The term of “co-generation” is often heard in the crowds of biofuel scientists and generally burnable fuels, because it provides both heat and electricity, through an intermediate mechanism. Nippon Telegraph and Telephone Corp (NTT) redefines this term, linking it to solar power in all of its meaning.
The company has shown a prototype of their “cogeneration-type amorphous photovoltaic power generation module” at NTT R&D Forum 2011 starting two days ago. Their module consisted of four pieces of Sanyo amorphous solar cells arranged in a sloping stair-like case, as you can see in the image, place in a water-filled container, covered with a transparent top.
The module can actually work with or without water. In the first case, the solar cells provide electricity normally, just like any other, but when the container is filled with water, the photovoltaic conversion efficiency raises due to the refraction and the reflection of light inside the liquid. They were able to demonstrate a 50% increase in the output current.
Because the solar cells NTT used aren’t very good at converting the infrared spectrum of light, the water takes over this task and collects the resulted heat. The system also has a water inlet and outlet, supporting integration into existing household heating systems.
Manufacturing costs are pretty high for the moment, but NTT is still researching methods to bring them down and eventually commercialize their innovation as soon as possible.