Stacking concrete blocks is a surprisingly efficient way to store energy
Huh, I&#x27;m less doubtful of this than I thought I&#x27;d be. Tower cranes are apparently surprisingly low-maintenance. I assume this is because they have to actively participate in their own disassembly [1] and major breakages are super difficult to deal with because they&#x27;re at altitude, so they <i>need</i> to operate reliably enough that they can always take themselves down at the end of a job or if they need a major repair (cracks found in main pivot ring, etc). Concretely (pun not intended), I found a document [2] saying that 10 tradesmen and $35k&#x2F;month in parts (together a bit more than $1m&#x2F;year) can keep a fleet of 70 tower cranes (15 metric ton lift capacity each) at ~80% utilization over a one-year period. So, yeah, I&#x27;d definitely believe that you could run these things at the quoted price.<p>1: <a href="https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=Nww6MN_Lxeo&amp;t=24s" rel="nofollow">https:&#x2F;&#x2F;www.youtube.com&#x2F;watch?v=Nww6MN_Lxeo&amp;t=24s</a><p>2: Annex 9, &quot;Example of the Use of Key Performance Indicators for Maintenance&quot;, in this PDF: <a href="https:&#x2F;&#x2F;www.mantiscranes.ie&#x2F;wp-content&#x2F;uploads&#x2F;2017&#x2F;01&#x2F;CPA-TCIG-0801-Maintenance-Inspection-and-Thorough-Examination-of-Tower-Cranes.pdf" rel="nofollow">https:&#x2F;&#x2F;www.mantiscranes.ie&#x2F;wp-content&#x2F;uploads&#x2F;2017&#x2F;01&#x2F;CPA-T...</a>