Total cellular ATP or NADPH measurement techniques are available but is it possible to measure ATP/NADPH specific to chloroplasts without isolating them? Any noninvasive technique will be very useful.
It is possible to obtain informations on energetic status of the chloroplast by electrochromism (absorbance variations of pigments caused by electrochemical proton gradient produced under illumination). However, you will need a specific spectrophotometer...
For more informations :
[1] B. Bailleul, P. Cardol, C. Breyton, G. Finazzi, Electrochromism: a useful probe to study algal photosynthesis, Photosynth Res, 106 (2010) 179–189.