Coal is retiring, and new sources of renewable energy like wind and solar are cheap and becoming more plentiful. But they are variable so energy storage is needed to help fill the gaps and maintain the reliability and stability of our electricity supply. That’s where Tasmania can help!
Lake Cethana, Lake Rowallan and Tribute pumped hydro opportunities stacked up as the most promising when we assessed them against a range of technical, environmental, financial and social criteria as part of studies to assess Tasmania’s pumped hydro potential.
These sites were selected from the original list of 14 potential pumped hydro options identified across Tasmania. They represent strong and sustainable development opportunities with the sort of long-term storage options the future national electricity market will need.
We are now progressing our feasibility study, to take a closer look at their potential and decide on the first site that could be developed.
You can learn more about this work in the “Pumped hydro feasibility study” section below.
Our recently completed pre-feasibility study, jointly funded with the Australian Renewable Energy Agency (ARENA), has identified a strong portfolio of cost-competitive future pumped hydro opportunities, with a combined capacity of 3400 MW.
As well as these promising sites, the pre-feasibility study has identified another three options that form a future pipeline of potential pumped hydro development – at yingina / Great Lake in central Tasmania, Lake Parangana in the state’s North West and between Lakes Margaret and Burbury on the West Coast.
Download the Executive Summary
Download the Summary Report
As part of our continuing geotechnical and geological investigations in the Mersey-Forth, we're currently doing further work on land west of Lake Cethana. This work is expected to continue into June 2020 and is part of our feasibility study into the potential of these sites for future pumped hydro development in Tasmania.
More detail on the works schedule is below.
Geological and geotechnical investigations help us understand the physical properties of the ground where major infrastructure might go. We need to know things like is the rock hard or soft, are there faults that may make conditions unstable, are there areas of potential leakage? This information is then used to inform the engineering design of the project.
Before we do field investigations, our team have looked at other information such as previous drilling reports from the area to help us decide where to drill.
Work sites and disturbed areas will be rehabilitated at the completion of work at each investigation area.
Over the course of these investigations, there may be extra traffic in these areas, and possible minor delays as large equipment is moved to and from the two sites. Please be aware when travelling through these areas and follow any traffic advisory signs.
Heavy machinery will be moved to site along these roads at the start of the preparatory civil works and access track construction. When the drilling investigation program starts, there will be large drilling rigs coming on to site. Download our geotechnical fact sheet.
The civil contractor creates safe access to the testing areas. This work involves minor vegetation clearing for access and drill pads and we will minimise site disturbance.
The roads that will be used for vehicle, truck and heavy machinery access are:
Once we have safe access, investigations can start with our specialist contractors.
The drilling machine will drill deep holes up to 485 metres at the Cethana site.
The drilling method collects a core sample of rock that geologists then use to measure and map the underground conditions. The machine sends the drill rods down deep into the ground and takes a ‘core’ of the earth – like coring an apple but on a much larger scale.
Test pitting involves digging a small hole to 5 metres deep with an excavator. After data and samples are collected, the hole is filled in and the site rehabilitated.
After our samples and data are collected, all holes are filled in and disturbed areas are rehabilitated. This work is done to the standards outlined in our Environmental and Social Impact Assessment.
We’re pumped to announce our three most promising pumped hydro sites and to get started on the detailed investigation of these key opportunities.
Work has now begun on a full feasibility assessment of opportunities at Lake Cethana and Lake Rowallan in the North-West and near Tribute Power Station on the West Coast. This will involve grassroots community engagement, geotechnical investigations and environmental, heritage and social assessments.
The studies undertaken during the feasibility stage include:
Check out the information below on selecting a pumped hydro site, for more information on the process ahead. If you'd like to know a little more about how pumped hydro works, we've put together this short video.
Selecting a suitable pumped hydro site for future development is a complex process! There are many different factors that we need to look at and we need to determine how to prioritise all of this information.
We use a process called “multi-criteria analysis”. This uses a number of technical, environmental and social criteria to assess sites.
The criteria used are:
We collect the best available information from each site and assess it against these criteria using both quantitative and qualitative methods to identify the top sites. Feedback was gathered from the community during our pre-feasibility study and that has helped shape the site selection and design process.
In the feasibility stage, more detailed, field based information will be collected to confirm assumptions, assess the suitability of the sites for development and to narrow down a preferred project design and layout.
Download our Feasibility Study Fact Sheet to find out more
Pumped hydro developments are major infrastructure projects that consist of water storages and underground structures including power stations, tunnels and caverns.
Before projects are chosen to proceed to development, you need to know what the surface and underground conditions are like at the site.
An important early part of the feasibility study is completing the work that helps us understand this.
One of the many different inputs we need is geological and geotechnical data, that tells us what the ground conditions will be like both at the surface and at depth.
We’ll be doing two types of geotechnical and geological investigations – test pitting and drilling – in the Lake Cethana and Lake Rowallan areas between September and December 2019.
We are targeting locations at Lake Cethana and Lake Rowallan where some of the major pumped hydro infrastructure might go – the intake from the lake, the water tunnels, the power station and the new upper water storage. The sites being investigated are on the western side above Lake Cethana and the western side above Lake Rowallan.
Download our geotechnical fact sheet for more information.
This is the sort of long duration (deep) storage the future electricity market will need as it transitions to greater penetration of variable renewable sources.
Work has already begun on a full feasibility assessment of our three top priority pumped hydro opportunities at Lake Cethana and Lake Rowallan in the North West and near Tribute Power Station on the West Coast. Geotechnical work has started in the Mersey-Forth, with site preparations to allow for the start of geotechnical drilling in October.
You can download the Executive Summary or the Summary Report.
Hydro Tasmania released a comprehensive report in April 2018 on its assessment of the state’s pumped hydro opportunity. Find the report here.
Pumped hydro energy storage systems have an upper and lower reservoir. The water is stored in the upper reservoir, ready to use when electricity is needed.
When demand is high and supply is needed, the water can be run through a turbine to the lower reservoir, generating electricity.
The water in the lower reservoir gets pumped back uphill when there is excess electricity in the system (which often happens with wind and solar).
Our short video explains how it all works!
More than 70% of Australia’s power currently comes from coal-fired power stations that are likely to close in the next few decades.
Wind and solar are becoming the dominant sources of new energy but they are variable. That’s simply because the sun doesn’t always shine and the wind doesn’t always blow.
That means energy storage will be crucial in the future, to help balance wind and solar energy in the system and ensure energy is reliably available when consumers need it.
Pumped hydro is a proven technology for storing large-scale clean energy and provides around 96% of total worldwide storage capacity.
Tasmania has natural advantages in developing pumped hydro because we have existing assets and storages, just waiting for the ‘add on’.
Want to find out more? Check out this short video.
We’ve put together some commonly asked questions about pumped hydro.
We welcome views from the Tasmanian community and will continue to keep you informed as studies progress.
We welcome your suggestions on the best way to provide project updates or for you to contact us with questions you may have.