what solar panels to buy ?

[onionbargee]

Can anyone give me the lowdown on solar panels, i want a 100w to start with, what type is the most cost effecient, are the cheapest ones £80 / 100 w value for money or are they just substandard ?

 

What kind of controller will i need ?

[steve hayes]

I recently bought two 80W for £98 each off fleabay and have been very happy with their performance.

[Thewatchmaker]

I recently bought two 80W for £98 each off fleabay and have been very happy with their performance.

They sound like a good deal.

Do you have a link or item number please?

[Ex- Member]

If you buy panels under 200 watt you'll pay around a quid a watt and they'll be basically 12 volt panels which can be operated and run by very basic charge controllers.

 

Usually panels over 200 watts are panels designed for house roofs are usually around 30 volts and require a MPPT controller which can glean more efficiency from the panel. These panels are much cheaper per watt around 60p in some cases, but these panels are bigger though and heavier 1.2 metres X 500mm av and weigh around 20 kilos.

 

http://www.savingene....uk/product/178

 

ETA

 

 

Personally I wouldn't bother with lower wattage 12v panels and go for the 200w + panels at the higher rated voltage. At least most of these type panels are passed for solar collector schemes so have to reach certain minimal requirements of efficiency and construction to comply with these schemes. The MPPT charge controllers required though are quite a bit more expensive than standard controllers for 12 v panels, having said that they are supposed to be more efficient and glean more energy from panels, up to 30% some claim. Based on the fact their cheaper overall and should be more efficient using MPPT technology to me those 2 simple facts makes them the most economical choice long term.

 

The panel it's self is much more sturdy than the smaller 100w panels and their weight and size makes them a bit more difficult to steal especially if fitted down with the proper bracketry.

 

Edited August 7, 2012 by Julynian

[Rebotco]

I have just installed a 100 Watt panel on my boat. Not the cheapest, but I went for the latest thin flexible monocrystalline panel. It cost £206 direct from China. Just stuck it on with Sikaflex, and it can be walked on and doesn't get in the way of my ropes. Won't get nicked either!

I also got a 10 Amp MPPT controller for under £50 - again from China, although a cheaper ordinary controller would be OK for that wattage. My main concern is to maximise battery bank trickle charging in the winter, when the boat's left for weeks and there's very little strong sunlight.

Could have done it cheaper, but less effectively for my needs.

[steve hayes]

They sound like a good deal.

Do you have a link or item number please?

 

Hi Watchmaker

 

This is the Fleabay store I got them from Solar Panels, prompt delivery too

 

Steve

 

 

Personally I wouldn't bother with lower wattage 12v panels and go for the 200w + panels at the higher rated voltage. At least most of these type panels are passed for solar collector schemes so have to reach certain minimal requirements of efficiency and construction to comply with these schemes. The MPPT charge controllers required though are quite a bit more expensive than standard controllers for 12 v panels, having said that they are supposed to be more efficient and glean more energy from panels, up to 30% some claim. Based on the fact their cheaper overall and should be more efficient using MPPT technology to me those 2 simple facts makes them the most economical choice long term.

 

The panel it's self is much more sturdy than the smaller 100w panels and their weight and size makes them a bit more difficult to steal especially if fitted down with the proper bracketry.

 

It is horses for courses, I wouldn't go for the enormous 200W+ panels as I want to be able to walk down the roof as I single hand the boat through locks. the 2 x 80W panels are end to end and are 550mm wide leaving plenty of room to walk past.

 

My panels are permanently (I hope) fastened to the roof using rubber bobbins allowing for the curvature of the roof and a bit of movement.

 

Steve

[onionbargee]

There are 100 w panels going for 50 quid on fleabay, + 16 euro's p+p. Obviously cheap Chinese products, i'm wondering if they are a bargain.

 

My link

[Ex- Member]

Hi Watchmaker

 

This is the Fleabay store I got them from Solar Panels, prompt delivery too

 

Steve

 

 

 

It is horses for courses, I wouldn't go for the enormous 200W+ panels as I want to be able to walk down the roof as I single hand the boat through locks. the 2 x 80W panels are end to end and are 550mm wide leaving plenty of room to walk past.

