Before he took the helm of Holy Cross in 2018, Hannegan was the founding director of the Energy Systems Integration Facility at the National Renewable Energy Laboratory outside of Denver. The facility was conceived as a “grid-in-a-box” where researchers could study how solar panels, electric cars, battery storage systems, and other so-called “distributed energy resources” affect the way electricity moves around a grid.
As more homes and businesses install their own renewable generation and storage systems, it makes it more difficult for centralized utilities to manage electricity supply and demand. Ensuring that electricity gets to the customers who need it, when they need it, is simpler when you have a small number of large power plants that run on predictable fuels like coal, natural gas, or nuclear. But the energy produced by distributed energy systems tends to be renewable and therefore highly variable—sometimes the sun is shining, sometimes it’s not. Moreover, there are a lot of distributed systems. Instead of managing a few large power plants, utilities would have to manage millions of small ones.
“Utilities are moving away from just selling electricity to end users to managing the networks and electricity flows,” says Haresh Kamath, a senior program manager for distributed energy resources at the nonprofit Electric Power Research Institute. “There’s a lot of advantages to having these energy systems close to the end users, especially if the utilities have some way to orchestrate and coordinate them.”
Generating and storing renewable energy closer to where it’s used can increase the resiliency of a grid by ensuring that the electricity keeps flowing to users even if the rest of the grid is damaged by wildfires or other disasters. But the price of resiliency is efficiency. The proliferation of distributed, variable energy resources creates uncertainty for electricity demand; utilities will either produce too much or not enough. For Hannegan and his colleagues at NREL’s Energy Systems Integration Facility, it was clear that to create an electricity supply that is clean, resilient, and efficient, the grid of the future will have to largely manage itself.
In 2016, the Department of Energy awarded the National Renewable Energy Laboratory a $4.2 million grant to develop autonomous grid control software as part of its Network Optimized Distributed Energy Systems or NODES program. The idea, says NODES project lead Andrey Bernstein, was to create algorithms that optimized electricity distribution both at the level of individual homes and at the level of the entire grid.
“The problem is that the current technology is not able to integrate very large amounts of distributed energy resources,” says Bernstein. “What NODES produces is a plug-and-play platform that enables the integration of millions of devices such as solar panels, batteries, and electric vehicles that can be controlled at the edge of the system.”
The algorithms developed by Bern and his colleagues turn the grid into a two-way street. Instead of the top-down approach in which a centralized utility dispatches electricity to end users, the autonomous control software allows distributed energy systems to push excess electricity back onto the larger grid in the most efficient way possible. If it’s a sunny day and rooftop solar panels are producing way more power than their owners need, there’s no reason for a utility to be burning as much coal or natural gas. But without a network of autonomous controllers keeping tabs on distributed generation, a utility has a blindspot and can’t take advantage of the excess clean energy.
The autonomous grid control software developed at NREL was designed for handling tens of thousands of energy systems. But what works in the lab won’t necessarily be able to handle the chaos of real life. So after three years of testing the algorithms at NREL’s grid-in-a-box lab, the NODES team was ready to test it in the field. The autonomous software was first tested on a microgrid at a small vineyard in California and later was installed in small control boxes in the basements of the first four houses built at Basalt Vista.
