Renewable energy sources such as wind or PV are directly sensitive to climate variables in obvious ways. In the case of wind energy, changes in seasonal wind patterns or strength would likely have significant positive or negative impacts because wind energy generation is a function of the cube of the wind speed. For PV systems, potential impacts require further research, however some experts anticipate that climate change could cause a decrease in global solar radiation which would lead to a corresponding decrease in solar cell output (US DOE, 2007).