Home » Visualising the Tesla big battery at Hornsdale

Visualising the Tesla big battery at Hornsdale

by Jack Simpson
Hornsdale Power Reserve

Lately I’ve been working with AEMO’s 4-second interval data from the National Electricity Market (NEM). Visualising the grid at this resolution is so fascinating, and I wanted to share a couple of figures I’d generated looking at the Hornsdale Power Reserve (the big Tesla battery). The figures have also raised a couple of questions for me which I’ve recorded below.

In all the figures, the battery has no dispatch target – rather it is responding to the automatic generation control (AGC) regulation instructions. In the figures:

  • Left y axis:
    • MW is what the battery was doing
      • Positive values mean the battery is discharging
      • Negative values mean the battery is recharging
    • Target Ramp is the dispatch target of the generator
    • Target Ramp + Reg adds in the regulation component to the target
  • Right y axis:
    • Hz is the mainland system frequency
2020-08-08 09:00-09:30
2020-08-08 23:00-23:30

Question: The battery does not appear to be as close to its targets as I thought it would – is this real or is the 4-second resolution too slow to see the true generation of the battery?

2021-04-08 09:00-09:30

Question: Could this be the battery responding to a contingency event as it is not generating in response to dispatch or regulation targets? That said, the system frequency doesn’t appear to deviate too much from 50 Hz.

I hope you found some of these figures as fascinating as I did – it’s amazing seeing how much the battery is doing in each dispatch interval! If you think you might know the answer to some of my questions, please let me know!

You may also like