Duke Energy’s plan to build gigawatts’ worth of new natural gas generators to supply its grid over the next 15 years has already drawn fire from clean-energy advocates who say it violates the utility’s long-range decarbonization goals and could leave customers paying for power plants that can’t economically compete with cleaner alternatives. To learn more, read “Duke Energy Faces Challenges to Its Push for New Natural Gas Plants.”
- In Duke’s integrated resource plan (IRP) for its Carolina utilities, only one of six pathways for reaching net-zero carbon by 2050 avoids building new natural gas plants. The rest propose between 6.1 – 9.6 gigawatts of new natural gas capacity.
- The IRP also notes that Duke is planning a massive build-out of clean-energy capacity, including between 8.7 – 16.4 GW of new solar and 1 – 7.5 GW of new energy storage, depending on each scenario’s targeted levels of carbon emissions reduction.
- A key issue highlighted by Duke’s critics is that its IRP appears to have inflated its peak electricity demands and underestimated the amount of resources available to meet its winter loads.
- A second key issue is that Duke’s IRP appears to undervalue solar power, batteries, demand-side management, and energy efficiency as cost-effective alternatives to building new power plants.
- An independent analysis by Synapse Energy Economics found that taking a solar-battery path could reduce overall system cost by $7.2 billion, out of a range of 15-year costs; reduce carbon dioxide emissions by tens of millions of tons per year; and provide enough capacity to carry Duke through its electric-heating-driven winter peaks without threatening grid reliability.
Path to 100% Perspective:
Duke is facing the challenge of the pressure to decarbonize quickly, all while maintaining reliability for their customers. Fast-start, flexible thermal plants can help utilities meet rigorous carbon reduction targets, maintain grid reliability and minimize costs. They are designed to burn natural gas today and convert to renewable fuels produced using power-to-methane (or hydrogen) in the future. Power-to-methane (PtM) is one of a growing number of power-to-gas processes. PtM sequesters carbon from the air through direct-air carbon capture. This process is coupled with electrolysis for hydrogen, and a methanation process to combine carbon and hydrogen into synthetic methane. The electricity used to power this process comes from excess renewable (e.g., wind and solar) or carbon-free (e.g., hydro or nuclear) sources. Thus, the fuel produced from PtM is renewable.
Photo by American Public Power Association on Unsplash