own forecast

[melmager]

I'm currently writing a Home Assistant integration for a price forecast for the provider Ostrom. However, the new price forecast data usually arrives at 2 p.m. and then lasts until 11 p.m. the next day.

If I want to transfer the forecast prices to emhass, do they always have to cover a day and always start at midnight, or can I also transfer longer data sets that aren't current start at midnight?

And consumption forecast: I can create an electricity consumption forecast for my heat pump based on the outside temperature. But the heat pump forecast is only one consumer. Is that a problem if the actual electricity consumption is higher afterwards?

[tbrasser]

That first part is no problem. In the latest test image / next release you can send timestamp, value dict and emhass will interpolate etc.

On your heatpump consumption. This is exactly emhass's job to predict for you.

[melmager]

to first part : cool
For impatient people like me - there is already an example of what the data should look like - maybe I'll add an extra sensor.ostrom_emhass with prepared data in my integration :-)

my Current sensor value :
[{'date': '2025-08-22T07:00:00.000Z', 'price': 26.58}, {'date': '2025-08-22T08:00:00.000Z', 'price': 24.49}, {'date': '2025-08-22T09:00:00.000Z', 'price': 20.92}, {'date': '2025-08-22T10:00:00.000Z', 'price': 17.54}, {'date': '2025-08-22T11:00:00.000Z', 'price': 16.32}, {'date': '2025-08-22T12:00:00.000Z', 'price': 15.87}, {'date': '2025-08-22T13:00:00.000Z', 'price': 16.34}, {'date': '2025-08-22T14:00:00.000Z', 'price': 20.7}, {'date': '2025-08-22T15:00:00.000Z', 'price': 24.57}, {'date': '2025-08-22T16:00:00.000Z', 'price': 27.19}, {'date': '2025-08-22T17:00:00.000Z', 'price': 28.49}, {'date': '2025-08-22T18:00:00.000Z', 'price': 29.31}, {'date': '2025-08-22T19:00:00.000Z', 'price': 28.67}, {'date': '2025-08-22T20:00:00.000Z', 'price': 28.13}, {'date': '2025-08-22T21:00:00.000Z', 'price': 27.1}]

[tbrasser]

#542, so the values seem compatible 1-on-1

Mine looks like this currently:

"load_cost_forecast": {{ "{" }}{% for entry in state_attr('sensor.frank_energie_prijzen_huidige_elektriciteitsprijs_all_in', 'prices') %} "{{ entry.from }}": {{ entry.price }}{% if not loop.last %},{% endif %}{% endfor %} },