Peak demand is the highest rate of electricity use. Fortunately, it only occurs a few times a year – usually on the hottest days of the year or on the very coldest days of the year, depending on your geography. Our power systems are prepared for these peaks (otherwise we risk potential blackouts), but as urban populations increase, and we add more variable renewable energy resources to our grid, we see more need to accommodate increases in peak demand. Traditionally, utilities would forecast demand in their service territories and resort to upgrading or building new peaking power plants to supply the anticipated increase in electricity demand. This solution tends to be land-intensive and has resulted in significant increases in greenhouse gas emissions.