The products of cyclic and non-cyclic electron flow are different. Cyclic electron flow helps to build the proton gradient for the eventual production of ATP.
Non-cyclic electron flow has two outcomes. First, it helps to build the proton gradient, albeit not as effectively as cyclic electron flow. Second, non-cyclic electron flow also produces NADPH.
When would it be MOST advantageous for a plant cell exposed to plenty of sunlight to run non-cyclic electron flow, instead of cyclic electron flow?