At the Lawrence Berkeley National Laboratory (Berkeley Lab) Guest House, guests who have business with Berkeley Lab can get a comfortable night's sleep—while experiencing a living example of some of the laboratory's scientific research. The Guest House is one of the demonstration sites and the testing site (or test bed) for the Demand to Grid (D2G) Lab in the Demand Response Research Center (DRRC).
Over the past year, the D2G Lab has been testing and improving strategies and standards for demand-side interoperability, wired and wireless communications, communication architectures, devices, and monitoring and controls technologies. All of these strategies and standards are part of research that will improve the efficiency of the nation's electric grid and the way it responds to fluctuations in demand or supply of electricity.
In fact, demand response is one of the biggest challenges faced by electric grid operators—balancing the moment-to-moment demand from consumers and industry with the shifting loads of incoming and stored electricity. Demand response can be manual, semi-automated, or fully automated depending on the market and customer choice, and customers can use advanced control systems to moderate how their facilities, equipment, or appliances respond.
As the electric grid has become more complex and diverse, automated demand response programs have been increasingly studied and tested in demonstration sites and cities and used commercially in utility programs over the last decade. Fully automated demand response does not involve human intervention but is initiated at a home, building, or facility when an external communications signal triggers pre-programmed load-shedding strategies.
In 2004, the California Energy Commission's Public Interest Energy Research (PIER) program initially funded the DRRC, managed by Berkeley Lab. The DRRC's research, development, and demonstration has led to a communications technology called Open Automated Demand Response Communication Standards (OpenADR), that standardizes the way demand response technologies work and interoperate within a "Smart Grid."
"OpenADR helps manufacturers of building automation equipment design products for Smart Grid implementation, and power aggregators incorporate demand response into their work," said Mary Ann Piette, the research director for DRRC. "OpenADR builds on more than 10 years of research to develop automated demand response technology and demonstrate it in buildings with utility, independent systems operator, customers, and commercial partners. The OpenADR specification uses open, non-proprietary, industry-approved data models—any interested party can develop products around it," she said.
The initial goal of the OpenADR research was to explore the possibility of developing a low-cost communications infrastructure to improve the reliability, repeatability, robustness, and cost-effectiveness of automated demand response. After the formal release of OpenADR 1.0 specifications in 2009 and implementation, the OpenADR standards are taking hold in the United States and around the world:
Early in 2011, Berkeley Lab's Grid Integration Group took the work one stop further—from commercial, industrial applications to residential demonstration through the D2G Lab at the Guest House.
"Our team has been doing other research on commercial and industrial facility grid integration and demand response and its market transformation," Rish Ghatikar, deputy leader for the Grid Integration Group, said. "We decided to use the Guest House as a residential appliance research lab since the infrastructure we needed for the set up was there," he said.
Demonstrations include communication between a multitude of end-use devices such as smart appliances, revenue-grade smart meters, and a home area network (HAN) gateway to receive demand response reliability pricing signals using OpenADR. Within the demonstration test bed, wireless and wired Internet (Wi-Fi), and in-home protocols and standards such as ZigBee Smart Energy Profile 1.0 and other proprietary protocols are used to interoperate with OpenADR and respond with a change in energy use.
The Guest House features appliances (heat pump water heater, refrigerator, washer, and dryer, loaned by the General Electric), an electric vehicle charger, programmable communicating thermostats, smart plugs, and dimmable LED lighting fixtures—all controlled by the HAN using DR signals and with Web-based energy visualization tools to provide information on energy choices being made during demand response events.
The Guest House's heat pump water heater is part of the demonstration. It has two modes of heating—resistive heating (where a heating coil heats the water) for everyday operation, and a heat exchanger that is used during a demand response event. The heater uses 4,500 Watts of electricity during standard electric mode, powering down to 550 Watts using the heat exchanger during demand response events.
Like the water heater, General Electric's other appliances; a washer and dryer, used by the guests, and a staff refrigerator, are "smart" appliances that communicate and switch to low-power operations in response to demand response signals.
The Guest House also features an electric vehicle charger by Coulomb Technologies, which will switch to lower charge levels during a demand response event. Before and during the demand response event, a message is displayed on the charger's screen letting consumers know what is happening and if they have to take any action.
