How weather changes affect renewable energy grids: ‘Moderate’ is the new ‘Extreme’

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From severe storms to unusual cold and heat waves, extreme weather events are impacting our electric utilities, grid operators, and customers more than ever before.

At the same time, our power sources are changing, with more renewable energy like wind and solar being added to the grid.

This combination of changing weather and evolving power sources raises important questions about how extreme weather and renewable energy will affect the reliability of our electric grid.

To explore these questions, analysts from the National Renewable Energy Laboratory (NREL) and Sharply Focused conducted a unique study. They aimed to understand how increasing renewable energy might change the way we think about and deal with extreme weather.

Marty Schwarz, an NREL power systems engineer and co-author of the study, explained, “We looked at two main questions.

First, we wanted to know if having more wind and solar power makes it harder to keep the power system running during extreme weather events.

Second, we wanted to see if these renewable technologies change what types of weather events we consider ‘extreme’ based on their impact on grid operations.”

Learning from the Past to Predict the Future

To create scenarios for their study, analysts used NREL’s Regional Energy Deployment System (ReEDS) model.

This model simulates how the bulk power system could evolve in the future. They looked at what the power system might look like in 2024, 2036, and 2050, with renewable energy making up 17%, 50%, and 65% of the annual demand, respectively.

They also gathered historical weather data from 2007 to 2013, as well as information on wind and solar resource availability.

This data was sourced from NREL’s Wind Integration National Dataset (WIND) Toolkit, National Solar Radiation Database (NSRDB), and historical electrical load profiles. By analyzing this data, they identified weather events that are crucial for modelers, utilities, and regulators to consider in long-term planning.

Defining New Categories of Weather Events

The historical weather events were divided into two main categories:

  1. High-impact events: These include cold waves, midlatitude storms, heat waves, and tropical systems.
  2. Events posing planning challenges: These include times when there is low renewable energy availability and high electricity demand, or high renewable energy availability and low demand.

With future grid scenarios and historical weather data in hand, the analysts tested how these factors might interact.

Rethinking ‘Extreme’ Weather

When we think of extreme weather today, we usually think of events that cause major disruptions, like hurricanes or massive storms. However, NREL found that the power grid’s impact from extreme weather events does not necessarily increase with more wind and solar energy added to the grid.

This study highlights that as we add more renewable energy sources, what we consider “extreme” weather might change. It’s crucial to understand these changes to ensure that our power grid remains reliable and resilient.

By planning for a range of weather events, including those that might not seem extreme today but could pose challenges in the future, we can better prepare our energy systems for the changing climate and the growing reliance on renewable energy.