Here is a new system that switches glass from transparent to dark quickly. A team of researchers at MIT have developed these self-shading windows that can save energy by blocking sunlight on hot days. Unlike similar solutions, this system doesn’t require a whole lot of power to work. As MIT News explains:
Once the glass is switched from clear to dark, or vice versa, the new system requires little to no power to maintain its new state; unlike other materials, it only needs electricity when it’s time to switch back again.
Electrochromic materials were used for this system. The next step is to make devices based on this concept for further testing. This technology may also be used for low-power displays in the future.