Coal fired power stations across Queensland, New South Wales and Victoria are scheduled to be retired over the next 20 years. Many of these individual power stations, such as Eraring (2800 MW) and Liddell (2000 MW) are comparable in size to Hydro Tasmania’s entire hydro generation (2500 MW). Australia’s power consumption will increasingly be met by wind, solar and storage, constructed across widely dispersed Renewable Energy Zones. Large amounts of energy will need to be transmitted enormous distances to reach the major load centers where it is needed.

Around the world, transmission has emerged as a critical bottleneck limiting renewable energy’s cost-effective contribution to the power mix. It is a challenge faced intra- and inter-state across Australia, and is widely attributed to the 40% drop in total renewable energy spending (including rooftop solar) from 2018 to 2019.

To unlock the generation capacity of Australia’s Renewable Energy Zones, significant additional transmission will be required. For example, VNI West, which will allow additional transfer capacity between Victoria and New South Wales, includes 350km of 330kV on existing corridors from Melbourne’s outer suburbs to the Snowy Hydro, and 1045km of 330kV and 500kV transmission lines on two new routes between Ballarat and Wagga Wagga.

Surprisingly, Tasmania’s Renewable Energy Zones are comparable in transmission distance to major load centers to those being developed in Victoria and New South Wales. Tasmania’s preferred pumped hydro sites are around the same transmission distance to Melbourne as Snowy Hydro 2.0, and not much further than from Snowy Hydro 2.0 to Sydney.

Over the next 15 years, 12,000 MW of retired coal will need to be replaced by 40,000 MW of variable renewable capacity and 8,000 MW of dispatchable capacity. Multiple Renewable Energy Zones will need to be unlocked to achieve it.

You can find out more about Hydro Tasmania’s pumped hydro investigations here: https://www.hydro.com.au/clean-energy/battery-of-the-nation/pumped-hydro

Image: Lake Cethana Pumped Hydro concept, one of Hydro Tasmania’s three short-listed potential pumped hydro sites