Solar panels and battery - any real world recommendations?

Do you have MCS for your old panels?

If yes, how will they know you installed extra panels without MCS?

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I got a quote of £6350 for 14 Aiko Neostar 2S 460W panels and roof installation - this is just panels and connection to my existing inverter. Do you think that's fair? I can't really get multiple quotes, as it seems that the companies with MCS have plenty of business currently and most don't want to deal with someone who has existing equipment.

Also it looks like Aiko Neostar 3S+ 470W panels are already available in UK. Do you think it's worth getting 2S now or wait a bit and potentially pay a bit more for 3S+? The price difference looks to be minimal - https://www.solartradesales.co.uk/solar-panels/aiko-solar-panels .

BTW doesn't it make you angry that in UK to get panels worth £1000 installed on a roof one has to pay £6350? If there were more companies with MCS and more competition surely the prices would be lower.
 
rtho782 said:
I have 30x445W bifacials on my main roof, connected to a Powerwall 3, and have just self fitted 14x645W Aiko bifacial panels to the garage roof/wall between garage and house.



Those are running on a 6kW Solax inverter, and all have optimisers.

I'm on IOG, about 99% of my import is at 7p, and exporting as much as possible for the 15p export.

Tempted by E.On but I'd need more battery to shift my usage to 6.7p, and as the garage is self install it doesn't have MCS, so they would accuse me of "brown export" and cut my payments.
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Interesting setup. Did you have to do anything to get the two talking or have they just played nicely?
 
Mercenary Keyboard Warrior said:
Interesting setup. Did you have to do anything to get the two talking or have they just played nicely?
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I followed the PW3 installer guide for DC+AC attached solar, and connected it to the "backed up" side of the gateway 3, so the Solax will keep running in an outage.

I had to acquire another Tesla CT clamp (a nightmare, as they won't sell to non-MCS persons), as my first CT was being used for site import measurement, as I have two EV chargers that don't go through the gateway.

I then discovered that it's not possible with PW3/GW2 to use L1 as a vRef for CT2 or CT3, and I'm on a single phase supply, so I connected a wire for vRef from the Solax MCB to L2..... Which most definitely does not comply with any design guidelines.

But, the end result is that it works perfectly. The PW3 doesn't have an export limit configured anyway, but it accounts for the Solax in it's generation stats etc. I monitor it all with Home Assistant and read the tigo and Solax values into there, and find the Tesla production by subtracting the solax from the reported tesla.
 
rtho782 said:
I followed the PW3 installer guide for DC+AC attached solar, and connected it to the "backed up" side of the gateway 3, so the Solax will keep running in an outage.

I had to acquire another Tesla CT clamp (a nightmare, as they won't sell to non-MCS persons), as my first CT was being used for site import measurement, as I have two EV chargers that don't go through the gateway.

I then discovered that it's not possible with PW3/GW2 to use L1 as a vRef for CT2 or CT3, and I'm on a single phase supply, so I connected a wire for vRef from the Solax MCB to L2..... Which most definitely does not comply with any design guidelines.

But, the end result is that it works perfectly. The PW3 doesn't have an export limit configured anyway, but it accounts for the Solax in it's generation stats etc. I monitor it all with Home Assistant and read the tigo and Solax values into there, and find the Tesla production by subtracting the solax from the reported tesla.
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It was the vRef I was intrigued about as from what I heard people doing basically what you have done end up with inverters competing.
If it works it works I guess :D
 
Mercenary Keyboard Warrior said:
It was the vRef I was intrigued about as from what I heard people doing basically what you have done end up with inverters competing.
If it works it works I guess :D
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So if all my non-backup loads were going through the gateway I wouldn't need to worry as I could use CT1 for solar import, but as I have 2 EV chargers I could draw 64A from non-backup and apparently GW2 only supports 32A in this way.

So yes, needed to use CT2. There isn't a scenario I can see that would cause current to flow on L2, as the vRef wire goes from the MCB to the backup side of L2, and nothing else is connected to L2, so it solves the vRef problem (there is now 240V on L2) without any actual current flowing.

The "real" fix is to have one of the new Tesla Remote Meters but honestly it was enough hassle talking an MCS installer into providing a CT, let alone one of those.
 
Johnson9 said:
Do you have MCS for your old panels?

