New building control systems and a pair of solar+storage systems will test the business case for greater integration of distributed energy resources.
Avista Energy is preparing to launch a “micro-transactive grid” in Spokane, Washington, that experts say illustrates the future of distributed energy resource (DER) management.
Beyond maintaining resilient power, the microgrid will provide visibility and control of smaller loads and enable trading of energy between two buildings in a way that could lead to new business cases and increased market participation for DERs.
And Avista is already working on other similar DER pilots that could help to expand the size and efficiency of the transactive microgrid.
The microgrid is located in the city’s University District, adjacent to downtown, and will allow two buildings operated by Washington State University to trade energy back and forth, charging batteries when prices are low or when there is abundant renewable energy. The system will allow the energy to be consumed when prices are high or during power outages to maintain system resilience.
The two buildings each include a pair of battery storage systems: a 500 KW / 1,500 KWh battery and a 167 KW / 337 KWh battery. A rooftop solar array on the buildings provides 100 KW each. The buildings also utilize advanced energy management systems that can monitor and control 60 individual loads.
“One of the great things we’re doing here is more granular load control,” Heather Rosentrater, Avista’s senior vice president of energy delivery, told Utility Dive.
Engineering work on the two-building grid is largely being handled by POWER Engineers. The project is expected to come online in March 2021.
“This project is a bit broader in scope than traditional microgrids,” Power Engineers project manager Greg Clark told Utility Dive. “A lot of times microgrids are constructed mostly for resiliency and to be able to support critical loads for longer periods. … We wanted to investigate four goals.”
Funded by the Washington State Department of Commerce, the project will examine how a combination of buildings and distributed energy resource assets can work together to provide grid services. The transactive environment will also tackle questions of DER optimization, including how utilities can best utilize the combination of battery storage and solar generation, and will consider how groups of buildings can be managed through the use of a central microgrid controller to manage assets in separate buildings.
Resilience is the fourth goal of the project, said Clark.
“Avista wants to understand better what kind of economic models they could provide for wider adoption of these types of systems,” Clark said.
Microgrids go beyond resilience
Microgrids in smart buildings are evolving beyond resilience use cases, according to Mark Knight, member chair of the Smart Electric Power Alliance’s (SEPA) Transactive Energy Working Group. He also serves as an industry adviser at Burns & McDonnell.
These buildings “have the potential to support their own transactive energy systems, but can also interact with a microgrid, for instance on a campus grid, and with other buildings to create a lot of flexibility and thus integrate renewables more effectively,” Knight said in an email.
A core component of a microgrid is the ability to balance supply and demand to maintain grid stability while disconnected from the greater power grid, according to Ben Ealey, principal of grid integration at SEPA. That requires different energy resources within the microgrid to be capable of providing flexibility.
A project like Avista’s “serves as an excellent entry point for new opportunities for the grid including transactive and market opportunities for community level aggregation” potentially including smart communities, buildings and campuses, Ealey said in an email.