PV+ - anybody heard of this?

[Chr!s]

Hi,

I am being touted by my local installer to add a module called PV+ to my residential solar array. This module is claimed to effectively improve efficiency of my installation by 20% (thereby increasing my FiT earnings) by balancing out and reducing overvolting, which they tell me cuts out generation for every period of overvolting. Forgive my brief description but that is as I understand what it is supposed to do!

The module costs GBP859.00 (fully installed) so is something worth finding out about before going for it.

Is there anybody who knows this equipment and can comment on the efficacy of the claims. Many thanks.

Hi, ask him to show you his calculations to back up his 20% claim, if your unit is not suffering from over voltage, where is the 20% savings coming from?

 

[whinmoor]

Complete twaddle. Best avoided.

 

[Gavin A]

Rob Latta,
I had a very similar sales pitch yesterday and, blow me down, I could get a discount as they had installers in the area.

I listened to the salesman who tells me that all panel arrays have a protection so if one panel goes over the rating for that panel (in my case 240w) then the inverter shuts down THE WHOLE array for 15 minutes so I lose all generation for that period. This may happen 4 - 5 times per day. This “PV Plus” irons these spikes out preventing the inverter shutting down so you record greater generation. He said between a minimum of 25% to a possible 40% depending on season etc.

Cost is £4000, at my current generation and return about 7.5 years to recoup.

Anyone able to corroborate that the panels are shut down so frequently?

please report them to trading standards & RECC if they are members, this is a scam based on complete lies, and by reporting the company you may save many others from being ripped off. Thanks.

 

[Gavin A]

I have heard of this (unfortunately).

I discovered some unscrupulous salesman had sold one of these DC PV+ units to my elderly mother, ripping her off to the tune of £2,500. After 6 months her FiT readings were slightly lower than the same period the previous year. I simply put this down to the panels maybe needing a clean. Before installation she was told by the salesman her FiT readings would double!

I'm personally seeing that the firm involved is reported to Trading Standards for this disgusting example of gross miss-selling.

My advice would be avoid at all cost in a domestic situation.

sue them as well please. Small claims court should be an open and shut case.

 

[LeeH]

Gentlemen, the best way to look at the product is like a G59 relay, if the grid reaches statutory limits then the device will switch the inverter out of circuit but on the grid side and not the inverter side.

It's gone quiet..

 

[Clodbuster]

This is the unit offered to me.
PV Plus | The Renewable Energy Hub - https://www.renewableenergyhub.co.uk/blog/pv-plus-unit/

 

[Clodbuster]

I had a reply from the manufacturer of my inverter and I copy their reply in.

“Thank you for contacting us, Inverters are designed to only convert the maximum DC input that the inverter is capable of, it does not read the generation of individual panels. The over voltage issue the PV Plus refers to only occurs in a very small number of systems usually farms and areas that are remote where the supply voltages can be less stable.

The voltage of the PV panels which is DC does not increase with the exposure to more sun, with a small amount of daylight the DC voltage of a PV module is almost at maximum so stays stable throughout the day, it’s the current which is directly affected by irradiance levels, so overvoltage of the PV system is not possible if the system is designed correctly and inverter will not turn off.”

So that solves the question.

 

[whinmoor]

This link explains how the output of solar panels can decrease as temperatures rise (and voltages reduce):

http://www.solar-facts-and-advice.com/solar-panel-temperature.html

 

[Rob Latta]

Whilst looking into this I did see an in-situ 1 year long experiment with two systems side by side on an industrial estate (one side of a roof with a PV+ system and the other side without). It shows a graph for 1 day with lots of up/down curves for the non PV+ system as it shut down when voltage was too high (compliance with regulations I think?) whereas the PV+ system shows a constant horizontal line because it didn't have to shut down, due to the PV+. The report is in PDF format and is at the light blue link that says "pv-final-data" at this page PV+ Grid Voltage Monitor Unit - http://matt-e.co.uk/are-you-getting-the-most-out-of-your-pv-system/ and is also available from this direct PDF link http://matt-e.co.uk/wp-content/uploads/2016/02/pv-final-data-V2.pdf

The results are quoted below. I kind of like it because I'm a sucker for something written up like a school science experiment but I don't really have the knowledge or experience to critique its validity

Results
The systems were commissioned on 24th June 2015 and have been left to run without interruption until the 24th of June 2016.
Final meter readings taken:

• System 1 Non PV+ 1558.66kWh
• System 2 PV+ 1744.97kWh

As shown in the table below both systems easily out performed the expected generation. However the PV+ unit achieved an additional 186.31kWh or 11.95% compared to the system without the PV+ unit fitted. <see the PDF for the table>

Conclusion
While the additional 11.95% increase is significant in monetary terms, especially for the early adopters on higher FiT rates, It should be noted that the test was carried out on an industrial estate where heavy loads on the local grid significantly lower the voltage during the working week. Thus reducing the need for and the benefits of installing the PV+. This theory is supported as most of the increase in generation was gained during early evening after local factories had stopped production but mainly during weekends when they are closed. It would be fair to assume grid voltages in residential areas would be more consistent during the day, therefore in areas of higher grid voltage, inverter off times would be more frequent meaning further loss on generation

 

[Clodbuster]

I see the trial was run by the supplier - those always make me take them with a pinch of salt.

Do I read it right - the inverters shut down because the mains voltage is above 244v - nothing to do with the panel generation?

 

[Martin Bradshaw]

Hi weve just had a matt-e pv+ fitted too, its connected directly after the inverter on the ac output. How is it supposed to protect from over voltage if its on the ac output ???

 

[LeeH]

I'm just thumbing through the manual...quiet at work at the moment.

Martin.

Q1 Did they install it within 1m of the consumer unit?

Q2 Does you voltage regularly go over 246V?

I'm just looking for reasons for you to get your money back from the robbing bar stewards.

 

[Worcester]

Not only that how does you system now comply with G83 if you have a device between the Inverter and the Grid ? ....