'Perlite' 250W PV panels: Any good?

[Markc]

So, perhaps a good indicator of a worthwhile panel might be its presence on PVSOL?

Which panels are included in PVSOL - and what's good/bad?
I'm sure that readers might find that kind of basic info very interesting.

Cheers,
F

I wouldn't see PVSOL as being particular over make or model in anyway shape or form and I certainly wouldn't use PVSOL as a guide to quality. It is a design tool, nothing more. Their database isn't made up of their preference. If you've seen PVSOL you would of seen the numbers of manufactures and panels on there.

 

[Markc]

The other option from the same supplier is the Taiwanese Ubbink Delsolar 250W Panel:

Ubbink Delsolar 250W Mono Solar PV Panel - MCS Accredited

Same price and spec, but available only with silver frames.

Are they in the database?

Spec now changed: it will be 2 x 16-panel strings.

Total 2 x 4 kW. Two inverters, two phases.

Directly South facing, unshaded steel building, 15º roof pitch (maybe upped to 20º with rear spacers), South Norfolk, UK.

Ubbink if was my option over the Perlite only because I do have knowledge of Ubbink product.

 

[dansk]

Eversolar inverters are fine, equal to a Fiesta in car terms, performs well, just a bit basic.

 

[Mark42]

… Diehl Platinum 3800S inverter …

Hey, Mark, thanks for the inverter recommendation. Looks good. 780Vdc max so not stressed at 600-ish.

Price OK too. I’ll go for this one.

Speccing this kind of thing for the first time is a hassle: so many variables!

Does it matter if one slightly over-specs the inverter to allow for adding a few panels in the future? Especially as panels get cheaper. There is enough roof space and it seems a shame to waste it.

Not so keen on Chinese Inverters though, and a 4600tl would be too small for 8KW and to big for 4KW.
Could you not use an SMA, maybe a waterproof one if needed, and fit the generation meter that end also.
I know people do, but I am not a fan of long DC runs, it is High voltage with no real protection, Your PV system will be no good to you if you end up dead.

Yes, I know, but I will absolutely certainly end up dead anyway. But not quite yet!

It will be underground SWA with earthed armour.

I have 12kV overheads across my garden, on crappy old poles and within easy reach of my digger, forklift and sons’ kites etc. So some MV DC underground will complete the set. We do have a defibrillator in the cupboard, and my girlfriend might even like me enough not to forget to use it …

BTW, SMA inverters won’t handle the voltage.

I don’t want to have to buy half a ton of copper just to keep the voltage drop down, which I would if I run LV AC to the house, since there’s not a lot of point in expensively harvesting the sun’s energy just to heat the ground with hot wires

My opinion, if you are happy to take a punt then go for it, would I sell an unknown panel to a customer? No I wouldn't.
I hope this helps.

Yes, it’s great advice and makes much sense. Thanks.

I spend much of my time doing stuff in a non-standard way and saving money, and do virtually everything myself. That way I can live in a fantastic house I could not otherwise afford.

 

[Markc]

Initial choice of inverters is the EverSol TL4600:

Solarexpo_grid tie inverter VDE_Solar PV inverter China OEM-EVER Solar

Does anyone know this model? Costs £1,350 + VAT

The panels will be series-wired in 16-unit arrays with an o/c voltage of approx 600Vdc, so they need an inverter that can handle this input voltage. It appears not many do, but this one goes up to 680V so should be OK.

The DC is being run over 100m from the barn roof to the house, on 10mm 4-core u/g SWA, so the higher the voltage the better, to minimise volt drop and energy loss.

If my choice the Ubbink Delsolar D6M250B3A, 1 String of 16 panels on Diehl Platinum 3800S, South at 15degree pitch is just over 3,600kWh per year estimate. The Perlite on the same pitch (15degree) is 3,400kWh per year. Same inverter and I do rate the Diehl range. 10yr warranty as standard.

 

[Markc]

Does it matter if one slightly over-specs the inverter to allow for adding a few panels in the future? Especially as panels get cheaper. There is enough roof space and it seems a shame to waste it.

Any future change to the system will need a new notification. That will take you over the 4kW FIT rate so a lower tariff on the entire system not just the additional. Might not be worth doing. It would also require a G59 application as it could be over 4kw per phase. I would try and use as much of the generated energy as you can and conserve where possible as well. If you increase your usage of self generated energy you will increase the saving on purchased energy. I have a client who has saved over 75% on his electric bill by doing this.

 

[Mark42]

If my choice the Ubbink Delsolar D6M250B3A, 1 String of 16 panels on Diehl Platinum 3800S, South at 15degree pitch is just over 3,600kWh per year estimate. The Perlite on the same pitch (15degree) is 3,400kWh per year. Same inverter and I do rate the Diehl range. 10yr warranty as standard.

Yup, I’m convinced and agree with you Mark.

Please check if a 20 degree pitch makes much difference. The higher Schletter brackets are expensive and may not be worth the bother. Although the self cleaning effect might also be better?

If you increase your usage of self generated energy you will increase the saving on purchased energy. I have a client who has saved over 75% on his electric bill by doing this.

Of course. And I believe the DNO pay for 50% of the generated energy whether you really export it or not. It’s crazy.

So it encourages intelligent use of the power to legally ‘defraud’ the DNO… Immersion heater goes on when the sun is shining, likewise washing machine, dishwasher etc. But only when there’s enough power available or it would be cheaper to use night rate instead. Care is required.