 

My panels are permanently (I hope) fastened to the roof using rubber bobbins allowing for the curvature of the roof and a bit of movement.

 

Steve

 

Fair point, he 250 watt panels are generally nearly 1 metre wide and of course the roof of a n/b is usually only around 5 f/t so just about a f/t clearance each side. lewisericeric fitted three in a row through the centre and they don't look too bad, so if you don't use the roof for walking still a possible option for a n/b

 

I always fancied the flexi panels rebotco has mentioned, but they're still a bit too pricey but a better solution all round for a boat roof possibly.

 

 

[Rob99fla]

There are 100 w panels going for 50 quid on fleabay, + 16 euro's p+p. Obviously cheap Chinese products, i'm wondering if they are a bargain.

 

My link

 

I have just bought 2 x 100W panels fro Ebay from this site:-

 

http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=150919722614#ht_3194wt_1182

 

and a Tracer MPPT 20A from here:-

 

http://www.ebay.co.uk/itm/20A-MPPT-Solar-Regulator-150V-PV-input-Battery-Charger-260W-520W-W-Meter-MT-5-/150920649768?pt=UK_Gadgets&hash=item2323925c28#ht_10035wt_1016

 

Total cost including carriage? Less than £210 the lot.

 

I have not received them yet but both are marked as shipped and both sellers have a great rating so lets see if all is OK. Im my experience, Ebay is fine as long as the seller has a very good rating.

 

I am sure someone is going to tell me they are not as good as other panels but I bet they are as I suspect many are now made in China these days like everything else. The same controller and similar panels from Midsummer Energy is £448. Nice profit if you can get it!

 

I am going to replace an existing Siemens 80W panel a good few years old, I think with a standard type controller. I am hoping this setup will keep the batteries going for 3-4 days when moored up instead of the 2 days now.

 

Just a point about Chinese products. I work in the CCTV industry. We buy CCTV lenses direct from a Chinese factory. They have been going since 1958. The lenses are very good quality and they have a good range of up to date lenses. We buy lenses for around £5-£15. The equivalent price here would be £40-£120 for basically the same thing and I suspect actually the same thing re-badged.

 

Anyway, I will see how it goes.

 

Rob

[Lesd]

Hi Rob,

will be interested to see what you think of them. Im thinking about buying a couple of 120w units from the same place.

Les

[matty40s]

Hi Rob,

will be interested to see what you think of them. Im thinking about buying a couple of 120w units from the same place.

Les

I wouldn't touch 12v panels now, I can get 24v 200W Mono panels for £160 , dimensions are 81cm wide, and if offset, still give you 1/2 the roof width to walk on. I will upload a piccy of my latest installation tommorow. Direct supply from China undercuts UK suppliers of identical kit by 50%.

[leeco]

Hi Rob,

will be interested to see what you think of them. Im thinking about buying a couple of 120w units from the same place.

Les

 

 

Hi Les,

I have just bought 2 120w from the same place and just boxing them up at the moment and nearly have them ready to fit in the next 2 days. I will let you know what I think.

 

Lee

[Rob99fla]

Hi Rob,

will be interested to see what you think of them. Im thinking about buying a couple of 120w units from the same place.

Les

 

Will let you know Les. I won't be fitting for a little while but will set up at to check the winter sun! I don't think we realise how much things cost from China. We judge all prices by our expensive Western standards. Best of luck

 

Rob

[DJ Lady Heidi]

Is there much difference between the solar ones and these new light type ones ?! A guy I was talking too at a Motorhome / caravan place was selling a 120 watt for £460 but said they work even when cloudy ?!

Anyone much experience with these types ??

This is more the type of weather I get where I am lol

[matty40s]

You can get 400W and an MPPT controller for £420. e's avin a larf...

and yes, you do get a certain degree of ampage, even on dull days.

