3.68 kW or 4.0 Kw - does SP Networks (Scottish Power) allow 4.0Kw installations?

[rgf1]

Just started in North Wales. I am confused between the 16a 3.68 kW requirement (eg SSE Scottish and Southern Energy) in their area without surveys etc. and the 4 kW maximum allowed for the FIT and the fact that at 4 kw the installation falls outside the limits of G83 requirements. The question is:

Can I install a 4Kw system in North Wales?
Does this still get the FIT at exactly 4 kW
Can I use the G 83 requirements.
If not, what does this actually mean in practice

Thanks

rgf1

 

[langstroth2]

The 4kw is band set by the government (DECC) at which the FiT rate drops, it is unrelated to DNO rules - which are concerned with output (i.e 16 amps threshold) from the inverter onto the local grid, rather than the capacity of the PV array.

Can I install a 4Kw system in North Wales?
Yes - if you get DNO prior approval OR
Yes - if the G83 approved inverter limits output to below 16amps

Does this still get the FIT at exactly 4 kW
Yes - at the highest rate. There's still FiT above 4kw, it's just a lower rate.

Can I use the G 83 requirements.
That seems to partly depend on DNO policy

If not, what does this actually mean in practice
A G59 submission - i.e a (more paper work) request for permission to connect prior to install, and a wait for the DNO to respond with a yes (with requests to make some inverter changes probably/ or yes with costs if local network needs upgrading) or no.

That's my understanding

 

[russgibb]

Personally, I would use an inverter that limits at the right value, then any bigger an array above that (within obvious limits) is a slight increase in yield in non-optimum conditions. Just make sure you do the sums correctly!

 

[rgf1]

I was coming to the conclusion that a 3.68 Kw inverter with a larger array would be a good solution to the problem. Does anyone have any views on what would be the optimum size (i.e. kW) of solar array I should install - the particular job in nearly south facing - within 10 degrees of South and the roof is at 10.5 degrees pitch -meaning, as I understand it - that the maximum output of any array would be 95% of the rated output of the panels. So I was thinking (97% inverter efficiency and 95% panel output would need a array rated at 93% of 4 Kw i.e 4.3 kW.
Also the installation is near to the coast and in stormy weather some salt is carried in the air - so the installation would be designed so that the panels could be washed down after a storm. The weather in this part of the UK is often quite overcast and I am favouring Phono Solar panels which seem to be rated highly both in sun and cloudy conditions - any comments. The Schuco panels seem to come out best in cloudy conditions - any comments about these panels. Any recommendations on other suitable (better!) panels would be gratefully received. Thanks rgf1

 

[Graeme Harrold]

Scottish Power have relaxed their stance on 4kW systems and as long as the inverter has a G83 compliance cert then you are good to go. ALWAYS the best bet is to pick up the phone and give them a call. Yes they are extremely busy people, but I have always had a helpful person on the phone/e-mail.

 

[Graeme Harrold]

I was coming to the conclusion that a 3.68 Kw inverter with a larger array would be a good solution to the problem. ..........(97% inverter efficiency and 95% panel output would need a array rated at 93% of 4 Kw i.e 4.3 kW.

Not a good idea as TIC now exceeds the banding for the FIT payment. Keep at 4kW or below.....

 

[FatblokeSolar]

Just started in North Wales. I am confused between the 16a 3.68 kW requirement (eg SSE Scottish and Southern Energy) in their area without surveys etc. and the 4 kW maximum allowed for the FIT and the fact that at 4 kw the installation falls outside the limits of G83 requirements. The question is:

Can I install a 4Kw system in North Wales?
Does this still get the FIT at exactly 4 kW
Can I use the G 83 requirements.
If not, what does this actually mean in practice

Thanks

rgf1

Hi

I contacted SSE a couple of weeks ago, twice (Perth) and they told me there was no limit to the system size I connected to the grid. Since then I have spoken to somebody with some sense at SSE (down south) and they confirmed the maximum limit is 4KW.

I got them to send me email confirmation.

I will be getting a 3.92kw system installed soon (Central Scotland)

Cheers

Dave

 

[Graeme Harrold]

You can connect as much as you want......just 3.68kW per phase without pre-authorisation (G83/2 or G59), its just if you go above the 4kW mark you drop down the FIT rates accordingly.