solar panels for beginners...

[Guest]

We normally keep our batteries topped up when away from the boat by leaving the Mastervolt on 'charge' while we are away. (Obviously on shore power when we do). Obviously this costs but not a lot of course. It obviously does all the things it's supposed to do to not overcharge but just keep them topped up.

 

So questions -

 

What would be the basic kit we would need to keep them trickle charged without shore power but using solar. We can be away from the boat for up to 2-3 weeks?

 

How do we connect what to what?

 

Cost wise - is it worth it how long (roughly) to recoup the cost of the kit?

 

I wouldn't envisage using solar at any other time unless there is a compelling reason to do so?

 

Cheers..

[mrsmelly]

We normally keep our batteries topped up when away from the boat by leaving the Mastervolt on 'charge' while we are away. (Obviously on shore power when we do). Obviously this costs but not a lot of course. It obviously does all the things it's supposed to do to not overcharge but just keep them topped up.

 

So questions -

 

What would be the basic kit we would need to keep them trickle charged without shore power but using solar. We can be away from the boat for up to 2-3 weeks?

 

How do we connect what to what?

 

Cost wise - is it worth it how long (roughly) to recoup the cost of the kit?

 

I wouldn't envisage using solar at any other time unless there is a compelling reason to do so?

 

Cheers..

 

Martin

 

Its a doddle I put two panels on my boat yesterday, I also had two on the last boat for 5 years. I have 160 amps which even today managed nearly 2 amps for a few hours. On gray winter days only about .5 of an amp. In the summer I find they run the fridge which I never switch off. I arnt one for boring figures but suffice to say they would keep you batts topped up in the winter if you left them fully charged and they would trickle charge your batts in the summer aT LEAST. Ebay is best for price dont go for rip off marine specials the cheapies are just as good. If you decide to do it let me know and Ill pop down and fit em for you.......you do stock cold beer dont you ? Forgot to mention roughly 250 squid for two panels, control thingy and cable.

Edited January 11, 2012 by mrsmelly

[cotswoldsman]

Martin

I am no expert but a convert to Solar Panels. Can I suggest you look at as an investment. I went for all singing and dancing ( as I do not have the luxury of shore power) I spent £1,000 in September having them fitted since then I have saved about £70 on diesel (and that is just the winter months) so at present I am showing a 7% return on my investment, I would be very disappointed if by the end of the summer I was anywhere less than 25% return on my investment. I also think when the time comes to sell my boat I will recover my investment either in the price of the boat or that it will be easier to sell.

[Guest]

Martin

 

Its a doddle I put two panels on my boat yesterday, I also had two on the last boat for 5 years. I have 160 amps which even today managed nearly 2 amps for a few hours. On gray winter days only about .5 of an amp. In the summer I find they run the fridge which I never switch off. I arnt one for boring figures but suffice to say they would keep you batts topped up in the winter if you left them fully charged and they would trickle charge your batts in the summer aT LEAST. Ebay is best for price dont go for rip off marine specials the cheapies are just as good. If you decide to do it let me know and Ill pop down and fit em for you.......you do stock cold beer dont you ? Forgot to mention roughly 250 squid for two panels, control thingy and cable.

 

Tim - Cheers - if I could I'd like to pop down some time and have a skeggy at yours.

[mrsmelly]

Martin

I am no expert but a convert to Solar Panels. Can I suggest you look at as an investment. I went for all singing and dancing ( as I do not have the luxury of shore power) I spent £1,000 in September having them fitted since then I have saved about £70 on diesel (and that is just the winter months) so at present I am showing a 7% return on my investment, I would be very disappointed if by the end of the summer I was anywhere less than 25% return on my investment. I also think when the time comes to sell my boat I will recover my investment either in the price of the boat or that it will be easier to sell.

 

Hi John

 

Yep your right, solar panels are brill...........just think if you hadnt spent 100 plus squid on a snake oil fan you could have even more solar...

 

Tim - Cheers - if I could I'd like to pop down some time and have a skeggy at yours.

