Just a heads-up about the upcoming firmware: in firmware 2.1.8 (to be released by this weekend), we added support for AP mode functions — all functions (except NTP syncing and weather data, obviously due to lack of Internet) are enabled in AP mode. This way the controller itself behaves like a router, and your computer or mobile app can directly communicate with the controller, you can set programs or start/stop zones directly without an external router.
Regarding peak power: the controller itself draws about 150mA in resting state (this is mainly the power needed by the WiFi chip). Each opening valve adds another few hundred mA of current draw.