Todd Woody at Grist has a post on a project in Texas to install a large battery for energy storage at a wind power plant - Texas to install world’s largest wind energy storage system.

They like to do things big in Texas, so it's no surprise that the Lone Star state will launch the world's largest wind battery storage project.

Duke Energy is not a Texas company, but it owns the aptly named Notrees wind farm in the Texas panhandle. The North Carolina power giant is teaming up with an Austin area startup called Xtreme Power to install a 36-megawatt battery at the 153-megawatt Notrees Windpower Project near Kermit, Texas.

That's one big battery. Such technology is likely to become crucial as wind farms become ever larger but erratic suppliers of electricity to the grid. In wind-blown West Texas, the region's massive turbine farms can generate more electricity than the grid can handle at some times while all but ceasing production at other times. That creates headaches for grid operators, and the ability to store wind energy and release it when needed would help smooth out the ebbs and flows of the electricity stream.

"This system will store excess wind energy and discharge it whenever demand for electricity is highest -- not just when wind turbine blades are turning. In addition to increasing the supply of renewable energy during periods of peak demand," Duke said in a statement.

Pacific Northwest grid operators will probably be watching the experiment closely. That region boasts abundant hydropower and huge wind farms, which has created situations when there's a surplus of both wind and water power and insufficient capacity on transmission lines to offload the electricity. Batteries would help, though it probably would take huge banks of them to have a significant impact.

The federal government is obviously interested in the technology. The Department of Energy has thrown in $22 million for the project, with Duke matching the grant with another $22 million.

Earth2Tech has an update on efforts to connect the major regional electricity grids in the US - Xtreme Power Joins the Transmission Hub Project.

The startups that have teamed up to build a transmission hub to connect the U.S.’s three major grids in the east, west and Texas are adding another startup player for energy storage. This afternoon, Tres Amigas, the Santa Fe, N.M-based company behind the transmission project, announced that they have partnered with Xtreme Power, a startup which provides groups of batteries for energy storage for the power grid. In June, Tres Amigas also signed on startup Viridity Energy, which makes software that dynamically manages loads on the grid in terms of energy pricing, renewable energy generation and energy storage.

Tres Amigas’ plan is to build a so-called “SuperStation” — the mother of all substations — that would use superconducting cables from American Superconductor Corp. that can carry 5,000 MW of electricity, are super-chilled to minus 300 degrees Fahrenheit, and can boost the lines’ carrying capacity. The substation itself would act as a hub and balancing authority, and would convert the alternating current (AC) from the three grids into direct current (DC) and then back to AC in order to move the electricity back out onto the three grids in an efficient and reliable way.

Xtreme Power’s batteries would provide storage for the SuperStation to help balance the flow of electricity, and importantly, to enable the addition of more clean power, which is variable, depending on the wind and sunlight, which aren’t always available. Xtreme Power’s batteries would store and release power in response to fluctuations in demand and supply at the hub.

Six-year-old Xtreme Power is building this type of storage system for other clean power projects, including a 10-megawatt storage system meant to back up a 30-megawatt wind farm planned for the Hawaiian island of Oahu. The developer of the wind project, First Wind, recently received a $117 million Department of Energy loan guarantee for the project, and Xtreme Power said it will be managing not only its battery, but the entire wind farm’s output via its own smart grid network. Xtreme has also tested a 1.5-megawatt battery system at another 30-megawatt wind project on the island of Maui.

For its batteries, Xtreme uses a PowerCell battery chemistry that it calls a “chemical capacitor,” which it says can beat lithium-ion batteries in terms of energy storage, efficiency, cycle life and cost. CEO Carlos Coe told us back in March that Xtreme’s PowerCell battery tech acts more like capacitors: charging and discharging at high speeds, while at the same time, maintaining the qualities that make batteries better than capacitors for long-term energy storage.