I have started working on ideas for a meter in the simulator to show the incoming (sunlight) and outgoing energy (thermal and reflected light).
So far, the hardest part of the project has been to develop the atmosphere data array and making sure it is updated correctly as the simulator cycles over time.
The problem with such a meter is that any indication will be transitory and time based. The current idea is to have a meter that will show the indicator in the centre when incoming energy equals the outgoing energy, then when one is greater than the other, the indicator will swing to the left or right.
Easy in theory, but in practice I have a feeling it will take some time, especially as the graphics and animation have to be dealt with.