If yes, how will they know you installed extra panels without MCS?

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I got a quote of £6350 for 14 Aiko Neostar 2S 460W panels and roof installation - this is just panels and connection to my existing inverter. Do you think that's fair? I can't really get multiple quotes, as it seems that the companies with MCS have plenty of business currently and most don't want to deal with someone who has existing equipment.

Also it looks like Aiko Neostar 3S+ 470W panels are already available in UK. Do you think it's worth getting 2S now or wait a bit and potentially pay a bit more for 3S+? The price difference looks to be minimal - https://www.solartradesales.co.uk/solar-panels/aiko-solar-panels .

BTW doesn't it make you angry that in UK to get panels worth £1000 installed on a roof one has to pay £6350? If there were more companies with MCS and more competition surely the prices would be lower.
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They won't know, and Octopus pay me for all my export.

However it seems that EOn have no life, run the tariff as a loss leader, and so compare your export to your predicted generation, and accuse you of "brown export" from battery if export exceeds predicted generation.

Obviously my generation exceeds my predicted generation, so not worth the hassle!
 
rtho782 said:
11.04kW
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So you are capped well below they potential peak of all your panels for export, but having those garage panels in the autumn/winter would really help your generation. If Octopus are paying you for all the panels I'd just stick with that tbh.
 
Johnson9 said:
I got a quote of £6350 for 14 Aiko Neostar 2S 460W panels and roof installation - this is just panels and connection to my existing inverter. Do you think that's fair? I can't really get multiple quotes, as it seems that the companies with MCS have plenty of business currently and most don't want to deal with someone who has existing equipment.

Also it looks like Aiko Neostar 3S+ 470W panels are already available in UK. Do you think it's worth getting 2S now or wait a bit and potentially pay a bit more for 3S+? The price difference looks to be minimal - https://www.solartradesales.co.uk/solar-panels/aiko-solar-panels .

BTW doesn't it make you angry that in UK to get panels worth £1000 installed on a roof one has to pay £6350? If there were more companies with MCS and more competition surely the prices would be lower.
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Sorry, realised I didn't reply to the second half of your post. Yes, MCS is a scam. A private organisation with no basis in statute that are a relic of the FIT scheme, they still manage regulatory capture and therefore hold export payments via SEG to ransom. They insist on "certifying" everything down to screws, and add little to the whole process, as they certainly don't step in on dodgy installers.

Nothing legally stopping any competent spark installing solar, but **** your export.

This is a recurring issue in the UK. We go "Zero % VAT! We're helping renewables!!" but then it only applies when you pay a >20% margin to some company that is itself being held to ransom by MCS, who are rent seekers.

Meanwhile, France just sell panels at 0% VAT.

It's not a green subsidy, it's a "random small business and MCS corporation" subsidy.
 
Journey said:
So you are capped well below they potential peak of all your panels for export, but having those garage panels in the autumn/winter would really help your generation. If Octopus are paying you for all the panels I'd just stick with that tbh.
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Yes yes, capped, I am definitely capped ;)

Octopus use smart reader readings to pay me for whatever I export. -£280 this month.

Current strategy is that at 0630 we discharge to grid at max rate to 50% battery. During the day we maintain this (staying at 50%), so excess solar flows into battery, and out when a cloud comes out. Then at 1900 onwards we switch to not exporting, and the battery is charged overnight.

If at any point in the day the import rate goes up from 7p, we switch to self consumption mode with a 5% backup reserve, where we'll avoid export (unless we're already charging battery at 5kW, current max) and avoid import (discharging down to 5% if required).


On some recent days I've generated 150kWh and exported 140kWh or so.
 
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rtho782 said:
Yes yes, capped, I am definitely capped ;)

Octopus use smart reader readings to pay me for whatever I export. -£280 this month.
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Slightly on/off topic, was reading a great investigation that if all the NIMBY complainers in the towns and villages who moaned about solar panels being installed in fields, put panels on their rooves instead, they would need 80% less solar farms across the UK. One of the biggest complaints is the farms don't reduce their electricity costs, but then they refuse to have panels which would, because why should I do it attitude. :D
 
Journey said:
Slightly on/off topic, was reading a great investigation that if all the NIMBY complainers in the towns and villages who moaned about solar panels being installed in fields, put panels on their rooves instead, they would need 80% less solar farms across the UK. One of the biggest complaints is the farms don't reduce their electricity costs, but then they refuse to have panels which would, because why should I do it attitude. :D
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The ones that amuse me most are those that moan about nearby fields having panels "but muh views" whilst covering their house in them.

