A one in 50 year storm hit South Australia this week causing extensive state-wide loss of power to homes and businesses.
Before the storm was over the political storm had begun, with politicians using the blackouts for political purposes and seeking to undermine renewable energy in Australia, pointing to the high renewable energy penetration in SA as the reason the state lost power.
As an electrical power engineer, i wanted to point out some things that are well known by electrical engineers, but perhaps not understood by politicians.
- Renewable energy sources are generally intermittent by nature, and unless large scale cost effective energy storage is achieved, cannot replace baseload power
- Having large penetration (percentage) of energy supplied by renewable energy can cause network instability where supply cannot meet demand, even for short periods, leading to load shedding and brownouts/blackouts
- South Australia is connected to Victoria and can supply additional power to meet demand so that no loss of power would come as a result of lack of wind (though the price of the energy would increase at that instant)
- The storm brought high winds and lightning activity
- Lightning overvoltages can cause a power system fault leading to a part of the network shutting down for safety
- High winds can cause trees to fall into power lines, and in SA resulted in more than 20 transmission towers collapsing – of course, for safety reasons, the power is automatically disconnected when these towers fall over
- A power system in general can withstand faults on the network, but when multiple faults occur, dropping off big loads, the system will have stability issues and will ultimately shut itself down – this is independent of how the power was sourced
The climate council has published a fact sheet about the event, and a video to help understand what really happened.