Dillsue

List them on ebay, FB marketplace and anywhere else with no or minimal fees.

Is yours a new build with plumber and spark on site already? With the BUS MCS umbrella schemes you can end up getting all the components, design and commissioning free with you just covering the install costs. Down side is you get what the supplier decides you need and not necessarily what you want/need. I looked at Cleanenergy where everything other than install would have been free but the pump they offered was way oversized and running costs would have been excessive so I'd be paying for their system for ever! I've just started on a self funded/self installed system with a used Therma V pump picked up off ebay:)

Slowly unscrew the pressure gauge. As soon as you can turn it by hand wiggle it and any pressure should vent via the loose threads. Slowly undo it while keeping wiggling, assuming at all times there's 2 bar trapped in the pipework. Keep towel handy!!

If or when the expansion vessels fail the pressure relief valve takes over to stop overpressure so fit one if there isn't one.

If you Google 15mm pressure relief valve you'll see what they look like. If you've not got on the pipework or Sunamp then you probably want to get one fitted to protect the sunamp. Have a look at the manufacturer's instructions for the expansion vessels as they'll tell you what the should be recharged to. The diaphragm inside can fail over time but youll know if they've failed if you cant pre charge them when removed from the install.

I don't think the mains supply gets anywhere near 13 bar so it's unlikely the 13 bar is coming from the mains, if that's where your "cold supply to the sunamp" comes from. If there's a non return valve on the supply then it's possible that as the sunamp charges and warms up the expanding water causes the pressure to increase?? The expansion vessels you mention should absorb this if they are working and connected. There should be pressure on the expansion vessels so probably worth checking that the vessels are connected to the pipework and that they are pre pressurised to allow the internal diaphragm to flex and absorb the expanding water. There should be a pressure relief valve on the vessel/feed to protect the sunamp being over pressured. Is that fitted and working?

?? 60% drop from 2022 figures by 2030ish, then climbs continuously to 2050 to get to the same level of gas generation we have now. See the graph in section 4.1 I guess the drop is on account of additional renewables deployed up til 2030. Thereafter I guess the ever increasing gas generation is to feed demand growth after we've maxed out renewable install. If there was an electricity price drop with renewable deployment it looks to be only a few years down the road before gas generation is on the rise again and bills with it??

Aren't the regs for fixed gas installs in houses different than those for connecting up a camping stove???

Not sure gas generation over the year is quite that low?? Tapping through last years generation graph on Gridwatch suggests not. Last year National Grid say gas did 26% but even though total gas generation is getting lower we need it to be there for when the wind doesn't blow or at half time in a big footy match apparently! Gov forecasts say gas is here to stay so I can't see the link between gas generation/standby costs and electricity prices being broken???https://assets.publishing.service.gov.uk/media/675c0ca798302e574b915336/eep-report-2023-2050.pdf

I bought a used inverter from and outfit called South West Renewables and they were helpful and professional. No idea if they do installs but maybe worth touching base with??

Save a search on ebay for your current model of oil boiler and you might surprise yourself with a good working spares boiler

We're almost into May already and without any firm plans you probably want to get the oil boiler ship shape to see you through next winter. Then do your research and build a plan as to the work you want to do. Once you have a plan you'll be able to size your heat pump more accurately based on the draught proofing and insulation levels in the plan. Remove the loft insulation and buy a box of 10 little nipper mouse traps. Once youve cleared the mice, seal up all the pentrations where cables/pipes come through the ceiling, fit rodent proof vents to the eaves and refit the insulation. You might want to use PIR over the tops of the walls to give decent insulation between rafters but leaving enough of an air gap to get airflow across the loft space. Don't expect any solar PV to contribute much to running your heat pump as solar generation is at its lowest in the winter when heat demand is at its highest

One of the not so publicised benefits of optimisers/micro inverters is that they allow you to have mismatched panels on the same string which is great for phased expansion of a system. We have 310 and 320 watt panels on one string and 335 and 405 watt panels on a second string with the smaller panels not affecting the output from the larger panels.

I think that to do what the OP is doing you'd need a few extra bits and bobs off the roof to get the same functionality with micro inverters. The thing to be conscious of with anything active up on the roof is replacement if they go wrong. I don't know what the failure rate is of micro inverters but we're waiting delivery of the 3rd failed optimiser from one of our systems. They come with a 25yr guarantee but that's not an indication of how long they'll last, just means we get the part free. Fortunately I have the kit to replace them so it's just my time to put up a scaffold tower but if you have to pay someone to change them it can be £100s

Google "Ofgem fit guidance" and youll find- https://www.ofgem.gov.uk/publications/feed-tariffs-guidance-licensed-electricity-suppliers And- https://www.ofgem.gov.uk/publications/feed-tariffs-guidance-fit-generators

The FIT rules changed in December 21 to allow alterations and batteries so make sure you find the version dated then or later

Read the FIT rules!! Your config is likely allowable with a new bidirectional meter doing net metering. Anything drawn from the grid and put into batteries is deducted from energy flow to the house/grid giving a net reading of what was generated from solar. It's all covered in the FIT generator rules and/or guidance docs from Ofgem. Don't expect or trust that BG staff will understand the finer details so you could well have a bit of an uphill struggle but you'll get paid in the end if you know and stick to the rules. There's also a guidance doc for FIT payers(BG) detailing how they should manage you so that's worth a read of the sections covering what you want to do. Have fun!

Great that you got your 8kw export. If you've not already done it have a read of the FIT rules re system extensions so you get all the total and net installed capacities correct

That's a G100 concept doc. Have you checked the ENA type test register for a compliance cert as a previous post reckoned Victron weren't going through certification?? Is it a G99 application you made to your DNO rather than a "notification"?

SEG is the government's successor to FIT and is regulated and must be paid if you apply with a qualifying system. Outside of SEG, Octopus and maybe others can buy your surplus on a Power Purchase Agreement(PPA) which is an unregulated contract between you and them. Octopus offer both a PPA and SEG but no point in going for SEG when you can get much more on their Fixed or Agile Outgoing tariff

Title is "help with first solar PV system". Bit confusing when you're actually expanding an existing system! The answer to your question about getting paid for FIT generation and separately paid for metered export on a PPA, is yes you can. We do exactly that. Scottish Power pay the FIT generation on our 4kw FIT system and Octopus pay the 15p/unit on the export from the total 12kw we have. You can only change between metered and deemed payments once every 12 months. If your extending your FIT system to 8kw you'll only get FIT payments on the original registered capacity of 2kw so as you say you'll get paid on 25% of what goes through the generation meter

The FIT scheme ended in 2019. If you mean SEG, last time I looked that generally pays a pittance- Octopuses 15p rate isn't SEG, it's a power purchase agreement that Octopus offer, can end anytime, and doesn't carry any government backing which SEG has, hence the G on the end

If you can't get consent for 8kw then you wont(shouldn't)get approval as your inverter eemingly doesn't have G100 certification to limit export below 8kw. Anything with more than 3.68kw rating and your DNO should always be your first port of call. Your MCS installer shouldn't power up, commission and certify for you without DNO consent. I'd speak to your DNO ASAP and hope you can blag 8kw.

AFAIK you need the system designed and commissioned by an MCS certified outfit to get the grant.

Up until the last few days we'd had 1 day of rain in the last 2 months.....witness the wildfires we've been seeing in the media. The nearest reservoir to us is only half full as we come out of winter. Might be worth being a bit conservative with something we really don't want to run short of??