Probably being over-optimistic as usual but...
Is it feasible to create a system with the following items:
Solar Garden Lights: Example
DC Booster ie http://www.ebay.es/itm/112468163238
ESP32 or ESP8266
that at night takes a reading from a moisture sensor and sends it via wifi to a control.
I guess that the battery would have to be able to keep enough power for 24hr of sleep mode for the ESP and then for the sending of data once a day.
Later I plan to swap the battery for a supercapacitor and create some sort of irrigation system but for now I just want to know if the battery from a small solar light will work through a booster in this way?