Testé in a project. wifi 802.11n, paquet send every 2seconde.
esp8266 powerd in 3.3V consum 33mA => 109mw
esp8266 powerd in 2.2V consum 26mA => 57mw
module work from 2v i use 2.2V for Security.
(i'dont use wifi_set_sleep_type(LIGHT_SLEEP_T ); because if i use me project d'ont work!)