Solar disappointment :-(

[Theo]

Today I had my first chance to check how they new panels are doing. Here are the details.

 

Panels fitted connected up on Saturday in dull light overcast in the evening. I reported in my other thread that I was getting 9A. Not so. On further investigation I had missed the very feint decimal point on the Tracer mppt controller display. It was 0.9A.

 

At that time the Smartguage was reading 64%

 

Arrived this morning in bright sunshine expecting that SG would be in the 90%'s. Not so again. It was reading 69%. The weather, as far as I know had been mixed, quite cloud but with bright intervals.

 

Today the weather was really bright. Sun all day and the SG at the end of the day read 89%

 

The Tracer state of charge read 100% at one time when SG was reading about 70% then a while later read 60% with the SG reading a bit more.

 

Obviously something is amiss and my immediate response to someone posting such a tale would be to check connections. I have not had time to do this today as I was plumbing in the washing machine. I would have said that I was pretty careful about the connections. Here is how the electrical system is set up:

 

Six solar panels (Ebay Product) connected as two paralleled groups of three in series. All connections to the panels are soldered I ensured that there are no dry joints. The wires are taken from the two banks of panels and down through a mushroom vent. The paralleling connections are made with yellow spades

Tracer mppt controller: This one.

 

The output of the Tracer is connected to the busbars of my domestic battery bank.

The Domestic battery bank consists of 8 off 93Ah Powersafe C90 batteries. They have been on Theodora since early 2009.

There is one similar battery connected as an engine start battery.

All domestic battery leads have CSA 25 sq. mm. The are of equal length with ring connectors crimped with a hydraulic crimper.

 

I have fitted Smartbank with Gibbo's recommended relay. I noted that during today Smartbank clicked in to connect the engine and domestic batteries.

 

Other, possibly relevant, information: the build quality of the panels is low. On the first one that I inspected the tabs from the solar panels were so soldered to the connectors. Three of the others had damaged connector box covers. One had the connector box in a different position from the rest so I had difficulty with the mounting system that I had designed assuming that they were all the same. Do I hear someone asking "Why didn't you send them back?" My answer is "Because I felt pressed for time and it was not a big deal to do the soldering myself."

 

I tested the panels as for as I could before I fitted them. That was not very far and limited to checking the open circuit voltage on a dull day. They were very much the same so I assumed that they passed.

 

Sorry about the long post but I have tried to give all the relevant info at the outset.

 

Ideas and things to check would be gratefully received.

 

Nick

 

 

[FidoDido]

The SOC readout on the Tracer is not something to take any notice of. It is a random number, plucked from the darkest set of Bistro mathematics.

 

I also find the voltage is 0.2V different from my Mastervolt MiCC panel. The amps match, though. It is only a £20 meter..

[MtB]

Pretty consistent with my own experiences of solar panels on two boats.

 

A waste of time and effort except in hot sunny weather!

 

 

MtB

[Bones]

Not a helpful post just one to say that I hope you manage to get it sorted out. I have 2 85w solar panels and 4 leisure batteries to go with my 1 starter battery. My Smart Guage tells me my batteries are over 80% . I have my fridge on. Your system sounds much swankier than mine so it sounds rather puzzling Fingers crossed you get it sorted really soon!

[b0atman]

Are you able to angle panels for maximum sunshine.

[Paul C]

What's the voltage reading of the battery bank just before you had solar power, and with solar power (when its sunny/when its night time)?

[matty40s]

The Smartgauge isn't so smart when solar is charging - but saying that, the SOC stated on the MT5 display is similar to cabbury cream eggs lifespan when faced with a blowtorch.

Your batteries, although I have seen them - are impressive- may not be completely the Couilles du Chien that they look....what has been the charging regime since they were installed, and were they affected by the water ingress??

Also, what are you running while the solar panels are charging??

The way your panels sit on the roof, you would be making best use of the Tracer by seriesing them all.

[Dalslandia]

it's mono crystal, that is best at direct sun light angled into the sun.

[Theo]

The SOC readout on the Tracer is not something to take any notice of. It is a random number, plucked from the darkest set of Bistro mathematics.

 

I also find the voltage is 0.2V different from my Mastervolt MiCC panel. The amps match, though. It is only a £20 meter..

 

Useful to know that the SOC on the Tracer is to be disregarded

Pretty consistent with my own experiences of solar panels on two boats.

 

A waste of time and effort except in hot sunny weather!

