Assess the viability of wind trees. We?ll put this in thewindiest city in the US listed as Amarillo at 13.6 mph average windspeed (assume constant winds) and assume an effective swept areadefined by the sum of the microturbine areas. There are 54wind foils that are 1-m tall (assume 1-m diameter swept circulararea times 0.5 apiece since they are ovals). The density ofair can be taken as 1.2 kg/m³.

(a) Find the steady state power output (W) of a wind treeat this location. Turbine efficiency can be assumed as60%. How many kW-h would it produce annually with constantwinds?

(b) The device costs $35,000. Compare to the currentinstalled cost of residential solar PV of ~$3/watt.

11,5ft 30,2ft 3 ft