# Assessment of the Value of Frequency Response Times in Power Systems

## TL;DR

This paper develops a MILP model to optimize the scheduling of various frequency response services, including fast-acting EFR, to enhance power system stability amid declining inertia due to renewable integration.

## Contribution

It introduces a novel MILP unit commitment model that simultaneously schedules inertial response, mandatory FR, and sub-second EFR, quantifying the value of faster FR products.

## Key findings

- EFR provides significant system stability benefits.
- Faster FR products can be cost-effective in future scenarios.
- Model helps optimize response time mix for system reliability.

## Abstract

Given the increasing penetration in renewable generation, the UK power system is experiencing a decline in system inertia and an increase in frequency response (FR) requirements. Faster FR products are a mitigating solution that can cost-effectively meet the system balancing requirements. Thus, this paper proposes a mixed integer linear programming (MILP) unit commitment model which can simultaneously schedule inertial response, mandatory FR, as well as a sub-second FR product - enhanced frequency response (EFR). The model quantifies the value of providing faster reacting FR products in comparison with other response times from typical FR products. The performance and value of EFR are determined in a series of future energy scenarios with respect to the UK market and system conditions.