Suck it up. If you want the field to be nothing but grass, buy it, and mow it.
 
rtho782 said:
Tempted by E.On but I'd need more battery to shift my usage to 6.7p, and as the garage is self install it doesn't have MCS, so they would accuse me of "brown export" and cut my payments.
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Eon won't take you on their domestic tariff with an array over 15kw anyway. You'd only be on their basic seg being paid 3p.
 
rtho782 said:
Sorry, realised I didn't reply to the second half of your post. Yes, MCS is a scam. A private organisation with no basis in statute that are a relic of the FIT scheme, they still manage regulatory capture and therefore hold export payments via SEG to ransom. They insist on "certifying" everything down to screws, and add little to the whole process, as they certainly don't step in on dodgy installers.

Nothing legally stopping any competent spark installing solar, but **** your export.

This is a recurring issue in the UK. We go "Zero % VAT! We're helping renewables!!" but then it only applies when you pay a >20% margin to some company that is itself being held to ransom by MCS, who are rent seekers.

Meanwhile, France just sell panels at 0% VAT.

It's not a green subsidy, it's a "random small business and MCS corporation" subsidy.
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Don't think you will find many with particularly good words for MCS, from consumers to installers.
There is clearly a need for something but its not in the form MCS is in right now.
 
Mercenary Keyboard Warrior said:
Don't think you will find many with particularly good words for MCS, from consumers to installers.
There is clearly a need for something but its not in the form MCS is in right now.
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Yeah, the bit that gets me is the whole "panels must be 400mm from roof edge" bit. I got so many people initially telling me how my garage didn't comply with "regs" (read: rules of a private organisation) and would obviously fly off into the distance at the first gust of wind (it's pretty sheltered, basically in a courtyard), and how I'd have RAIN on my head if I stood near the edge of the building (if it's raining, I'm going inside mate).

I wonder how many people have had far fewer panels than they could have had due to this.
 
200sols said:
It'll be obvious to them you're exporting more they actually do seem to check. Also technically you may be liable for taxes if you are generating so much more than your house consumes.
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I am aware. I pay tax if I generate more than 120% of my annual consumption. I probably actually don't, two EVs, I have a server rack using 1kW 24/7, and two 9kW ASHPs to heat the house in winter.

That's not to say I only export 20% of what I generate - I export everything I can and then import later. But the rules are that it's tax free if I generate less than 120% of my annual consumption, not that I only export 20% of my generation. Pre-solar, Consumption was about 24MWh a year.
 
200sols said:
Eon is trialling a system similar to Octopus so regarding export so it may change in the future. One other thing with Eon is brown export, if you export from your battery all the time and export more than your MCS certificate expected generation they have been querying it. Obviously people dumping batteries in the late evening and then topping up at cheap power just after is not good for them or the grid. I'd like to see a system reward us for exporting like that during the peak period but that's another story. One thing for the people who force export batteries to be aware of if considering the switch.
I signed up on V6 a few months ago and recently switched to V7, lower standing charges for me. The fixed rate and specifically allowing non EV people is a big plus over Octopus for me.
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Was thinking about the brown export thing earlier.
Surely they can just look at the timings rather than comparing to vs MCS cert.
My cert is clearly well under from last two years, like 20% under, thus year at this rate far more.

I mean anyone exporting serious amounts of solar in the UK after 9pm is clearly not doing so from excess generation.

Have you got some links to it, assume its forums or something, I am intrigued. :)

I mean for me I do my export at 10pm until 12pm thats enough to take what could be a 90% full batt to a low teens batt.
I could move that earlier and spread it out more but its just easier to do it later.
Right now no incentive to start earlier but I could easily do so.

Think it was Aus I saw where export above a certain amount outside certain hours was penalised.
They have a much larger issue with excess household solar at certain times in the day than us for obvious reasons.

I hadnt thought, or forgot, so if/when I switch to Eon I am going to have to dig all the paperwork out again!?
 
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