Energy Consumption Update

[Bootneckshuffl]

Hi all

Posted on here a while back about my energy consumption in my M3P. Was a great thread with a lot of comments thanks.

Been doing some investigating with wh/mi and have noticed a massive difference if I turn off climate altogether. Now I understand of course that using climate would obviously impact the energy usage and wh/mi but I’m seeing a 100-150 wh/mi difference between having it on and off. It’s set to 20 Auto.

Anyone have an idea of what typical extra usage one would expect to see when using climate? Does that 100-150 wh/mi sound right?

 

[Mrklaw]

Hi all

Posted on here a while back about my energy consumption in my M3P. Was a great thread with a lot of comments thanks.

Been doing some investigating with wh/mi and have noticed a massive difference if I turn off climate altogether. Now I understand of course that using climate would obviously impact the energy usage and wh/mi but I’m seeing a 100-150 wh/mi difference between having it on and off. It’s set to 20 Auto.

Anyone have an idea of what typical extra usage one would expect to see when using climate? Does that 100-150 wh/mi sound right?

doesn't sound right to me. Whats your before and after? and what kind of weather and journey profile? Short trips won't let the car warm up so you'll only ever report the peak usage, and not allow for the lower power needed to keep at temperature for example.

 

[Bootneckshuffl]

doesn't sound right to me. Whats your before and after? and what kind of weather and journey profile? Short trips won't let the car warm up so you'll only ever report the peak usage, and not allow for the lower power needed to keep at temperature for example.

I thought the higher energy usage was just a winter thing but even in the “warmer” days we’ve had (like today 13 degrees), still seeing this higher spike with the climate on. I understand it’s a difficult one to diagnose and obviously the trip itself comes into the equation too.

 

[GRiLLA]

How far are you going? If the car is warming the cabin up to 20 it will use a lot of power to become warm but far less to keep it there. It would average out over a journey of about an hour.
If you are doing lots of short trips, then you are just cycling the temperature up and down.

 

[Peter 224]

Is the car a recent (2021 onwards) with a heat pump and the Octavalve?

My M3 Dual Motor is an April 2021 build and uses between 200 and 300 whr/mile and the climate control is set on "Auto"

 

[Bernard_S]

Another thing to bear in mind is the fan speed, if you have high fan speed set then the car has to heat up a significant volume of cold air. It takes a significant amount of energy to head air from say 0 degrees C to 22. Run at the lowest speed you can get away with the keep the car up to temp. Can make a 20% difference in the depths of winter.

 

[MrBadger]

Even without having to heat air, the fan speed will have a considerable power draw at higher speeds. I have a fan at home, heart rate controlled, which without directly measuring actual power would seem to add around 150-200W to the home load. Our MVHR also draws a considerable amount of energy when on high speed purge, and that is a low energy fan. At normal speeds, its just below 20-30W, but will quickly consumer significant power when having to push large amount of air around.

There is a graph somewhere, showing fan speeds vs energy consumption on some Tesla's. At the time when I was looking at it, I remembered that it matched my experiences. Certainly over time, you can pick out the drives when HVAC was on manual and fan speed would have been 1 or 2. Auto seems to bottom out at 4, very occasionally 3 for short periods if I had been waiting in the car before hand.

 

[Bootneckshuffl]

Is the car a recent (2021 onwards) with a heat pump and the Octavalve?

My M3 Dual Motor is an April 2021 build and uses between 200 and 300 whr/mile and the climate control is set on "Auto"

Nah, July 2020 M3P

 

[HenryT]

I have a fan at home, heart rate controlled...

Is that part of the Peloton system?

 

[MrBadger]

Is that part of the Peloton system?

No. Its made by Wahoo and works with any BLE or Ant+ heart rate signal. Certainly powerful enough to keep you cool when its 30+ and you are generating several hundred W yourself.

Its pretty easy to spot (consumption in red) when the fan was turned on then off again. That's an uplift of around 200W. Just pushing air around, although quite a bit of air - not just some piddly little desk fan.

 

[HenryT]

No. Its made by Wahoo and works with any BLE or Ant+ heart rate signal. Certainly powerful enough to keep you cool when its 30+ and you are generating several hundred W yourself.

View attachment 781255
Its pretty easy to spot (consumption in red) when the fan was turned on then off again. That's an uplift of around 200W. Just pushing air around, although quite a bit of air - not just some piddly little desk fan.

I never knew such things existed. Makes perfect sense now you've explained it.

 

[Adopado]

Even without having to heat air, the fan speed will have a considerable power draw at higher speeds. I have a fan at home, heart rate controlled, which without directly measuring actual power would seem to add around 150-200W to the home load.

I like your badger. (That is not a euphemism.)

Maybe someone with a Canbus reader (as per Bjorn) can see the car usage change when switching in the fans and heating/AC.

 

[Bootneckshuffl]

Another thing to bear in mind is the fan speed, if you have high fan speed set then the car has to heat up a significant volume of cold air. It takes a significant amount of energy to head air from say 0 degrees C to 22. Run at the lowest speed you can get away with the keep the car up to temp. Can make a 20% difference in the depths of winter.

Thing is the temps the last few days have been decent. Cabin

Even without having to heat air, the fan speed will have a considerable power draw at higher speeds. I have a fan at home, heart rate controlled, which without directly measuring actual power would seem to add around 150-200W to the home load. Our MVHR also draws a considerable amount of energy when on high speed purge, and that is a low energy fan. At normal speeds, its just below 20-30W, but will quickly consumer significant power when having to push large amount of air around.

There is a graph somewhere, showing fan speeds vs energy consumption on some Tesla's. At the time when I was looking at it, I remembered that it matched my experiences. Certainly over time, you can pick out the drives when HVAC was on manual and fan speed would have been 1 or 2. Auto seems to bottom out at 4, very occasionally 3 for short periods if I had been waiting in the car before hand.

awesome insight, thanks

 

[Avendit]

How far are you going? If the car is warming the cabin up to 20 it will use a lot of power to become warm but far less to keep it there. It would average out over a journey of about an hour.
If you are doing lots of short trips, then you are just cycling the temperature up and down.

I suspect this is your answer. Even once the cabin air is up to temp you still need to bring all the trim, seats etc up. Takes a while and uses a fair bit of power, but does mean your first 20 mins are not indicative of your 3hr drive.

 

[Peter 224]

Since the V11 update it is clear that when set to AUTO the heated seats come on before the cabin air has been heated to the desired temperature. I suspect that this gives a heating effect and places a lesser demand on electricity used to heat air and blow air. Climate control is now "set and forget" in that the car interior seems to quickly reaches the temperature you asked for.