One major challenge of using wind as a source of power is that the wind is intermittent and it does not always blow when electricity is needed (Wallisiewicz 63). The intermittency issue is why the wind farms are not as financially profitable compared to other power sources which can operate all the time. As a full scale utility, few sites have enough wind to justify construction at the current level of technology. Wind power technology has made vast improvements in the recent years allowing slower wind speeds will be viable. This will allow a decrease in intermittency, thereby increasing the power output and revenue. Over the 20 year life of a small residential turbine, an owner could receive approximately $14,000 net revenue through both energy credits as well as tax credits (Gipe 76). A medium size would garner about $550,000, and as size increases the economics improve too.