Any users/installers of GiveEnergy inverters?

[puffernutter]

Pre-amble
About 3 years ago I had a solar power system installed on the front roof with GiveEnergy inverter (GIV-HY3.6) and 8kW battery. I have no issues with what I have, just with the way energy prices are increasing I'm looking to sweat my assets a bit more! I have found an installation manual but no "users manual" as such. Looking at the quote we had, the roof had 9 390W PV panels arranged in two strings (5 and 4). However, looking at the inverter there are only two cables coming in and the dashboard shows low volts and no current from string 2 (so I assume that is noise) and in fact I only have 1 string of 9. That could be very beneficial.

The question
I am fortunate in having a large area of roof on the garage that is south facing and not shaded, ideal for more PV panels! The inverter is 3.6kW, but it also states that the maximum input is 17A/string, so it seems I could add a second string. The bad news is that the garage is quite a way away from the house, but if I spec the cable from the PV array (max 600v and 17A) to achieve a minimum volt drop (which I know I have seen somewhere) is there any reason that I can't just plug another string of 9 PVs into the inverter?

As long as I don't exceed the 17A per string I should be OK?

Cheers

Peter

 

[gaz1]

are you set at the rateable value that is being fed to the main grid as any more to the grid wont be paid for or will be blocked

if your doing it for yourself then you would need the whole system again and then feed into your system or feed it into something else

heating / charging a car

im not sure if you can upgrade those solar panels either something id like to do myself as with new tech i would like to upgrade those panels for better panels that produce more electric

so yours are at 390w and the newer ones are better but with solar panels failing on certain solar emitors the value is decreased by years of use therefore your panels may only produce 2/3rds of the rateable output value whilst newer solar panels would still produce more output than what you have already installed

 

[drjim]

How far away is far away?

If you have a pair of MC4 connectors unused on your inverter then you are ready to roll, just connect an array up.

It will already have an MCS certificate so you can apply for an export rate of 15p/Kwh from your supplier, and it should all pay for itself reasonably quickly.

Rails and panels are cheap, £1k will get you 4kwp as long as far away isn't a mile 4mm cable should be OK, you can upgrade to 6 if you like, but you can go 50m away without too much trouble.

City plumbing is probably the go to.

 

[puffernutter]

@gaz1 - thank you for the comments - some more background. As @drjim has identified, this was professionally installed and I have a MCS certificate and a spare set of inputs. I know that panels degrade, but these are only 3 years old. They are on the roof of the house and are not ideally located, but the house points the way it does! We get most generation in the afternoon. This is an old 3 bedroom terrace with four adults (2 parents, two children) and 6 dogs. We have a high baseload of between 1.1 and 1.3kW (we have tired our best to get it lower). If we are lucky in high summer the battery may get to 40 or 50% of an afternoon, the idea with the new PV array on the garage is to get that to 100%. If the battery is full, the system will heat the hot water (we have an immersion) if the water is hot, we can export. So far we have never heated any water, let alone exported!

@drjim - I have measured it now and it is around 60m from the end/start of the string to the MC4 connectors. I was going to use the same panels as on the roof as I know they are compatible and they are around £77 plus VAT each, I'll get a further 9. I've now found the datasheet for the inverter and the max PV power is 7.5kW.

I am happy installing all the panels, running the wires and connecting to the inverter, as far as I can see, all the clever s/w bits is to do with WiFi and USB, when connected, it should just start working without needing and software mods/upgrades.

Thanks for the very useful replies

Cheers

Peter

 

[drjim]

You can get higher powered panels for less nowadays, I have these on my shed roof

LONGi Solar Hi-MO 6 425WP Full Black PV Module LR5-54HTB-425M

LONGi new generation HPBC cell technology opens a new chapter in the mass production of high-efficiency cells and continues to lead the reform of the industry.The efficiency of LONGi HPBC cells exceeds 25.0%.The efficiency of the PRO version HPBC cells exceeds 25.3%. LONGi Hi-MO 6 is a product...

www.cityplumbing.co.uk

But going with the same does have an element of logic to it.

 

[J1nx]

What voltage are you seeing on string 1? Around 300Vdc max would indicate 9 series.

The panels will almost certainly be producing 90+% of new output. 390W panels are unlikely to be worth replacing financially.

You shouldn’t have an issue installing an additional string but you are near capacity at full production anyway. You won’t exceed 17A with any normal panels. Watching the maximum voltage is more important.

You will gain significantly in overcast days though.
Can you point the panels differently to the existing ones, SE or even ESE? This will likely yield more production and lengthen the hours of production.

 

[Gareth J]

As you've found, there are lots of different limits, none of which should be exceeded.

If you can stick within them, the only reason not to modify your setup is that in doing so, you'll unfortunately void your MCS certification.

There are quite specific ways in which you can modify and retain MCS, please look into them first.

If you don't, it's quite possible for whoever is paying you for export to notice a change, either an over generation from smart export data or an implausibly large increase in export compared to historical/local data.

However, you do have a battery and could, with some export limitation from the inverter, use it to mask any changes and hope to stay under the radar.