[IainW]

just been reading up on mono vs polycrystalline vs amorphous, found this:

 

"Monocrystalline solar modules are the most expensive and there is a reason for this.These modules are made from a single large silicon crystal. Typically, a monocrystalline module will begin producing electricity at about 5% of maximum sun energy while a polycrystalline module will start producing power at about 10% maximum sun energy.This means that the monocrystalline module will produce energy for more hours per day and in lower light conditions.Additionally, the monocrystalline module will perform better and produce more energy in hot conditions.

 

Polycrystalline solar modules are made by taking raw silicon and forming it into an ingot.This ingot is sliced into cells.Polycrystalline cells typically are less efficient than monocrystalline as they require slightly more light to start up and they output less energy at higher temperatures."

 

then:

 

"Theory is all very well, but in practice there s very little difference between mono- and poly-crystalline cells, both in terms of low light and heat tolerance.

 

However there is a very real difference between the two crystalline types and amorphous cells. The latter are more efficient in low light, partial shade, and particularly high temperatures loosing only around 0.2% for every degree rise in temperature above 25 degrees compared to 0.5% for the crystallines (note this is panel temp which is typically 25-35 degrees above air temp in the middle of the day). In some tests amorphous cells have even produced more energy at high temperatures.

 

The downside is that amorphous panels generate only around half as much power (edit: per sq m) as the others so you need twice as many panels for the same output. Despite this, a few years ago they were actually cheaper per watt than the crystallines, but now are often significantly more expensive. Consequently, you will usually get more kWhs for your dollar by spending the same amount on mono/polycrystalline panels."

[Justme]

It depends on your definition of "works when cloudy".

 

Will you get some power / energy? Yes

 

Will it be much? No

[Boaty Jo]

I wouldn't touch 12v panels now, I can get 24v 200W Mono panels for £160 , dimensions are 81cm wide, and if offset, still give you 1/2 the roof width to walk on. I will upload a piccy of my latest installation tommorow. Direct supply from China undercuts UK suppliers of identical kit by 50%.

 

24v is what we need.

Do you have a link please

 

Thanks

[Lesd]

I wouldn't touch 12v panels now, I can get 24v 200W Mono panels for £160 , dimensions are 81cm wide, and if offset, still give you 1/2 the roof width to walk on. I will upload a piccy of my latest installation tommorow. Direct supply from China undercuts UK suppliers of identical kit by 50%.

 

You've confused me Matty (I know, dont say it. I dont understand the reference to 12v. That panel is 120w with a Vmp of 18v.

Did you see my other thread where Pete drew those pictures ? He recommended putting a pair of new 18V panels in series and have those in parallel with my two current 18v panels (also in series). All linked back to a 30/45a Tracer MPPT

 

Les

 

Thanks Rob and Lee, look forward to seeing how you get on

[bottle]

Being as Matty is not here at the moment.

 

12v panels are actually (usually) 18v

 

24v panels are actually (usually) 36v

 

I have four 100 watt panels that are 18v wired in series parallel, just the way Pete told you to do yours

 

Edit: at the moment I am getting half an amp and it is persistently raining.

Edited October 11, 2012 by bottle

[George94]

at the moment I am getting half an amp and it is persistently raining.

 

That is why they are called solar, and not pluvial.

[Psycloud]

I wouldn't touch 12v panels now, I can get 24v 200W Mono panels for £160 , dimensions are 81cm wide, and if offset, still give you 1/2 the roof width to walk on. I will upload a piccy of my latest installation tommorow. Direct supply from China undercuts UK suppliers of identical kit by 50%.

 

 

24v is what we need.

Do you have a link please

 

Thanks

 

I would also be interested in this link I may just start a solar project for something interesting to do.

 

David

[Rob99fla]

You've confused me Matty (I know, dont say it. I dont understand the reference to 12v. That panel is 120w with a Vmp of 18v.

Did you see my other thread where Pete drew those pictures ? He recommended putting a pair of new 18V panels in series and have those in parallel with my two current 18v panels (also in series). All linked back to a 30/45a Tracer MPPT

 

Les

 

Thanks Rob and Lee, look forward to seeing how you get on

 

Hi. The panels arrived yesterday from Germany. Opened one and it looks fine. So, that part is done. Just need the controller to be delivered now and finally fit to the boat. Might wait until spring now.

 

Hope this helps.

 

Rob