Wind Power Generation Comparison

[OUmecheng]

Homework Statement

Two sites are being considered for wind power generation. In the first site, the wind blows steadily at 7 m/s for 3000 hours per year, whereas the second site the wind blows at 10m/s for 2000 hours per year. Assuming wind velocity is negligible at other times for simplicity, determine which is a better site for wind power generation. Hint: note that the mass flow rate of air is proportional to wind velocity.

Homework Equations

e=KE=(V^2)/2
E = me

The Attempt at a Solution

Ok so I found e1 and e2 with the first equation.

Which gives me 24.5 and 50 J/Kg (respectively)

But I'm stuck now. How can I find m? It says that that the mass flow rate of air is proportional to wind velocity but how can I tie in time? Any hints would help.

I can tell that the second site would be more efficient, but I can't explain why.

 

[NascentOxygen]

But I'm stuck now. How can I find m? It says that that the mass flow rate of air is proportional to wind velocity but how can I tie in time? Any hints would help.

They are probably wanting the site with the highest annual mass flow, where
mass flow = mass flow rate x time