May 2, 2016

Pursuing Grid Flexibility, Avoiding Grid Lock

New software busts through time barriers that prevent new energy resources from getting onto the grid

GridLab-D has several applications that demonstrate some of its capabilities. This Solar Demonstration Simulation shows the effects of clouds on photovoltaic penetration. Enlarge Image

Distributed energy resources (DERs), like renewable solar photovoltaic and energy storage systems, are part of the answer to a more diversified power supply. When brought together, these resources can provide the necessary supply flexibility to help meet demands. There is a complicated gap, though, between renewable generation sources and the electric grid: the "interconnection" application process. This important, but time-consuming, review function has become a roadblock—instead of a pathway—to diversifying our energy resources.

A new software tool, called GridUnity™, offers cloud-based analysis services that allow utilities to upload their distribution system planning models and translate them into a format used by GridLAB-D™. Developed by the U.S. Department of Energy's Office of Electricity, GridLAB-D™ is an open-source tool for studying advanced "smart" distribution grids. When paired with Qado Energy's user-oriented tools and interfaces, the resulting new scalable interface for simulating smart grid resources automates the interconnection analysis steps and cuts the processing time for each application from roughly 80 days to only one and a half hours. This not only reduces administrative costs, but more importantly, also increases grid reliability through the integration of DERs and accelerates the adoption of clean energy, such as solar, to meet the President's goal of 20 percent renewables by 2030.

United for a Better Grid Interconnection Application Process

Each new distributed generator or storage system must go through a process in which utilities conduct an engineering review of the new proposed energy source. For example, a home with solar—or photovoltaic—power could be a good resource for the grid, but conducting the study that determines that it is safe for the distribution system is costly and time consuming for the utility. As the pace of adding these resources continues to accelerate, conducting these engineering studies is becoming quite burdensome. Depending which state you live in, it could be months, even years, before you are approved.

GridUnity™ started as two solo technologies—Qado Energy with a cloud-based software application, and PNNL with GridLAB-D™. GridLAB-D™ simulates a smart grid with the addition of loads, batteries, and solar systems, but it was still research grade—suitable for lab simulations and studies, but not particularly user-friendly for industry.

"It would have cost three to four times as much to build GridLAB-D™ if we had made it more 'approachable' at the outset. Our hope was that companies like Qado would come along and build those interfaces," said PNNL engineer Rob Pratt, manager of the Lab’s GridWise™ program.

And they did.

"When we looked at PNNL's technology, we realized we could put together the pieces and re-architect them into a highly scalable cloud solution. By balancing complexity and ease of use, we've taken a highly specialized tool and made it more flexible in the hands of an engineer," said Brian Fitzsimmons, serial entrepreneur and founder of Qado Energy.

Today, both organizations are collaborating on a California Solar Initiative research project with California Edison to help the utility understand how much photovoltaic energy it can host before the distribution system requires more investment, and compare the costs of various technologies to mitigate the impacts. GridUnity™ is at the heart of the research.


About PNNL

Pacific Northwest National Laboratory draws on its distinguishing strengths in chemistry, Earth sciences, biology and data science to advance scientific knowledge and address challenges in sustainable energy and national security. Founded in 1965, PNNL is operated by Battelle for the Department of Energy’s Office of Science, which is the single largest supporter of basic research in the physical sciences in the United States. DOE’s Office of Science is working to address some of the most pressing challenges of our time. For more information, visit For more information on PNNL, visit PNNL's News Center. Follow us on Twitter, Facebook, LinkedIn and Instagram.

Published: May 2, 2016