Crossposted on Engineering SE
Here and here show possibility to combine photons of lower energy to one higher. Thinking of an application, it could be used to dissipate heat from laptop. Liquid cooling device collect the heat from heat sink. Then the device makes infrared photons with the heat and send photons to an "upconversion" device. This device combine infrared into visible light photons and shine onto conventional solar cell.
One would think why not using thermoelectric generator which still needs to dissipate heat; however, by imagination could "upconversion" package waste heat collected using waste heat and turn them into light? My sentences may appear rudimentary as they are just ideas.