We can certainly infer from the above pictured conception that it was a sustainable Christmas present from Sanwa Shutter Corp. That is because these state-of-the-art electric window shutters are equipped with advanced solar cells, and they were conscientiously unveiled by the Japanese company on 25th of December.
Named in the usual Japanese stoic manner as the ‘Madomoa Screen S Solar Type’, these photo-voltaic window shutters were specially conceived for single family homes. In this regard, the shutters open and close only by the electricity generated by their PV cells, which are fixed to their outer facades. Each of the solar cells are actually 550 mm x 58 mm amorphous silicon (Si) PV components, which individually have a maximum output capacity of 1W. The total electricity generated in turn is stored in a connected nickel-metal-hydride rechargeable battery.
According to the company, the daily electrical energy required for the shutters to function (that is automatically open and close) is about 1.3Wh. So, as per the calculations, the shutters need to absorb at least three hours of sunlight each day to properly function. However in emergency situations, the shutters can also operate for five continuous cloudy days. This is due to the sturdy battery component integrated within the ‘green’ system.
Finally coming to the commercial scheme of things, this particular window design pattern is a follow up to Sanwa’s PV equipped garage shutters, released back in November of this year. And, as always the solar windows cost much more ( ¥201,600 or approx US$2,399) than Sanwa’s conventional windows (¥90,405 or approx US$1,049). But this upfront cost should ultimately get covered due to the savings from eschewing conventional electricity.