Getting temp from well

[chucka]

I need some help. We have a well. The top of the well with pressure tank is a in-ground concrete housing about 400 feet from the building that contains a computer/wifi. We want to monitor the temperature because we can experience -30 degF temps. We did, and it cost $2100 for repairs. I'd like to take a reading, say, every 30 minutes and if below 35 degF send an email/text alarm.

So I know how to get the temperature with a ESP32. My problem is the 400+ feet + concrete. Ethernet over Power? ESP32 to ESP32 - would requre an external antenna. So suggestions, please.
Thanks

[ESP_Sprite]

It depends on what you need. If you can run an Ethernet cable, Ethernet + PoE is probably the solution that requires the least amount of maintenance aside from the initial Ethernet run. If running a cable is not possible, you could simply use a large battery to run the ESP32 - while it is in deep sleep, it will use nearly no power, and waking up every 30 mins and sending a reading can be done pretty quickly. (Do keep in mind what battery chemistry and type you use, though - some don't take too kindly to being run at very cold temperatures)

To get the data over, you have multiple options. You could go with WiFi if you can get the reach (an external antenna will help there, especially if you can get a directional one), and if you're OK with having a 2nd ESP32, you can use the long range WiFi mode of the ESP32. If that doesn't give you the reach, you could try LoRa or something similar, or even add a 4G cellular connection to the solution (although that probably would eat into your power use.)

[chucka]

Thanks for the response.

There is power in the pit. I'm going to ask/argue/suggest that the BSA Troop the our org sponsors build a Wishing Well over the pit. If I succeed it may end the need for monitoring as the structure would insulate the top of the pit. However, money wise, the cost of a ESP32, some wire, old spare parts, an external antenna is small enough to say "Hey, why not?".