The DNO said no

JKenH

I have previously mentioned that due to an oversight a DNO application wasn’t submitted at the time my panels were installed. A retrospective application was submitted for 10kw as I wanted to add a few more panels. I have now heard back from my installer that the DNO has said we can’t export more than 5.9kw without upgrading to a 3 phase supply the rough estimate for which is about £10k.

I already have installed 4.2 kwp facing approximately WSW and 3.6kwp facing ESE. Each array has a 3.6 kw inverter. Because of the orientation of the roofs they don't peak at the same time.

Is there a device available to cap overall export from two inverters? I can live with 5.9 kw overall but I dont treally want to have to scale the inverters down individually to get to 5.9kw.

Any suggestions welcomed.

K

Martyn1981

What a bummer!

Are the inverters in the same location, could you switch to a single larger inverter that's capped at 5.9kW? Solaredge, just a fancy way of achieving the same.

There are some devices that cap based on export not generation, but you'll need to get the Google machine out, probably need to change inverters, and also they'll have to have been approved by your DNO, and still early days.

Possibly some battery work around, but again, will need lots of changes, and DNO approval.

I've only got the broadest thoughts and ideas here, nothing specific nor particularly helpful, sorry.

1961Nick

I'd be thinking along the lines of a single larger inverter with the capability to cap the export at 5.9kWh.

The 3.6kWh inverters are capable of around 6.6kWh combined & with background consumption at 300w (?), the theoretical excess is currently only around 400w.

Because of the opposing orientations you're not going to peak on both inverters at the same time so I doubt you'd ever achieve 5.9kWh as things stand.....so nothing lost.

pile-o-stone

Ask your DNO if they have any approved export limiting devices you could use. I live in the northwest and our DNO approves the use of ENA100 compliant devices:

http://www.energynetworks.org/electricity/engineering/distributed-generation/engineering-recommendation-g100.html

More details here:
https://www.sma-uk.com/solar-systems/export-limitation.html

It’s a sorry state of affairs that the planet is dying and people who install solar are being asked to pay to improve the grid AND export their energy for free. Surely the DNO should do grid strengthening work for free if it’s receiving free renewable energy in return?

mgbond

I might be wrong here but my understanding was that you could have a 3.6kw inverter so max about 5kw solar panel system without DNO. Also a 7kw system if you ha e a battery. So could you just not add a battery.