https://blog.wongcw.com/2018/11/09/energy-vault%e5%88%a9%e7%94%a8%e6%b7%b7%e5%87%9d%e5%9c%9f%e7%a3%9a%e6%89%93%e9%80%a0%e5%87%ba%e5%b7%a8%e5%9e%8b%e9%9b%bb%e6%b1%a0/