Solar Panel Installation Topic

[WiseOwl]

Hi all,

 

We have just purchased a 57ft semi-trad narrowboat to be moored on the Aire and Calder canal.

 

I have tired to do as much research on solar panels and batteries as possible but so far have been a little overwhelmed. I know there are a lot of other solar panel topics but I would like to see what tips and recommendations people have for this current setup.

 

We have 1 x starter battery and a bank of 4 x lead 110ah leisure batteries, also a Victron 12v to 230v inverter.

 

We are looking for a solar array of 500w. I think this should be suffice, we will not be living aboard but in Summer we do not want to rely on running the engine for hours as we do not have a mains hook-up.

 

Is there a step by step guide for installation, I don't think it can be that hard but I also don't want to make an expensive mistake. 

 

Any tips or links to guides would be appreciated! 

 

Cheers

Jamie

[Chewbacka]

I have 440w of solar and so long as the weather is fairly sunny we are self sufficient’ for electric power from about Easter to September.  Winter you will get nothing much.

 

suggest you have a read of this.    https://www.bimblesolar.com/beginnersguide

[Ian F B]

Before considering the installation,first make the boat as energy efficient as possible,e.g.l.e.d.lights,low power consumption fridge,do an energy audit,and go from there.Read the forum posts on batteries  and away you go!????

[Robbo]

13 minutes ago, WiseOwl said:

We have just purchased a 57ft semi-trad narrowboat to be moored on the Aire and Calder canal.

 

Is there a step by step guide for installation, I don't think it can be that hard but I also don't want to make an expensive mistake. 

New boater as well?  Number One Tip; don't change anything, use the boat for a couple of years and then figure out if you need them, this tip goes for anything you also have planned for changing the boat.

Edited October 29, 2018 by Robbo

[Alan de Enfield]

7 minutes ago, WiseOwl said:

We are looking for a solar array of 500w. I think this should be suffice, we will not be living aboard but in Summer we do not want to rely on running the engine for hours as we do not have a mains hook-up.

 

During about May to September you will achieve an average of about 50% of the rated output (due to clouds, showers etc etc) for about 10 hours per day - so - roughly 178Ah per day.

This should be sufficient for normal usage, but every one has different ideas of 'normal use'.

If you are into 'heavy consumption'  appliances (Gaming computers, washing machines, coffee machines, toasters, deep fat fryers etc etc) then it may not be enough.

 

Ideally you should be working the 'other way' and doing an electrical audit first, and then building your generation systems to suit.

 

For October to April it is better to assume 'zero' from solar and find alternative sources, such as a generator.

Anything you do get in this period (and you will get 'some') should be viewed as an unexpected 'bonus'.

[Richard10002]

If you have the space, around 500w of solar via MPPT should be a no brainer. April to September self sufficient for most boaters, and not much between October and March.

 

No need to wait two years for this  

[Scholar Gypsy]

The other thing to think about is the trade off between output/efficiency and appearance,  impact on navigation etc.

 

 I went for panels that sit flat on the roof,  even though that is less efficient.  (In fact I can remove the panels and store inside. )

 

Bimble were very helpful https://nbsg.wordpress.com/2018/04/23/fitting-the-solar/

[Dr Bob]

1 hour ago, Richard10002 said:

If you have the space, around 500w of solar via MPPT should be a no brainer. April to September self sufficient for most boaters, and not much between October and March.

 

No need to wait two years for this  

I agree with Richard. We have 500W of solar and it is just right. We had 200W the first year and it was not enough. No need to wait.

I would not like to have more than our 4 panels as it would restrict room on the roof which at times you need room to walk on - ie when going up locks on the GU (or other wide canals).

[WiseOwl]

Thanks for the advice all, I agree we should spend a while on our boat to work out what is essential. However, I just think you cannot go wrong with getting some panels. As long as they are installed properly etc. Glad to hear that 500w works for you, I think this is what we will aim for.

 

It would be good if there was a general guide for installations. For example, Showing 'solar panels -> MPPT -> batteries' type thing. I will just keep having a good look around.

[WotEver]

39 minutes ago, WiseOwl said:

It would be good if there was a general guide for installations. For example, Showing 'solar panels -> MPPT -> batteries' type thing. 

You just described it. What specifics are you unsure about?

[Tony Brooks]

1 hour ago, WiseOwl said:

Thanks for the advice all, I agree we should spend a while on our boat to work out what is essential. However, I just think you cannot go wrong with getting some panels. As long as they are installed properly etc. Glad to hear that 500w works for you, I think this is what we will aim for.

 

It would be good if there was a general guide for installations. For example, Showing 'solar panels -> MPPT -> batteries' type thing. I will just keep having a good look around.

 

Try: solar panels -> isolation switch (optional) -> MPPT -> fuse close to batteries -> batteries

 

The isolation switch is to save you covering the panels or disconnecting them when the battery is disconnected from the controller for some reason. Disconnecting the batteries while leaving the solar input running may allow the controller to set itself to 24 volts.

[Robbo]

1 hour ago, WiseOwl said:

Thanks for the advice all, I agree we should spend a while on our boat to work out what is essential. However, I just think you cannot go wrong with getting some panels. As long as they are installed properly etc. Glad to hear that 500w works for you, I think this is what we will aim for.

 

It would be good if there was a general guide for installations. For example, Showing 'solar panels -> MPPT -> batteries' type thing. I will just keep having a good look around.

Personally I think 500w is way too much for basically a "leisure" boat and it's a lot of roof space and expense for something that may be not be needed.   A little solar is always good is what is said, but if you find you take your boat out every other to third day, solar isn't really required.    Also how does the boat provide hot water?   If it's currently the engine you probably end up running it anyhow!    As said above, just use the boat as is for a year or two and then re-evaluate on what's needed after.  It will save you time and money. 

[mrsmelly]

7 minutes ago, Robbo said:

Personally I think 500w is way too much for basically a "leisure" boat and it's a lot of roof space and expense for something that may be not be needed.   A little solar is always good is what is said, but if you find you take your boat out every other to third day, solar isn't really required.    Also how does the boat provide hot water?   If it's currently the engine you probably end up running it anyhow!    As said above, just use the boat as is for a year or two and then re-evaluate on what's needed after.  It will save you time and money. 

Good advice. All our useage is different. I took my solar off for the repaint and havnt put it back on, over a year now. We cruised very nearly every day from march till end of september which fully charged the batteries and gave a tank of hot water. We cruised during the day so whacking the charge in from the alternaters. Moored on an evening or afternoon with full batteries that didnt go down even to half so charged again next day. I am now plugged in to mains so again solar would be a waste as apart from the mains its also late in the year to get any useable sun and mains hook up is peanuts. If we were wintering off grid the solar again would be a waste of money. Solar is good for boats that dont move much in the summer and are off grid but thats a bout all. 

[WiseOwl]

3 hours ago, Tony Brooks said:

 

Try: solar panels -> isolation switch (optional) -> MPPT -> fuse close to batteries -> batteries

 

The isolation switch is to save you covering the panels or disconnecting them when the battery is disconnected from the controller for some reason. Disconnecting the batteries while leaving the solar input running may allow the controller to set itself to 24 volts.

Thanks Tony, this does confirm to me that it is pretty straight forward. Maybe even enjoyable haha

4 hours ago, WotEver said:

You just described it. What specifics are you unsure about?

I guess I would have been thinking about what size circuit breakers, fuses and size of wire to use but maybe I am over thinking it. If I get a kit I imagine all of these items will be the right size ready to go.

[WotEver]

2 minutes ago, WiseOwl said:

If I get a kit I imagine all of these items will be the right size ready to go.

Exactly so. Someone like Bimble will give you everything you need. 

[Tony Brooks]

13 minutes ago, WotEver said:

Exactly so. Someone like Bimble will give you everything you need. 

 

Not so sure about the cable conductor cross sectional area. For the panel to controller it would depend upon the run length and if you connect in series, series parallel or just parallel unless they assume parallel and size accordingly.

 

The controller to battery cable can be assume to take the controllers maximum current but then it still needs the cable length considering.

 

I think the OP is right to be concerned about this but if he reads up on the options for connecting the panels, advantages and disadvantage. Tells us how he intends to connect them, the panes size and cable run length (out and back) then we would be able to advise.

 

For my first panel Run by the Sun supplied a length of 2 core 2.5mm mains flex as part of the "kit". Far from ideal in my view and contrary to the BMEA codes.

