Stop solar panels from producing energy when electricity price is negative. Tibber / Enhpase Envoy

So I have solar panels and a Enphase Envoy-S-Standard-EU, and a energy contract with Tibber, thus variable energy rates.

Sometimes the energy rate is negative, and that typically happens when there is a lot of wind and lot or sun.

At this time I wish to completely stop producing energy with my solar panels. I’ve contact Enphase for this, and support of Enphase recommend a up sale. I had to get a Envoy metered, a 400-500 euro upgrade. That all sounded a bit silly to me, and I started to post my question on the Enphase forums;

https://support.enphase.com/s/question/0D53m00009LsV77CAF/is-it-possible-to-temporary-stop-returning-power-to-the-grid?fromEmail=1&s1oid=00DA0000000aQ9D&s1nid=0DB2G000000Kz2X&s1uid=0053m00000D7jwV&s1ext=0&emkind=chatterCommentNotification&emtm=1711375023548&t=1715587012418

It took me a long time to figure out, but it’s possible to temporary stop your solar panels with this setup like so;

On the digital port of the Enphase is a resistor, if you disconnect this resistor, production will halt completely.
image

If you connect a relay to the resistor like so;

You can control it with the relay. I bought this relay; https://www.tindie.com/products/a_lab_technology/zigbee-4-channel-relay/ Because I didn’t want another adapter, you can connect it with 220v, and it’s zigbee and has total of 4 relay’s, which can be used for other purposes.

It will all end up looking like this;

And a simple automation to switch when the price is negative;

alias: Turn off solar production when energy price is negative
description: Turn off solar production when energy price is negative
trigger:
  - platform: state
    entity_id:
      - sensor.electricity_price_tibber
condition: []
action:
  - if:
      - condition: numeric_state
        entity_id: sensor.electricity_price_tibber
        below: 0
    then:
      - type: turn_on
        device_id: 823e72a517eb4aa6468ca
        entity_id: b3a06ead7db486952a330
        domain: light
      - service: notify.notify
        metadata: {}
        data:
          message: >-
               Energy price is negative
          title: Energy price is negative
    else:
      - type: turn_off
        device_id: 823e72a517eb4aa6468ca
        entity_id: b3a06ead7db486952a330
        domain: light
mode: single

With an other automation I make sure my heat pump is on ‘Forced On’ heating my boiler to 60 degrees.

Hope this will help others!

2 Likes

That is a neat trick. Do you mind sharing where this automation script would go? I have a quite a similar application in mind.

Nice, thanks for sharing @Lectere.

When restoring production does it resume right away or is there some delay?

That’s a good question;

When disableling the production;
I flip the switch at; 08:00:13
I measure the result at my powermeter at: 08:00:49

When enableing the production;
I flip the switch at; 08:32:38
I measure the result at my powermeter at: 08:32:52

So via my P1 / powermeter it’s all within a minute. I did notice a big delay when using a Enphase counters, I assume it’s the fault of Enphase. Specially when switching off.

The delay may come from the Envoy inverter polling cycle.

Over a span of 5 minutes one can see these changing one by one, not all at the same time.

So values might only be going to zero in the second inverter scan scan that falls after the disabling as the first one may still report the last part of production from before the disabling.

Is it necessary in Sweden?

Hi @catsmanac, thanks a lot for sharing! I’m in the same situation, so I’ll definitely give this a try. I don’t even have to purchase a relay, since I have a Shelly Pro EM50 in my fuse box, and I didn’t find a useful application for the relay on that one yet. I guess now I have found it! :wink:

Good to see you found it @bartkummel, keep us posted how’s going. I’ll close the issue in github.

Al kudos are for @Lectere for explaining how to do this.

Ok guys, I understand that this works, in the sense that production stops and starts by breaking the connection to this transistor.
But?
Can anybody tell me what it does inside the Enphase Envoy system and whether this might hurt the system in some way?