Duke combines solar, storage in smart-grid trial
Duke Energy detailed on Tuesday a smart-grid program that pushes power generation and storage to edge of the transmission network.
The company is testing what it calls a "virtual power plant" at a substation in Charlotte, N.C., that it hopes will allow it to use electricity more efficiently.
The substation--where electricity is distributed to a local neighborhood--is equipped with a 50-kilowatt solar array, enough to supply at least five homes when operating. The 213 solar panels either feed electricity directly to the grid or to a 500-kilowatt zinc bromide battery.
About 100 households in the McAlpine Creek area have been equipped with a home energy management system that lets consumers view electricity consumption in real time and participate in energy-saving programs.
Utilities in general are seeking ways to curtail electricity at peak time, such as the middle of a hot summer day, when they may need to fire up expensive and polluting auxiliary power plants to meet high demand.
Rather than bring on new power capacity during peak times, the McAlpine Creek substation will draw stored electricity from the battery. Duke also expects to be able to level off demand through the residential energy management system.
Consumers can volunteer to have their air conditioner thermostat adjusted or drier heat turned off for a short period to reduce energy usage. The information about power reduction--aggregated across the different homes--is communicated back to Duke via a network so the utility can supply electricity to meet adjusted demand.
Duke earlier this month said it has contracted with Cisco Systems to build out a smart-grid infrastructure in a build-out expected to cost about $1 billion over the next few years. At the McAlpine Creek substation, there are both smart meters and sensors along the power lines to transmit information back to Duke's retail energy desk.
That information on electricity supply and demand creates a deluge of data that requires sophisticated data handling and analysis.
Duke has designed a system to analyze the information in real time using data analytics supplier Integral Analytics and event-processing software company Aleri, Anuja Ratnayake, Duke's manager of strategic initiatives and technology assessment, said during a conference call last week.
Martin LaMonica is a senior writer for CNET's Green Tech blog. He started at CNET News in 2002, covering IT and Web development. Before that, he was executive editor at IT publication InfoWorld. E-mail Martin. 
