This post looks at fifteen kinds of utility or grid scale energy storage solutions that are either in wide use or have significant potential to supply the energy storage capacity that will help make the grid both more efficient and more robust. These range from pumped hydro, which is by far the most prevalent form of energy storage at this scale to compressed air, thermal storage, advanced batteries, fuel cells and purely electric storage systems.
The Environmental Protection Agency (EPA) has released the 1.0 version of the Energy Star for Servers specification. This first release only covers standalone servers with one to four processor sockets; it does not yet cover servers with more than four processor sockets, or blade servers of any size. Three criteria are being weighted by the specification: power supply efficiency, virtualization functionality, and energy-efficiency benchmarks and standards for measuring and reporting energy use.