The above ship is not power stable, so it will show that it is near 0% power capacity.
This is kinda useless information though, you either know the ship is "stable" or "not stable". There's no reason to show an actual power capacity bar of the ship.

A better change would be to show how much power recharge it has and how much is used of it.

• Reactor Power 5K e/sec 60% used
• Reactor Power 500 e/sec 200% used -> power unstable: orange color if power used > 100% and internal capacity > 10% or so

You can furthermore change the power bar colour depending on its current state:

1. Power stable ( used <= total power regen ): blue color
2. Power unstable with capacity remaining (capacity < 100% && capacity > 5%): orange color
3. Power unstable with no capacity (capacity < 5%): red color