Last year’s 1 in 50 year storm in South Australia which knocked out transmission lines and cut power to the state bought a new term to the debate about the reliability of renewable power – “frequency control”. After the loss of the transmission line wind turbines went off line, as they were designed to, one of the reasons for this was that the transmission failure cut the supply of a stable frequency provided to the asynchronous wind-turbine generators.
As a result of this its been claimed that we need coal for baseload generation in order to provide frequency stability. More specifically last week Australia’s Prime Minister Malcolm Turnbull said that “we need more synchronous baseload power,” a clear reference to frequency control.
However there are also engineering solutions that can enable wind turbines to operate without the need for coal power to be providing a reliable stable power supply. These include the “big batteries” being built in South Australia and Victoria, and demand response. In Australia’s national electricity market, there is a special sub-market for what is termed “frequency control ancillary services (FCAS).” Such services can either very quickly increase, or decrease, electrical load to maintain a stable frequency. Lithium ion batteries and demand response (switching large loads) when connected to automated control mechanisms are effective at providing these FCAS services.
Frequency Control in Action
And Mr. Turnbull and others don’t need to look outside of Australia to see such solutions in operation. King Island is predominantly powered by wind-power, and by incorporating a liquid electrolyte flow battery for energy storage, a flywheel for frequency control, and demand response, the island is sometimes powered without its diesel generators operating at all. That is, its powered by 100% renewable power, with no fossil fuel generation needed for frequency control. And this system has been built and designed by an Australian company, Hydro Tasmania.
We don’t need coal to provide frequency control, we do need clever engineers, and marketplace rules that facilitate and encourage the uptake of renewable energy. On becoming Prime Minister Mr. Turnbull’s key word was “innovation”. I urge him to visit King Island and see an innovative solution to energy security.