Newbie help - please help me understand

SuprDoc

selfish-table

Have:

growatt battery and hybrid inverter
zappi
IOG and export tariffs

There seems to be quite a discrepancy between MyEnergi, SHINE, and Wonder Watt readings.
On the whole - there some variation in solar panel production - which I'm not too concerned about and expect differences due to lag, etc.
However, it's the house load, battery charging, and pull from the grid which gives me confusion and at times anxiety around how much energy is being used/ wasted!
I understand that the various systems are not compatible, but I assume that the numbers should all add up reasonably nicely? At times, there quite a big difference which I can't account for!
Thanks in advance.

MrMessy

SuprDoc what I think you're seeing is the difference in refresh rates for the various phone/web apps.

For example, the MyEnergi app refreshes approx every 10 seconds, WW every 5 minutes, don't know about Shine but my Giv Energy app is 10 seconds if I'm home or 5 minutes if I'm away. Add to that, even if they refreshed at the same rate, they're not necessarily in sync with one another.

In essence, you're seeing spot readings that are all taken at different times from one another. When no one is home and a clear day, you'd have more or less constant readings, so everything would appear to be together. As soon as you add varying loads and some broken cloud, all the different apps appear to be all over the place.

Hope that helps a little.

SuprDoc

MrMessy Thanks MrMessy - I did figure that might be the case, and wanted to double check.

I am on IOG EV tarriff. May I please check with experienced/ experts:

this means that EV can charge at anytime of the day for 7p/KW (this is what Octopus tells me)
in the day - I can get a boost/ octopus will give me 'intelligent schedules).
overnight - its a straight charge - 11:30 - 5:30 am.

during the day - I can use home battery and draw off grid only if I need it.

is there a setting I need to check to ensure that the EV in the day WON'T draw from my home battery?

thanks

MrMessy

SuprDoc this means that EV can charge at anytime of the day for 7p/KW (this is what Octopus tells me)

as long as you're using the Octopus app, and allowing them to schedule the charging.

in the day - I can get a boost/ octopus will give me 'intelligent schedules).

No and yes.
If you use "Boost"/"Charge now" from the Octopus app, it will be at full price.
If Octopus create a schedule that happens to have daytime slots, they will be at the cheap rate.

overnight - its a straight charge - 11:30 - 5:30 am.

Correct. The core hours are always cheap rate, regardless of whether the EV is charging, or not.

during the day - I can use home battery and draw off grid only if I need it.

Absolutely.

is there a setting I need to check to ensure that the EV in the day WON'T draw from my home battery?

This is the most important setting, the others on the page you can adjust to suit your requirements. Make sure you save any changes.
https://app.wonderwatt.com/intelli-octo

SuprDoc

MrMessy <<<--- you are MrWonderful !!!

Thank you for clarifying.

in the intelligent setting:

What situation would smart charging be more advantageous?
is it to be greener or more prudent - if the forecast is to have adequate solar?
the risk being that the weatherman is wrong??!

I don't understand the advantage/ disadvantage of auto charge rate - could someone elaborate pls.
Similarly why would one want NOT to have schedule active?

At present I have:

smart charging - on
Autocharge - off
active schedule.

Thanks again.

MrMessy

SuprDoc charging from your own solar is most definitely the greenest, but not necessarily the most financially beneficial, given that on IOG you can import at 7p and export at 15p.

What situation would smart charging be more advantageous?

If you have a DNO restriction on your export, you may need to self consume or store what you can't export, otherwise it's effectively lost.

I don't understand the advantage/ disadvantage of auto charge rate - could someone elaborate pls.

Less strain on the batteries/inverter if you can spread the charge across the whole 6hr core period.
Let's say you have a 5kW inverter and 10kWh of battery, you could charge from empty at 5kW and be done in 2 hrs, or you could charge at 1.7kW and spread it out. If your batteries/inverter are outside (many are IP65/66 rated for outdoor use), it would also keep them warm in winter. Batteries typically have a reduced charge/discharge rate if the cells get too cold.

Similarly why would one want NOT to have schedule active?

Good question.

admin

MrMessy Similarly why would one want NOT to have schedule active?

Good question.

We copied the mechanics from the normal Schedules basically, where it does make sense. But perhaps not as much for IOG. Think of it as an evolutionary left-over, a vestigial organ, much like the human appendix. 😉

KristianS

As there is a dedicated Pause Schedules page, which also has a Schedule Pause toggle for IOG, one might suggest this toggle is superfluous to requirement and could lead to double negative ambiguity. Off on one page, and on, on another. Or vice versa

admin

KristianS The negation doesn’t work that way in our implementation, but we’ll remove the IOG active flag and keep it active by default and under the hood, and allow users to manage on/off via IOG pause.