Add sensor device classe for reactive energy

[toreamun]

Support for device class reactive power (var) has just been added by #688 and home-assistant/core#62010. Reactive energy (varh/kvarh) is often also used when reactive power is used. Reactive energy should be added as a device class and varh and kvarh as units.

[emontnemery]

Can you try to list integrations which could make use of this?

Also, maybe a bit off topic, but do you know cases where consumers will be charged for reactive energy?

[DennisHedberg]

There are many versions of custom ESP32 solutions that talks with the Powermeter via HAN / P1 port. Integration done via standard MQTT with HA.
As stated above some of the sensors needs a device class for Reactive Energy, varh, kvarh
All new meters in Sweden have this.

I think only factories, business etc. pay for Reactive Energy in Sweden today.

https://energynordic.com/sv/reactive-energy-impact-sme-electricity-bill/

[balazs92117]

Both kvar and kvarh units are provided via P1 port (DSMR) in Hungary too!

[balazs92117]

https://www.home-assistant.io/integrations/dsmr/ could use reactive energy (varh/kvarh) too.

[banditdk]

All electricity power meters have this unit, should be supported in HA.
SensorDeviceClass.APPARENT_POWER is allready supported, SensorDeviceClass.REACTIVE_POWER is not.

[Breina]

We can add my integration to this list as well. It's about energy monitoring per circuit.

https://github.com/Breina/PowerTagGateway

[piotrtobolski]

As a result of discussion #688 support was added for reactive and apparent power. Energy meters that support those values report also reactive and apparent energy. Basically all integrations that support reactive and apparent power would benefit from this. It seems like a no-brainer to add this class to HA with respective units.

There were already bug and even PRs on core to add this as it is quite simple change but both were rejected until architectural decision is made:
home-assistant/core#85507
home-assistant/core#98453

Can we have this decision made? It seems like a simple one.

cc @emontnemery @MartinHjelmare

[banditdk]

it is fairly hard to mention integrations, when it is a standard data point in all power meters. And most are receiving this data from the power meter via esp home or mqtt. Not a bunch of individual integrations.
Abit like only having kW but not supporting kWH.

[parautenbach]

Out of honest interest: What would the general user do with this information? Many users don't even understand the difference between power and energy.

[piotrtobolski]

In some countries you pay not only for active energy but also for reactive one. AFAIK it will be more and more popular due to high reactive power draw from the heat pumps. In Poland for now only big businesses pay for the reactive power but in some cases even households may need to pay for it.

Reporting apparent or reactive power is standard feature on almost all power meters. I use modbus tcp to integrate with my meter but there are plenty other ways to connect to a power meter.

[dgomes]

I bet many use-cases involve MQTT, hard to count those.

[Breina]

@parautenbach My project is used by electricity professionals as well, so I guess this information is relevant for tracking a circuit's performance in industrial settings.