Best Dual Inverter combo for 7.5kW?

[PvNewbie]

Hi

I'm trying to design the best inverter/panel combination for an (up to 7.5kW) system....single phase. They need to be G59 certified as the 'simplified fit' scheme has now ended. I can get close with an SB4000TL + SB3000TL (7kW) but the customer would like me to get closer to 7.5 if possible. The SB3600TL sadly isn't G59 rated(yet??) so wondering if anyone has any other suggestions.

Cheers

Newb

 

[SolarCity]

How about two Power One 3.6 OUTDs?

Or two Kostal Piko 3.6?

 

[PvNewbie]

I don't think they're G59 certified are they?

 

[SpitfireW'sale]

would this install not be G83/2 rather than G59?

 

[PvNewbie]

would this install not be G83/2 rather than G59?

No...DNO has specified they must be G59 as the 'relaxed rules' timeframe for allowing G83 inverters on > 16A has now expired. So things 'harder' to install now on these marginal systems.

 

[BruceB]

x2 4000TLs

 

[PvNewbie]

Thanks Bruce but the DNO won't accept 8kW output, given the panels kWp is > 8kW. 7.5kW is tops.

Any advance?

 

[dansk]

Well Fronius 3.6TL + 4.0 = 7.6, surly you can get away with this.

Fronius United Kingdom Ltd. - Info & Support - Document Downloads

 

[dansk]

Kaco Powador 8600 7.2kw and G59 KACO new energy GmbH :: Powador 8600Powador 8600

 

[Earthstore]

You have not said what orientation the system is, if it is a split system, where it is located in the UK, and all the many other aspects of system design.
Just because you have 7.5kwp of panels, does not mean you need a 7.5kw inverter.

This is meant to helpful by the way.

 

[BruceB]

Thanks Bruce but the DNO won't accept 8kW output, given the panels kWp is > 8kW. 7.5kW is tops.

Any advance?

x2 4000TLs each throttled back to 3.75kW

 

[PvNewbie]

You have not said what orientation the system is, if it is a split system, where it is located in the UK, and all the many other aspects of system design.
Just because you have 7.5kwp of panels, does not mean you need a 7.5kw inverter.

This is meant to helpful by the way.

Thanks Earthstore for your 'helpful' comment. I know enough thanks to this forum and what I've learned over the past 2 years about location, kWp of panels, TIC/DNC etc. As I said earlier I've got > 8kW of panels. In fact I'm trying to get 9kW on (36x250W) on a perfect south facing roof at 5 degrees. I'd like to get 7.5kW of output if I can as this is the MAX the DNO...(Western Power) will allow without 11,000Volt system shutdown and network upgrade which is beyond customer's budget.

Bruce....I'm interested in the 2x4kW SMA's....How would you throttle them...and get DNO approval?

Newb

 

[BruceB]

There is a setting available through the installer menu that sets the maximum output power. If the DNO has said you can have 7.5kW then just declare the TIC/DNC as 7.5kW and adjust the setting.

 

[SpitfireW'sale]

No...DNO has specified they must be G59 as the 'relaxed rules' timeframe for allowing G83 inverters on > 16A has now expired. So things 'harder' to install now on these marginal systems.

So does this mean that there is no such thing as G83 stage 2 now? In effect, any system over 16A / phase needs to have a G59 certified inverter or G59 equipment / testing done?
Could someone point me to some literature about this so I can read up? Thanks

 

[PvNewbie]

Look at this... http://www.energynetworks.org/modx/...g/distributed generation/DGCG G59 Nov2011.pdf

Things were tightened up 2nd March (curiously).

Newb.

 

[SpitfireW'sale]

Do you specifically have to have a G59 type verified inverter for any system over 16A? Or is it more that you need to have pre applied to the DNO with the correct G59 forms completed.

 

[PvNewbie]

I did an Application for Connection for a generator > 16A per phase and the conversation I had with two engineers were they had to be G59 certified as the 'relaxed rules' were no-longer in operation. My conclusion is that now, if you go over 16A, you need to pre-apply (as always) and it has to be G59.

So, as before, where I put a single SB4000TL in, I did a G83 pre-application, I now do a G59 pre-application. Hope that makes sense.

 

[Gavin A]

stage 2 is now really for multiple installations in the same area.

 

[SpitfireW'sale]

I spoke with one of our engineers to clarify this issue for myself after contributing to this thread, and thought my investigations may help others. (better late than never!)
Anything over 16A is now G59 as PVNewbie correctly stated. If the inverter is not G59 certified it does not necessarily rule it out as being possible to use for an install over 16A. The G59 certificate simplifies the connection process of the generator to the grid. If the inverter is not G59 certified, you will need to comply with the regs as described in section 6.1.4 and 12.2.5 of the ENA Engineering recommendations G59/2-1

As a reply to the original post - We distribute for SolarMax, and both their 4200S and 6000S are both G83 and G59 certified (together with all of the 3 phase "MT" range being G59 certified, but they would not be suitable in this case)

 

[sedgy34]

power one 10kw is g59 and nearest for purpose

 

[SpitfireW'sale]

power one 10kw is g59 and nearest for purpose

I think that's 3-phase?

 

[sedgy34]

I think that's 3-phase?

it is yes my mistake didnt see the single phase bit

 

[whlphil]

SMA 7000TL they are G59 i think, Steve at Wind and Sun has some in I think that he got for a job for me last year, I'm sure he'll be looking to get rid ;-)

Its a little on the low side at max DC 7200w but not far off

 

[st3ve]

Yes, the Power_One PVI-10.0-OUTD-S-IT is single phase and has 2 MPPTs and up to 6 inputs.

 

[Worcester]

@PVNewbie, As I undertsand it the problem is limiting your output to the max allowed by the DNO, but not comprosing on production...

1) Try the EMMA EC - double win, 1) use as much energy as possible that uou generate, and 2) can limit the export. so you'd get a float top to your export without limiting power / energy production. used to be called EMMA GVS, Emma GVS | Worcester Renewables now called EMMA EC (need to update our page EC can be added as an option to any EMMA

2) SMA also have an export control device that powers down parts of the array to meet the DNO's limits, though not yet seen one of those installed in the UK POWER REDUCER BOX


Both the above are common practice in other countries, as usual , UK is a bit skow to catch on .....

 

[SpitfireW'sale]

Yes, the Power_One PVI-10.0-OUTD-S-IT is single phase and has 2 MPPTs and up to 6 inputs.

Power One PVI 10.0 is a three phase inverter with two MPPTs.

 

[SibertSolar]

For a 7.5kWp system, single-phase, you could choose an Eltek 7200TL - single-phase, G59/2 approved, 8.1kWp max PV, 3 string inputs (MC4, 1 MPPT), embedded data-logger (30yrs), IP66, 98% peak eff., transformerless, built-in DC switch (Santon), 10yrs warranty.