Long Duration Energy Storage (LDES) stands as the pivotal technology driving the integration of renewable energy into our power grids, accelerating the journey towards carbon neutrality. Although the LDES Council lacks a precise duration definition, the US Department of Energy (DOE) identifies long-duration as having a storage capacity of 10 hours or more. LDES offers an affordable, reliable, and sustainable solution, facilitating the transition to renewable energy sources.
While wind, solar, and other renewables emerge as the most cost-effective forms of generation, the challenge lies in aligning their supply with demand, especially during peak periods in the morning and evening, traditionally addressed by burning fossil fuels.
The recent upheavals in the energy sector have underscored the need for an affordable, reliable, and clean energy system, elevating energy security on the global agenda.
Beyond bridging supply-demand gaps, LDES can play a crucial role in increasing the share of renewables in the energy mix, ensuring resilience in prolonged durations for unreliable grids (such as isolated or off-grid locations), facilitating cost-effective 24/7 renewable power purchase agreements (PPAs), and providing essential stability services to the grid. It is estimated that the world's electricity grids will need to deploy 8 terawatts (TW) of long duration energy storage by 2040, representing a market potential of USD 4 trillion.
Technologies suited to longer durations
The essential attributes of energy storage technologies lie in their energy capacity (the overall stored energy quantity) and power (the discharge rate). These characteristics can either be coupled (linked together) or decoupled within a storage technology. Technologies that enable a more flexible decoupling of power and energy capacity, allowing independent scaling of each without affecting the other, may be better suited for extended-duration applications.
Pumped Hydropower
Pumped hydropower, representing 95% of all energy storage in the United States, involves pumping water to a high reservoir during low power demand and releasing it during high demand. While the technology is mature, construction costs are high, and geographical limitations exist.