I've a part roll of 6mm DC cable floating around. Let me know length requirements if you go for it and need to use 6mm.

 

[drjim]

That would be the case with an old feed in tariff system but this being newer shouldn't be an issue.

 

[gaz1]

The question
I am fortunate in having a large area of roof on the garage that is south facing and not shaded, ideal for more PV panels! The inverter is 3.6kW, but it also states that the maximum input is 17A/string, so it seems I could add a second string. The bad news is that the garage is quite a way away from the house, but if I spec the cable from the PV array (max 600v and 17A) to achieve a minimum volt drop (which I know I have seen somewhere) is there any reason that I can't just plug another string of 9 PVs into the inverter?

ok back to you and since the garage is in full southern sun then id fit new panels on there and disconect the house to something else

make sure the garage goes to the grid whilst the house panels feed me

thats if you want full solar generation using the southern facing roof and thats if you can fit the same size panels or new panels generating the same

 

[puffernutter]

As you've found, there are lots of different limits, none of which should be exceeded.

If you can stick within them, the only reason not to modify your setup is that in doing so, you'll unfortunately void your MCS certification.

There are quite specific ways in which you can modify and retain MCS, please look into them first.

If you don't, it's quite possible for whoever is paying you for export to notice a change, either an over generation from smart export data or an implausibly large increase in export compared to historical/local data.

However, you do have a battery and could, with some export limitation from the inverter, use it to mask any changes and hope to stay under the radar.

I've a part roll of 6mm DC cable floating around. Let me know length requirements if you go for it and need to use 6mm.

To date I have exported zero! One option is to get the same company to add to the system, but when I can do a lot of the legwork myself it seems daft to pay someone to do it. A bit like "Part P" if I can do the work and pay someone to check it and then do the final connection and sign it off, that would be great.

The data is confusing, the inverter has a maximum PV input of 7.5kW but and output of 3.6kW. So with two strings of 9 panels (if, for example I use the same panels) then I will be within those limits. All I really want to do is make the best use of the solar power and as the battery rarely gets past 40-50% on a sunny day (because of our base usage) if I can get it to 100% on a sunny day, that will be quite a saving. Heating the hot water is a bonus and then see about exporting, although we have no arrangement to export as yet as we have never got close to needing to!

Peter

 

[Gareth J]

That would be the case with an old feed in tariff system but this being newer shouldn't be an issue.

Still potentially valid with SEG, though as payments will be so much less, I guess they may be less inclined to check. But yes, if as in this case, export is always very low, probably nothing to worry about.

 

[Gareth J]

To date I have exported zero! One option is to get the same company to add to the system, but when I can do a lot of the legwork myself it seems daft to pay someone to do it. A bit like "Part P" if I can do the work and pay someone to check it and then do the final connection and sign it off, that would be great.

The data is confusing, the inverter has a maximum PV input of 7.5kW but and output of 3.6kW. So with two strings of 9 panels (if, for example I use the same panels) then I will be within those limits. All I really want to do is make the best use of the solar power and as the battery rarely gets past 40-50% on a sunny day (because of our base usage) if I can get it to 100% on a sunny day, that will be quite a saving. Heating the hot water is a bonus and then see about exporting, although we have no arrangement to export as yet as we have never got close to needing to!

Peter

View attachment 486469

Does indeed look like you can just plug in a second string. It's a higher DC input Vs AC output than most inverters. But presumably to fit in with the 3.68 kW limit.

Don't worry about using the same panels, use whatever fits; both physically and capacity wise and is a reasonable cost/quality.

 

[drjim]

Any export would need a smart meter but would just get paid as it was exported.

My little 2kw system occasionally leaks out to the grid even with a solic 200 connected to the immersion, I'm looking to add a g98 3.6Kw inverter with batteries but will be aiming to self consume all of it.

 

[Wolf1608]

I had a Givenergy system at my last house. As its a 3.6 hybrid it will have already been limited to 3.6kwh export limit in the inverter. Adding extra panels will increase your potential charge rate of the batteries, up to its max rate. Max battery charge rate was 2.6kwh if I remember correctly. In peak generation conditions the inverter will first charge the battery, then export but only up to the max 3.6kwh limit. The rest is shed/ lost ( never did understand how it did that. Something to do with voltage or something).
Only issue with Givenergy stuff is the warranty, they do log and photo every install.

 

[puffernutter]

A quick update. I have approached two local installers of Givenergy systems. One replied, I sent them my specification and then nothing. The other came back suggesting that I needed another inverter, ID2 meter. LORA and all sorts of stuff. He reckoned that with a 3.6kW inverter and 3.6kW on the roof a second string will max it out. I responded by saying that the roof panels only gave most power in the afternoon and even then my 8kW battery never got beyond 50%, so there must be some spare capacity. The new panels on the garage roof will face south and be unshaded, so they can start generating early in the morning and when the battery is full, I have solar boost to my water heater.

Since then, silence.

I'm not looking to power Wiltshire, just make best use of the capacity of my system and I reckon this second string will do that!

