Hold charge until peak period

mrtnbcky

Hi, and first of all can I say how impressed I am after around a week of being a Wonder Watt user!

I've tinkered around and the changes I've made have impacted my GE system pretty much in line with how I expected them to - something I can't say has been my experience in just shy of a year of being a GE portal user!

My question relates to those bleak months ahead...... I know we're enjoying the sunshine at the moment, but it won't last, and as I recently switched over to Octopus Flux, I'm keen in the winter months, to make sure I've charged up fully in the off peak overnight slot, then to hold onto the charge, allowing my daytime usage to be pulled from the grid until 4pm ticks round, and then only use battery-stored energy during the peak time, reverting back to grid usage again once my battery hits a certain percentage to get me through to off peak again on phantom load.

Is this a sensible way to run things? Our system has run entirely on GE's 'dynamic' or 'Eco' mode up until we switched to Flux, and I'm keen to maximise the benefit - I'm more than happy to buy cheap electicity off Octopus and sell it back to them for a profit, but in winter I'm cautious about getting stung during that peak 16:00-19:00 slot.

admin

mrtnbcky Hi, thank you so much for your kind words. It's amazing to hear Wonder Watt is working for people. :-)

Great question and suggestion. So basically another schedule like:

Keep battery at SoC during
Time from:
Time to:

Would that work, do you think? Happy for other Flux users to chime in here.

Cheers!
Wim

Dai

admin
Hi,

I think the use case would be how does a user with a daily peak supplier charge period use a smart charging algorithm to avoid importing grid electricity in this peak supplier charge period (ignoring battery response time which of course are not in the user’s control)

Personally I would be think that your smart charging algorithm would need to know the time of the start peak supplier charge period (4pm) and the minimum SoC the user wants to have at this point and work back from there to get the cheapest way of ensuring that level whether that the ultra cheap flux early morning period or the daytime standard period based on the load prediction the user has supplied and real time usage during the day. As a flux user my aim would be not to touch grid import between the peak supplier charge period at anytime in the year. GivEnergy are talking about providing 2 charging windows at some time in the future but that is based to charge up to a capped charge percentage and of course if the 2nd charge period is not early enough you may not be able to “load” up the battery quick enough to get to the level you require at 4pm or you pull in too much because it goes all the day up to the max. A better approach, IMHO, for flux (as Octopus have it set up now) for a smart charging aIgorithm would be working automatically how to get a minimum SoC at a specific point in time during the day for the cheapest combination of pKwH charge by Octopus.
Hope this helps

admin

Dai Thanks for the explanation, that makes sense yes.

I think an initial iteration of this might be to have a second charging window with user-specified settings/conditions. And as that is currently not supported at the inverter level for GivEnergy, it would need to be managed outside of that and controlled by Wonder Watt.

Requires a bit of rearchitecting, but definitely doable.

mrtnbcky

Thanks Dai this is exactly what I was trying to request, but you have articulated it better than I did! 👍

Dai

mrtnbcky the thing is such functionality might be also suitable for those on the Octopus Cosy tariff and have a battery, the import p/Kw is even higher at peak rate than it is for flux 😳

MartynK

Not sure if this works for GE inverters/batteries, but with Growatt when setting a TOU import schedule, if you extend the TOU import time after the 02:00 to 05:00 Flux off peak rate to 15:59, after the battery is at 100% SOC, the grid continues to feed the load and effectively stops the battery discharging, and hence once the TOU period ends, the battery will start to discharge. As I say, not sure of this works with GE though.

Dai

MartynK in the GE Environment we have the ability currently to set up a daily export “window” but the GE code on it’s portal (currently) then doesn’t automatically return the setting to the inverter’s normal (called Eco) mode at the end of the window and you have to remember to check and reset it yourself at the end of every export window. So effectively full export has to become a manual process because at approximately 7pm you always have to check/reset the inverter operational mode which is a pain to do it every day. With the GE app, if you fire off a manual export it does then return the inverter (99% of the time) to the normal operating mode, but then you have to remember to engage export mode at 4pm and disengage it at 7 every time, which is a right pain in the a@“e. Different software solution mostly with HA are available (including exported based on solar forecasts) but the USP of wonderwatt is that it can automate all this without us the user having our own HA instances and coding knowledge.

