Analogue wired cameras come in at a few dozen mW. And those aren't actually low power or anything, I bet you can get cameras using far less than that. Cameras

Analogue wired cameras come in at a few dozen mW. And those aren't actually low power or anything, I bet you can get cameras using far less than that. Cameras with built-in DSP and WIFI probably won't fit into that power envelope, though.