I would like to try the power saving modes Andreas Sexauer described in the wiki:
ESP-specific APIs
APIs related to deep sleep and watchdog timer are available in the ESP object.
ESP.deepSleep(microseconds, mode) will put the chip into deep sleep. mode is one of WAKE_DEFAULT, WAKE_RFCAL, WAKE_NO_RFCAL, WAKE_RF_DISABLED.
but I have no luck to use ESP.deepSleep(). I get an compilation error and guess I miss an include. But ESP.h would not work. Am I missing something?