By Bill Conlon, President
March 31, 2021
Extreme weather events, from the polar vortex in ERCOT and MISO to wildfires in the west, and superstorms on the east coast, are compromising grid reliability and highlighting infrastructure interdependence. We experienced in stark terms how our modern life depends on reliable power for water and sanitation, communications and transportation, heating, cooling, and healthcare. Reliable power requires constant availability of primary energy resources in the form of water, wind, sunlight, or fuel. Extreme weather and climate change have compromised hydro resources, becalmed wind farms, caused fire ash to block the sun, and frozen fuel supplies. Reliability in the face of these extremes will require a broader, holistic, systems perspective that prioritizes consumers’ need for service.
Realistically, these extreme challenges will be with us for a century or more — throughout the transition to net-zero or net-negative emissions, and beyond. But the energy transition is essential and urgent. Rather than focus on the limitations of generation technologies — wind, solar, natural gas — we can synergistically integrate these systems to build resiliency— leveraging each technology’s strengths to bolster reliability and improve sustainability.
Integrated resource planning to meet an objective (cost, sustainability and reliability) typically results in siloed procurement of renewable, conventional, and storage resources. Faster progress on decarbonization can be achieved with integrated procurement of mutually complementary resources able to reduce cost by enhancing overall resource utilization and blending critical resources to enhance reliability and permit grid sectionalizing.
Unifying the renewable and conventional grids via hybrid energy storage provides just such a holistic glide path to meet climate objectives and maintain reliability at the lowest cost. Large-scale hybrid energy storage – delivering tens to hundreds of gigawatt-hours – is feasible today with thermal energy storage using liquid salt or liquid air in above-ground tanks or with underground mechanical storage of compressed air. These hybrid approaches build on proven components already deployed at utility-scale in power plants around the world to leverage existing assets, personnel, and know-how.
With abundant long-duration storage, accelerated deployment of renewable resources can be greatly expanded without curtailment. Stored energy can be time-shifted, reducing the fuel Heat Rate and emissions of thermal generation to provide low-carbon dispatchable power when wind or solar are unavailable. Thermal storage also improves the operability and ramp rates of thermal units, expanding their economic and environmental operating range to buffer the variability of intermittent resources.
The fuel efficiency of hybrid energy storage aids resiliency by reducing the burden on gas infrastructure, as well as reducing the cost burden associated with emerging use of expensive or scarce renewable fuels. Both underground compressed air and liquid air hybrid systems can also provide on-site gas storage for fuel security.
Hybrid energy storage presents a unique opportunity to rapidly integrate our current and near-term energy resources to improve asset utilization, reduce emissions, and enhance resiliency. The fastest paths to meaningful carbon reduction are the ones we can execute immediately at reasonable cost.
This post originally appeared in Energy Central‘s March 2021 Special Issue on Power Generation.