Dillsue

Thats a misnomer. If a house has a 15kw heating demand, any 15kw heat source will heat it. The confusion lies in that gas boilers have traditionally been massively oversized so when a gas boiler fires up its got loads of excess capacity to get radiators up to temperature quickly. Heat pumps loose their efficiency when they have to produce hotter water than optimum, such as when trying to heat a hot water tank or heating a house via undersized radiators. Heat pumps are going to need a big mindset change in the way that heating systems are used. Particularly for rental properties theres a need to get the system designed, installed and set properly by someone who knows what they are doing. Therell also be a need to spend time explaining to home owners/tenants how to best operate the heating.

Staying within the G98 rules youre limited to 16A/3,68kw export per phase so 1 phase export limit is 16A and 3 phase export limit is 3 x 16A. For a 3 phase system you can use a 10/11ish kw inverter with a G98 cert OR 3 x 3.68kw inverters each with a G98 cert. If you want to go more than 16A on any phase then its G99 application. If you want to have 20kw of panels on a single phase Im not sure youll find an inverter that can cope with 20kw input and have a 16A G98 limited output

Isnt that the usual curve for the orange gas generation?

Did they rework the pipework to the solar coil when the cylinder was replaced? There should be a non return valve in the pipework from the upper tapping on the solar coil to stop warm water rising from the coil to the collector. Maybe the NRV is faulty, fitted the wrong way round or missing altogether? Our controller has a store(cylinder) cooling function which circulates fluid through the coil to the collector in an attempt to cool the cylinder if the temp is too high. Its a long shot, but if youve got that feature could someone have tweaked the settings so the controller is cooling the cylinder?

Hang onto the boiler and add a HP......keep your fuel options open

It wasnt wired back to front, it was just the display was only showing import figure. That may have been because it only shows the current flow direction and you only looked at it when system wasnt generating and importing to power the inverter?? I think you can change what the display shows but a read of the manual would be needed!!

The picture you posted seems to show a meter that logs import and export. Are you sure the .9kwh youre reading isnt the inverters import showing the total nightime consumption when the grid powers the inverter??

Google CIGA who provide CWI insurance and have a list of registered installers. They are good to their word as we claimed on the guarantee a few years back and a survey and remedial work were all done in a few weeks without any fuss.

When considering whether to let your DNO know about any increase in export capacity, theres probably lots of reasons for and against but heres a couple worth considering. Firstly, we're waiting for a FOC transformer upgrade but while we wait Ive temporarily hooked up 3kw of panels on top of the 4kw system we already have. When the sun shines we're pushing the house voltage way over UK limit to the point that the temporary inverter shuts down. As we're the only house on the transformer its only affecting us and no one else is going to complain. If youre on the same LV supply as others and you push their voltage over the limits with unapproved generation, there could be bother coming your way. Secondly, if you install generation without approval and several of your neighbours do the same but get approval, if theres any problems it will be you that gets notice to disconnect and may have to pay for grid reinforcement before you can reconnect. With elec prices going skyward and the gov removing vat there could be a surge in install so maybe worth getting approval before others jump on the bandwagon and use up spare grid capacity. We were going to connect up the extra PV and say nothing until we thought about it and put an application in. Once you got approval its fairly certain its there for life

A dollop of seagull s**t, a bit of saharan dust, or passing clouds all constitute shading. Optimisers/micro inverters also allow individual panel monitoring/fault finding, the use of mismatched panel outputs and with Solaredge give a safe DC shutdown if the inverter is powered down. Quite a bit of extra outlay but well worth it, in my view👍

Ive got a pdf version that has informal approval for the G99 application Ive just submitted. You can probably edit it with a pdf edittor or tipex. PM your email address and Ill send it through. If you want to donate a tenner to Alzheimers Society I can update the CAD source file with your details and produce a bespoke pdf from that. PM your email address, house address, MPAN number and description of the location of the PV isolator

+1 If distributed/micro/embedded generation isnt controlled we'll collectively start frying the grid were so reliant on.

