It won’t keep the milk cold in the office refrigerator, but University of Cincinnati researchers say their concept for using the sun to light interior spaces is way more efficient than turning solar irradiance into electricity and then using that to power light bulbs.
The researchers call the concept SmartLight, and it’s basically a way to direct the massive amount of sunlight that hits office buildings to where it’s wanted, when it’s wanted.
The heart of the system: “electrofluidic cells” (as the name suggests, these are cells filled with fluid that can be electrically manipulated, and are now used for a wide range of purposes, including displays like E Ink). In the Cincinnati design, a grid of such cells would be powered by embedded photovoltaics, and applied near the top of a window. According to the researchers:
Each tiny cell – only a few millimeters wide – contains fluid with optical properties as good or better than glass. The surface tension of the fluid can be rapidly manipulated into shapes such as lenses or prisms through minimal electrical stimulation – about 10,000 to 100,000 times less power than what’s needed to light a traditional incandescent bulb. In this way, sunlight passing through the cell can be controlled.
With that, light could be programmed to be bounced and focused around a room to fit needs and desires. Even more valuably, perhaps, “Yet another portion of light might be transmitted across the empty, uppermost spaces in a room to an existing or newly installed transom window fitted with its own electrofluidic grid,” the researchers say. “From there, the process could be repeated to enable sunlight to reach the deepest, most ‘light-locked’ areas of any building. And it’s all done without needing to install new wiring, ducts, tubes or cables.
The researchers even have an idea for what to do when the sun’s not shining:
SmartLight can funnel surplus light into a centralized harvesting- and energy-storing hub within the building. The stored energy could then be used to beam electrical lighting back through the building when natural light levels are low. The Smart Light’s grid is so responsive – each cell can switch by the second – it can react dynamically to varying light levels throughout the day, meaning office lighting levels would remain constant during bright mornings spent catching up on email, stormy lunch hours spent eating at your desk, and late nights spent reviewing the budget.
Now, if this sounds a bit pie-in-the-sky and futuristic, it is true that Smart Light needs work. The researchers say “much” but not all of the “science and technology required to make the SmartLight commercially viable already exists,” and that’s what needed now is “enough funding to create a large-scale prototype which could call the attention of government or industry partners interested in bringing SmartLight to market.”