SWIS Observatory

Stress days make the transition legible.

The operating days where rooftop solar, minimum demand and the evening ramp expose what an isolated grid must still hold together.

Record: 90 operating days
Lens: Demand, solar and ramp
Source: AEMO WEM

Lowest operational demand

The registered-generation floor, before rooftop solar is added back.

019 May 20261039 MW
0210 May 20261073 MW
0320 Apr 20261239 MW
0422 Apr 20261239 MW
056 May 20261271 MW

Highest rooftop PV share

Behind-the-meter solar as a share of the underlying-demand proxy at its daily peak.

Reading the record

A stress day is a system question, not a score.

A low registered-demand day can still carry high underlying demand once rooftop PV is restored. A steep ramp is not automatically a failure. The point is to see which resources stayed online and what operating capability the system was using.

Open daily record

0110 May 202659.7 %
029 May 202657.4 %
0322 Apr 202656.8 %
048 May 202655.6 %
0520 Apr 202655.1 %

Steepest evening ramp

The rise from the daily operational-demand minimum to the evening operating peak.

015 July 20261695 MW
0218 June 20261618 MW
0314 June 20261600 MW
0416 June 20261583 MW
053 June 20261554 MW