Upgrading Inverter on a FIT system

[openspaceman]

Well I moved to Octopus and have asked to be removed from the deemed export database, it is apparently a lengthy process so I am still waiting.

This should preserve my FIT payment but remove the payment from half which I produce and is deemed to be exported. I think this will mean I lose about 2.5p per kWh from my payment but may get at least 5p for my exports and maybe 15p if Octopus approve the application for SEG before they drop the rates.

The rest I am hoping will be revealed.

[cojmh]

OK, so that seems to confirm that it is mostly right .... I wonder if they will pay the export on the full amount of the two systems then .... I will be interested to know how this goes

[nowty]

Yes,

If you replace your current (non grid charging) hybrid inverter for a modern standard hybrid inverter it should have the ability to charge the batteries from the grid. Therefore you need to replace your current "Total Generation Meter" with a "Bidirectional Total Generation Meter" with the agreement with your FIT provider. The "net" register correctly records your generation whether you use the grid charge function or not.

An example of such a meter,
https://midsummerwholesale.co.uk/buy/me ... onal-meter

Then if you opt out of deemed exports and move to SEG (warning its a one way ticket), your export is then measured via your smart meter. And yes all the non FIT PV and forced discharge (if you have that facility) from your battery is measured, not just from your original FIT system. Just don't tell Octopus you have any non MCS kit, its still within the SEG rules (there is no subsidy on SEG) but they don't have to accept it. You need your original MCS certificate and Octopus will apply to the DNO for an export MPAN number to associate with the export resister on your smart meter.

Also the rules for SEG is that some "brown" export, which could be mixed with grid leccy to charge the batteries (which will include some FF) is allowed but the SEG provider does not have to accept it. Octopus also say in the T's & C's they don't have to accept it but they currently do accept it.

[openspaceman]

Also the rules for SEG is that some "brown" export, which could be mixed with grid leccy to charge the batteries (which will include some FF) is allowed but the SEG provider does not have to accept it. Octopus also say in the T's & C's they don't have to accept it but they currently do accept it.

This must be because there is currently no way to differentiate it from other export once a battery is involved??

[cojmh]

Thanks Nowty for such a good explanation.

Seems like this will be the way to go when the second system is installed. Perhaps might be able to reuse the solax inverter in another property .... So it won't be wasted.

In terms of the 'forced discharge' that you mentioned. I have not come across this before. Why would anyone do this? I have read a about people buying electricity at cheap rates and reselling back to the grid at peak times and making money on the difference. Is that what you mean or is it something different?

Thanks

[nowty]

Thanks Nowty for such a good explanation.

Seems like this will be the way to go when the second system is installed. Perhaps might be able to reuse the solax inverter in another property .... So it won't be wasted.

In terms of the 'forced discharge' that you mentioned. I have not come across this before. Why would anyone do this? I have read a about people buying electricity at cheap rates and reselling back to the grid at peak times and making money on the difference. Is that what you mean or is it something different?

Thanks

Yes, if say you have Octopus Agile Outgoing, or Flux tariffs, you get paid a higher rate at peak period. Therefore if you can force discharge (export) to the grid during this time, you get more of the higher rate. However not all inverters do it.

There is a short thread showing examples here.
https://camelot-forum.co.uk/phpBB3/view ... f=14&t=160

[nowty]

Also the rules for SEG is that some "brown" export, which could be mixed with grid leccy to charge the batteries (which will include some FF) is allowed but the SEG provider does not have to accept it. Octopus also say in the T's & C's they don't have to accept it but they currently do accept it.

This must be because there is currently no way to differentiate it from other export once a battery is involved??

Yes,

https://www.ofgem.gov.uk/sites/default/ ... _final.pdf
Brown vs green export
4.26. Green Export is electricity generated by an eligible installation solely from one of the
eligible low carbon energy sources.

4.27. A SEG licensee is only obliged to make SEG Payments for renewable electricity that
is exported (“Green Export”) by an eligible installation.

4.28. Where the export meter for an eligible installation also records, but cannot
determine the amount of, electricity exported from another source (“Brown
Export”), a SEG licensee is not obliged to make SEG payments but they can if they
wish. Examples of “brown export” may include export from a non-SEG eligible
installation, from co-located storage that is charged from a source in addition to or
other than the SEG eligible technology or from a standby generator.

4.29. A SEG licensee can choose to make a SEG payment for all export recognising that it
includes a combination of green and brown export. Alternatively, they may require a
generator to install suitable metering to calculate the brown export and deduct that
from the overall exported electricity. Or they may pro-rate output or use estimates
to calculate the green export.