Ghatikar and his team have preprogrammed all of these appliances to operate in a low-power-using mode when test signals are sent to emulate a demand-response event.
|Demonstration Area||Solution Providers
|Residential appliances, thermostats, plug-load meters, HAN integration, data analysis||GE, CloudBeam, Radio Thermostat, NEST, Itron, SilverSpring|
|OpenADR technologies and auto-demand response systems for end uses, strategies||Akuacom, AutoGrid|
|Lighting controls, communication, and technologies||Lunera and NEXT Lighting, CloudBeam|
|Electric vehicle chargers and grid integration||Coulomb Technologies, Auto-Grid|
|Analytics and Visualization||GE, CloudBeam, Akuacom, AutoGrid|
"Smart" appliances are one piece of the puzzle, but the way information moves between consumers and the electric grid—and the way it can be viewed and monitored—is the foundation for demand response success. The D2G Lab is demonstrating and testing a variety of communication architectures including the Energy Service Interface, a generic interface between the service provider and the customer that can be a Smart Meter, a gateway or devices in residential settings, building management systems for commercial buildings, and energy management and control systems for industrial facilities.
OpenADR signals are used at the D2G Lab, and can be sent over a variety of networks and transports (including the Internet) from a variety of entities (including the utility). Once the demand response event signal is sent, the appliances and equipment respond by changing the power use for a short period of time. Customers can always override the changes and continue using the appliances normally, though likely at a higher energy cost and compromised reliability of the electricity supply.
These signals are monitored, and energy usage information for each appliance and end-use device is collected (for example, at 10-second intervals). The performance information is stored locally or in the "cloud" for easy access, available from any web browser on a computer or smart phone.
"We want consumers to be able buy these kinds of devices and appliances inexpensively and then use them with any demand response service providers," Ghatikar said. "Let's say a homeowner buys a smart thermostat or appliances in the Bay Area and then wants to move to Southern California. They will want to take their thermostat or the appliances with them and for them to be able to communicate with and respond to the demand response signals from another utility as well," he said.
First-year operations of the D2G Lab have effectively demonstrated the goal research areas, identified new areas of research and development, and validated findings and conclusions that benefit the wider demand response community. In addition to continuing existing demonstrations, the D2G Lab's second-year goals include conducting new demonstrations that provide a suitable grid integration research and demonstration framework for Berkeley Lab's new FLEXLAB—a research facility opening later in 2013 to study energy efficiency technologies in buildings.
FLEXLAB provides a set of tools to allow research in how buildings components and systems can be designed and controlled to support the U.S. Department of Energy's (DOE's) Energy Efficiency and Renewable Energy Grid Integration initiatives. Improving the flexibility of electric loads in buildings will allow the electric grid to be more cost effective as more intermittent renewables are used in the supply systems.
|D2G Capabilities||Performance Parameters
|Lighting system control, energy and peak demand||System energy use, and peak demand; energy savings relative to non-controlled 1980s retrofit base-case in twin cell|
|HVAC control, energy and peak demand||Zonal load measurement, hydronic or air|
|Robust data acquisition system to accommodate additional instrumentation||Flexibility to integrate experiment-specific measurement hardware with existing testbed instrumentation|
|Demand response automation server and client designs||Client-server capabilities, price and reliability signals, latency testing|
|Energy and demand response models||EnergyPlus and Modelica tools to model control strategies, HVAC, lighting, and whole "testbed" energy use|
The FLEXLAB, or the Facility for Low Energy Experiments in Buildings, offers researchers a unique opportunity to collaborate in development, simulation, and validation of efficient building technologies. FLEXLAB will provide structures for manufacturers to conduct focused research and product development on single components or whole-building integrated systems. Building industry researchers can investigate building envelopes, windows and shading systems, lights, HVAC, energy control systems, roofs and skylights, or interior components such as furniture, partitions, and raised floors. The building loads can be controlled with electric batteries or integrated with Electric Vehicle chargers. The FLEXLAB will expand the DRRC's demand response research
Rish Ghatikar, Deputy Leader, Grid Integration Group and Project Lead
Janie Page and Chuck McParland, Lead for the Appliances and the HAN
Sila Kiliccote and Vish Ganti, Lead for the D2G
Vish Ganti, Project Coordinator, Technologies Demonstration and Analysis