FoxESS Community - Owners & Installers Forum

Hi,
We had 20 solar panels installed in February, and are gradually getting an understanding of how it all works.
We are currently on Octopus Flux (not the intelligent one) and are keen to start up the forced discharge between 4-7pm, especially now the prices have all changed. We initially started up the overnight cheaper importing, but turned it off at the start of March as we don’t seem to need it.
Our installer set up the forced export for us earlier in the month, but it seemed to result in us also importing far more than usual, so we turned it off again!
We make very little solar after 4pm, as we are surrounded by trees. We had asked our installer to set the min Soc to 60% for the 4-7 forced export, so as to have enough left in our battery for cooking in the evening and breakfast etc before the panels start producing again the next day. This figure was because we had worked out we use about 40% of the stored energy during this time. I think our installer set it up to discharge everything in one go….would it make a difference to set it so it slowly discharges over the 3 hours?
Can anyone explain why we would be importing more because of the forced discharge? And is there a way to stop this? There seems little point in forcing an export if we are also being forced to buy it back at the most expensive time!

Can you provide some data behind your question? Exporting is normally not worth it when it comes to return. Best to leave it in self use mode or charge up overnight if you're on a cheap rate.

Hi Rachel,

The picture is is our set up for a 15 panel with a Fox EP11 battery. Basically, we can get by on all the solar that the panels generate from about 10am until 4.30pm, it runs the house, including dishwasher & washing machine tops up the battery and a small EV and exports the rest to the grid. I've set it to force discharge to the grid between 4.30pm and 7.00pm, but stop when the battery reaches 35% so we have enough for the evening and early morning.

Seems to work really well for us, with minimal reliance on the grid and a good level of export to the grid. This is good whilst the sun is shining, but I imagine come the autumn we'll be topping the battery up during the cheap nighttime rate and using it to supply the house with no export.

Hope it helps

Tim

Rachel Sorensen wrote: Thu Apr 03, 2025 8:32 am Our installer set up the forced export for us earlier in the month, but it seemed to result in us also importing far more than usual, so we turned it off again!

That suggests that you are exporting so much of your battery capacity, that there isnt enough left to run your household. Also, if you are importing during the peak hours, that suggest that you have peak demands which are exceeding the ability of the battery current limits. I have this with our electric showers - it takes 10kW to run the shower but regardless of the state of the batteries, they can only provide half the current necessary, so the other half is being taken from the grid. The solution is not to exceed the battery current capacity during peak price hours. The Fox web panel graphs can show any grid demands during the peak period. A snapshot of that screen would be helpful (remove the other lines first)

Rachel Sorensen wrote: Thu Apr 03, 2025 8:32 am We make very little solar after 4pm, as we are surrounded by trees. We had asked our installer to set the min Soc to 60% for the 4-7 forced export, so as to have enough left in our battery for cooking in the evening and breakfast etc before the panels start producing again the next day.

This is sensible but it does suggest that the 60% figure is too low for your particular household, or that as above, your usage involves high current drain items which exceed the battery ability to deliver current.

Are you using multiple electric showers during peak periods or in the evenings ?

I have 16 panels producing a theoretical maximum of about 7-8kW, but the inverter clips this to 5kW. And my system survives fine normally from 1900hrs to 0800 the next day on 39% or less - but we dont use any high power items after 4pm

Your 20 panels should be producing much more power than mine does (although I have full sun coverage until sundown), so what inverter size do you have and what battery capacity do you have ?