There's a reason used servers are so cheap on ebay: if you run them 24/7 their electricity cost makes them unattractive compared to new hardware (often within a year).
Said in another comment, my server averages around 100-200W. It's equivalent to running a gaming PC.
The reason there's a lot of cheap servers on eBay is that their support contracts expired and are absolutely ridiculously expensive to maintain for a big company. It's easier to get a new server (which will likely have performance and efficiency upgrades as well) than to continue maintaining a server that no longer has a support contract.
The reason there's not many servers in people's hands is size and noise. Servers aren't meant to go in a house; most people don't have server racks in their home. And by default, the fans are jet engines, even behind closed doors.
Your cheap TX electricity is, unsurprisingly, mostly gas. And if you look at data from 12h ago it was more coal than wind.
> According to ERCOT, nearly half of Texas’ electricity was generated by natural gas-fired power plants in 2019. Coal-fired plants and wind power each generated about 20 percent, while the state’s two nuclear power plants — the South Texas Project near Bay City and Comanche Peak near Glen Rose — supplied a total of 11 percent. Solar, hydroelectric and biomass resources provided most of the remainder
https://comptroller.texas.gov/economy/fiscal-notes/2020/augu...
If you need really cheap (and local!) compute for short periods of time, picking up one of those servers can still work out cheaper than renting from a cloud provider.