11 January 2018, The Conversation, A month in, Tesla’s SA battery is surpassing expectations. It’s just over one month since the Hornsdale power reserve was officially opened in South Australia. The excitement surrounding the project has generated acres of media interest, both locally and abroad. The aspect that has generated the most interest is the battery’s rapid response time in smoothing out several major energy outages that have occurred since it was installed. Following the early success of the SA model, Victoria has also secured an agreement to get its own Tesla battery built near the town of Stawell. Victoria’s government will be tracking the Hornsdale battery’s early performance with interest. Generation and Consumption Over the full month of December, the Hornsdale power reserve generated 2.42 gigawatt-hours of energy, and consumed 3.06GWh. Since there are losses associated with energy storage, it is a net consumer of energy. This is often described in terms of “round trip efficiency”, a measure of the energy out to the energy in. In this case, the round trip efficiency appears to be roughly 80%. The figure below shows the input and output from the battery over the month. As can be seen, on several occasions the battery has generated as much as 100MW of power, and consumed 70MW of power. The regular operation of battery moves between generating 30MW and consuming 30MW of power. Read More here