The EIA predicts that wind and solar energy sources will continue to increase in the United States, accounting for 16% of total power generation in 2023, up from 14% last year. However, as adoption of renewables continues, questions around how to create a reliable energy grid given the intermittency of power sources like sun and wind persist.
Referred to as a “duck curve” due to its resemblance to a duck, the below chart from California Independent System Operator (CAISO) shows a deepening gap between supply and demand of solar power throughout the day. It highlights problems in areas like California with high solar adoption– too much solar energy is produced during the day but not enough at night. Grid operators face a difficult challenge – they need to curtail production during the day to protect the grid from overload, but they also need to find ways to ramp up quickly to meet a sharp uptick in demand as the sun sets.
In addition to the duck curve challenge with solar, climate change may lead to less predictability from already intermittent power sources. For example, in June 2023, as Canadian wildfires sent plumes of smoke southward through the Northeast US, New England experienced a 56% dip in solar production in one week. This is because smoke acts as a barrier to solar panels, and heavy ash can accumulate on panels blocking sunlight. As climate change exasperates problems like wildfires in already dry regions, the impact on solar production will need to be addressed.
However, the effects of climate change on the reliability and predictability of renewables are not limited to solar. While research on the impact of climate change on wind patterns is still emerging, one recent study suggests GHG emissions could reduce onshore wind power density in the US and Canada by 15% by 2100 –with some regions reduced by as much as 40%. Moreover, the study predicts increased seasonal variability in wind power densities – creating a challenge for grid operators who will need to balance widely changing outputs from month to month.
Various solutions will play a part in creating a more sustainable and reliable energy mix. In the near-midterm, natural gas will continue to play an important role. Natural gas plants’ ability to quickly ramp up, supplying power to supplement solar and wind sources in as little as one hour, helps solve fundamental intermittency issues like the duck curve.
Some industry experts have suggested that natural gas infrastructure could also play a crucial role in supporting intermittent renewable energy sources by enabling better storage and transportation of renewables. For example, electrolyzers could use surplus electricity produced during particularly sunny or windy times to split water into oxygen and hydrogen. Hydrogen could be stored or transported through existing midstream infrastructure. Technologies like the Sapphire FreeSpin® turboexpander system can be used to maximize the clean electricity, and minimize waste produced in a future hydrogen distribution and consumption network.
While no perfect solution exists, one thing is clear: the intermittency issues with solar and wind energy are here to stay and may, in fact, get worse as climate change impacts predictability and variability of these sources. Our clean energy transition will, realistically, need to include a more stable backup and supplemental energy source like natural gas for the foreseeable future.
