Berlin-based energy control company Younicos already has more than 100 megawatts of energy storage installed worldwide. In 2015, it took what it learned from those projects and applied it to the Y.Cube, a compact, easy-to-install storage unit for lithium-ion battery blocks. Younicos's unique power conversion system and smart software manages the unpredictable flow of energy from renewable sources such as wind and solar, acting as a kind of buffer to keep the grid--which was designed for the continuous flow of fossil fuel energy--in balance, and facilitating the smooth transition to a renewables-based power supply. The Y.Cube's small size means storing energy is cheaper and easier compared to similar systems with the same power rating. In 2015, Younicos scored a contract with Duke Energy to replace the batteries at the largest wind-connected storage facility in the U.S., and received a contract to use its Y.Cube in the first solar-plus-storage system, set to come online in Texas this year.