Solex company is producing electricity directly from a solar source by using a large array of solar cells and selling the power to the local utility company. Solex decided to use amorphous silicon cells because of their low initial cost, but these cells degrade over time, thereby resulting in lower conversion efficiency and power output. The cells must be replaced every four years, which results in particular cash flow pattern that repeats itself. Determine the annual equivalent cash flows at i=12%.