The design space for long-duration energy storage in decarbonized power systems

Abstract

Long-duration energy storage (LDES) is a potential solution to intermittency in renewable energy generation. In this study we have evaluated the role of LDES in decarbonized electricity systems and identified the cost and efficiency performance necessary for LDES to substantially reduce electricity costs and displace firm low-carbon generation. Our findings show that energy storage capacity cost and discharge efficiency are the most important performance parameters. Charge/discharge capacity cost and charge efficiency play secondary roles. Energy capacity costs must be ≤US$20 kWh -1 to reduce electricity costs by ≥10%. With current electricity demand profiles, energy capacity costs must be ≤US$1 kWh -1 to fully displace all modelled firm low-carbon generation technologies. Electrification of end uses in a northern latitude context makes full displacement of firm generation more challenging and requires performance combinations unlikely to be feasible with known LDES technologies. Finally, LDES systems with the greatest impact on electricity cost and firm generation have storage durations exceeding 100 h.

Understanding the Role and Design Space of Demand Sinks in Low-carbon Power Systems

“…This model is described in detail in [14], but an overview is provided in Appendix F and its configuration for this study is described in more detail in Appendix E, with a setup similar to the one used in [4]. In its application in this study, the model considered detailed operating characteristics such as thermal power plant cycling costs and constraints (unit commitment), limits on hourly changes in power output (ramp limits) and minimum stable output levels, as well as intertemporal constraints on energy storage.…”

“…Demand-side flexibility (such as time-shifting of EV charging and heating) is also likely to be greatest over periods of hours [3]. While long duration energy storage systems (LDES) are in development and have the potential to provide significant flexibility to the grid, significant technological advancement is necessary for this class of storage technologies to be cost-effective [4]. An alternative method of providing long duration flexibility in the operations of a decarbonized electrical grid is through flexible electricity loads, which we term 'demand sinks' (also sometimes referred to as 'Power-to-X'): technologies that flexibly use excess or low-cost, low-carbon electricity to produce some useful or valuable output product [5].…”

“…The technology must be energy intensive (e.g. energy costs represent a major share of costs, such that operating around the availability of low-cost power is economically sensible) 4. Flexible operations must be highly automated such that significant costs are not incurred for idled labor during periods of low or zero output 5.…”

The Role of Biowaste: A Multi-Objective Optimization Platform for Combined Heat, Power and Fuel

“…Defined as a carbon-neutral energy source, biomass can be regarded as a promising energy storage option, compensating for the progressive phase-out of fossil fuels. In this context, Sepulveda et al (Nestor, 2021) have recently highlighted the role of firm low-carbon technologies in balancing future energy systems, decisively contributing for cost-effective zero-emission systems. The policy-enhanced requirement to generate negative CO 2 emissions places biomass in the center of renewable energy use (IRENA, 2016).…”

The Iron-Age of Storage Batteries: Techno-Economic Promises and Challenges

“…Battery pack cost estimates for iron-air compared to lithium-ion batteries.Comparison with other existing energy storage technologies: The the cost of the iron-air battery pack system at US$25/kWh is considerably lower cost compared to lithiumion batteries which are generally designed for portable energy storage applications. Current estimates for the cost of lithium-ion for EV and stationary storage applications are shown in Potential for long-duration iron-air storage batteries: Recent studies24 on the long duration energy storage systems capable of addressing intermittency in renewable energy generation should have a system cost ≤US$20/kWh, while also noting that charge efficiency plays a secondary role. The iron-air system shows considerable promise in this context with the material costs of about US$4/kWh and total system cost US$25/kWh with room for im-…”