Prioritising insulation and draughtproofing will likely give a better reduction as well as save money. Without a clear energy saving plan no one will be able to size heat demand so oversize rads and HP will likely go in costing the OP money

The ebay panels youve linked to look to be poly crystalline which lose their output a little quicker than mono but could still have good output if not too old. Ive just completed collecting components for 9.5 kw of panels split over 2 arrays. Its taken 3 months to get the right kit at the right price but just do your research and take your time. Likely youll need to shell out for a new inverter as cheap/secondhand G98 compliant inverters are thin on the ground.

Nice one. Personally, Id always want a choice of heat inputs so not wholly reliant on a single source. In the OPs position keep the boiler as primary source for now but have a separate coil for a future HP. When the HP goes in keep the boiler as a back up....who knows where hydrogen development is going in the future

Speak to Newark Copper cylinders, tell them what you want to achieve and let them design the cylinder. Id specify a coil each for the boiler, ashp and solar thermal to keep your options open. Also have 2 immersion bosses so you can have flexibility over where heat directly. Get extra insulation. May cost few £100 more but youve got flexibility in the future....who knows where fuel/energy cost and technology are going

At 9kw its quite a substantial system needing a G99 application. Our DNO charges £250+vat just to look at an application. Installers have got their admin and drawing to add to that. If 24 x panels are split over 2 pitches then scaffolding cost could be a fair bit. Assuming youve got a material schedule to go with the quote youll easily be able to work out material cost from online sellers. Our DNO told me a couple of weeks ago that they had received loads of G99 applications recently suggesting the trade is busy. If thats the case its likely a sellers market and you could be paying a premium just now. May be worth waiting til the autumn/winter when everyones forgotten about solar??

+1. I dont think many people appreciate the embodied energy/emissions wasted and caused by smashing something up and then buying something to replace it. On top of emissions is the environmental damage attributed to disposal and sourcing new raw materials.

Thats not my very recent experience with SPEN. We want to double our PV output from 16 to 32amp and need G99 approval. Emailed SPEN, someone phoned me back the next day, a couple of phone calls/emails later and we have an in principle agreement. Our transformer is under sized by modern standards so SPEN are changing that FOC. Weve a design verification fee to pay but seemingly nothing other than that. What came out in conversation was that they are currently getting lots of applications from trade installers who are submitting s***e, so they get rejected. You cant blame the DNOs for installers cutting and pasting the wrong info.

The timing was to get PV installed before the price cap got raised so there'd be no unfitted equipment lying around. The intent was for self install where people could or with supported install using roofer/spark. No PV installers as they all seem busy.

Having had the power off for 3 days over xmas in the 90s we've not been without a generator since. If youre on overhead line grid supply I think youd be nuts not to have a small back up generator. Predictions are storm intensity is likely to get worse and youve only got to look at what happened in the north of england/scotland a few weeks ago to realise that it takes time to repair storm damage leaving some people without power for weeks. With most storms happening in the winter when the suns not shinning theres a fair chance batteries may not be fully charged and very unlikely to keep the lights on for more than a day or two if the power goes off. £200 for a small genny seems a no brainer to me if youre on a vulnerable supply.

I dont know if it will???? A few months back I started a WhatsApp group of about 15-20 contacts who I knew could fund a PV install with a view to bulk buying as a group and hopefully enjoy some sizeable discounts. 1 person had already installed solar and no one else was interested!

If you want cheap/secondhand panels then ebay. If youre not bothered about matching panels then just buy as they come up at the right price/near by. Bare in mind that if youve got electrically mismatched panels, the lowest output panel will bring the output of the whole array down, unless wired in what could be complicated wiring if youve got a few variants of panel. Micro inverters or optimisers get round panel mismatch so a good solution if your collecting panels as you go.

If this install is on a garage roof and theres access to the underside of the roof mount micro inverters or optimisers in the garage roof where they are accessible anytime. Get the roofer to notch the tiles and feed the cables through a slit in the felt next to a rafter

MCS is only required if you want to get paid for export. With 2.4kwp and batteries youll likely only ever export significantly when youre on holiday but certainly not enough to warrant the premium an MCS installer charges