How To Get Solar Panel Wired ?

[matty40s]

Just now, LadyG said:

OK, I have a modern 40 amp epever/tracer controller [yet] to be wired up, to 2x 275 W panels, thinking a 50 amp fuse would be OK in UK

That's what I would usually fit between controller and batteries, yes....given that the max output from the controller is 40A. 

[Sea Dog]

On 19/05/2020 at 20:40, LadyG said:

hi S/D, could you explain why series is "better" than  //el in this scenario.

I thought //el would work better all round 'cos any shade knocks 'em down

Hi Lady G,

 

My reason for saying that, in the scenario we were discussing, is that controllers "kick in" when the voltage from the panels exceeds a minimum level (iirc mine is 16v).  If the panels are, as fairly typically, a bit over 18v, then it needs a fair bit of energy from the sun to get the panel to exceed the 16v threshold. In series the voltage from each panel is added together, whilst in parallel the voltage doesn't change. Panels in series, will therefore exceed the 16v threshold much earlier in the day or at lower light levels.  

 

The power produced in watts is a product of the current and the voltage (P = V * I). As I said, in series the voltages are added, but in parallel it remains the same whilst it's now the currents that are added. So, all things being equal, there's no difference in total output between parallel or series.  

 

When things aren't equal though, then series is probably better in low light as explained, whilst parallel is probably better when there's shading, because any panel producing little or nothing is bypassed rather than being "in the way" as it would be in series.

 

Bypass diodes improve this series shading disadvantage somewhat, but it is fairly easy to be able to swap between the two configurations, so some folk prefer series in winter and parallel in summer.  I wired mine to be able to do that, but in practice I simply haven't needed to, so I stick with series for my pair all year.

 

I know you have had answers, but I didn't want to ignore your query and I hope that explains things from my perspective.

[Alan de Enfield]

41 minutes ago, Sea Dog said:

My reason for saying that, in the scenario we were discussing, is that controllers "kick in" when the voltage from the panels exceeds a minimum level (iirc mine is 16v).  If the panels are, as fairly typically, a bit over 18v, then it needs a fair bit of energy from the sun to get the panel to exceed the 16v threshold.

Why do folks use 18v - 20v (or around that voltage) ?

 

I never gave it any consideration as the panels I bought from Bimble were 170w, 120v 'Low-Light' panels*.

I regularly get 90+ volts out of them.

 

No problem in kicking the MPPT into life.

 

* Apparently designed for 'higher latitudes' where the angle of the Sun is lower.

 

 

[TheBiscuits]

20 minutes ago, Alan de Enfield said:

I never gave it any consideration as the panels I bought from Bimble were 170w, 120v 'Low-Light' panels*.

I regularly get 90+ volts out of them.

 

Are you sure?  120V at 1.4A sounds odd to me.

 

If they are in series the volts might add up to 120V, but there are not many 120V panels out there.  3 x 40V on the other hand are common as solar panels on houses ...

[Alan de Enfield]

18 minutes ago, TheBiscuits said:

 

Are you sure?  120V at 1.4A sounds odd to me.

 

If they are in series the volts might add up to 120V, but there are not many 120V panels out there.  3 x 40V on the other hand are common as solar panels on houses ...

It is a single panel, no sign of it being an 'assembly' of 3 panels.

 

From memory it was a cancelled order for (I think Scandinavia) that Bimble picked up.

 

They were discussed a few years ago and Bimble were involved in the thread (Post #11)

 

 

Edited May 21, 2020 by Alan de Enfield

[TheBiscuits]

9 minutes ago, Alan de Enfield said:

It is a single panel, no sign of it being an 'assembly' of 3 panels.

 

Interesting, thanks Alan.  What physical size is it for a 170W panel?  Is it comparable to my 6 year old 240W or the more modern 300W domestic panels?

 

It's the eternal tradeoff of roof space vs watts and quids!

 

  

[Alan de Enfield]

21 minutes ago, TheBiscuits said:

 

Interesting, thanks Alan.  What physical size is it for a 170W panel?  Is it comparable to my 6 year old 240W or the more modern 300W domestic panels?

 

It's the eternal tradeoff of roof space vs watts and quids!

 

  

I don't recall the width but that was the critical dimension for me as it had to fit between the legs of the Radar arch.

The boat is in lockdown in N Wales so I cannot even get there.

 

 

At the time we were discussing these dimensions (Post 1 in the thread quoted above)

 

The 170w panels are 1257mm long and only 35mm thick as opposed to the 235w ones which are 1650mm long and 46mm thick so the 170w panels are considerably smaller.

 

A pure guess would be that the width was 2/3rds the length (say ~900mm)

29 minutes ago, TheBiscuits said:

It's the eternal tradeoff of roof space vs watts and quids!

 

And - the length of the 'Solar season'

[LadyG]

On 16/07/2019 at 17:55, NewCanalBoy said:

Why is this one 5 quid ?!

 

https://rover.ebay.com/rover/0/0/0?mpre=https%3A%2F%2Fwww.ebay.co.uk%2Fulk%2Fitm%2F123811227899

it's PWM and not MPPT, inefficient and a "sort of lookalike" [ie it's blue] Having said that, I believe Victron have rather undersized solar connection sockets [ Will Prowse mentions this in a later compritive video] 

I don't know if anyone pointed out that a fridge is not a small gadget, but a major energy gobbler, if you want to keep your fridge [is it a 12 volt fridge], and use it, this solar panel is no use.

A cold cranking battery is for engine starting, they are cheap. A deep cycle leisure battery is horse of a different colour. What I am saying, in layman's terms, these two items are not much use to you for your domestic power demand.

NB n the US mains voltage is 110 AC, . The UK  uses 240 volt appliances [mains]

Edited May 22, 2020 by LadyG

[WotEver]

6 hours ago, LadyG said:

The UK  uses 240 volt appliances

230V (nominally). 

[Alan de Enfield]

Corned beef reported as being beyond its BB date.

[beerbeerbeerbeerbeer]

2 hours ago, Alan de Enfield said:

Corned beef reported as being beyond its BB date.

Mmmm.. 🤤 corned beef with mashed potatoes 😋 and HP sauce. 

[Mad Harold]

25 minutes ago, Goliath said:

Mmmm.. 🤤 corned beef with mashed potatoes 😋 and HP sauce. 

HP sauce is for nancy boys!

Daddies is the stuff or Hammonds Chop.😃

[beerbeerbeerbeerbeer]

6 minutes ago, Mad Harold said:

HP sauce is for nancy boys!

Daddies is the stuff or Hammonds Chop.😃

Ooh yes Daddies 🤤 

Can’t say I’ve heard of Hammonds Chop, am I missing out? 😳
 

[Alan de Enfield]

12 minutes ago, Mad Harold said:

Daddies is the stuff or Hammonds Chop.

 

Nay, nay, nay, 

57 times nay....................