Use of Network Electricity

Hi, We had a GivEnergy battery installed late last year and we are now benefitting from the better weather and much lower use of network electricity. I have noticed over the last few days that as we have managed to maintain a 100% charge on our battery we have used only the odd unit of network power. However can someone explain to me why, when we have a fully charged battery, we are using the odd unit from the network? I would welcome someone explaining it in relatively simple terms as physics was not my subject! I have a few theories but would welcome someone giving me the benefit of their knowledge

Many thanks

Gordon

Ramp up/down time.

The inverter cannot* instantly react to changes in household usage. That said there are some improvements in responsiveness to come, when the current beta software is released to all.

And* is not allowed to instantly react. To protect the grid, can't have everything suddenly going from 0 to 100 and back so to speak.

I’d also add that there is a limit to what can be discharged, so mine is 2.6kw but my electric shower is a 9kwh one, so there will be a need to draw from the grid for these high draining devices/appliances. Same if you have multiple items on at once, e.g. oven, dishwasher, washing machine, etc. I have learnt very quickly to put things on in sequence!

TX200 Beta software sounds interesting 🙂 Is the quicker response time noticble? We import roughly 500 watts a day from the slower response. I understand it’s also subject to regulations.

simon_rb (I assume you mean 500Wh per day = 0.5kWh) Yes, the faster response is definitely noticeable. There is still some lag, but it's a lot better.

TX200 It's interesting that the regulations forbid quick reaction: without a battery, when I switch on the kettle, the import load immediately goes up 3kW, then when it turns off, it immediately goes back down. Does the inverter immediately discharge the battery when it decides to act (so that the grid sees another large step), or does it ramp the discharge to smooth the step ? (So that the grid sees a sawtooth rather than a square) ?

DD well... From what I've read on here you'd assume it'd be gradual.

But taking that kettle example, when my kettle clicks off I go from importing a bit to exporting a lot (battery+grid going to the kettle).

The inverter I think gets updates from the EM115 every 10 seconds? so it won't immediately know about the swap from import a bit to export a lot

Maybe once it knows it is then supposed to gradually ramp back? But until it knows it can't.

If only I had a live view of my smart meter. Maybe the Octopus Home Mini thing can do that, if it ever arrives. IHD and I guess even GivTCP not good enough for such precise measurements.

andrew_bond haha yes, 500wh a day average (my bad). Ah that’s good then. I look forward to that being released 👍🙏

TX200 I thought the EM115 communication was in the milliseconds, I know we see it every 10 seconds on the app if directly connected.

I did read somewhere that if the inverter is behind a gateway (or everything runs through it like the Victrons) then it doesn’t need to have the delayed responses. Someone on YouTube is running a Victron setup and imports 10wh a day it was.

simon_rb oh maybe. I guess that'd make sense with the faster reaction time too. Think I've read somewhere you shouldn't query it too frequently, but I guess that's to avoid collisions with the inverter, cloud, app, etc.