Buildings consume a significant portion of the overall energy produced. Over 20 percent of global energy production is consumed by buildings alone. In the U.S., buildings account for 40 percent of total energy production, and more specifically, buildings consume 70 percent of total electricity and 50 percent of total natural gas production. Thus, buildings are a significant and fluctuating load on the power grid that needs to be maintained. Furthermore, building energy usage surpasses other industries in many countries, and these numbers are projected to increase.