# Sizing Storage for Reliable Renewable Integration: A Large Deviations Approach

## TL;DR

This paper models the reliability of renewable energy systems with storage using a Markov modulated fluid queue, providing insights into storage sizing to meet reliability targets, supported by real-world wind data case studies.

## Contribution

It introduces a formal probabilistic model for assessing reliability of renewable-plus-storage systems and characterizes the asymptotic behavior of load loss probability as storage capacity grows.

## Key findings

- Derived fundamental limits of reliability for renewable-storage systems.
- Provided a method to determine storage size for desired reliability levels.
- Validated the model with real-world wind power data.

## Abstract

The inherent intermittency of wind and solar generation presents a significant challenge as we seek to increase the penetration of renewable generation in the power grid. Increasingly, energy storage is being deployed alongside renewable generation to counter this intermittency. However, a formal characterization of the reliability of renewable generators bundled with storage is lacking in the literature. The present paper seeks to fill this gap. We use a Markov modulated fluid queue to model the loss of load probability (LOLP) associated with a renewable generator bundled with a battery, serving an uncertain demand process. Further, we characterize the asymptotic behavior of the LOLP as the battery size scales to infinity. Our results shed light on the fundamental limits of reliability achievable, and also guide the sizing of the storage required in order to meet a given reliability target. Finally, we present a case study using real-world wind power data to demonstrate the applicability of our results in practice.