Similar to
oxidative phosphorylation, this process produces ATP from a
proton gradient. The gradient is set up by pumping protons using energy absorbed from photons (light).
Chlorophyll bound to membrane proteins is excited by the absorbed photon, and the energy is transferred through a series of carriers as an
exciton (an electron-hole pair).
This energy is also used to make reduced NADH cofactors for the carbon fixing reactions (RUBISCO). So, in this respect it again mirrors the oxidation chain which consumes NADH while pumping protons. Additionally, chloroplasts split water (photolysis) while mitochondria produce water (from oxygen and protons). Thus the two systems are balanced in a production-consumption cycle. This is not surprising if you consider the view that Oxygen was the world's first pollutant.
hv hv (-)
| H+ NAD | NADH ( )
_V__ | ___ \ _V__ / _| |_
-----| |-------QH----| |----| |-------| |----
|Phs2|-elec->|---->|b6f| |Phs1| |Fo F1|
-----|____|-------Q-----|___|----|____|-------|_____|----
/ \ | -(PC)->
H20 (H+ Pool)