IOG - maximising imports overnight & maximising solar exports
- Edited
Tima441 from what I recall, you're whole house setup is fairly similar to mine ie. EVs, solar, batteries, HP.
What's your typical daily household consumption, not including EV and HP? Would your batteries cover this in a day with no solar?
I have a 2 stage strategy...
ATM I'm not pausing the battery charging (because of the HP), so the solar is going load, batteries, then grid.
However, I have a battery emptying schedule set...
Each slot would empty 10% of my battery capacity. They're set with conditional SoC checks. I did a "how to" starting here https://community.wonderwatt.com/d/315-intelligent-octopus-go-limited-beta/237
When the weather is a bit more consistently warm mild, and I'm not needing additional charging slots, I'll add in the pause charge from the Giv portal maybe starting with 13:00-17:30 and gradually bring the start time forward.
By May, I'd expect it to read 05:30-17:30.
To give you a rough idea, this is how my solar looked for last year (ignore April, I was faffing)
Best thing is to try it, and see how you get on. If you need anything else, let me know.
MrMessy many thanks for the comprehensive reply. Its really helpful to get me started.
My setup;
16kw ashp uses circa 5800kwh/pa
Imports circa 10 - 12,000kwh/pa Inc EV
EV say 3000kwh/pa
GivEnergy Gen1 3x8.2kw batteries = 24.6kwh
6kw PV solar via GivEnergy Hy-5.0 Gen 1 inverter
2.4kw pv solar via Solaredge inverter
PV total annual production circa 6500kwh
Exports circa 2700kwh/pa in 2024
Hot tub in July boosted usage that month!
Base Winter usage is say 40kwh/day but of course during cold weather might be nearer 60kwh
Base Summer usage is say 10kwh/day - so easily covered by batteries
I anticipate significantly increasing PV Exports this year which will be covered by Imports at night. Maybe increasing from 2700kwh to 4000kwh (or more). Net saving say £80
Interesting question is whether to take the exports further by dumping batteries each evening and then recharge at night. I suppose if we consider with vat & round trip losses.. Imports might be costing 9p so a 6p profit with Exports at 15p.
Every 1000kwh = £60 profit/savings
Maybe I could achieve an average of 150 days/pa and 10kwh? So boosts savings by £90 over and beyond the solar Exports above.
Thanks again... I'll get playing!
MrMessy
Main problem I have that reduces ability to charge/discharge is the Gen1 rate is 2.6kwh per hour.
But that should be OK... I need to set discharge at say 19.30 to empty 10kw.
Strictly 6 hour night charging slot may only be able to charge around 15kw. Some extra slots will of course help.
So it's going to need a bit of trial & error to see if worthwhile vs faff! I don't want to have to make tooooo much daily effort and would like to automate as far as practical.
Tima441 I have to admit, I've been giving this way more thought than is healthy but, if you set discharge schedules with an SoC query, they are fully automated, so no further effort required. Also, I'd definitely split them in to smaller chunks (rather than just one which either runs or doesn't).
If I've done my sums about right, your inverter could discharge approx 15% of your battery capacity/hr. Bear in mind you need roughly 3.0kW DC for 2.6kW AC, also I think your batteries are 80% DoD, so useable capacity is approx 19.5kWh.
For example, you could do this...
followed by:
70% 18:15-19-:15
55% 19:30-20:30
40% 20:45-21:45
25% 22:00-22:30
13% 22:45-23:15
In theory, if the whole lot ran, your batteries would be empty at the end. Due to charging limitations you may not find that desirable whilst the HP is running, so you could just make say the last 2 inactive until later in the year.
It's also worth remembering that IOG smart charging trumps any discharge schedules that are running. I think I gave an example of this in the other thread, so you don't have to worry about switching the schedules on or off.
JayC @admin would you have a look and see if WW could add this as an additional automation/ Schedule Type: Giv 'Pause Charge' (found within the Control section)
For example: if Solar Forecast is greater that X kWh then Pause Charge from hh:mm to hh:mm, followed by Return to Not Paused
Whilst in the summer I can do this manually and more confidently win in the shoulder months I have to manually turn this on and off dependent of the weather.
