I was considering installing 3 KW of solar panels in addition to the 5.8 KW I already have installed. An application was made to the DNO and they have come back with a fee of £1500 to strengthen the network to accommodate the additional export from my solar. Annoyingly, I don't really export anything as my parents live in a granny annexe and are home all day, my wife works part time and so is often at home during the day, we have 2x fridges, 2x freezers, going all the time and any excess goes via the iBoost into our 350l heatbank's two 3kw immersion heaters. I was also considering a battery installation (@5% vat as it is combined with the solar installation) to mop up any remaining excess.

I guess the first question is whether people feel that it's worth paying that fee for the additional 3KW of storage?

If not, then do I just scrap the idea of additional solar, or are there other options?

I'm in the Manchester area, so I don't know if my DNO would accept an EMMA export restriction unit? If so, does anyone know how much these cost?

Additional connection fee: I do not have any firm calcs to back this up, but I would have thought it would be a struggle to justify the £1,500 DNO charge plus the cost of the panels, installation, potentially an inverter upgrade etc... as you can import a lot of electricity for that money.

Batteries: I've mentioned on a different thread previously that I went to a presentation from a PHD student who had written their thesis on battery storage. Their conclusion was that for the domestic market it would be a long time until they were economical.

I'm bit behind with current pricing, FiTs etc. A few years ago, I considered upgrading from 3.84kW PV to 10 kW PV and asked our DNO for an estimate for putting in three-phase. They weren't keen on coming out to see but I pushed them for some indication and they said at least £10k plus costs of trenching. That put an end to that idea!

By the sound of it, it looks like you have done the easiest items and are now into marginal returns. Batteries may become more attractive if we get more time of use or peak use tariffs. Do you record daytime and night time electricity use, electricity import and export and how much is diverted to iBoost? Worth gathering the data so you can take advantage if or when differential tariffs become available.

Seems like a relatively cheap deal to me, my DNO asked for £25K + VAT to reinforce the network for my additional panels. I still don't really understand why given the max export current would have been significantly less than my max current demand. The issue seems to be voltage, which sits at a high 245V overnight, so not leaving that much headroom for additional generation. I felt the DNO was using me as an excuse to make additional profit, the cables back to the substation/transformer were only replaced 7 year's ago.......I felt they could have changed the transformer to lower the voltage slightly, given the voltage never goes below 240V, but apparently that's not possible.

I then looked at 3-phase, they said there wasn't 3 phase to my home, I said I could see 4 cables going to the telegraph pole next to my home and 4 take-off points to the cabling further down the road. They said it probably wasn't connected, and I would have to pay for additional cabling up the street. I eventually gave up, but when I spotted some maintenance workers up a telegraph pole down the street a few months later, I got them to check the wiring, and there was 3 phase all the way to the telegraph pole outside the house. They say that their workers test can't be guaranteed, and have now offered me a compromise, pay the full amount for the cabling all the way down the road, and they will give me a discount if it turns out I do have 3 phase cabling.

This is the problem with monopolies, you have no choice and they can potentially rip you off.

No I don't as nearly everything is now, rightly so, evacuated tube.
So would be a case of cobbling together something yourself. If it is vented, it gets away from the certification (G3) I think.

The drainback tank looks like this.

Some work is contestable, which I think means you can get a suitably qualified person in to do it.
May be worth looking at that.
And
It is kW not kw

The DNO bloke at ENW is excellent, just a couple of hours after sending my email, I have a response.. Very impressed.

He said that there is no official time scale for fitting the solar, but that they would be chasing for commissioning paperwork after 12 months, and that it would be a further 2 months for them to carry out their network strengthening work.

He also responded to my query of fitting a three phase supply. It would cost between £3k to £4k to have it fitted, but would allow us to install upto 15kW of solar generation without further costs for network strengthening.

I could leave the main 4kW array attached to the main house, with the 1.5kW on the woodshed roof attached to the granny annex and 3kW attached to the garage and studio apartment (We would use this to charge an electric vehicle).

I think I read that you can receive FIT and export payments for arrays split across three phase, is that correct?

If it is, then this could help mitigate some of the 3 phase installation costs, because at the moment any additional solar doesn't qualify for FIT or export payments.

Posted By: ActivePassiveSSE the DNO installed a meter which permanently posts an error, saying I am trying to fiddle the meter by reversing the current, the manufacturers says the meter isn't compatible with PV, but SSE refuses to replace it.......

What do Ofgem say about SSEs response?

Alternatively I'd suggest trying to use the Consumer Rights Act. I don't think you actually have a relationship with the DNO as regards the meter installation, but I think you bought the right to a suitable meter from your electricity supplier by signing a contract with them, so I think I'd go to them muttering about the Act and insisting on a suitable meter, quoting the manufacturer's statement that it is not fit for purpose..

It is, as skywright says, normal.
It is also useful as you can use it to monitor when you are exporting.

https://www.blog.tempusenergy.com/blog/2017/11/7/eeasrky6d5wpb2rovod20qkknbmhmk