Critique my solar quote!

Netexporter

If I was buying again, I’d request a Giv AIO unit, so it can output more power to run the oven + dishwasher + kettle + something else allll at the same time.

Yes, it would be worth getting a quote for the A-i-O for the islanding, especially if you are in a rural area prone to power cuts. Being able to output 6kW could also be a nice little earner during the power saving sessions - £24 per hour is not to be sniffed at!

richc1981

Waywardmike said:

I have an old FIT system and a couple of years ago was looking for an AC coupled inverter and battery to add to it.  I ended up with quotes for two systems one using Growatt and one using Givenergy much like yourself.  I knew nothing about either companies.  I really wanted a Givenergy system, the system looks better and I joined their Facebook  group and the app and UI seemed great, but they were having supply issues at the time and it was looking like ~6 months till I could get it installed. 

I'm massively impatient, so went with the Growatt, which I might add was significantly cheaper with a slightly bigger battery (~£1500 cheaper).  It's been installed now nearly two years and has been absolutely flawless.  I've had to do nothing, it was a bit of a learning curve understanding why it does what it does (if it drops under 10% it charges from the grid to 12% so it never goes flat etc..).  The App that comes with it is completely useless, bordering on unusable IMO, but others seem to not have a problem with it so that's probably just because I like to monitor closely.  I almost immediately switched to a 3rd party app with a Rasp Pi, which gives me complete control, almost real time updates, and stores all my data locally on the Pi so I'm not reliant on Growatt's servers which regularly seem to be down.  I finally managed to get a smart meter this year and am now on Octopus Go, and use WonderWatt which predicts the next day's solar output and then charges the battery to a set % in my cheap period accordingly.

I'm still a member of Giv's Facebook group, and in the early days I was like 'What have I done?' as they seem to be very proactive in app and software development, and the tech support appears unrivalled.  That being said, and I know a Facebook group is where people go to discuss problems but it does seem like the app and software and firmware are plagued by bugs and problems, so it looks like you'll probably need the tech support.

They have a real issue with measuring the state of charge (SOC) of their batteries which is somewhat fundamental, this appears better with their AIO product as it's not discussed as much but this may be because there's less of them out there.  As far as I can tell they're the only manufacturer which require calibration of their batteries.  This process requires fully charging the batteries (often using the grid at inappropriate times) and then fully discharging them, this is done at installation initially but as this seems to be the main fix for the SOC issue, people are having to do this regularly. This would annoy me no end as I don't have metered export so that would be energy paid for and then lost to the grid for me.

Maybe if I do encounter a problem with my Growatt and have to rely on their legendary terrible customer service I might feel differently but currently I feel like I've dodged a bullet.

Thanks for this.  I have seen similar reports of issues with the givenergy batteries.   Perhaps they have a much larger market share than growatt and issues are inevitable but it is a concern.  Conversely there seem to be fewer bad reports on growatt,  the installer I’m speaking to likes their stuff because it “just works”.  The ability to use 3rd party apps (are you using solar assistant) is a bonus for me.

Waywardmike

richc1981 said:

Thanks for this.  I have seen similar reports of issues with the givenergy batteries.   Perhaps they have a much larger market share than growatt and issues are inevitable but it is a concern.  Conversely there seem to be fewer bad reports on growatt,  the installer I’m speaking to likes their stuff because it “just works”.  The ability to use 3rd party apps (are you using solar assistant) is a bonus for me.

Yep, Solar Assistant, probably the best £50 I've spent.  I have it running on a Pi Zero 2 W (£15), and it's been great.  Initially it didn't have as much functionality for my inverter but loads has been added since, and it now has everything I need. I never look at ShinePhone anymore.

I think it's been mentioned before but it's not very cost effective if you want to expand the system.  I'd love another 6.5kWh battery but at around £3000 it'll never be worth it financially.  The alternative would be to get rid of the battery and buy a couple of Pylontech US5000's, I'm led to believe they work with Growatt inverters, but that seems a bit drastic.

richc1981

From further discussion with installer they can do 10kwh of growatt AXE batteries for same price as 8kw of givenergy.  I reckon that would see us through 9/10 days with some sensible load shifting.  