 

No problem Martin. Just let me know when yuo are down.

[cotswoldsman]

Hi John

 

Yep your right, solar panels are brill...........just think if you hadnt spent 100 plus squid on a snake oil fan you could have even more solar...

 

Have my ecofan set up now to generate electricity.....................well I think I have

[Guest]

Martin

I am no expert but a convert to Solar Panels. Can I suggest you look at as an investment. I went for all singing and dancing ( as I do not have the luxury of shore power) I spent £1,000 in September having them fitted since then I have saved about £70 on diesel (and that is just the winter months) so at present I am showing a 7% return on my investment, I would be very disappointed if by the end of the summer I was anywhere less than 25% return on my investment. I also think when the time comes to sell my boat I will recover my investment either in the price of the boat or that it will be easier to sell.

 

John - that is way over what I planned for it to cost - I can see how your installation would suit you as a liveaboard/CC'er but I'm really just looking at a way of keeping the batts. topped up in my absence.

 

When we are off shorepower and actually on the boat we tend to be on the move anyway.

 

But thanks.

 

No problem Martin. Just let me know when yuo are down.

 

I'm on the boat at the mo - possibly coming up to Woodlesford on friday - any good??

[cotswoldsman]

John - that is way over what I planned for it to cost - I can see how your installation would suit you as a liveaboard/CC'er but I'm really just looking at a way of keeping the batts. topped up in my absence.

 

When we are off shorepower and actually on the boat we tend to be on the move anyway.

 

But thanks.

 

Martin I do realise that you would not need as many panels as I have. I was trying to answer your question on how long it would take to get your money back, by looking at it another way. So in other word if you spend like Tim £250 would you save £25 a year to get a return of 10% on investment. Does your cruising pattern not involve staying in one place for more than 24 hours?

[Paringa]

I am a convert too...

 

This is my set-up.

 

3 x 175 Watt 24V panels so 550 in total...

 

Into a Steca 2020 controller...Non MPPT but a good one

 

6 x 110Ah batteries wired to give 24Volts

 

Last year - according to the Steca - 10,000 Amp hours were produced.

 

Now i don't really know what that means but in the summer i run all i need from the panels which are just flat on the roof. In the winter i have to run the gen.

 

However you look at it it has to be saving me a few quid in running costs off-set against the purchase price which was about £1000 3 years ago.

 

Any of you clever people able to work out the saving? The gen uses about a litre an hour and the battery charger on bulk is 25Amps at 24Volts...

[mrsmelly]

John - that is way over what I planned for it to cost - I can see how your installation would suit you as a liveaboard/CC'er but I'm really just looking at a way of keeping the batts. topped up in my absence.

 

When we are off shorepower and actually on the boat we tend to be on the move anyway.

 

But thanks.

 

 

 

I'm on the boat at the mo - possibly coming up to Woodlesford on friday - any good??

 

Bloody typical. We are at Whitley bridge at the moment. May go back to Woody at weekend. Or you can pop along here ? I am working in engine bay tomorrow so will be here or whenever to suit.

[Guest]

Martin I do realise that you would not need as many panels as I have. I was trying to answer your question on how long it would take to get your money back, by looking at it another way. So in other word if you spend like Tim £250 would you save £25 a year to get a return of 10% on investment. Does your cruising pattern not involve staying in one place for more than 24 hours?

 

Got you John - yes I see.

 

Yes sometimes we stay in one place more than 24 hours.

 

Bloody typical. We are at Whitley bridge at the moment. May go back to Woody at weekend. Or you can pop along here ? I am working in engine bay tomorrow so will be here or whenever to suit.

 

We will be going home Sunday or Monday - will you be at Woodlesord by then?? - no rush though I could call next time I'm down.

[matty40s]

Got you John - yes I see.

Yes sometimes we stay in one place more than 24 hours.

We will be going home Sunday or Monday - will you be at Woodlesord by then?? - no rush though I could call next time I'm down.

