How to include fixed costs per month in energy cost calculations?

[rotund cedar]

Hi everyone, so far, my searches have been semi-successful.

I want to include fixed costs per month in my energy cost calculations, and I have no idea how.

Probably the best solution was to divide the monthly costs by hours in a month and then create a helper sensor for it. Seen here: https://domoticarte.com/en/p/calculate-electricity-bill-home-assistant/#fixed-costs-price-sensor.

My energy provider (Planet B Net Zero Energy — Germany) gives me a rate per month which is fixed, and I would like to avoid errors by dividing a 30-day month by 28 days, for example.

Can I add a utility meter helper for monthly energy consumption and multiply it by the current price? Then use this and add the fixed price? That is my best idea right now, but I can see that it only takes the last current price and doesn't store price based on the hour/quarter it was consumed, right?

Moreover, I am a bit surprised, that I don't find more 'proper' solutions on this. Is this a German 'problem'?

Anyway, all help is appreciated.

Okay, I did some more searching here, and it seems the topic has been discussed a few times already. The conclusion is, it not being simple to calculate.

Is there something like a total_increasing sensor with the costs from the energy dashboard? Given such a sensor, one could use helpers to do the rest.

[split forge]

The easiest way I've found to do this is:

1. Template sensor calculating the average cost per hour (easy to update at the start of every month)
2. Template sensor that adds in current consumption power x cost per kWh to give total cost per hour (you can do this combined with 1, I just wanted to keep it separate)
3. Integral helper to turn cost per hour into total cost - can be plugged in to the energy dashboard

[rotund cedar]

1. You mean something like fixed costs / days in month / hours in day?

[split forge]

yeah basically.
I'd do something like:

{% set first_this_month = now().replace(day=1) %}
{% set first_next_month = (first_this_month + timedelta(days=32)).replace(day=1) %}
{% set month_length_in_hours = (first_next_month - first_this_month).total_seconds() // 3600 %}
{{ fixed_costs / month_length_in_hours }}

[late abyss]

I don't see how that can work, because you can't know the energy consumed in advance?

[split forge]

... Why would you need to know that?

He's talking about spreading a fixed cost over time so it's recorded sensibly - the cost for the energy used is separate to that

[late abyss]

You're spreading a fixed cost across all consumed energy right?

[split forge]

No

It's calculating a cost per hour not cost per energy

[late abyss]

Ok

[rotund cedar]

@late abyss would it be possible to return the calculated cost (from the energy dashboard) back as a sensor? It records per hour, is that correct?

@split forge thank you for the help! However, I was indeed hoping for a solution where I didn't need to split the fixed costs per hour.

[late abyss]

Costs are stored in _cost sensors, so after adding the integral sensor to the dashboard you will be able to access that

[late abyss]

There is no such thing as fixed costs in the energy dashboard so this is th only way

The energy dashboard is not meant to be used for administration

[rotund cedar]

Perhaps I wasn't clear enough about my intentions. I don't need to see it in the energy dashboard (even though I also not understand why it cannot be displayed there).

The created sensor seems good enough to me. I can create a utility helper for it on a monthly schedule. And then a template sensor to add the fixed costs to it.