 

 

MtB

Thanks for that but this opinion does not square will heaps of other posts from Roger Gunkel onwards.

[Paul C]

Well.....solar power allowed me to turn the fridge on on Sunday, and return to the boat on Wednesday to a cold fridge/freezer and fully charged batteries. Had we had no solar, the batteries would be pretty drained by now.

[Theo]

Are you able to angle panels for maximum sunshine.

No. I decided to mount them flat for maximum convenience of boating. Research seemed to indicate that in diffuse light conditions you get the most output over the hours of daylight with them flat.

What's the voltage reading of the battery bank just before you had solar power, and with solar power (when its sunny/when its night time)?

12.5 last Saturday and 14.2 volts today when there was no load.

[dor]

Last weekend, in reasonably bright weather, my flat-mounted 100W panel with standard controller was giving over three amps. Which is a reasonable amount in April and as good as I would expect. Certainly not a useless contribution.

[matty40s]

Pretty consistent with my own experiences of solar panels on two boats.

 

A waste of time and effort except in hot sunny weather!

 

 

MtB

far more effective in cold sunny weather actually...

 

I havn't run my engine for power now for around 3 weeks. My fridge has been on for a month too.

 

Thoodora is a narrowboat, with the panels in line and flat - the extra voltage produced from seriesing would outweigh the potential losses from shadow - especially where you are presently moored - with no trees!

Edited April 9, 2014 by matty40s

[Paul C]

 

12.5 last Saturday and 14.2 volts today when there was no load.

 

I'd not worry then, at the end of the day electrical loads need to 'see' a 'voltage'. In other words, while they're drawing current, the voltage needs to remain above a figure (which is probably lower than you think). The solar power helps, enormously, with this. Unless there's lots of panels, they're going to charge a large battery bank slowly. So long as they can charge it when its sunny, more than you can discharge it when its not, all is okay.

[Ex- Member]

I have to say I feel this seems a complicated way to fit solar. It seems like you have everything connected ok but there seems plenty of room for error with all those soldered connection.

 

 

I just wonder the sense in buying 6 x 40w individual panels to create 240w when one single panel high voltage panel can give you the same, and most of which are TUV approved, so assured quality parts & components. No soldering just 2 straight connections with MC4 connectors. Not only that it appears you've paid well over a pound a watt, where larger panels are as low as 60/70ppw

 

I'm guessing possibly space forced this purchase, but if you shop around you can get varying sized higher voltage panels.

[DeanS]

Buy a clamp meter from Maplin.

It lets you measure the current leaving the controller and going to the batteries.

 

If you have been running the engine at all, the solar controller wont push anything out until the battery voltage drops down.

The solar controller wont push out much if the batteries are already charged.

As a test, when you have some sun...run all your boat pumps, and switch on all your 12V lights, invertor etc...so the batteries are loaded....and then check the current leaving the solar controller (with the clamp meter). It should jump up and supply more current, because it will see that there is a need for it (which the batteries may not be wanting if already well charged.)

 

I have 2 sets of 2 panels. Each pair is wired into it's own controller (Tracer MPPT). On very sunny days, I have seen each controller shoving out almost 30Ah...a total of about 55Ah between them. We were running a lot of things through the invertor at the time. If you switch off the load...and the batteries are already charged, the controller could send out nothing...even on a sunny day.

 

It's all about the demand.

 

I'm not a solar guru.

[Theo]

far more effective in cold sunny weather actually...

 

I havn't run my engine for power now for around 3 weeks. My fridge has been on for a month too.

 

Thoodora is a narrowboat, with the panels in line and flat - the extra voltage produced from seriesing would outweigh the potential losses from shadow - especially where you are presently moored - with no trees!

I will check in a bit, Matty, but I think that the 120V open circuit that the panels would give all in series would be too much for the controller.

 

N

[Paul's Nulife4-2]

Yep, I've had solar for years,and have to be honest I wasn't a great fan,I couldn't see any real benefit at all. Until last year, when I stopped my interpretation of CCing as I always had plenty of power.

I can now see a good return for my small,120w Amorphous very shallow angled installation.

Yep quite surprised actually.getting up to 5 or 6 amps an hour,on more than one occasion.

(But normally around the 1amp an hour average)

Edited April 9, 2014 by Paul's Nulife4-2

[Ex- Member]

far more effective in cold sunny weather actually...

 

I havn't run my engine for power now for around 3 weeks. My fridge has been on for a month too.

