Energy Bars can be easily added to powers to indicate a power level, energy, or whatever. To add one, just add this to your power json:

"energy_bars": {
   "energy_bar_name": {
       "max": 500,
       "auto_increase_per_tick": 1,
       "auto_increase_interval": 20,
       "color": "#fc8803"
   }
}

energy_bar_name must be a unique name of your bar so you can reference it later.
max is the maximum value of what your energy bar can hold. You can dynamically change this with a command if you desire.
auto_increase_per_tick (optional) can be used if your energy bar is passively charging up.
auto_increase_interval (optional) can be used to determine when auto_increase_per_tick is getting depleted (in ticks).
color (optional) is the color of your bar, duh.

With this set up the bar will appear, in the next section you can see how you can use.

Ability Usage

The most common usage for energy bars will be depleting them when using an ability. You can simply add this to an ability to do so:

"energy_bar_usage": {
   "energy_bar": "energy_bar_name",
   "amount": 10
}

There is also a condition which you can add to make sure the energy bar has enough energy:

"conditions": {
   "unlocking": {
      "type": "palladium:energy_bar",
      "energy_bar": "energy_bar_name",
      "min": 500
   }
}

Syncing with Scoreboards

In some cases it might be useful to sync the value of the energy bar to reflect the current score of a player. You can easily do that in the energy bar itself:

"energy_bars": {
  "test": {
    "color": "#ffffff",
    "synced_value": {
      "type": "score",
      "objective": "objective_name",
      "fallback": 0
    }
  }
}

fallback would be the value that is used if the objective/score can't be found.
You can also do the same for the max_value:

"energy_bars": {
  "test": {
    "color": "#ffffff",
    "max_value": {
      "type": "score",
      "objective": "objective_name",
      "fallback": 0
    }
  }
}

Both are combineable of course.

You can do the same with Palladium Properties aswell, if you have set them up using KubeJS:

"energy_bars": {
  "test": {
    "color": "#ffffff",
    "synced_value": {
      "type": "palladium_property",
      "property": "your_property_name",
      "fallback": 0
    }
  }
}