I think you have to be prepared at least for Symbio going bust in September or over winter. 

Their issues with OFGEM have been going on for sometime regarding financial information and a final order was proposed in August. I wouldn't personally be banking on them surviving the winter. 

https://www.ofgem.gov.uk/publications/symbio-energy-final-order

Although separate, their painful customer service reviews can't be helping matters. 

@batalto I'm behind the curve here - only just realised that there are EV tariffs which are less than normal off-peak ones. How does the supplier differentiate between your use for EV charging and other uses overnight?

@mike-patrick I've only seen EDF which use a specific charger. The rest seem to do it by making the tariff at midnight to very early so people don't have many uses. I'm switching to Octopus Go and they don't have any way to check, but they state you can use whatever you want during the time.

@mike-patrick 

@batalto my setup is as follows :

12 x JASolar 455w Panels (5.46kWp south facing array) Enphase Microinverters IQ7+, Lux AC ESS 3.6kW, 2 x 2.4kwh = 4.8kWh Aoboet Battery storage, Lochinver far North, west coast of Scotland. What I see is the array clipping out at 3.5kWh from the potential 5.46. This is due to the inverter only giving me 3.6kw from the array but it can also add the battery storage so if I use my Shower which is the most energy high usuage device I have (circa 8kwh I guess) then I can power it via solar and battery up to around 7kwh. The batteries are the thing that I wish I had got more of as I think having a 10kwh battery storage would make me very much self sufficient with regard to usage and I know that the solar arrange would charge them easy during the day to full capacity but even then I could recharge at night if I know the weather is going to be bad the next day etc. I think ill add an iBoost to my hot water tank and have been looking at the Mixergy water tanks as a replacement for my current one. It appears to be very efficient and allows for my solar PV power. WWW.mixergy.co.uk   I’ve added the link purely for information its not an endorsement as I haven’t used it in real life yet and still have to order one if it makes sense in the long run for my setup. 

@batalto Do you need to own an EV in order to go onto the Octopus Go Tariff? 

@info no they don’t care how you use the tariff 

@boblochinver You could look at getting a second inverter string, thereby allowing you to get maximum out of your array? I have 2 strings plus a micro inverter on a single panel which is a little out of way on an odd angle of roof - I hit my maximum easily on a clear summers day. That said my array is spread around the house, with 2kw being east facing, 2kw being west facing and the other 4.4kw being south facing. This gives a broad daily production as I catch the sun from the moment it comes up, to the last dregs in the late afternoon.

Adding more batteries would be easy enough, but you would need a second hybrid inverter. Like you I am limited by my batteries, which can only output a maximum of 3.2kw. Even if my demand was 4kw and the batteries had it, I would still need to buy 0.8kw from the grid. I've considered another hybrid inverter to make 2 strings in parallel - this would give me 6.4kw of output from the battery bank and would more or less cover anything I might throw at it. The only exception would be when everything is turned on e.g. Oven, Induction hob, Immersion, Tumble drier, washing machine, dishwasher etc, but those instances are rare.

Given the new ASHP I am going to see how we get on this winter and then consider the options. I can always bulk out my batteries easy enough, they are modular. But peak power output can only be fixed with another inverter.

@batalto Thank you for that advice. I will fill my boots with overnight electricity.

Mike

@mike-patrick batteries are fairly useful in taking off the hard edges, even on a gloomy day like today my battery is currently at 73% charged

@batalto Hi, not sure what you mean by a second inverter string as they are all enphase micro inverters so all individual for each panel ? i have what looks like 9 on one set and 3 on another set ? basically the top row on the roof has 9 facing south and the 3 are just below in-between some dormer windows so they get just a little bit less sun than the top row. I dont think it would change the amount of power that I am currently getting unless I was to add a new Lux ac inverter ? the batteries id love to add to but the Aoboet batteries are terrible for finding and a complete monopoly on buying from a closed group of providers in the UK like they wanted just over £3200 for 2 more batteries and that was just to ship them to me and for me to fit them ! 

@boblochinver just looked up your battery and it looks like a rebrand of the Pylontech batteries. I'd have a look and compare but they look identical to me. Might not be a step too far to think you can just add them in as is.