So, while I think it's pretty hard to do what you described, i.e., split a higher-energy photon into two lower-energy photons, I know the essence of the idea was to harness their energies and explain it in a non-overly technical way. Another idea, and I might hesitate to say better for much of the world in 2018, would be to split light's spectra and apply the optimal spectrum for PV to the panels and send the UV spectrum to glass with water flowing through it. Much of the world lacks safe water, and this could go a long way towards disinfecting much of the world's drinking water. And unlike the electricity from the PVs, this would be cheap to store.
It's 6 years later; how has the research gone? Plus an idea...
So, while I think it's pretty hard to do what you described, i.e., split a higher-energy photon into two lower-energy photons, I know the essence of the idea was to harness their energies and explain it in a non-overly technical way. Another idea, and I might hesitate to say better for much of the world in 2018, would be to split light's spectra and apply the optimal spectrum for PV to the panels and send the UV spectrum to glass with water flowing through it. Much of the world lacks safe water, and this could go a long way towards disinfecting much of the world's drinking water. And unlike the electricity from the PVs, this would be cheap to store.