TL;DW: Incorporating pumped hydro storage into skyscrapers is a possibility. Not necessarily practical, but possible.

  • evasive_chimpanzee@lemmy.world
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    3 months ago

    I’m pretty disappointed in scishow for this one. Usually, they are pretty good.

    There are, in fact, deep conceptual flaws. There are a lot of grifters trying to sell ideas to fight climate change that can be easily defeated by high school level math. They try and spin the obvious shortcomings as “engineering challenges” where you could figure out a way to make it more efficient if only you invested in them enough. The math just doesn’t even check out at 100% efficiency.

    Potential energy is m x g x h. Let’s do the math for the Burj Khalifa. The top floor is at 585 meters. According to their published fact sheet, there are 57 elevators, and the service elevator has a capacity of 5500 kg. Let’s pretend that every elevator has this capacity, and they all go to the top. It would store 5500 x 57 x 9.8 x 585=1.797 GJ. This is about 500 kWh, or about the energy used by 17 average American homes for a day.

    According to wikipedia, the cheapest Tesla has a 57 kWh battery, so if there are 10 electric cars in the parking garage, they can store more energy than all the elevators.

    Hyperloops have the exact same issue, the math never checks out, so any company promoting them is fraudulent.