I love the work that has been done to the Energy dashboard. Finaly a central and local way of getting insight to my energy consumption.
I realy like the addition of the gas utility meeter with 2021.9 Home assistant.

A small addition to the historical gas use graph would be a degree day overview. This helps to see if any improvements or adjustments to the heating system have effect.
Much like the estemated solar production that is now projected on the solar production graph.

"A âdegree dayâ is a unit of measure for recording how hot or how cold it has been over a 24-hour period. The number of degree days applied to any particular day of the week is determined by calculating the mean temperature for the day and then comparing the mean temperature to a base value of 65 degrees F. (The âmeanâ temperature is calculated by adding together the high for the day and the low for the day, and then dividing the result by 2.)
If the mean temperature for the day is, say, 5 degrees higher than 65, then there have been 5 cooling degree days. On the other hand, if the weather has been cool, and the mean temperature is, say, 55 degrees, then there have 10 heating degree days (65 minus 55 equals 10).

Why do we want or need to know the number of "degree days?"
It is a good way to generally keep track of how much demand there has been for energy needed for either heating or cooling buildings. The cooler (warmer) the weather, the larger the number of âheating (cooling) degree daysââŠ and the larger the number of heating (cooling) degree days, the heavier the demand for energy needed to heat (cool) buildings."

I totally agree that this will be very useful, but I would love to have it in the Generic Thermostat were the outside temperature sensor is used as an entity source.

âdegree daysâ or Daily temperature is the average air temperature measured every hour change during a day.

A low resolution âdegree daysâ sensor for any location can be calculated based on the sun sensor, where the average temperature of: Sunrise, Solar noon (at the topp), Sunset and the last one at Solar lowest + the average of minimum and maximum temperatur during the 24 hour period.

The âbase valueâ as you reffere to, can be diffrent depending on your location. We use 17Â°C so this shuld be a parameter into the sensor.

Then based on the Derivative of the outside âdegree daysâ sensor compared to a âdegree daysâ value for the room (with out any extra heat/cooling), it would be posible to estimate the âtimeâ it will take to gain or loose 1Â°C of temperautre diffrence. Or how much Power defined as energy over time is required. Watts are defined as 1 Watt = 1 Joule per second (1W = 1 J/s)

Then in the Climate entity it would be possible to get Home-assistant to learn and predict the Power (Watt) needed to heat/cool the room to reach a given set temperature to a given set time.

The value the climate entity need to calculate/learn, is the heat transfer coefficient or (how âmuchâ J/s the walls in the room is âleakingâ).

K-value thermal conductivity of the room is also a good sensor value, how much heat is leaking to the cold side pr second e.g at night with out a heat source.

Direct sunlight on a wall, will also have a considerable effect on the temperature, but that would be an additional sensor for the equation.

I think it can be much simpler (and it would be better to keep it only in the energy dashboard). If you give the energy dashboard an outside temperature sensor and a setpoint, the degree day can be calculated. Then in the dashboard itself you can show the graph as before, or divided by degree day. This will essentially ânormalizeâ your data and enable you to compare heating energy use effectively.

Alternatively one could implement a degree day integration (it can be done via a template sensor I guess). Then it can be used in multiple ways, one of which is as described above.

So in short, I think the minimum that is required for this to be useful is support for a degree day value in the energy dashboard. I just donât have a clue how to code something like that (I would be able to create an integration though).

I would really love to see this implemented in the energy dashboard.
This way you can better compare day, month or even year data to see if meassures like isolating, tuning the heatpump, etc had a,hopefully positive, effect on energy (gas/electricity) consumption.