Naturally this is a concept design that could really make a difference to the visitors of any city, it is a man hole cover that direct the person to the nearest public transport and how far it is.
It is a simple enough idea, but they are usually the best ones anyway as the simpler the idea more chance it has of getting off the ground.
This man hole cover uses rain water for power, so there is no need for it to be wired up to the mains power supply either.
The rainwater flows through the gaps onto a fan which rotates, this in turn will charge the battery pack, simple and yet very effective.
Source [Gajitz]