[Detling]

I found less than 500 watts didn't allow me a day off the boat when out cruising. Sometimes we like to go out for the day by train or bus and come back after eating out in the evening, this prevents running engine as we are not aboard during the 8 to 8pm slot, also we have no need of hot water, but the fridge keeps running, so we have used a fair bit of battery. 300 watts did not keep the battery charge up but 500 does unless it is a very dull and dismal day when we would probably cancel our day out anyway.

[WiseOwl]

30 minutes ago, Tony Brooks said:

 

Not so sure about the cable conductor cross sectional area. For the panel to controller it would depend upon the run length and if you connect in series, series parallel or just parallel unless they assume parallel and size accordingly.

 

The controller to battery cable can be assume to take the controllers maximum current but then it still needs the cable length considering.

 

I think the OP is right to be concerned about this but if he reads up on the options for connecting the panels, advantages and disadvantage. Tells us how he intends to connect them, the panes size and cable run length (out and back) then we would be able to advise.

 

For my first panel Run by the Sun supplied a length of 2 core 2.5mm mains flex as part of the "kit". Far from ideal in my view and contrary to the BMEA codes.

I think I would have been looking at 2 x 250w/50v panels wiring them in series (only because I have seen someone else do this). Great tips here for the cable sizes -Simple so far then, I just need to work out where I want them and how long the cables will be then work from that.

[rusty69]

We started with 1 x 250W, then 2 x 250W, now 4 x 250W. Three in series through one MPPT and one through a separate MPPT.

 

Next plan is to Put 2+2 in series. We also tried them in series-parallel at some point.

 

1000W is far too many,and we could easily manage on 500W, but the panels were going cheap!

[WotEver]

Series or parallel. Always a good discussion point.

 

Series gives you greater voltage for an mppt controller to track in low light. However, if it’s a Tracer controller (one of the most common) they seem to get a bit stuck at low light levels and not track very well. Series also means that both panels must be unshaded. A hint of a shadow on one panel drops the whole output down. 

 

Parallel reduces the shadowing problem but doesn’t give much of an output in overcast and dull days. 

 

I think if if I were installing then I’d arrange for the configuration to be easily swapped between the two arrangements and then try it each way around for a month each, then repeat (but not at this time of year of course). 

[Johny London]

I have 2x150w in series and intend to add another series pair in parallel to the first pair. I think a good compromise regarding in case of shade.

If you bring all the panel wires all the way to the controller (individually) you can easily hook them series or parallel, and though you'll be buying a longer length of cable, it wont have to be super heavy duty (as the main run would be if you paralleled the lot).

[Sea Dog]

9 hours ago, WiseOwl said:

Thanks for the advice all, I agree we should spend a while on our boat to work out what is essential. However, I just think you cannot go wrong with getting some panels. 

Well, you can go wrong - you can choose the wrong panels.  Some boats have standard house roof panels a few mil below a metre wide, which probably give the best bang for buck, but if they're fitted aft this means walking along the boat roof is now out. Others have slimmer, but lower output panels, typically 670 mm wide although other sizes are available, allowing you to walk past with ease.  Once you've had your boat a while, and got your preferred ways of working sorted out, you'll know whether you need to preserve that roof access.

 

However, my first action on entering a lock whilst steering is to identify my route off the boat, either to escape, to deal with an emergency, or perhaps for a less urgent reason. If you are single handing, or just sharing the work, you may also need to be able to get on and off in the lock depending on your preferred method.  When the water is low, this access route is most frequently over the roof to/from a ladder in the middle of the lock.   If you want to be able to do that, you might wish to avoid full width panels aft or even go for ones you can walk on.

 

 

[Neil T]

Audit your consumption. Crucial. I use very little power and with 750 watts of flexible panels sikaflexed to the cabin roof I can walk over all of them, and get enough solar in the winter. All the less enthusiastic comments here fall away if you can get into your batteries  more than you use in winter.  

Size of yr battery bank also a big factor in tiding you over a couple of horrible days. 

In the end it’s what you can spend. 

400w of panel and 300AH lead acid batteries will get you by in summer possibly. 600AH deep cycle 2V cells (making up to 12V ) and 800w of panels / MPPT controller etc might mean you’re light fantastic all winter.   

(It’s always fascinating to learn what folk think is ‘normal’ power consumption.)

It’s such a personal habit thing. I only run my fridge in summer. In Winter the keel plate cold box is more than sufficient. If I had to run the fridge in the dog days of winter I’d probably say none of the above is possible....

 

Edited October 30, 2018 by Neil T