Dillsue

3.68kw/16a or less is still notified rather than applied for. Personally Ive not found the G99 process complicated if youre clear on what you want to do. If youre installing a second system with a battery then I beleive you can get SEG if its an MCS install. I think you also have to give up the deemed element of your FIT payments so that all export is metered and paid for via SEG. Youll need a smart meter to do that. If you hoping not to export much then you probably want to have a good think about giving up the FIT deemed payment It wasnt quite clear to me if you were altering your FIT system but I think youre very restricted in what you can do and risk loosing your payments if you fall foul of the scheme rules!

As I understand it Solaredge inverters require a minimum of 8 optimisers so probably not an option anyway unless you go for one of the smaller optimiser integrated systems you mentioned previously. I beleive Solaredge produce a tool that allows you to disable the safe 1volt output feature when comms to the inverter is lost. This allows you to use their optimisers with any inverter so not locked to a Solaredge inverter. Im not suggesting you go for a Solaredge system but my experience of the 2 SE systems we have is nothing but positive....so much so a 3rd SE system is going on my daughters roof in the next few weeks. If youre thinking of changing to landscape orientation on account of the shading from snow, consider how much snow you get in Cambridge, how long the snow persists for and how much generation youll loose for a couple of days of snow cover when your panels are generating next to nothing in the winter anyway

If youre getting FITs the original system will have been MCS installed and met with all the regs. Assuming thats the case youll either have an export limited inverter with a 16 amp export limit, or there would have been a DNO application in 2014 to export more than 16 amp... the predecessor to a G99 application. If youre adding another array and /or AC coupled batteries youll need to put in a G99 application to export(or potentially export) more than the 16 amps?? you already have. If you want to throttle the new array youll need a G100 application aswell to cover the export limitation device/system. All gets complicated above the 3.68kw/16amp limit!!

Exactly as you say, work out loss for each room then add them up. Factor in ventilation/draught loss and thats it done. If you can use MS Excel its very easy to do, otherwise its long hand on paper with a calculator. Using Excel allows you to easily see the impact of changing materials/thickness. A while ago Which produced some very good books on building and this one on Ebay 144467667935 explains the calculation process and gives U values for lots of differing materials in use up to the publication date. If youre planning on using newer insulation youll get U values from the manufacturer online.

If youre looking to expand the system onto your flat roof you probably want to get a bigger inverter or check the inverter linked to can handle the power input you may end up with. My personal preference would be an optimiser per panel so that a single optimser failing doesnt take out to much generation.

With a relatively small PV array, thats probably the best strategy with an easily accessible timer to so can tweak times easily if theres a bright/dull period forecast. Remember that in the winter when you need the HP most youll be generating the least and vice versa in the summer. Nice weather in spring and autumn should see usage vs generation a bit more balanced

That statement is correct but what youre missing is that a bigger power input will be required to drive the larger ASHP.....COP remains the same but power input and power output both increase in the same proportion to maintain the COP. Put the insulation and triple glazing back in and youre back to a 5kw pump still with the same COP but lower power input, lower cost and lower emissions

Google "solamax manual" and you find a comprehensive manual on ST systems including schematic system drawings. No "r" in solamax!

A typical residential punter puts circa 4/5kw on their roof wired to a 3.68kw export limited inverter. All they have to do is fill in a G98 notification form and send it to their DNO. No fees, no drama, easy peasy. As has been mentioned the G98 notification is straight forward to complete. As its a notification and not an application, so long as youve used a G98 compliant inverter they can't stop you having your PV. They may ask for clarification if youve made a mistake but that's the worst that is gonna happen

In my experience its straight forward dealing with the DNO, but you do need to know what it is youre asking them. In previous posts youve mentioned 20kw, 11kw and 3.68kw. Different rules apply depending on what you want to do. Have you actually looked at any of the forms? They are pretty straight forward. I dont really agree with your frustrations about controlling the public exporting to the grid. If it were a free for all, we'd have melted copper, burnt insulation and smouldering transformers all over the country, and no electric.

If you want to go down the route of an oversize system with export limitation then youll need to get permission from your DNO with a G99 application. If you propose an export limitation device or the DNO asks for one, then youll also need a G100 application. Both G99 and G100 aplications each have their own costs. On top of design verification fees our DNO wants £375+vat to witness an export limitation system. If you want more than the 3.68kw G98 limit then speak to your DNO as they may well be able to accomodate you generating more. Ours was very approachable and we seem to have informal agreement to have 2 x 3.68kw export. Hopefully get that formalised when they process our G99 application.

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.