I wonder if anyone has considered charging a storage heater with any excess energy during a sunny day, then releasing it in the evening?

 

[Mark42]

OK, getting there. One final(?) point: My house is end-of line, with three houses supplied from one small pole transformer, 240/480 split-phase.

The voltage is often high, up to around 248V.

I have read that the SMA inverter over-voltage trips at 253V (ie 230V + 10%) so has lost peak revenue for people in a similar situation to mine.

Does anyone know what the Diehl does? The manufacturer's brochure states max o/p voltage as 230 +- 20% Does that really mean that it will produce 276V before tripping? (ie 552V between 180 degree-opposed phases on my split-phase installation with two inverters)

Presumably there’s a country-specific trip setting? I’ll call the supplier tomorrow to ask. Is there a UK regulation trip voltage? If it’s the assumed 230+10% I can see mine tripping whenever it tries to overcome the local, say 248V supply.

Is this a known problem? Presumably the DNO won’t care, since so long as they’re below 253V, they are legal. The fact a consumer can’t export when the local grid voltage is high is the consumer’s problem, not theirs.

 

[Earthstore]

This might help you, look up voltage optimisation device (google) or voltage optimiser, basically, they regulate the incoming voltage to 220v.
I have not had much to do with them, but you seem quite clued up.
Also, I am sure you are aware you will need to get DNO approval if you go over 16amp (3.68KW is G83, basically fit system then tell the DNO what is installed) over this is G59,which means you have to get permission first.

 

[Mark42]

This might help you, look up voltage optimisation device (google) or voltage optimiser, basically, they regulate the incoming voltage to 220v. …

Thanks Earthstore. I looked up the ‘V-Phase’ unit.

But their web site states a lot of woo and I’m unconvinced. Is it trying to break the laws of physics? (In my experience, a rarely successful enterprise )

Surely if the voltage is dropped, the current increases? Or if not, the time taken to ‘do work’ increases. For example it takes a certain amount of energy to raise a litre of water in your kettle from room temp to boiling, whether the energy is supplied at 240V, 220V, 9V or by a bunch of candles.

Their site cites an example of a washing machine using less electricity at 220V rather than 240V. But these things are thermostatic. Surely it would take a little longer to complete the cycle?

I’m puzzled. Unless it’s a legal way of fiddling the DNO’s meter, which maybe runs slower at lower voltage (I know nothing of metering technology), but even then, it would run for longer as your kettle heated up. I just don’t get it.

Getting back on topic, I doubt it would be possible to ‘back feed’ PV via this device. And it looks like it is not connected to the incomer, but only to an individual final circuit, or circuits. The instruction video is strangely silent on the details.

Also, I am sure you are aware you will need to get DNO approval if you go over 16amp (3.68KW is G83, basically fit system then tell the DNO what is installed) over this is G59,which means you have to get permission first.

Yes, thanks. Due to private advice from a very helpful member of this forum yesterday, who I have now engaged as a consultant, I amended my notifiable 10kW commercial proposal to TWO non-notifiable 4kW installations; one per phase. I had no idea that you could just present the DNO with MULTIPLE 16A PV supplies on polyphase installations. It’s bloody marvellous. And also means it will easily be done and dusted by 3 March.

And no talking to the bureaucratic DNO: Yippee!

I’d better leave this addictive medium now and get the JCB out. I have a trench to dig!

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WHAT A GREAT FORUM: My amateur research here and elsewhere has stopped me making a major design and installation error, also missed by some professionals, which might have meant re-trenching, and scrapping wrongly-specified SWA.

Here’s something I learned which might help others: if installing PV on a rural site with higher than normal mains voltage, and the array is a long way from the incomer, THINK CAREFULLY: it may be best to run MV DC back to the incomer area on thinner armoured cable; do not put the inverters near to the array at the end of a long AC line, unless you use very high CSA AC cables, with all the attendant expense to avoid volt drop. Otherwise the inverter may drop out due to overvoltage on sunny days when the unit ramps up its own voltage to try to overcome an unusually high mains supply and shove it down thin copper all the way back to the incomer. Many people have had this problem worldwide.
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[Mark42]

And so it goes on - a much cheaper panel: HJ Solar HJM250M-32

Usual guarantees, £179 / 250W panel

HJ Solar Mono 250W Panel - HJM250M-32 at Swithenbanks Alternative Energy | Grid Tie Inverters | Solar Photovoltaic

They look like any other. Higher voltage than usual. Has anybody used them?

Cheers, Mark

 

[marcuscrackus]

I fit the Perlight 250w Mono Blacks supplied from Buy PV Direct. I have had no problems with the panels as far. They seem to over produce when new. Construction is excellent and the price provided from But PV Direct can't be beaten.

 

[JulianC]

You work for Buy PV Direct and I claim my five pounds.

 

[marcuscrackus]

Nope i dont work for them. but i do live just down the road. And the prices i get from them and the service cant be matched....

 

[mtp7389]

Their application for trademark status in the US was just completed in 2011. I would be skeptical buying from a company so new in the U.S. market

Has anyone ever used these Chinese panels?:

Perlight 250W Mono Photovoltaic Solar Panel - Black Frame

Perlite PLM-250M-60 BLACK

I’m ordering 10kW on Monday unless anyone tells me of bad experiences!

£9,500 for 40 panels.

They are MCS accredited and have all the usual guarantees.

What do you think?