The city shall possess and hereby reserves to itself all the powers granted to cities by statute and constitution to acquire, construct, own, operate, improve, enlarge, extend, repair and maintain, either within or without its corporate limits, including but not by the way of limitation, public utilities for supplying water, light, heat, power, gas, sewage treatment and garbage and rubbish disposal facilities, or any of them, to the municipality and the inhabitants thereof; and also to sell and deliver water, light, heat, power, gas and other public utility services without its corporate limits to an amount not to exceed the limitations set by statute and constitution.