OK, let's spec this system.

[nowty]

Thanks Nowty, the inverter model is Sunny Boy 3600TL-21 so looks like I misremembered the 3.8 and it's 3.68kw.

Another alternative but unfortunately its pricey and difficult to find a UK installer is a system similar to mine (I did all mine DIY). You also need a Sunny Home Manager 2.0 which adds to the costs.

I say this because you already have a v21 Sunny Boy which is compatible with the Sunny Home Manger and Sunny Islands. The smallest Sunny Island 4.4M has a 3.3kVA grid output so should be compatible with the light tough G99 application and then you have a complete combined system with nice Sunny Portal monitoring and programming via a simple webpage for off peak grid charging.

If he was to install another PV system in the future (on the barn) would the system allow aother Sunny boy inverter/Sunny Island to be added to the same system and provide upto 7.68kW across the whole system i.e would it provide a simple way to extend the system on the same phase rather than require use of the other phase for the barn. Just thinking of possible future expansion and what might be the most flexible approach?

Yes I meant to add the Sunny Home Manager can take between one and three phases so the second phase could also go through it which would be an advantage if adding more inverters on the other phase in the future. I'm not quite sure how it handles the grid export with multiple phases though, I personally only use it with a single phase system.

[SafetyThird]

Ah that’s interesting. I was wondering if I could connect any new system to the battery pack if it was on a second phase.

Given that 6kw of solar, an DC inverter and doing mostly self install would still cost at least £3k and wouldn’t help that much in the winter, perhaps putting that £3k into a Ripple investment first would pay more dividends through winter months.

[nowty]

Ah that’s interesting. I was wondering if I could connect any new system to the battery pack if it was on a second phase.

Given that 6kw of solar, an DC inverter and doing mostly self install would still cost at least £3k and wouldn’t help that much in the winter, perhaps putting that £3k into a Ripple investment first would pay more dividends through winter months.

If I had the ripple wind farm and the cheap rate tariff deal several years ago my battery bank would not need to be as big as it is now.

But a lot of my lithium battery bank is cheap re-used faulty units bought at an average price of circa £100 / kWh. So my 10 x 4.8kWh units = 48kWh cost me be about £5k, but a lot of work involved.

In comparison my 8 x 2.4kWh Pylontechs = 19.2 kWh cost me £800 each, so that's £6.4k. They are slightly cheaper now but not much.

My gross battery size is 67.6kWh but I only use 45kWh of that capacity for safety and longevity.

£5.5k in ripple WT1 nearly covers all my current usage and my further £4.5k in WT2 will in effect give me a very large virtual grid battery with plenty of excess.

Its quite an interesting concept to compare the ripple wind turbines to a virtual grid battery.

[pudding]

After all the back and forth on my other thread, I'm now ready to actually spec and purchase a battery backup system. I've decided against the Victron setup simply because so many people talk about the noise the Multiplus 2 makes and, as the system is going to be indoors, noise is a major factor. I've also decided not to worry about additional PV etc yet. I can always add a hybrid inverter/battery/panels to the other phase of our split phase supply later, or perhaps put that money into investing in Ripple which may give better results in the winter. So, a simple AC coupled inverter and batteries with the ancillaries to connect it all and have a backup circuit to which I'll connect the house lighting circuits and one ring main that powers the office.

I'm planning to go with 4 x Pylontech US3000C batteries, to give me a battery size of 14kwh. Plenty to get started with and can be added to later as needed. The main choice now is the AC inverter. There's 3 I've been looking at: The sofar ME3000SP, the Solis 3Kw 5G RAI and the Luxpower ACS 3600.

The first two seem to have near identical specs with max charge/discharge of 3000w/60A and 3000w/13A for a backup circuit. The Luxpower has max charge/discharge of 3600VA/70 and backup output of 16A/3600VA, which looks like a better option if price is similar. I can't seem to find a price for the Luxpower on it's own, just with a battery kit.

Does anyone have comments/suggestions based on real world use for these inverters or any reason I shouldn't go for the Luxpower?

Hi all, perfect timing to join this forum and this thread in particular. I'm in exactly the same position here, with a 4kW system already with a FiT from about 7years ago. I'm looking at getting one of the 3 inverters listed for an AC coupled system and Pylontech batteries too, either 4xUS3000 or 3xUS5000, whichever I can get my hands on in decent time/price.

Like you say, specs are very similar for the inverters. I did notice though that the Solis only seems to use 1 CT clamp around the mains supply, whereas the SoFar uses 2, one around the mains and then one around pv output. Does this mean the Solis is missing some info or feature because of this? I havent got as far into details of the Luxpower yet, does that use 2 or 1 CT clamps for any particular reason?

