Nightly mode change

General
#1

Hi,

I have Solar Panels with a Peak Power of 16kw and a battery with a capacity of 15kwh. Im Winter times, when the Heat Pump uses a lot of electricity, the battery is empty very fast.
My idea is to change the mode during night so that the standby power is supplied but the heating power is taken from grid. The heating tariff is 16ct/kwh while the normal tariff for the house is 40ct/kwh. This way, i intend to safe money.

What is your opinion?
Has someone tried That before?
Image attached! Test Phase between 3am and 4am.

IMG_4182
IMG_41821792×449 93.4 KB

#2

can you just have the heap pump not run at night?
is your battery flat before the morning or do you still have charge?

#3

Yeah, valid questions.
That depends on many factors, e.g.:

  • How much battery SoC (state of charge) is left from the day
  • When is the sun raising up
  • What is the outside temperature
  • How many rooms have the heating activated
  • …

I want to have a maintainable algorithm that does not need duzends of if-else constructs.
Limiting the discharge leads to a battery loss of ~2% per hour (15% in 7h). I can estimate pretty good when to start this mode when I want to have 30% for the energy consumption of the breakfast time.

Currently, I am experimenting with the outside temperature, such as
if temp < 2° then activate discharge limitation at 0am
elif temp < 3° then activate discharge limitation at 1am
elif temp < 4° then activate discharge limitation at 2am
elif temp < 5° then activate discharge limitation at 3am
elif temp < 6° then activate discharge limitation at 4am
elif temp < 7° then activate discharge limitation at 5am
else no limitation

First results look promising. But tuning is always possible :slight_smile: