FoxESS Community - Owners & Installers Forum

Hi All,

Thanks to William et al for setting this up. I've been hanging around the Facebook group for a while but it's time now to put my head above the parapet!

My setup is 16x JA405 Panels on a South-south-east facing roof, H1-3.7-E Inverter and 2 x HV2600 batteries...a third one is awaited but no idea when that may be coming. The Panels are supposedly optimised with Tigo TS4-A-O optimisers - I say supposedly because although I believe they are supposed to communicate to Tigo's cloud App I can't seem to find them...another question outstanding with the installer.

Looking at some of the systems everyone's installed I admit to feeling a bit jealous - particularly around battery capacity.

I've also been asking the installer for an upgrade to the Inverter (to 5 kW) - we have a Hybrid Volvo that charges at 3.7kW and as soon as it starts charging the Inverter is maxxed out and I start pulling from the grid to support any load from the house. It's incredibly frustrating to see the Inverter charging along at 4.5kW on a sunny day and still be pulling 0.5kW from the grid.

We're on Octopus Go (as of 6th October), and force charging the battery and car in the offpeak hours...I'm looking forward to seeing the bill!

I've also been playing with Home Assistant - I have to say that I knew nothing about HA but by watching William Eccles YT videos and reading the posts in the FoxEss facebook group I've managed to get a dashboard or two of sorts running. TBH, setting up HA is only really about the data reporting, but in time perhaps some automation will come but I have a very dumb house with only a few smart gadgets - EDDI, Zappi, and others are going to have to wait until I've got more money! HA is running on a virtual machine on Virtual Box on Windows 10, but at some point I really need to move to the Pi as the old Desktop is drawing almost 100w... it's a bit ironic to use nearly 2.4kWh per day just to see how much electricity you are consuming!

Anyway...that'll do as an intro. I'm not a prolific social poster but I will be listening!

Cheers,

Robin

Great intro & welcome.

Out of interest why did you go for a 3.7kW inverter and not a 5kW with 16 panels? Was it a DNO restriction?

Will,

Why 3.7 you ask? I suppose caveat emptor applies...I was so desperate to get solar installed before the summer (I really badgered the installer to get moving) and it was only just after the initial price rise. I'm sure I discussed the power needs with the sales people and then also with the engineers doing the survey but it appears that either between them or me the possibility that I might exceed 3.7kW at any time didn't occur...until it the system went in and I started to see the issue.

I have pointed out to them that sticking a 6.5kW array on the roof and then limiting what the inverted can put out to just 3.7 makes no sense, and there have been "helpful" noises about an upgrade, but nothing so far. It's interesting though because I have seen the panels put out 5 kW in the Summer when the battery is empty - the inverter is taking from Solar what it can, and putting the rest into the battery so it's not all wasted.

In truth, it's not a massive issue. The car takes just 2.5 hours to go to full, so the cost is really just an extra 0.5kWh or so when I'm charging off solar and the House is running on base load. I've got a full car and solar battery in the morning through Octopus Go but sadly, the weather in Shopshire for the next few months will probably prevent me from using solar to "top up " the car during the day.

Please let me ask a question back - the DNO restriction on export I understand, but doesn't the inverter have a software setting that would stop you from exporting more than 3.7? I mean, if the combined load in the house is 1 kW and the array is producing 5kW, can the inverter be throttled to ignore the 0.5 kW that it could export over and above the 3.7 restriction (assuming the battery is full, of course)? Would this mean I could upgrade to a 5kW inverter without having to get DNO approval?

Cheers,

Robin

I tend to go with a 5kW as standard because most ovens are 3kW and you'll find for most homes you'll be dipping into the grid a lot vs a 5kW inverter supporting a larger 5kW continuous discharge rate. Again not a massive issue but I'm interested why installer downsize the inverters so often when the inverter costs between a 3.7 and 5kW is sub £100 in most cases.