# Homework Help: Wind Power Generation Comparison

1. Feb 5, 2012

### OUmecheng

1. The problem statement, all variables and given/known data

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.

2. Relevant equations

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

3. 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.

Last edited: Feb 5, 2012
2. Feb 7, 2012

### Staff: Mentor

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