Google is going to implement a new energy saving feature in a new datacenter in Taiwan: thermal energy storage. This new technique is already used by a couple of datacenters, it works by using chilled liquid or ice as a thermal battery to save electricity costs:
Full details at GigaOM.
Thermal energy storage systems commonly use chilled liquid or ice to act as a thermal battery, enabling a data center operator to run air conditioning at night (when rates are cheaper) and during the day pump the chilled liquid around the facility for cooling.
Thermal storage systems are particularly good ways to save money when peak power grid rates are high, and using liquid or ice is a cleaner and longer lasting way to store energy than batteries. A Google exec says that a potential increase in electricity rates in Taiwan is one reason for building the new system, and the exec also notes that the Taiwan Google data center will use 50 percent less energy than typical facilities.