HSS overview

The Hydro Supply Security (HSS) test applies a deterministic methodology to calculate the risk of a storable hydro supply shortage by assuming that storable hydro is treated as the last resort supply of energy. The HSS test is encapsulated in a simplified version of the vSPD model.

The HSS test is similar, but not identical, to the notion of a Hydro Risk Curve (HRC) as published by the system operator. The purpose of risk curves, or a hydro supply security test, is to quantify the risk of extended energy shortages in a straightforward manner using a well-understood set of assumptions. The HSS test is encapsulated in a simplified version of the vSPD model. It applies a deterministic methodology to calculate the risk of a storable hydro supply shortage by assuming that storable hydro is treated as the last resort supply of energy. A range of assumptions regarding plant availability and hydrological conditions can be explored using the HSS test.

Only the energy market is included in the HSS test; reserve and frequency markets are excluded for now. The SPD-like energy model calculates the power flow in a system modelled with losses. The deterministic methodology is designed to make the model transparent and comprehensible to a broad audience of market participants. The Authority appreciates the shortcomings of this methodology in that it doesn't completely imitate actual supply behaviour, demand response, and the effect of ancillary markets. While the HSS test may be less precise than a method employing confidential participant information that is unable to be published, it nevertheless provides a lower bound on the underlying risk of extended energy shortages.

Download and install HSS

Users should appreciate that alpha versions reflect models that are still at the very early stages of development and have yet to be rigorously tested or verified.

HSS with Excel (alpha version)

Last updated: 20th February 2012

HSS user guide

Draft document: Draft HSS user guide

Last updated: 20th February 2012