Episode 05: A Tale of Two Grids (Distribution vs. Transmission System)

Today’s guest, Lorraine Akiba, is President/CEO of LHA Ventures. Lorraine is a recognized thought leader with technical expertise and knowledge in the development of Hawaii’s renewable and clean energy policy and regulatory framework. Previously, she was Commissioner at the Hawaii Public Utilities Commission, which presides over all regulated public utility matters in the state. Prior to this appointment, she was a partner at McCorriston Miller Mukai MacKinnon LLP and at Cades Schutte LLP, and led the environmental practice teams at both firms. Lorraine co-chairs the Low Income Consumer Solar Working Group of the Low Income Energy Issues Forum, a diverse national consortium focused on innovations that make utility service more affordable.

Specifically, the solar working group is addressing actions and recommendations for successful integration of community solar. She is also a member of the Resiliency Strategy Steering Committee for the City and County of Honolulu and is a member of the U.S.-Japan Council. Lorraine holds a JD from the University of California, Hastings College of the Law and graduated with honors from the University of California at Berkeley with a BA in political science.

For a more in-depth background on how the traditional U.S. electric grid works, see the Energy Information Administration’s Electricity Explained: How Electricity is Delivered to Consumers. For more on how the system is changing with grid modernization and the integration of distributed energy resources, see the Interstate Renewable Energy Council’s A Playbook for Modernizing the Distribution Grid.

For an in-depth primer on how the energy system is regulated in the U.S., read the Regulatory Assistance Project’s Electricity Regulation in the United States.

The episode touches on microgrids, which are “a group of interconnected loads and distributed energy resources that acts as a single controllable entity with respect to the grid. It can connect and disconnect from the grid to operate in grid-connected or island mode” (from the National Renewable Energy Laboratory). Put simply, a microgrid connects one or more customers to a local energy resource (which could be renewable, like solar or storage, or fossil-fired) and can be operated independently from the grid.

The episode walks broadly through: 

• what the electric distribution system is;
• what the electric transmission system is; 
• and how they intersect and why it's important to operate them in coordination with one another.

Key Takeaways:

• We need closer coordination between the transmission and distribution systems
  • “Both the transmission and the distribution system have to work in concert with each other in order to ensure a safe and reliable energy system. That synergy is becoming increasingly complex as distributed energy resources, like local solar and storage, grow. But this is also one of the most exciting areas of policy and technical innovation…”
• Climate change and extreme weather events make it even more imperative to have better coordination between the distribution and transmission systems:
  • “As we can see, just this month across our country, extreme weather climate change impacts are wreaking havoc on the energy system. From a management perspective, to be able to deal with outages or to be able to bring power back up again, there needs to be that integration. There needs to be some redundancy and to be able to have resilience to address these challenges.
  • That's why I'm a firm believer that it is important to really be able to utilize the distributed energy resources, the distribution system, which is closer to where the demand is, so the supply actually can meet the demand. But with more climate impacts—whether it's wildfires, or hurricanes, or typhoons, or what have you, floods—it is more important to be able to keep communities and smaller areas energized. We have the technology to do it, if we can make sure to coordinate between the two systems of delivery of energy.”
• DERs and microgrids can serve as resilience and reliability resources:
  • “There has to be enough reliability, resilience, should something like a hurricane occur, an earthquake occur that disrupts that system. You can make better usage of the distributed energy resources. And in fact, they can actually be the means to have resilience. If something's happening climate-wise or a storm comes in, you could maybe power stuff locally through a microgrid and isolate off pockets of a larger transmission system so that the whole system doesn't go down. That's kind of the concept in Hawaii.”