Dillsue

Again your correct that if you opt out of FIT deemed payments for PPA(Octopus Outgoing) then yes you have forgone your right to FIT payments both deemed and metered. But what is being said is about opting out of FIT deemed payments for FIT metered payments, not PPA.

See section 6.8 of this https://www.ofgem.gov.uk/publications/feed-tariffs-guidance-renewable-installations Accreditted = MCS Non accreditted= non MCS

I'd be surprised if anyone would touch 400vdc as all plugs are IP2x rated. Anyone would have to try hard to touch the live bits of an MC4 connector. You'd have to ask your roofer, or you plug em in

All generation goes through the generation meter and you get paid a proportion related to the proportion of existing FIT capacity and new extension. No MCS needed to retain your FIT payments on the original capacity. Only need MCS if you want SEG or Outgoing on the extension capacity. Read the section on extensions in the guidance I linked to earlier.

With MCS the extension is eligible for SEG or a direct route to Octopus Outgoing. Without MCS youre not eligible for anything. The original capacity remains eligible for FIT regardless of who installed the extension.

No MCS needed for the extension unless you want to claim SEG on the additional generation. Once you've added capacity notify your FIT payer and they'll be expecting a jump in generation and pay you pro rata for the proportion generated by the registered FIT capacity

So who's paying for the eleccy from my self installed array....legitimately?? FIT?- not MCS= no payment SEG?- not MCS= no payment Octopus outgoing?- not jumped through their hoops= no payment So who's paying?

Get a roofer to fit the rails and panels and plug them into the existing system yourself. No spark needed as they are all factory assembled and tested- same as an IKEA table lamp which you don't need a spark to plug in.

I think you do!! Non FiT generated eleccy isn't eligible for FIT export payments so you have to be able to identify the FIT element and the non FIT element which you can't do if they are running through a single meter. They definitely dont earn the same payments.

Try this https://www.ofgem.gov.uk/publications/guidance-generators-co-location-electricity-storage-and-hydrogen-production-under-ro-fit-rego-and-seg

All he needs to do is add panels to the FIT system and change the inverter if it can't handle the new DC input. Declare the additional generation capacity and get paid pro rata for the existing generation meter. Simples!

Your correct, the FIT Generation Meter measures generation only. It's used for generation and deemed export payments. If you're on metered FIT export, then that's done by the premises smart meter. If you've got FIT and non FIT generation going through the export meter then it's not possible to measure the FIT element so you go onto deemed payments. No mention of how you've been previously paid in the Ofgem guidance.

Had a quick look at FIT guidance for eleccy suppliers which contains the following- "6.72. Where it is not possible or practical to measure export by export meter readings, export should be deemed for accredited FIT installations with a total installed capacity of up to 30kW. For the accredited FIT installations where export is permitted to be deemed, the Secretary of State determines the percentage of electricity deemed to be exported. Such a determination is published at least 1 month before the beginning of each FIT Year." I read that as its obligatory to make deemed payments if an export meter can't accurately measure FIT export. So if you've been on deemed then moved to metered export, all you need to do to move back to deemed is add some none FIT Generation which renders your FIT export meter reading inaccurate. At that point your leccy supplier is obliged to move you back to deemed???

Not sure that's necessarily correct! If you add PV in addition to your FIT system it's not possible to use metered export as there's more going through the meter than just FIT export. What you are saying is that export payments would then end??

I have long been under the belief that you can choose metered or deemed and could revert to deemed if you wanted to. Dont know where I've got that from but may be worth looking into. Deemed is certainly the way to go if you'll be daytime charging a car or battery

Sorry, replying to JamesPa!!

Assuming your existing is a FIT system?, look up the OFGEM guidance for FIT generators and either the guidance for generators(you or me) or FIT payers(electric Co.) includes schematics on allowable configurations for battery hook up. Basically it mustn't be possible to charge the battery from the grid and then discharge through the FIT Generation meter. Only site generated eleccy from your acredditted system can pass through the generation meter. DNO requirements are separate so an AC coupled battery downstream of your generation meter will likely meet with FIT rules but need G99 approval from your DNO

When I looked at the Octopus non MCS scheme you needed BC sign off that your roof is structurally able to take the extra weight and you need a part spark sign off. Potentially £500+ for those on top of the Octopus fee. Member if youre buying secondhand inverters to make sure they comply with current grid standards, if you want your connection to be legit

Yep. A PV diverter will do that for you. Ideally you want 2 immersions in your tank and a diverter that will heat the top of the tank first and switch to the bottom immersion when the stat in the top one switches off.

For export limitation, G100 requires the limitation to be password protected by a factory or installer password that the user shouldn't have! If you go for an inverter over your DNOs 5kw limit you'll need one with a G100 cert and professionally installed to comply. No idea if your DNO is bothered with such things?? Our DNO said if we went for export limitation they'd want to witness it and charge several hundred £ for the privilege If you go with a 5kw inverter with a G99 cert that should limit to 5kw but check the cert. I don't know about other manufacturers but Solaredge allow up to 200% DC input of the inverters rated AC output so an SE5000H can have 10kw of panels connected

Yep, with the right setup. If your battery is DC connected and your inverter carries a G98 cert then good to go.

I may be wrong but for your export I think Octopus accept manual readings where smart meters won't connect. They're obliged to pay SEG rates so if a smart meter isn't sending data, manual readings is the only way they can meet that obligation. Doesn't help with variable tariffs though!

Your azimuth figure should be -30 for a SES facing roof but that's not going to make a huge difference. Remember that to use PV, without batteries, you need to use it when the sun is out and generating. If you or your guests are out during the day and back in the evening to cook/wash etc then you'll be exporting lots of surplus PV during the day and importing in the evening. The only way to more accurately compare your usage with forecast generation is to use hourly figures.

Top of the quote says 10.9kw so probably just cut and pasted from previous quote

No apology needed. From lots of posts it seems that DNOs across the country do things slightly differently and I just wanted to see if that was another DNO quirk