We had solar and an AIO installed last year. We currently have a 5kW DNO export limit but are capable of generating 10kW peak. If we hit 5kW export the inverters have their generation limited which is a waste of energy.
I would like to prioritise export to the grid and if this exceeds 5kW then divert anything generated above this to the car.
Could someone please tell me if the GE car charger can be configured to support this scenario? Thank you.
zag164 how about diverting to your hot water tank or a heat battery?
zag164 Sorry, I meant to reply... I'm quite interested in how this is implemented. Presumably there's a separate solar inverter generating AC, and I think that plugs into the AIO Gateway ?
I assume that only the solar inverter can impose a limit on the generation, by clipping - there's nowhere you can just dissipate an excess of 5kW power if there's nothing in the house that can consume it. So does the solar inverter have a CT clamp on the meter tails so that it can detect excess export?
But the AIO can also generate more than 5kW of AC. Does that also have a CT clamp on the meter tails, and does that also have to reduce output if there's excess export.
If there is excess export, which system takes priority in reducing its output? Presumably you want it to be the AIO rather than the solar inverter.
Is there a chicken-and-egg problem - if you wait until you can detect that there's more than 5kW of export, the solar will already have had to start clipping. Though I guess that if you do divert, and the export is reduced, the inverter would be able to reduce clipping and increase its output.
I suspect that this is a sufficiently edge case that you'd need to have an external agent to detect the problem and turn on diversion. But it would be sufficient to start solar charging - after that, the chargepoint would presumably take care of grabbing as much as is available.
zag164 This probably doesn't help, but... Zappi chargepoint has similar modes to solar and hybrid. The solar mode has a couple of parameters: how much solar there needs to be before it starts charging (since you don't want to start just as it reaches the 1.4kW minimum, and then have it stopping and starting); and how much power to leave behind (which is primarily intended for prioritising different possible energy sinks).
So there, I might implement what you want by setting the setting the first parameter to around 5kW, and the second to something like 3kW. That way, it won't start charging till it gets to 5kW, and will only consume 2kW initially. As the solar increases, so will the charging rate, but it will still leave some export.
If you have similar parameters available, you might be able to do something along those lines. (It's not quite what you want, since once it gets to 7kW, you'd prefer to be charging with only 2kW rather than 4kW, but at least it avoids clipping.)
I should have asked whether you needed it to be fully automated, or were happy to intervene when there was clipping.
DD Thanks for the replies. This is how our equipment has been installed. On the solar side, we have an 11.7kW array across 3 planes of panels. These are split across 2 x 6kW Solis Inverters, connected to a Solis export power manager (EPM) via Modbus which constantly monitors the generation of the inverters and has a CT clamp grid side. We can generate and consume as much as we want in the house/EV charger but if the export hits 5kW, the EPM winds back the solar generation from the inverters. Any power output from the AIO is handled in the same way. For example, if we were dumping the AIO battery to the grid on a sunny day (unlikely!), the CT clamp on the EPM would detect this and wind back the solar generation of the inverters to zero if necessary. Whilst we have 2 x inverters, and a separate EPM, you can connect a CT clamp to a single Solis inverter in the same way.
Bringing this back to the EV charger, I did originally look at the Zappi but would prefer the GE EV charger to keep it under the same GE ecosystem which integrates well with Home Assistant. As I knew about the export margin on the MyEnergi products was hoping the GE EV charger had the same functionality but perhaps it is not there yet. Another option would be to divert to hot water as billG suggested but I need GE to make the product first!
zag164 For example, if we were dumping the AIO battery to the grid on a sunny day (unlikely!), the CT clamp on the EPM would detect this and wind back the solar generation of the inverters to zero if necessary.
So there's no hardware in place that would stop you exporting 6kW from the AIO. You'd just have to take care to avoid doing so. (But as you say, unlikely to happen in practise.)
Since you already have Home Assistant, I guess you'd have to implement some sort of scheme yourself. Might have to use grid charging mode on the EVSE, and use scripting to dynamically adjust the power you want to use. (Despite the name, it will of course consume exported power rather than importing.) Unless there's some way to control the max charge rate in solar mode...
DD The AIO is G100 rated and has an installer set export limit, so 5kW in our case. That means we can't ever export more than the 5kW DNO limit. There's an additional level of security so if the comms link between the inverters and the EPM fails, the inverters will stop producing altogether.
DD Since you already have Home Assistant, I guess you'd have to implement some sort of scheme yourself. Might have to use grid charging mode on the EVSE, and use scripting to dynamically adjust the power you want to use. (Despite the name, it will of course consume exported power rather than importing.) Unless there's some way to control the max charge rate in solar mode...
I suppose I could but I was hoping that I wouldn't have to. I'll get one installed and take it from there. I'm also applying to increase our DNO limit above 5kW. In our area (UK Power Networks) anything up to 5 is automatically approved.
zag164 Oh... sorry, I had assumed that you were already actively using HA, but maybe you just meant that you choose the system so that you could if you needed to.
I'm still avoiding HA - for now, it seems overkill for my simple needs, so I'm just using scripts using the API. But if you need to be able to respond fairly quickly to changes in output, it would be necessary to have sort of active polling directly to the inverter. (Does the chargepoint have the same local access, or is that only through the inverter ?)