AES gets closer to commercial deployment of grid-scale energy storage

Power company AES Corporation has taken a significant step towards the commercial deployment of grid-scale energy storage.

The development emerged with the successful completion of a demonstration and validation programme for a two-megawatt 500 kilowatt-hour battery system purchased by AES Corporation.

AES Corporation and Altair Nanotechnologies, post their agreement last year, have been developing a suite of energy storage solutions. This first solution is a modular unit designed to deliver in excess of one megawatt of power and 250 kilowatt-hours of energy per unit. Multiple units can be linked together in systems to provide both more power and more energy storage.

According to Altair, the grid-scale validation is expected to open new markets in the utility sector for Altair’s battery technology. The tests are important as they also indicate that lithium-ion batteries can be used for utility-grade energy storage. Right now, most short-term energy storage is done by lead acid batteries.

This demonstration also suggests that the technology could be used for several other utility applications.

For testing, the system was installed and operated at a substation owned by Indianapolis Power & Light (IPL), an AES company.

The system contained two one-megawatt battery storage units each consisting of one Altairnano 250 kilowatt-hour lithium titanate battery stack, AC-to-DC power conversion system, HVAC units, a control system and transformers to connect to the IPL grid.

The capacity of each unit was tested by repeatedly charging and discharging at one megawatt for 15 minutes during the process. In a second test, two megawatts of power from each of the units were used to show the capability of paralleling two separate systems. Additional testing included simulated frequency regulation, which involved switching the units from charge to discharge at up to one megawatt of power every four seconds for several hours.

The programme was developed and validated by KEMA, Inc. and executed by AES personnel and subcontractors.

Chris Shelton, director - Energy Storage Development, AES said, “Fast-responding, high-efficiency energy storage systems such as these will create a more resilient grid and allow for increased use of variable generating sources such as wind and solar.”

As per the information available, A123 Systems, which makes batteries for plug-in hybrids and power tools among other devices, is also actively pushing into utility storage.