In the mean time I have bought 10 second-hand "tubs" (with all the fixings) to go on the garage roof at 1/2 full price and I reckon with 200m (2 x 100m reels) of cable, a bunch of connectors, 9 panels (maybe 8) and an isolator I will be around £1500, so it's worth giving it a go, with or without a certified installed. After all, it's just attaching 2 cables. what could possibly go wrong......

 

[gaz1]

to me they have been badly installed and shouldnt have been installed unless the owner wanted them to continue to install them knowing that they would not give the power output needed to do a full charge

my roof gets full sun in summer but not in winter east / west house but the garden gets full southern sun

you might get a little bit more than you bargained for if they do check your install as it would be classed as modified even though id probably do it myself

with this in mind you maybe refused to be able to supply the net so my advice here is look at charging and powering your own system up as this could be on the cards theres no way im going to powering the net for nothing and letting them have power for free just because they dont like it

 

[Farside]

A quick update. I have approached two local installers of Givenergy systems. One replied, I sent them my specification and then nothing. The other came back suggesting that I needed another inverter, ID2 meter. LORA and all sorts of stuff. He reckoned that with a 3.6kW inverter and 3.6kW on the roof a second string will max it out. I responded by saying that the roof panels only gave most power in the afternoon and even then my 8kW battery never got beyond 50%, so there must be some spare capacity. The new panels on the garage roof will face south and be unshaded, so they can start generating early in the morning and when the battery is full, I have solar boost to my water heater.

Since then, silence.

You obviously know enough about the setup so they can't baffle you with boolshine, and just drop the call.

 

[J1nx]

to me they have been badly installed and shouldnt have been installed unless the owner wanted them to continue to install them knowing that they would not give the power output needed to do a full charge

my roof gets full sun in summer but not in winter east / west house but the garden gets full southern sun

you might get a little bit more than you bargained for if they do check your install as it would be classed as modified even though id probably do it myself

with this in mind you maybe refused to be able to supply the net so my advice here is look at charging and powering your own system up as this could be on the cards theres no way im going to powering the net for nothing and letting them have power for free just because they dont like it

The DNO is not concerned with the panels, not at all. The inverter is all that matters. G98 will not be removed.

Not sure you can accuse the installers of a bad install because the roof they fitted on isn’t due south.
Infact two orientations can be beneficial under a G98 install, as Puffernutter is thinking, longer periods at max limited output is achievable. Batteries also prefer longer, slower charges rather than short high current charge rates, more efficient and less degradation.

 

[Gareth J]

A quick update. I have approached two local installers of Givenergy systems. One replied, I sent them my specification and then nothing. The other came back suggesting that I needed another inverter, ID2 meter. LORA and all sorts of stuff. He reckoned that with a 3.6kW inverter and 3.6kW on the roof a second string will max it out. I responded by saying that the roof panels only gave most power in the afternoon and even then my 8kW battery never got beyond 50%, so there must be some spare capacity. The new panels on the garage roof will face south and be unshaded, so they can start generating early in the morning and when the battery is full, I have solar boost to my water heater.

Since then, silence.

I'm not looking to power Wiltshire, just make best use of the capacity of my system and I reckon this second string will do that!

In the mean time I have bought 10 second-hand "tubs" (with all the fixings) to go on the garage roof at 1/2 full price and I reckon with 200m (2 x 100m reels) of cable, a bunch of connectors, 9 panels (maybe 8) and an isolator I will be around £1500, so it's worth giving it a go, with or without a certified installed. After all, it's just attaching 2 cables. what could possibly go wrong......

I intuitively guessed that two 3.6 strings on a 3.6 inverter would overrate the inverter too. Your specification would seem to suggest otherwise though. If you're confident that's correct you should be good. Especially, as you mention, panels are in different orientations.

It sounds like you have enough information to give it a go. Is you shed a tin roof? That's a really cheap/quick installation if so. No rails required.

What could possibly go wrong? Well, you could easily put 400VDC across your chest for one thing. Think carefully about the order in which you wire things. Never work on anything live, never plug/unplug anything under load. A pair of 1000v gloves and use as a last resort.

 

[puffernutter]

to me they have been badly installed and shouldnt have been installed unless the owner wanted them to continue to install them knowing that they would not give the power output needed to do a full charge

my roof gets full sun in summer but not in winter east / west house but the garden gets full southern sun

To be fair, this is the only roof (on the house) that had enough area and it gave us 9 panels, the rear has a large dormer which uses up most of the available space. Also, despite our best attempts we have (what I suspect) is a high, what I call, baseline usage of around 1.2-13.kW (that is with nothing "extra" turned on and what you will see during the night. When you add kettles, cookers, washing machines, you can soon see that even with 3.6kW being generated (absolute maximum) we lose 1.3kW to our load so what goes in the battery is reduced. If I can have a more consistent power generation through the day, even if the inverter has to "loadshed" I reckon we'll be OK. Plus, further back up the thread I found a specification for this inverter that showed it could cope with 7.5kW PV power, so I reckon we're good!