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!

4 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?

@ToonVos, that’s a valid question, one which I unfortunately can’t provide an answer for. Based on the Envoy manual you might ask your installer if they can assist with/provide DRM to your installation if you want to avoid any warranty issues/concerns.

The resistor seems to be part of the DRM provisioning which is required for Australian market. DRM is Demand Response Management and allows some central system to signal Demand Response commands to electrical equipment like HVAC, Inverters and what all supports this. This can be used by a central system to drive Energy consumption and production.

In the installation manual (Dutch) (AU) see section 4 which describes this option. According to the manual the external resistor on the Envoy is to bypass the DRED (Demand Response Enabling Device) which would send these DRM signals. As long as the resistor is in place the commands are ignored.

If removing the resistor connection without any other connection to send the DRM signals is fine or not I don’t know.

Based on what is reported in this thread I assume what seems to happen is that by removing the resistor, the Envoy apparently reacts to DRM signals on the other pins of the connector, none of which are present. So DRM 0 signal is not present either and is required to operate the device when using DRM according to the DRM description. This seems the reason production is switched off.

According to an Envoy question response only DRM0 command is supported.

The DRM signals:

DRM 0 Operate the disconnection device
DRM 1 Do not consume power
DRM 2 Do not consume at more than 50% of rated power
DRM 3 Do not consume at more than 75% of rated power
DRM 4 Increase power consumption (subject to constraints from other active DRMs)
DRM 5 Do not generate power
DRM 6 Do not generate at more than 50% of rated power
DRM 7 Do not generate at more than 75% of rated power
DRM 8 Increase power generation (subject to constraints from other active DRMs)

Great find. Unfortunately today I discovered that my Envoy S doesn’t have these ports :frowning:

Doesn’t your Envoy have the resistor on the bottom side as shown in the original post at the top? My 2 year old Envoy-s has it.

No. Here’s a pic of the pcb:

Ah I see what you mean by no connectors. Mine is 2 year old Envoy-S not metered, and has the connectors.

I just wanted to share my experience after trying a similar setup to control my Enphase system using the DRM0 port.

I tried to remove the resistor, and also tried to control it with a relay. I can hear the relay of the gateway switch, and all inverters stopped producing. But after returning to the default setup, only a portion of my microinverters resumed production — in my case, 13 out of 20. All 20 were still detected and communicating with the Envoy, but only 13 were producing power. The remaining 7 stayed idle. It is now 6 hours later, and they are still not producing power. The lightning bolt icon on the Envoy stayed red.

So somehow using DRM0 to control the production doesn’t seem to work that well. At least for me.

How long does it take for you before the micro inverters were producing power again?

Wierd, I didn’t have that problem. For me it takes to long to shut down. Sometimes maybe 10 minutes before everything

This morning, all inverters were producing power again. It seems like it needed 1 night to recover. Not sure why i’m having a different experience.

My setup consists of
20x IQ7+
1x Enphase Envoy-S-Standard-EU

Maybe we have different inverters in use?

Tried setup with relay.
Not a success.
My setup consists of 19x IQ7+ and an envoy-s-Standard-EU.
After test, 12 panels producing and 7 doing nothing.

Looks like IQ7+ microconvertor is not made for this type of switching.

1 Like

Same here. 34 IQ7+ microinverters, but they do not shut down when disconnecting the resistor :weary:

For me, this did not work at all. Disconnecting resistor did not stop power production.
For now, “Production Switch” in Envoy software seems to be my best option, although that takes almost half an hour.
Envoy-S Metered, Firmware: D8.2.4382, Hardware: 800-00554-r03