Warning Siren - St. Louis, MO - Solar Power on Waymarking.com

County of power panel: St. Louis Independent City
Location of panel: alley between Jefferson Ave. & Indiana Ave., N. or Crittenden St., Benton Park

Not sure how this works, but solar panel on siren pole which I assume stores the necessary juice to make it go when it needs to go

"The new warning sirens are meant for any type of hazard that may threaten the city, with the primary one being tornadoes, which is why they are tested the first Monday of every month at 11 am (weather permitting). St Louis County also tests at this time, but none of the ones in the county are voice-capable (and they have a list of all 200+ locations online so don't need help with that). The old sirens are mechanical with a large motor spinning a powerful fan and chopper to create the noise. They could do just two signals....a steady alert and a wailing up and down attack signal and were controlled via leased land-lines. The new ones are loudspeaker cells stacked on top of each other that can range from 1 to 10 units tall, though most in the city are 7 cells tall. They are all solar-powered and run off of batteries so that they can still send out a warning at night or even when the municipal power has been out for a week. Most fire stations have one up on a pole in back and there are others scattered around on telephone poles throughout the city. I have found most of the locations in the city from Delmar south but will go explore around the northern sections more to find others. I attached a picture of one of the newer models and though not the best picture of one, it has a building in the background that makes it more board-related. They are fairly easy to find as many are at fire stations and once you have found several and plotting out approximate 1-mile or so coverage rings (depending on the number of speaker cells) you can see where gaps in coverage are and the approximate area of where another one should be. The old system is much more intriguing though and up until 1999 when the new system began to be installed, St Louis had one of the oldest running warning siren systems as very few cities still retained their WW II sirens and instead had ones installed in the 50s, 60s, and 70s with Civil Defense funds during the Cold War. " ~ Sirenboy St. Louis