With summer approach (and a few sunny days having been and gone), my mind has turned to anything else I can do to further optimise my setup.
I’ve currently got my GivEnergy system set to charge overnight and with excess sunshine during the day, using Eco Mode for the latter. It’s all working OK at the moment (there have been a few issues over the 3 years since I’ve had it, but GivEnergy have always been helpful in putting things right).
Given that:
on Octopus Intelligent Go and Outgoing, my export rate is double my overnight import rate; and
in previous summers, the battery hasn’t always fully discharged during the day,
I’m considering adding a manual timed export for, say, half an hour at the start of (or immediately before) the overnight cheap period, to eke out a bit more arbitrage each day.
My question is: can anyone see any reason not to do this? The main nagging doubt is that, given that it will mean there’s a daily period of the batteries being drained at maximum inverter power, it might shorten their lifespans, such that it’s not worth the extra few pence a day. Does anyone have any thoughts on that, or any other considerations I might have missed?
The general advice is to exercise your batteries so that they reach the extremes. I am also on iOG, I have a good-sized solar array and batteries. This is my setup’s day:
So my battery spend most of daylight hours fully charged with excess PV being exported to grid. Then the battery empties down to 4%, exporting @ 15p/kWh and it recharges overnight @7p/unit.
With the current amount of PV generation, I am in profit by over £5 per day. My aim is to come out with an overall annual cost of £0 with the summer profit compensating for the winter cost.
My view is that I have purchased the batteries and I want to use them. I don’t think reduced battery lifetime would be significant and who knows what might happen to tariffs in years to come.
My mind has turned to anything else I can do to further optimise my setup.
I have Predbat in Home Assistant set up to control my system. It is a truly great piece of software. So there is your challenge!!
It will give you the ability to control your charge / discharge - or you can just let it do it’s stuff and it will figure out how best to use you full system
Loads of people on here use it, and I have just enabled the latest feature on it which gives you information on if you are using the correct tarriff
Thank you both. This is really useful. I’ve been using HA on my Pi for years, but PREDBAT had somehow passed me by. I’ll definitely check it out, although my HA setup’s reliability has been poor for a few weeks and it’s starting to put strains on my marriage due to light switches not always working, so fixing that had better be my priority! In the meantime I’ll set my batteries to manually discharge at the end of the day, as discussed above.
In the meantime I’ll set my batteries to manually discharge at the end of the day, as discussed above.