The hopes of a group of a un-connected solar farms and several aspiring new solar projects in the Northern Territory have been a another blow, this time by new limits imposed on the main transmission line that runs from Katherine to Darwin.
Power & Water Corporation, which manages the main grid in the Northern Territory, issued a notice last week advising that the transport of power north along the 132kW transmission line linking Katherine with Darwin had been limited to just 40MW, down from 97MW.
The explanation of the new limit was to ensure that the line capacity did not exceed the size of the large generating unit in Darwin, which is about 40MW.
The move is designed to mitigate the risks of the transmission line failing – as a result of storms, winds or some other issue – but raises questions about the future of the territory’s stranded solar farms.
Two of them – 15MW solar farms at Batchelor and Manton – have been unable to generate because of the strict rules governing dispatch on the local grid. It effectively means they need battery storage, but the developers and owners say that this was not known at the time of construction.
Another solar farm, the 25MW Katherine facility, has now started generating small amounts after completing a small battery storage system, while another project – the 50MW Livingstone solar farm – is also hoping to connect to the grid.
The NT has promised a review into the dispatch rules to try and find a solution for the stranded solar farms, and it has also opened a tender for 100MW of new solar farms – accompanied by big batteries – although these will need to be built close to Darwin and the main gas generator at Channel Island.
The NT has also issued a contract for a 35MW, one hour battery for Darwin, which is currently being commissioned, but this is likely to be used principally as a back-up to the gas units, and to help smooth out the impact of rooftop solar, which dominates production in the middle of the day.
