Application process energy consumption monitoring?

With the current limits of battery technologies and growing orientation to greener technologies, is there a way of monitoring the energy consumption of a process like we monitor CPU consumption?

It could be a target for our future products, if carbon tax becomes a reality. It could be another thing for which we test.

It's a bit more than just cumulative resource consumption, because different resources use different amounts of energy and energy consumption is not linear sometimes. Given we had a way of monitoring, we would discover why battery is so crappy with Mountain Lion for example.

What do you think?