what is the area of the wind farm? The optimal efficiency, η = 0.49 and  The ideal spacing for a turbine is 300m by 1000 meters  Answer in km2

Dresden, Germany has a population of 700,000 and a population density of2200 km-2 in the urban area. Assume that the electrical needs of Dresden are an average of1.0 kWe per capita and these are satisfied by a wind farm consisting of 100 m diameterthree-rotor wind turbines operating at optimal efficiency and with optimal spacing. If thewind velocity is constant at 7 m/s, what is the area of the wind farm? The optimal efficiency, η = 0.49 and The ideal spacing for a turbine is 300m by 1000 meters  Sustainable energy, 2nd edition, Ch 10, Problem 17P

A fan manufacturer rates his fans at 152 mm water gage static pressure for 10 m of air per second at 21°C, 1,200 rpm and static efficiency of 69%. At what speed, in RPM, would these fans operate to develop 130 mm water gage when the temperature is 316°C? (14) O 1470 O 1670 O 1770 1870 1570

Consider two identical wind turbines with a hub height of 40 m, one located in flat agricultural land and one located above a forest. What is the relative output power for the two turbines if the wind velocity is 10 m/s at a height of 100 m in both cases? Pagricultural/Pforest = ?