4kw or just <4kw get 43.3p?

[STEL]

Quick question!

I always presumed systems had to be <4kw aka 3.99kw to get the top FIT rate, as that's what's stated on all the FIT tables out there. Is it correct though that we can use 250W panels, get a bang on 4kw system and still get the 43.3p payback?

Thanks.

 

[grandfortune]

i think if you search the forum there are a few posts about it, i think its governed on the inverter you use.

cheers
grand

 

[TedM]

The Total Installed Capacity (for that is the determining factor for the FIT band) is up to and including 4kW for the highest rated PV tariff. Some people use < simply because it's too difficult to find the ≤ sign. (Have a few, I've got plenty here ≤≤≤≤≤≤≤≤≤≤≤≤≤≤≤≤≤≤ - just make sure you don't waste them as I have not got an infinite number.)

Each of the bands is always 'less than or equal to' whatever the upper limit is.

And, yes, some (hopefully most if not all) installers will rate the system based on maximum inverter output - so you could have 5kW of panels with a 4kW inverter. But you will need to satisfy the DNOs G83 limit too. They may be happy with 4kW or may insist on no more than 3.68kW - at least without extra costs.

 

[delleray]

Quick question!

I always presumed systems had to be <4kw aka 3.99kw to get the top FIT rate, as that's what's stated on all the FIT tables out there. Is it correct though that we can use 250W panels, get a bang on 4kw system and still get the 43.3p payback?

Thanks.

some inverters can restrict the max amount to 3.68 to meet G83/2
if the G83 approved inverter limits output to below 16amps then you can install 4kw of panels.

d

 

[langstroth2]

some inverters can restrict the max amount to 3.68 to meet G83/2
if the G83 approved inverter limits output to below 16amps then you can install 4kw of panels.

d

...or you go via the longer winded G59 prior approval route and install 4kw without the inverter limit.

 

[SolarCity]

Don't get confused between the DNO restrictions (16A - 3.68kW) and the FITs threshold (4kW).

 

[delleray]

bs agreed but if monday gov says 8th december:cry_smile:
it'll have to be 3.68kW to get it 'approved' in time

d

 

[listmaker]

Sorry if this is a silly question, but do you need to apply for G59 permission if using an inverter to restrict max output, or can you just go with the G83 route and inform them afterwards?

 

[SolarCity]

I'm not sure I understand what you mean. You only need to apply for G59 if the system is capable of producing more than 16A. If your inverter is restricted to 16A then you are under G83 conditions and you can inform them after the install.

 

[listmaker]

Hi BiggsSolar, should have been clearer. We were advised to go for an SMA 3300, and told it was G83 compliant, but the tech data says max output is 18A, do you know if this can be restricted to 16A?

 

[SolarCity]

18A? Are you sure that you're not looking at the data for the 3800? The SMA 3300 is not rated at 18A. Are you the customer or the installer?

 

[listmaker]

Hi, my husband is the installer, but it's his first installation (on our own home) that he's hoping to get assessed on. I was looking through the data last night, will check again, maybe I was looking at the 3800. Is the 3300 ok then for G83?

 

[SolarCity]

The 3300 is fine for G83.

One thing I would say is that I'd urge you to be very, very quick if you want to take advantage of the current FITs rate. If you look at the other threads on this forum you will see that you will more than likely miss the deadline.

However, if you let me know some of your details of your install (number of panels, orientation, pitch of roof), I'll try and recommend you an inverter which will suit.

 

[listmaker]

Hi, I know it's the FIT rate change which has made me panic and now I'm worried about all details of the install! We've already started the install, 4kw system with SB3300 inverter - recommended by supplier and also checked on Sunny Design to check compatibility. Does this sound ok? I'm really worried we are going to miss the deadline, so unsure what to do?

 

[SolarCity]

4kWp system with SB3300 inverter should be ok - I'm not a fan of the inverter though, simply because there are more efficient models out there.

As for your install, some others on this forum are in a similar kind of position - apparently you can get an MCS firm in to certify it for you although I'm not entirely sure about the legality of that.