NEM Local Temperature Alerts

High ambient temperatures reduce the efficiency and the reliability of thermal power stations, wind farms and solar farms, hence their available capacity. The power transfer capability of market network services (MNSP) also reduces at high temperatures. Hence, basing available capacities of plant on forecast local ambient temperatures provides a better representation of supply availability in the NEM.

AEMO developed the NEM Local Temperature Alerts process in November 2020 to signal the risk of high temperature affecting available capacity. This process uses weather stations across the NEM that are close to or have similar weather characteristics to where generation clusters are located. In October 2023 a review of this process saw the number of reference weather stations increase to 18 across the network (previously 16).

A suitable set of alert levels called NEM Local Temperature Alert Levels have been determined for these weather stations^[1]

Participant communication

When forecast temperatures for these weather stations are equal to or greater than the NEM Local Temperature Alert Levels, AEMO will publish a market notice reminding Generators and/or the MNSP to review the weather forecast in the local area and if required, update the available capacities in their dispatch offers or availability submissions consistent with the forecast temperatures.

The market notice includes the following information:

• Local Temperature Alert Levels
• Reference weather stations
• Region/s and period the Local Temperature Alert Levels are forecast to be met or exceeded

Selected weather stations and their Local Temperature Alert Levels are listed in Table 1.

NEM Local Temperature Alert Levels

[1] This has reference to AEMO power system operating procedure SO_OP_3703 – Short Term Reserve Management.