 

If it helps, the supplier I and John have used is M & R Controls of derbyshire. They supply and fit if wanted, or post, or you can collect. They are also a real company who talk plain English and will advise best system for you, not what makes them the most money...........you can also haggle......ask John!!!

[Guest]

Thanks for all the input.

 

just a tad confused by the 12v/24v thing - surely 12v only is what I should be going for on a NB with a 12V system.

 

It seems it could be as simple as -

 

Pos and neg from panel

 

to

 

Pos and neg on controller

 

to

 

Pos and neg on your batteries

 

Have I over simplified it??

 

but then what happens when you are charging your batteries by the alternator when under-way or whilst on shore power will this harm the panels or the controller.

[matty40s]

Thanks for all the input.

 

just a tad confused by the 12v/24v thing - surely 12v only is what I should be going for on a NB with a 12V system.

 

It seems it could be as simple as -

 

Pos and neg from panel

 

to

 

Pos and neg on controller

 

to

 

Pos and neg on your batteries

 

Have I over simplified it??

 

but then what happens when you are charging your batteries by the alternator when under-way or whilst on shore power will this harm the panels or the controller.

 

my controller is set (VERY APPROXIMATELY !!!)at 14,5v. Above this, it stops the flow to stop the baterries boiling over.

Panel-controller-batteries. the alternator only charges at 14.3V so no problem.

I have noticed that when hooked up to shoreline, (which shows constsnt 13v on my Heart Panel, as soon as the sun comes out, even at this time of year, the reading goes straight up to 14v, and starts to twitch the 14.5v diode.

[Guest]

my controller is set (VERY APPROXIMATELY !!!)at 14,5v. Above this, it stops the flow to stop the baterries boiling over.

Panel-controller-batteries. the alternator only charges at 14.3V so no problem.

I have noticed that when hooked up to shoreline, (which shows constsnt 13v on my Heart Panel, as soon as the sun comes out, even at this time of year, the reading goes straight up to 14v, and starts to twitch the 14.5v diode.

 

So I am guessing now - unless you physically disconnect the supply from your solar panels via. your controller you risk over charging your batteries when on shorepower and using your mains charger or when under-way and charging via. your alternator

 

- I thought the controller would know this and stop passing charge to the batteries from the panel(s)

[matty40s]

So I am guessing now - unless you physically disconnect the supply from your solar panels via. your controller you risk over charging your batteries when on shorepower and using your mains charger or when under-way and charging via. your alternator

 

- I thought the controller would know this and stop passing charge to the batteries from the panel(s)

 

unfortunately, as my name is not Gibbo, I do not know.

However, my batteries seem fine, and there is always a fridge running and something charging, so maybe it's just saving me leccy credits????

I am not connected 24/7, I only stick a card in every now and then.

[Jason Day - Sheffield]

my 2 penn'orth - also speak to Midsummer Electric, person I spoke to was a liveaboard and supplied quality kit we are pleased with.

 

cheers

[Titan]

Read this post with intrest,

As ive gutted everything from our boat, the electrics are yet to be planned and installed, and i believe i will go solar, choosing more pannells rather than double extra lge alternator setups, i sort of figure by the time ive purchased alt contolers and biwire two alternators. might as well go for 6 x solar pannells coupled up to decent traction cell. like i said yet to be planned fully but advise readilly sought regards Martin

[mrsmelly]

So I am guessing now - unless you physically disconnect the supply from your solar panels via. your controller you risk over charging your batteries when on shorepower and using your mains charger or when under-way and charging via. your alternator

 

- I thought the controller would know this and stop passing charge to the batteries from the panel(s)

 

 

The control thingy looks after all that palava for you, you dont get a problem with over charging. The wiring up is just as simple as you described.

[Biggles]

I have 490w of solar at 36v. Why the hell are the MTTP controllers so damned expensive?

[Grace and Favour]

Thanks for all the input.

 

just a tad confused by the 12v/24v thing - surely 12v only is what I should be going for on a NB with a 12V system.

 

It seems it could be as simple as -

 

Pos and neg from panel

 

to

 

Pos and neg on controller

 

to

 

Pos and neg on your batteries

 

Have I over simplified it??

