Is this salesman right

[UNG]

Talking to the future son in law of one of my mates he tells me he has just ordered a 4.4kw installation split between a roof facing east and one facing west he's been told that because of the way the panels are sited (East and West) he will be about 10% down on the maximum output so he will be generating 4kw. From what I've read on here this sounds extremely optimistic

So the question is to those more knowledgeable on PV does this sound right or has he been mis-sold this and if so what output might he realistically achieve

 

[TedM]

It depends on a lot of variables, mainly the angle of slope of the roof but I agree that only a 10% loss is optimistic.

See http://www.electriciansforums.net/p...west-split-4000tl-my-pv-system-take-look.html where an owner with a 3.9 kW system equally split east-west reported maximum output of 3156 W and annual production of only 731 kWh/kWp. That's roughly a 20% deficiency compared to expected output from a due south facing system.

And, of course, that peak output is likely only for a very short time each day in the height of summer compared to the duration of peak output that will be sustained by a south facing system.

 

[moggy1968]

the other thing worth noting is that he may not qualify for the higher rate of FiT as he has gone over 4kW, even though he has a 4kW inverter. It's all to do with the semantics of definitions. This is a highly contentious issue being fought out at the moment with some installers and the FiTS providers (and OFGEM) so I would play on the safe side and keep it to 4kW for now.

You must ensure that any installer uses a CORRECTLY SET UP 2MPPT tracker inverter

 

[Ian-LS]

I was about to make that same point that Moggy has made. Feed in Tariff forms ask for number of panels and peak rating so the intructions from OFGEM are that 4.4 kW of panels will be treated as above 4 kW so will get the lower (currently 13.99p/kWh) Feed in Tariff. I would also stick to 4 kW of panels

 

[UNG]

This subject seems to be a minefield if's and but's with ever changing goalposts

Thanks for the food for thought which I will pass on as it seems the salesman believes they will get away at the 4kw rate for fits because it's an east / west system

 

[moggy1968]

you might, you might not, and for the sake of .4kw extra it really isn't worth the risk.

 

[SRE]

Might help to get a quote from someone who installs rather than a salesman. We're a two person outfit and so customers always talk to someone who knows what they are talking about. Sales people need to make sales, installers like to install properly so they never have to go back and happy customers recommend them. It's a different perspective.

 

[Worcester]

See my earlier comments re TIC and DNC and what should appear on the MCS certificate / database (It's a can of worms...)

 

[BruceB]

I was about to make that same point that Moggy has made. Feed in Tariff forms ask for number of panels and peak rating so the intructions from OFGEM are that 4.4 kW of panels will be treated as above 4 kW so will get the lower (currently 13.99p/kWh) Feed in Tariff. I would also stick to 4 kW of panels

The EON FIT application form does not ask for TIC or kWp of panels, just DNC - presumably because that is all that used to be on the MCS certificate. So if you feel lucky.......

 

[SolarRoofSols]

The EON FIT application form does not ask for TIC or kWp of panels, just DNC - presumably because that is all that used to be on the MCS certificate. So if you feel lucky.......

However, I think the BG form just asked for DNC but they have recently asked someone in our area to clarify exactly what they have installed. My thoughts are that there will be some auditing happening in the future to check that people are not fraudulently declaring system sizes under the FIT threshold when in fact they have 1 or 2 panels over.

 

[BruceB]

I would not throw the word fraudulently around carelessly. There are some of us who have read the legislation carefully and think a similar charge could be laid against the authorities and power companies involved in the way they are misinterpreting the definition of TIC.

 

[SolarRoofSols]

No offense meant but that is how a FIT provider could potentially see it in the case of the OPs, case depending on how they interpret TIC/DNC. It is a can of worms and I wouldn't want any of my customers to be in a position of having to fight it out later with their provider and potentially jeopardise their FIT contract.

So I'm with Moggy.

 

[BruceB]

No offense taken and my tongue was firmly in my cheek when I said,"So if you feel lucky......."
It would have to be a strong willed customer for me to agree to it now and the margin for the customer is less than it was a year ago