Rewards for Responsible, Real-time Energy Management
Transactive Network Project demonstrates energy negotiation between buildings and power grid
Imagine a city in the middle of a deep freeze. The local power grid is struggling to keep up with everyone's heaters. What if the grid could automatically communicate with buildings in the area and negotiate reduced power consumption in exchange for a financial incentive? A large hotel that's only half-full due to the weather could dial back its thermostats, saving money on their bill and enabling the grid to divert that energy to homes and schools.
Funded by the DOE's Building Technologies Office, PNNL and collaborators recently completed a 2-year Transactional Network Project that successfully demonstrated cooperative decision-making is possible for buildings. They used a software platform called VOLTTRON™ that allows communication between the grid and a building’s physical devices or systems to control how and when those devices use electricity.
Based on the promise shown in early field demonstrations, Transformative Wave Industries out of Kent, Washington, will pilot VOLTTRON in six locations and is spreading the word about the software to their utility and industry partners. Similar to the rooftop unit project, previously supported by BTO, they are targeting small-to-medium sized commercial buildings and creating a service based on VOLTTRON to deliver both energy efficiency and grid services.
"We are one step closer to the dream of smart, dynamic buildings connected to a smart, dynamic electrical system," said Dennis Stiles, program manager for buildings research at PNNL. "In this vision, whole buildings are aware of the collective energy use of all their devices and manage how and when those devices use electricity. This reduces energy bills, ensures the comfort of building occupants, and shifts loads to make energy use more predictable and relieve pressure on the grid."
Such "self-awareness" also includes diagnostics, recognizing when electric devices stray from their normal operations and need maintenance. In this streamlined energy ecosystem, buildings use less energy and adapt to the world around them.
Demonstrating the Concept with VOLTTRON
To enable collective communications and decision-making between buildings and the grid, PNNL researchers developed a computer software platform called VOLTTRON. This tool provides a "digital hub" for buildings to share data and make energy decisions.
From July 2013 through December 2014, VOLTTRON enabled two commercial buildings—one in Washington state and the other in California—to monitor and control their rooftop heating and cooling units. Sensors installed in each of the 11 rooftop unit recorded the units' operations, sending the data to VOLTTRON via the Internet. After crunching the data, VOLTTRON sent commands back to advanced controls installed in each unit, which then adjusted unit operations based on predetermined goals. These "transactions" took place in a matter of seconds.
Three different computer applications developed by PNNL ran on VOLTTRON to either identify problems with the units' operations or to negotiate reduced energy use during times of peak power demand. During three different peak demand demonstrations, data showed that unit energy consumption was reduced by about 25 percent.
In addition to the rooftop heating and cooling demonstration, two other national labs—Oak Ridge and Lawrence Berkeley—tested VOLTTRON to control commercial lighting, supermarket refrigeration systems, and rooftop solar panels.
Researchers are currently exploring the use of VOLTTRON to manage emerging technologies that connect to the power grid, such as renewable energy, battery storage, and electric vehicles.
The latest developments in transactive controls and grid integration were recently discussed at the Second International Conference on Transactive Energy in Portland, Oregon. For more information, see the conference website, or visit DOE’s Sensors, Controls, and Transactional Network website.
VOLTTRON and Beyond
In September 2014, VOLTTRON 2.0 was released and introduced agent mobility, secure agent packaging, and resource monitoring. It is open source and can be downloaded by visiting https://github.com/VOLTTRON/volttron.
Researchers at PNNL continue to improve the technology, with version 3.0 under active development with features such as:
- Enhanced security based on the results of penetration testing
- Supervisory agents able to detect issues with agents and devices and take corrective action
- Management utilities for easier administration of a distributed VOLTTRON deployment
- Increased modularization of key components such as device communication and data storage, making it simpler to swap in alternative technologies