Thinking ahead to higher solar production .. for (say) Apr to Oct if my batteries are filled overnight at 7p I will not need to charge them further in the daytime (24kwh batteries are more than enough outside heating season) so would prefer to maximise exports at 15p... not filling batteries from solar.

my ideal scenario would be as follows:

  1. Always charge batteries (ideally) using both overnight IOG slots and dynamic additional slots.
  2. Using batteries to supply home demand in the day whenever there is insufficient solar.
  3. Solar will be used for home demand when available
  4. Exporting ALL solar not needed for home demand. I.e. NOT filling batteries

I guess I'm looking for:

  • "hold" on charging batteries from solar during the day
  • ideally the "hold" would be overriden by dynamic cheap charging slots. Maybe impossible?
  • but discharge continues to work normally

Can WW recognise charging from grid dynamic slots ... without also charging from solar? If necessary I'd be happy to lose summer dynamic slots as I doubt they'll be very important to me.

I suppose it might be viewed as splitting "hold" into 2 elements

  1. Hold charge
  2. Hold discharge

Hold charge would be the main piece I need so that the batteries do not charge (from solar) for a period that I can set. My main solar production is say 09:00 to 15:00 so outside those times I would benefit from IOG dynamic & overnight slots.

Have I explained what I mean?!

Last year I produced circa 6500kwh solar
I exported approx 2000kwh
I used approx 3300kwh directly
I filled batteries with approx 1200kwh

I'm thinking I may be able to significantly increase my exports at 15p and replace with imports at 7p. On above figures perhaps only 1200kwh would save £96. But in reality I suspect actual exports might be increased even further.

Any thoughts?

    Tima441 I do exactly this, once the heatpump is mostly off , and it's a surprisingly simple solution, which may or may not work for you.
    Which inverter do you have?

        Tima441 in the web portal, inverter, remote control, do you have this option....?

            MrMessy I don't think so .. in Gen1?
            I can't see remote control.. or looking in wrong place?!

                MrMessy ah yes, thanks. Somehow on mine it's not so visible. But no matter... I see it now!

                Just need to figure out what I need to set!! Any hints?
                I expect I can work it out .. in the end!

                    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.

                                  MrMessy this was mine from Monday, when it was unexpectedly sunny (except at 1pm ffs). Cold overnight too, as you can seen by the defrosts every hour. I'd made a quick tweak because of the saving session, but the rest took care of itself...

                                      MrMessy I'm very grateful for the time and inputs! Will get my head round it all... and if I can't... I think I'll just set it anyway and see what happens!

                                          Tima441 once you've had a go, it's not really that tricky. You just need to fine tune to suit your specific needs.

                                          Let us know how you get on.👍

                                            12 days later

                                            MrMessy Timely reminder: I'd forgotten all about this, yet more money you are making us.
                                            Best set the calendar set to turn off in September. (Your XS Dump schedules have been fantastic.)

                                                6 days later

                                                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.

                                                    JayC Yeah we'd need to ensure this is easily doable for the other inverters we support too.