There are few CEOs as flummoxed as utility executives watching the future rapidly approaching to snarl their systems with power flowing in every direction from generators scattered throughout their networks. Picture erupting mayhem as "Arnold" crashes to earth in
target="_blank">The Terminator target="_blank">He's back
target="_blank">He's back, baby.
A centralized, 20th-century system could never coordinate and dispatch the future's hundreds of thousands of distributed energy sources, especially since many of them will be intermittent, like wind and solar.
Relax, power executives, you can breath a little easier. Help is on the way.
Total techno eye candy, a 5 MW lithium-ion energy storage system was recently given a media catwalk in Oregon. Portland General Electric's gorgeous new system - part of a demonstration project - will store excess electricity produced by solar and wind (which is very abundant in Oregon and difficult to manage). It's also an integral part of a regional smart grid project, and although the the Department of Energy has sponsored several across the nation, this is the only one to integrate diverse renewable energy sources.
As apart of a real time test conducted by the Pacific Northwest Smart Grid Demonstration Project, the "battery" or energy storage system, built by Indianapolis-based EnerDel (press release) and packed with 1,440 rack-mounted Li-ion batteries, sits at the core of a local microgrid, and will enable about 500 customers to tap into its stored power.
The CEO savior
The system's brain and utility CEO savior, the transactive control center ties the micro and regional grids together and makes sure all of the energy sources play nice. Developed by scientists at the Pacific Northwest National Laboratory, transactive control can help utilities effectively balance supply and demand for electricity.
Basically, it's a market-based system that
will allow PGE to store energy when market prices are low and pull from battery storage - rather than buying power - when prices are high.
The key to transactive control is a two-way communication signal that contains information about what power is available (and at what price) and what power is needed by end users. This information - all the way from the source of electricity, such as dams or wind projects, to the home - allows intelligent devices and consumers to make smart energy decisions, improving the efficiency of the regions' power system.
Centralized intervention is over: this system distributes decision-making throughout its many nodes, where devices are programmed with the prices they will respond to when they see a value signal that matches.
Consider a feeder line, for example. When it becomes overloaded, it sends a value-based demand reduction signal. Consumption points capable of demand response can then bid to curtail demand. The lowest bidders will get the job. In theory, the constraint will be alleviated at the lowest possible cost.
Implementing a demand response program
Integrating intermittent renewables is done by letting demand follow intermittent supply at a speed not possible through central dispatch, capturing how the wind supply and forecast varies to translate that into incentive signals, or prices, which are updated every five minutes and sent to participating utilities.
Typically, other power production has been adjusted if wind production fluctuates, but that comes at a price and, in the case of hydropower systems, wear and tear. In the future, when wind production slows, a smart grid could help shift the change in power to the demand side, which would cut
back after receiving the signal to use less power.
In this test, PGE is also implementing a demand response program, tasking the customers to shift energy use to off-peak periods, when energy demand is the lowest.
Researchers will collect and analyze the trial data from the Salem Power Center. The information and experiences from project participants will support a better understanding of how the benefits of smart grid technology may be realized for the region and our nation.
Photo: Storage Batter, Portland General Electric, Photos: Transactive contral center, PNNL - Pacific Northwest National Laboratory