MartynK

Dai That's good news for the GE community, and a real benefit of wonder watt. Keep going guys, you're doing great :)

Gazzagreen

I have just written a post about the Cosy tariff before I seen this post. New Tariffs will be coming thick and fast from companies like Octopus in the future so we have to be ready to take advantage of that. Scheduling of the inverter is vital in today's world of complexity I feel, and I am disappointed that GivEngery have not included a better scheduler into their portal. It's their only weakness as their hardware and batteries are excellent for a lower price than something like a Tesla battery. Software is hard so I commend the writers here for trying to better things for us.

I just joined today so lets see how things go. Hopefully I have set everything up right for Flux. I just need the export to stop at about 40%, then I would like the battery discharge to pause, then at 7pm go to ECO mode again to operate normally for the rest of the night. I know it not as complex as that ATM, but as time goes by hopefully we can have the software do things like that in the scheduler?

Funny enough, the cheapest thing to do for me using flux is to import in the flux period, its even cheaper than importing sunlight as i can get more money selling sunlight back to Octopus than use it myself!!!! The cosy tariff could be the same?

Gazzagreen

Here is the info for the Octopus Cosy tariff. It will be ideal for the winter months and is designed for those of us with a heat pump. Charge battery twice a day, once during the night then again three hours directly before the peak hours so you have a full battery for the peak! It should work great for us. I am hoping I can run the house on battery all day on cheap electric.

I asked Octopus about swapping tariffs when we need to take advantage of the different tariffs. They replied we can change tariffs when, and as often as we like without charge. So to me, Flux for the summer to get all the export rates! Cosy for the winter, no export rates at all but two cheap rate Cosy periods. Rest of the day a standard day rate.

https://octopus.energy/smart/cosy-octopus/

How does it work?

Cosy Octopus is a 3 rate tariff with double dip Cosy Hours every day: six hours of super cheap electric to warm your home.

A day rate, set at the standard Flexible Octopus rate in your region.
Two cosy periods of super cheap rates between 04:00 - 07:00 and 13:00 - 16:00 every day, 40% cheaper than the Flexible Octopus rate in your region.
A peak rate between 16:00 - 19:00, 60% above the Octopus flexible rate in your region.

here are my rates, they will all be simular...

Day rate:
29.48p / kWh

Cosy rate (04:00 - 07:00 & 13:00 - 16:00):
17.69p / kWh

Peak rate (16:00 - 19:00):
47.17p / kWh

Standing charge:
48.66p / day

Prices include VAT.

admin

Gazzagreen Thanks for the details on the Cozy tariff. Hopefully we’ll finish our restructure of schedules over the next week or two.

In terms of switching, I thought there was some type of limitation, that you can only switch Octopus tariffs once every 9 months? I’m sure I read that somewhere. OK Googles, looks like that’s for a Tracker product and switching back.

Is there an issue that whilst you are in between switching (and could probably take two weeks or so), Octopus might put you on a standard tariff?

Gazzagreen

Last time I switched between Octopus go and Flux, I think it happened practically immediately, or at least overnight. Of course I might not of noticed any delay as i wasn't logging my usage then, but it definitely was quick and not 2 weeks.

Acejames87

Growatt has the option for multiple charging schedules so it would be good if you have peak period setup for 4-7pm that something like 2.30-4pm it will charge battery from grid if below a certain level to make sure you dont import in peak time.

Obviously if the inverter doesn't support it dont allow adding multiple schedules but if the inverter is a growatt inverter this is how it could be solved

admin

Acejames87 Yeah this is in the pipeline, but is quite a tricky change to manage, because we want to make sure we offer the same functionality for GivEnergy users too so the experience is consistent.