Cameras would be controlled by a microcontroller. Arduino and Raspberry Pi would be my top choices.
Raspberry Pi would be my number one choice. the camera attachment that is purchase able for it is surprisingly good for it's low cost.
A Python script would need to be ran constantly on the Pi. This script would either record a live feed at low fps and bitrate, or take a picture every second, and transmit that data to a server, whether it be a website, cloud service, or even a home ftp server.
The script will be as minified as possible in order to reduce power usage.
The Pi will be powered by either a power bank, small solar panel, or both.
The Pi will transmit data through either WLAN, or mobile network.
Looking forward to hearing back from you.