So here is a little more complex of a solution, I will do my best to explain. We start by creating a timeline, which acts as a component of the blueprint we are using, in this example we are using the character blueprint.
When this timeline updates, we want our energy to regenerate, so we add a small value to it every time the timeline updates. These timelines are set to looping so they will update until stopped. Notice we add delta seconds to them, because like tick, we do not know when they last updated, World Delta Seconds is our fallback here, because it knows the time between the world’s last tick and it’s current tick, it may be off by a little bit regarding our timeline’s delta, but it will give us an acceptable value regardless. Also note the top value is being multiplied by a scalar, which may or may not be a good way for you to ‘slow down’ the regeneration.
You will also notice that I am updating two energy values each. This is not entirely necessary, but it is driving a value I have attached to a widget that tells me it is working as intended in my test environment, you may have something similar.
Finally, when the bar is full (equal to 1) I call Stop on my timeline, which is how we get improved performance over Tick, if we just let these things run forever, they will actually be considerably more expensive.