PNNL transactive energy projects aim to improve DER integration

by Ethan Howland
APPA News
December 17, 2020

The Pacific Northwest National Laboratory (PNNL) is working on two projects designed to show how “transactive energy” can help efficiently manage distributed energy resources (DERs) such as rooftop solar.

Using market-based constructs, transactive energy provides a framework for the grid, buildings, electric vehicles, appliances and DERs to communicate with each other to balance real-time electricity supply and demand, according to the PNNL, a Department of Energy laboratory.

A more transactive energy system can improve efficiency, cost, and delivery while providing environmental benefits through the expanded use of intermittent renewable resources, according to PNNL. The approach could “substantially” reduce the amount of money spent updating and maintaining the nation’s energy infrastructure, the DOE lab said Nov. 23 in announcing the projects.

“Getting to the future transactive system will require advanced and automated control and coordination methods to enable the participation of flexible electrical loads,” Hayden Reeve, PNNL program manager, said.

The separate PNNL projects focus on technology deployment in Spokane, Washington, and on simulations of Texas’ primary power grid, operated by the Electric Reliability Council of Texas (ERCOT). The efforts are supported by the DOE Building Technologies Office and Office of Electricity, respectively.

PNNL tests transactive systems in Spokane

One project centers on Avista Utilities’ Eco-District, two buildings designed to test a shared-energy model where a centralized heating, cooling and electrical system can serve the energy needs of a group of buildings.

The buildings include solar panels, battery storage, thermal storage and sensors that track ambient conditions, air quality, occupancy and other attributes in real-time, according to Avista, an investor-owned utility.

In a multi-year, $7 million project, Avista plans to see how incentives can be used to manage the buildings’ energy loads and balance on-site energy demand, generation and storage in real-time, in a way that benefits the grid and provides flexibility for the building operators and the utility.

PNNL will bring to Avista’s project transactive energy management techniques developed at the laboratory-led Clean Energy and Transactive Campus.

The techniques include: intelligent load control, transactive coordination and control, a market-clearing mechanism, and automated fault detection and diagnostics, according to PNNL.

By being part of Avista’s project, PNNL said it will be able to refine the transactive energy management techniques and help develop a “shared-energy” model that other building owners and communities can use.

“Early on, our goal in CETC was to eventually conduct a broad field test to apply and evaluate some of the transactive and other energy-efficiency technologies we developed and demonstrated,” Srinivas Katipamula, a PNNL scientist, said. “Avista’s Eco-District aligned with DOE and PNNL objectives.”

Besides Avista’s two buildings, the project will include nearby retail and institutional buildings, according to Katipamula.

PNNL studies DER integration based on ERCOT model

Meanwhile, to see how transactive energy can help integrate DERs, PNNL researchers are conducting large-scale modeling, simulation and analysis based on ERCOT’s footprint, with the results extrapolated to reflect the U.S. grid.

“We are looking at participation of DERs from two perspectives: What we would see with an amount of renewable generation similar to that currently found in the Western U.S., as well as much higher levels, which would provide an idea of what’s possible if trends toward higher levels continue,” Rob Pratt, a PNNL engineer, said.

In addition to DERs, the project models a distribution system operator, the entity that conducts planning and operational functions associated with an electricity distribution system, including DER coordination, and a transactive network to realize the coordination, PNNL said.

Using the sophisticated modeling, PNNL researchers are studying the engineering and economic performance and identifying ways to provide economic benefits to grid operators and customers, according to the laboratory.

The researchers expect the study will affect two key products: a distribution system operations business framework and a compatible, field-ready transactive network design for coordinating DERs. The products will enable expanded testing of the concepts by industry and research institutions in simulations and the field, PNNL said.