way thats about £1350 to £1687 just for the panels & then aprox £500 for a good controller & about £1500 for a good inverter that will last with heavy duty use. Say £3.5k all in with the needed disconnects, breakers, cables ect.

 

 

So yes it can be done.

 

But I doubt you will want to.

[blodger]

I currently have an 240v immersion which is only supposed to be used when connected to a landline.

 

Would it be possible to add a solar panel via inverter to power this for warm/hot water , thus freeing me up from using the eberspacher on a daily basis??

 

Obviously in Winter it would need a back up, but would it work in summer??

Not to detract from what Justme has posted:-

 

12 & 24v immersion elements are available, used for dump loads, for the wind and solar market.

 

I would have thought it made sense to directly connect solar panels thereto than store power in batterries and or invert it to 240v ac to use 240 element currently fitted.

 

If I had thought ahead when I had to replace the calorifier I should have replaced the 1kw 240ac element with a 12v maybe. I got a 1/2kwatt one that the inverter/batteries could handle easier intending to fit it but it came to late. I suppose you only want the hot water when using the boat but it would only be a matter of switching instead to trickle charging?