Step Onto The Manhole

Don’t worry you won’t fall in. This is the “Eco Sign” for you, a digital manhole cover that harnesses the rainwater to power it. Tap a foot left or right and it gives you instant info on the nearest train station or bus stop. Maps and signboards be damned! A multifunctional manhole with a rocking display…and all the thieves vying for it!

Designers: Cheolyeon Jo & Youngsun Lee

Eco Sign – Electronic Manhole Cover For Directions by Cheolyeon Jo & Youngsun Lee




  • Hm.. says:

    OK, little complecate..
    I see the basic concept and it’s good story..

    But if we go deeper, it doesn’t make sense.
    When we don’t hv rain,, how could it make energy???

    Why do we hv to put that expensive device into the manhole is got big pressure everyday.
    Why not into the Kiosk?
    We still hv better way, I think…

  • b0g3l says:

    interesting mechanism. but i feel like this could be applied much better being something else rather than a directive manhole

  • mif991 says:

    I like the thinking involved in this, but the designer forgets (conveniently) to take into account the cost of producing something that would take heavy duty abuse. Oh, I forget, the goverment pays for $100K toilets, so I guess it shouldn’t be an issue.

  • Chelsea says:

    Sounds and looks rather complicated. I bet this would be an extremely costly device to implement.

  • Mike says:

    Innovative design should offer something useful in a neat and creative package. This device is a gross overcomplication of a simple directive sign.

    A sign, — even glowing and of brushed aluminium, if you must be sheek — doesn’t even require buttons to show bus/train info, as it can show both together! Amazing.

  • Shon says:

    perfect example of design for design’s sake. The quality of Yanko’s submissions has been getting worse and worse.

  • Jayce says:

    Arn’t we forgetting something… most manholes are IN THE STREET! Lets have people standing in the middle of the street looking down, trying to read direction. No traffic tie ups or deaths there….

    • Brennan says:

      Oh, you stole my point, lol.

      Manholes are indeed in the MIDDLE of the road, where large, fast moving VEHICLES are traveling.

      I guess it’s a way of killing tourists who are looking for directions… just get them out there on the road with the promise of leading them to the museum and…

      And cars running over buttons 24/7, that’s harsh on the electronics…

      • Brennan says:

        Also, grade 10 physics class will tell you that potential energy is lost as soon as it hits the ground (since it becomes kinetic energy) and those slots are mighty tiny for rain to be falling inside without touching anything else.

        And, actually, what is the kinetic energy of a raindrop?

        I did some research and it looks like someone did it with piezo electric generators (which would be a lot (a LOT) more efficient than a propeller) and they got between 1 microwatt and 12 milliwatts per drop. Per square meter is about 1 watt-hour per year. Since the manhole slots are about 1/10 of that in area you get: 1/10th watt hour per year.

        Which means? It would take 600 years to get enough energy to power a 60 watt lightbulb for one hour assuming it rained constantly.

    • Brennan says:

      Do designers take physics anymore?

      Doing some research found me that even using piezo electric generators (which would be a lot better than that prop. blade) you would yield about 1 microwatt and 12 milliwatts per drop. Per square meter it’s about 1 watt-hour per year, assuming it rained constantly.

      Your slots are about 1/10th that area, and thus 1/10th the power generation.

      it would take 600 years of charging to power a 60 watt lightbulb for one hour, assuming it rained constantly for 600 years on that spot.

      • JC says:

        As silly as it sounds, no, they usually dont. I had 4 years in physics before going into design so functionality was always a big thing for me. I quickly became known as the ‘downer’ in the class for telling everyone that their product wont run on fairy dust and magic.

        For this product, the only thing i could think of was getting hit by a car…enough said.

  • powaz says:

    A manhole cover generating power? Maybe. A manhole cover that pedestrians are supposed to read? LUDICROUS!

  • john browner says:

    interesting idea, great for an afternoons thought into a new concept but if anyone had wasted longer than that on this project its worth finding a new career.

    There is potential energy in rain water but not in small localised solutions like this. If you need directions you are not from the area- so how would you know that you needed to walk on the manhole covers to find out information.

    Keep up the good work, great as an idea but not practical at all.

  • Nolan says:

    I am pretty sure the designers are referring to the potential energy of the water before down the manhole (Not the point of manholes mind you, but the diagrams show water flowing in) to rotate the fan (In which case a water wheel setup would be more efficient in this case than the proposed fan). I do not think they are trying to salvage any of the kinetic energy from the rain drops on their trip from sky to ground. Piezo electric generators in the ground getting energy from people walking would be interesting though…

  • dave says:

    i can’t believe that treehugger promoted this — imagine if you got hit by a car or a bus while trying to read where to get a bus or subway… really not smart. People need to stop making gimmicks and start making smart solutions.

  • Aniko says:

    What if the design were used to power street lamps? It would work very well in cities located in tropical regions where it rains more than 150 inches per/yr.

    • Brennan says:

      Perhaps they need large funnels on the street lights to gather the rain on the lights themselves?

      To wire from man holes to the light under all that concrete would be brutal…

  • yosef shuman says:

    I was going to rip this design a new one, but apparently it’s all already been done….

    At least I’ve regained some confidence in my fellow design-critiquing humans.

    Thanks kids!!

  • cody says:

    oorrrrr maybe a scale! Ya knever know when you need to check your weight!

  • cody says:

    oorrrrr maybe a scale! Ya knever know when you need to check your weight!

  • Henry KAKA says:


    This is the best…

    I like this
    perfect for our Manhole project Waiting for your
    permission to use the idea….

    Best Regards,,,,,


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