 

but then what happens when you are charging your batteries by the alternator when under-way or whilst on shore power will this harm the panels or the controller.

 

Mafrtin - I found an explanation of MPPT Solar Charge Controllers that I could understand (explains 24v for 12v boat)..................(Solar-facts.com)

 

 

Maximum Power Point Tracker Solar Charge Controllers

A basic charge controller simply performs the necessary function of ensuring that your batteries cannot be damaged by over-charging, effectively cutting off the current from the pv panels (or reducing it to a pulse) when the battery voltage reaches a certain level.

 

A Maximum Power Point Tracker controller performs an extra function to improve your system efficiency.

 

The efficiency loss in a basic system is due to a miss-match between voltage produced by the pv panels and that required to charge the batteries under certain conditions.

A 24 volt battery will require upto about 28 volts to fully charge it. When the battery being charged is in a fairly low state, it's voltage (under charge) may only 24 volts.

Our PV panels, which we refer to as 24 volt panels, need to be able to charge the batteries on a bright day (not only in full sunshine) so are designed to produce at least 24 volts in those conditions. In bright sunshine hover, these panels may be cable of producing 40 volts. In-fact, they are likely to produce their rated output power (volts x amps) at 32 - 34 volts.

When the battery is at 24 volts, it will be pulling the panel voltage down to 24 (assuming no voltage drop in your cables). This results in the panels producing significantly less than their rated output and therefore there is a loss in efficiency.

 

 

 

 

How Does MPPT Help

An MPPT controller, in addition to performing the function of a basic controller, also includes a DC voltage converter, converting the voltage of the panels to that required by the batteries, with practically no loss of power. In other words, they attempt to keep the panel voltage at their Maximum Power Point, while supplying the varying voltage requirements of the battery.

Furthermore, a 24 volt system with an MPPT charge controller may have the panels wired in series to produce 48 volts, maintaining the ability to provide some charging current in dull conditions, when a standard system would not provide any charge.

 

Manufacturers claim up to 40% power increase from your panels using MPPT, which is most likely to be achieved when battery levels are low and/or light levels are low.

 

 

[lesrollins]

As anyone used the following panels Kyocera or Sanyo I cannot seem to google any reviews. Can you get a fixing kit to allow the panel to lay flat when travelling and then tilt when required or as anyone got any suggestions to make a fixing kit. And would it be better to have two 135w panels or one 250w panel. When we get a boat I would like to fit solar panels to keep the batteries topped up rather than keep running the engine. Quoted £278 for the 135w kyocera panel and £420 for the 250w sanyo panel.

[NB Willawaw]

Kyocera are good for rigid panels - don't have experience of the Sanyo.

[Ryeland]

There are some tilting mounts on eBay, using the friction hinges from uPVC windows. I have made something similar, which rotates as well.

 

M&R Controls also do a tilt and turn mount.

 

Richard

[Chris Pink]

We normally keep our batteries topped up when away from the boat by leaving the Mastervolt on 'charge' while we are away. (Obviously on shore power when we do). Obviously this costs but not a lot of course. It obviously does all the things it's supposed to do to not overcharge but just keep them topped up.

 

So questions -

 

What would be the basic kit we would need to keep them trickle charged without shore power but using solar. We can be away from the boat for up to 2-3 weeks?

 

How do we connect what to what?

 

Cost wise - is it worth it how long (roughly) to recoup the cost of the kit?

 

I wouldn't envisage using solar at any other time unless there is a compelling reason to do so?

 

Cheers..

 

1. I am a huge fan of solar.

 

2. If you have shore power to top your batteries is peanuts

 

3. to recoup your peanuts with a solar panel will take decades.

 

If you have no other use for solar, don't do it.

 

 

 

Eta: I posted before reading the rest of the topic which is rapidly going way and above what you are talking about. If you do go for solar go for 50W max and a £15 controller. If you have spare money do something else with it.

Edited January 23, 2012 by Chris Pink