1. The problem statement, all variables and given/known data The daily load demand of a grid is given by P=Pmax * cos(pi*t/24). Here -12hrs ≤ t ≤ 12hrs. Maximum power occurs at (t=0) and minimum occurs at (t= ±12). A 10 GW hydro power plant with pump storage is available for base load operation. The turn-around efficiency of the storage system is 0.7. Find the peak load. 2. Relevant equations 3. The attempt at a solution I found the average power in terms of Pmax which comes out to be: Pavg=2*Pmax/pi. but now I couldn't figure out how to proceed. Any help will be greatly appreciated.