My plan is also to install an extra 3kW of solar panels with its own inverter at the same time as batteries (G99 application being prepared I believe by electrician/installer so fingers crossed). So with the SoFar in particular, I'm assuming it'd be possible to use the PV CT clamp to place around the live AC cable from both existing solar panels inverter and new install, such that the SoFar would detect the total current from bothPV installs together, even though they would be 2 separate independent PV arrays with their own inverters? Would this be possible with the other 2 (Solis seems to only monitor mains current so not sure?)

Also, any clues as to where to source a SoFar inverter? I cant find stock anywhere in the UK, same as the batteries. Hoping that in a month that situation has changed.

Sorry for the hijack, hopefully not too much of a sidetrack.

[SafetyThird]

Hi and welcome to the forum, looks like we might be able to share the knowledge for our systems. The manual for the Luxpower inverter shows two CT clamps are supplied and it shows their connections on page 7 of the manual. https://luxpowertek.com/wp-content/uplo ... 1.0-03.pdf

Batteries are in short supply currently and late April/may seems to be when the next shipment arrives in the UK from what most sites are showing. Although, many places are saying they’ll only supply them as part of a system setup.

Hoping to hear back from some suppliers with quotes this week.

[pudding]

Thanks very much for the link. The Luxpower does look good and seems to be the best choice out of the 3, if prices and availability were similar. Now, where on earth can you actually buy one from though?! Same with the Pylontech batteries, I was looking at ITStechnologies, but their ETA's for preorder seems to have gone back a month now to start of June Happy to hear about any recommended installers, I'm mid Cornwall.

[Stinsy]

The sole UK distributor for LuxPower inverters is “Infinity Innovations” they use the “PV-PRO” trading name. Their website leaves something to be desired, but prices have previously been keen (25% cheaper than similar Solax/SoFar units).

Pylontech batteries have been in strong demand for a year or more. You can guess why! If one container-load is sold before it even gets here you have to reserve your batteries from the one after that. It is just a feature of the market. Tradesparky had a stock of US2000s for a reasonable price a few months back, they sold out fast. Bimble have some US3000s coming end-of-May. However the “new normal” is that you have to order this kind of stuff and wait for it to arrive. Prices are going up rather than down too.

[pudding]

Thanks for the info. Just sent an email to both Pv-Pro and Infinity, and my god, their website's are awful, so slow with database errors. All I want to do is buy the inverter!

Checked out Bimble but they seem to be only selling their Pylontechs as part of bundles or by adding to existing orders unfortunately. Looks like it might be 10% deposit and wait for ITS to get their next batch in June.

[SafetyThird]

Spoken to one local installer and they've quoted £7100 for the Luxpower ACS 3600 with 4 x US3000C batteries, including wiring/breakers etc and installation. They wanted me to order and then, when things are in stock, which they think will be about a month, they'd come and install it. I asked for someone to come and survey so they know what issues there may be or how I'd like it done and was told 'that's not how we normally do things' which I found somewhat surprising. They have said they'll see when they might have someone in my area who could pop in and take a look at everything but didn't know when that would be.

I'm not ordering £7k worth of gear without someone taking at look at the place and knowing how I'd like to install things. They said they just come and install and I asked them what battery brackets they use and was told 'we just stack them on the floor by the inverter' and I said that wasn't an option as then the front door wouldn't open. If they don't know what size additional breaker box would be needed for the EPS install etc, how can they know to turn up with the correct items on the day of install?

Think I'd like to chat with another installer before going that route. The also wouldn't quote supply only of the inverter, only installed systems with at least two batteries so no diy install that way.

Waiting for Energy Innovations to get back to me with some other local dealer information.

[Joeboy]

Spoken to one local installer and they've quoted £7100 for the Luxpower ACS 3600 with 4 x US3000C batteries, including wiring/breakers etc and installation. They wanted me to order and then, when things are in stock, which they think will be about a month, they'd come and install it. I asked for someone to come and survey so they know what issues there may be or how I'd like it done and was told 'that's not how we normally do things' which I found somewhat surprising. They have said they'll see when they might have someone in my area who could pop in and take a look at everything but didn't know when that would be.

I'm not ordering £7k worth of gear without someone taking at look at the place and knowing how I'd like to install things. They said they just come and install and I asked them what battery brackets they use and was told 'we just stack them on the floor by the inverter' and I said that wasn't an option as then the front door wouldn't open. If they don't know what size additional breaker box would be needed for the EPS install etc, how can they know to turn up with the correct items on the day of install?

Think I'd like to chat with another installer before going that route. The also wouldn't quote supply only of the inverter, only installed systems with at least two batteries so no diy install that way.

Waiting for Energy Innovations to get back to me with some other local dealer information.

You are right to be wary. Two red flags that I see.