Solar assistant looks great, plus it seems can integrate with home assistant and run it on a wall tablet or similar.  

ecraig

You reckon a 10kwh battery fully charged would last you 9 or 10 days!? Your usage when it clouds over or goes dark must be ultra low. 

there are people on this forum better placed to give you better thoughts than me, but… why the battery?

My pv array is much smaller than your proposal at 4.8kwp and my growatt battery is 6.5kwh, but my battery will be down to 20% or less in winter, even when I fully charge it until 0730 from the grid each day from 0030.

I might be misinterpreting your message, but I don’t see why you’d bother the expense of a battery. 

Alnat1

I took the comment to mean the 10kWh battery, recharged each day, would last them on most days, 9 out of 10 days, not that it would run the house for 10 days on 1 charge.

richc1981

ecraig said:

You reckon a 10kwh battery fully charged would last you 9 or 10 days!? Your usage when it clouds over or goes dark must be ultra low. 

there are people on this forum better placed to give you better thoughts than me, but… why the battery?

My pv array is much smaller than your proposal at 4.8kwp and my growatt battery is 6.5kwh, but my battery will be down to 20% or less in winter, even when I fully charge it until 0730 from the grid each day from 0030.

I might be misinterpreting your message, but I don’t see why you’d bother the expense of a battery. 

Ha yes some terrible grammar there, apologies I meant that it would meet our requirements for 9 out of 10 days. 

I have decided to forgo the battery for now and see how I get on with the solar with some sensible load shifting to take advantage of any surplus or use the cheap overnight ev tariff rate.  

I think I will go for the growatt. I’m not bothered about the app as i will use solar assistant.  I have a 10 year warranty on the installation so if it breaks I’ll be dealing with the uk installer or if they are no longer around, the insurance backed guarantee, failing that my credit card company.  Growatt customer services would be the last resort.

I can see the givenergy support is good but then maybe it needs to be given how many people are having problems?  I’ve joined a couple of GE Facebook groups and there are long standing problems with their batteries which they seem unable to resolve.  

ecraig

If you’re going to save money now by removing battery, have you maximised the roof?
could you use the cash and have more panels instead?
I love having a battery, but I sort of wish I had more panels on my roof now - I could fit 24 on my roof and wish I opted for more. 

BTW, solar assistant looks great, but the growatt app isn’t that bad.
its a bit weird and takes some getting used to - ie, you change your times to import from the grid, press enable and it’s done. When you view that part of the app it says disable instead of enable next to the time you’ve previously enabled.
youll learn to quickly accept the nuances. 

Screwdriva

ecraig said:

If you’re going to save money now by removing battery, have you maximised the roof?
could you use the cash and have more panels instead?
I love having a battery, but I sort of wish I had more panels on my roof now - I could fit 24 on my roof and wish I opted for more. 

Forgive me if my memory fails me Craig but I believe you have a SolarEdge inverter paired to the Growatt battery? You should easily be able to add 4-6 more panels on the existing inverter if you don't "clip" during June/ July. Or you could sell on the inverter and "upsize" with the existing system as is (warranty will transfer to the new owner). 

Re: Growatt, I've probably said enough but thought it best to share my favourite anecdote about the brand, from a veteran PV installer, Dom. Hope you have a better experience!  

ecraig

Screwdriva said:

Forgive me if my memory fails me Craig but I believe you have a SolarEdge inverter paired to the Growatt battery? You should easily be able to add 4-6 more panels on the existing inverter if you don't "clip" during June/ July. Or you could sell on the inverter and "upsize" with the existing system as is (warranty will transfer to the new owner). 

4 to 6 and I’ll clip a lot in the summer with the 3680 inverter.
i either go heavy with an extra 8 to 12 with a larger inverter than I have, or I go with an extra 2 or 3 panels with existing inverter. Still with some clipping, though.

It’s definitely a thought I am considering, but might not be a job till 2025 in all honesty.

My opinion is that the OP should definitely maximise the roof if they aren’t already.