 

Thoodora is a narrowboat, with the panels in line and flat - the extra voltage produced from seriesing would outweigh the potential losses from shadow - especially where you are presently moored - with no trees!

 

 

Same with us sinse 07 March so a wee bit longer, although we've just had 5 bleak days on the trot and batteries were getting very low. Have put genny away and being determined not to run the engine we switched fridge & inverter off over night.

 

On day 5 though we did have to run the engine, batteries were 11.9v after resting again overnight run the engine for 1.5 hours in the morning, that was Monday, today though by 1pm we were back in float mode. But basically we've gone 3 weeks + without additional charging other than just mentioned.

 

We're still using tilting and following the sun through the day, but TBH the sun's getting to the point where the gain is decreasing, so we'll probably leave them flat for the next few months.

 

We had 181 amps today with 740w of solar. was pretty sunny but cloudy intervals.

[Theo]

The main concern was not today's performance (except for the random numbers generated by the Tracer's SOC display which I will heretofor disregard). It was the fact that there appeared to be almost no gain between last thing on Saturday and first thing this morning.

 

Someone asked for the loads that had been applied. Nothing between Sat and this morning. Occasional Water Pump and inverter used for very brief burst on a mains power drill.

 

N

I have to say I feel this seems a complicated way to fit solar. It seems like you have everything connected ok but there seems plenty of room for error with all those soldered connection.

 

 

I just wonder the sense in buying 6 x 40w individual panels to create 240w when one single panel high voltage panel can give you the same, and most of which are TUV approved, so assured quality parts & components. No soldering just 2 straight connections with MC4 connectors. Not only that it appears you've paid well over a pound a watt, where larger panels are as low as 60/70ppw

 

I'm guessing possibly space forced this purchase, but if you shop around you can get varying sized higher voltage panels.

I would agree but what I wanted was a long narrow strip of panel that would allow me to walk along the roof beside them and to have a space in the middle for the hatch to open into.

 

N

[bizzard]

Flexible solar panels could be stuck onto the top of a big balloon ''or ex army barrage balloon'' filled with helium and tethered to your boat on a long string or by the electrical wires from the panel. One of these could be raised up above the most highest cloud level to take advantage of full time sunlight.

A little red flashing light might be needed on it to warn off aeroplanes and high flying swans that might peck and pop it.

[FidoDido]

I will check in a bit, Matty, but I think that the 120V open circuit that the panels would give all in series would be too much for the controller.

 

N

Tracer do a 100v and a 150v version of the controller. The one Bimble sells is the 100v version, so yes, too much.

 

Check the voltage of the batts in the dark with no load (or switch the controller off by removing fuse and wait a couple of hours). Will give you better info.

 

With 240w you have the potential for 15A or so from the panels if the batteries demand it. It will take along time to charge all of your batteries from a lowest SOC at that A.. 150 Ah would be well over 10h of maximum potential charge, which you won't get this time of year.

[Ange]

Pretty consistent with my own experiences of solar panels on two boats.

 

A waste of time and effort except in hot sunny weather!

 

 

MtB

That's definitely not been our experience!

 

Since we fitted ours we've not had to run the engine at all to charge the batteries from May to September - they've definitely paid for themselves plus given us a better quality of life.

 

We turned the fridge on for the first time this year today and Dave had ice in his drink - that wouldn't have been possible without running the engine pre solar.

[Ex- Member]

That's definitely not been our experience!

 

Since we fitted ours we've not had to run the engine at all to charge the batteries from May to September - they've definitely paid for themselves plus given us a better quality of life.

 

We turned the fridge on for the first time this year today and Dave had ice in his drink - that wouldn't have been possible without running the engine pre solar.

 

Nor ours, but of course that depends on how much solar in relation to your use. We've been almost totally solar sufficient since 07 March, just 1.5 hours of engine running following 5 bleak days, and we have moved of course so a couple of hours generation then.

 

We have 740w of solar though and I reckon we use about 150ah per day, sometimes more. At this time of year on a reasonably sunny day we'll glean 200ah we'll regularly overproduce from April to August, we're thinking of getting a small freezer table top freezer from April to Aug to use the excess energy. I posted the amps we gleaned through winter.

 

Nov Average 75ah per day.

Dec 42ah per day.

Jan 54ah per day.

Feb 84ah per day.

 

Not to be sneezed at, and ended up averaging just 1.5 hours a day of generating between boat engine and Honda generator, mostly Small generator.

[MtB]

This is where the difference lies.

 

I have 160w of solar on one boat, and 100w on the other.

 

MtB