The ES Pipe: Waterwheel concept could be installed in existing pipes to provide energy for light bulbs.
Korean designer Ryan Jongwoo Choi has come up with an eco-friendly concept for generating energy that can be built into everyday habitats. The ES Pipe: Waterwheel can be installed between existing pipes, and uses a number of mini turbines to generate power from the flowing water. Every time someone turns on the tap, energy is generated, which can be stored in light bulbs placed in the pipe. These bulbs can then be taken out at night to light an area with the accumulated energy.
Check out the video below to see the concept in action: