Demand Side Resources Are Crucial to Flattening the Duck Curve

When the coronavirus outbreak began in early 2020, governments instituted travel restrictions, school closures, mask mandates, and social distancing requirements to ease the burden on the already strained medical system. As the pandemic progressed, testing kits, hospital beds, ventilators, and hospital staff were in short supply, creating gaps in the system’s ability to provide adequate care. With insufficient medical supplies, the focus turned to controlling the demand for medical care. “Flatten the curve” was the mantra repeated by government and public health officials. The idea was that, by limiting the amount of people who are sick at one time, peaks in demand for medical treatment could be avoided and the medical system wouldn’t become overburdened. What do the COVID-19 pandemic and the energy industry transition have in common? They both involve supply and demand, and an approach that considers both is required for success.

As the effects of climate change get more extreme with unprecedented heat waves and increasingly frequent natural disasters such as hurricanes and wildfires, the energy industry is transitioning away from centralized fossil fuel sources to distributed renewable ones. But an increase in the amount of non-dispatchable solar and wind capacity installed in recent years has resulted in peaks in supply that don’t match those in demand. The resulting duck curve presents one of the biggest challenges in transitioning to a zero emissions energy sector. In late afternoon, solar supply begins to drop off as the sun sets, but electricity demand continues to increase as people return home from work and school, resulting in steep multi-hour demand ramps. These demand ramps stress the grid and require fossil fuel plants to be quickly brought online.

Multiple Approaches Are Needed to Flatten the Duck Curve

How can the duck curve be flattened? Energy storage is one part of the solution, but it will not be sufficient on its own. Demand side resources such as energy efficiency and load flexibility can complement energy storage and allow for a complete transition to renewable resources. Foundational energy efficiency improvements such as upgrading HVAC equipment, lighting, and water heaters and improving building insulations can lower overall demand for electricity. Enabling two-way grid communication in flexible building loads and EVs can allow grid operators to control when electricity is allocated to meet that demand. The result is the ability to shift load from peak demand periods to periods with high renewable supply without sacrificing end user comfort. Moving from a follow the load model to one where demand is controlled can ensure reliable service in a grid powered by renewables.

Complex societal issues require supply and demand considerations to be part of their solution, and the transition to clean energy is no exception. The transition to a zero emissions energy sector cannot be solely focused on increasing renewable energy supply. Demand side resources can lower electricity demand and reduce supply instability on the grid, clearing a path to a net-zero electricity sector.