Does Tasmania Have Pumped Hydro?

Pumped hydro storage (PHS) is a type of hydroelectric energy storage used by electric power systems for large-scale storage of electricity. PHS plants store energy in the form of gravitational potential energy of water pumped from a lower elevation reservoir to a higher elevation. During periods of high electrical demand, the stored water is released through turbines to generate electricity. The lower reservoir acts as a balancing reservoir for the system. In essence, PHS allows surplus generation at off-peak times to be stored and used during peak demand periods.

The basic principle of PHS has been understood for well over a century. The first use of pumped storage was in the 1890s in Italy and Switzerland. PHS now accounts for over 95% of all grid-connected energy storage worldwide, with an installed capacity of over 130 GW as of March 2012. PHS plants, like conventional hydroelectric plants, can respond to load changes within seconds. This allows PHS plants to provide continuous electrical supply and grid stability.

Sources:

https://en.wikipedia.org/wiki/Pumped-storage_hydroelectricity

https://www.sciencedirect.com/topics/engineering/pumped-hydro-energy-storage-system

Table of Contents

Pumped Hydro in Tasmania

Pumped hydro has played a major role in Tasmania’s electricity system and economy since the early 20th century. According to Hydro Tasmania’s website, the state’s first hydroelectric power station opened at Waddamana in 1916, bringing clean electricity to homes, businesses and farms across Tasmania.

As Hydro Tasmania notes, the organization was initially focused on harnessing Tasmania’s hydroelectric potential, given the state’s dramatic topography and high rainfall in many areas. This early focus on hydropower allowed Hydro Tasmania to become a leader in renewable energy over the past century.

Tasmania’s pumped hydro capabilities developed within this broader context of hydropower expansion across the state. According to Wikipedia, Hydro Tasmania built one of Australia’s first pumped hydro facilities in the 1960s. Pumped hydro now accounts for around 30% of Hydro Tasmania’s total generation capacity.

Current Pumped Hydro Projects

Tasmania currently has three major pumped hydro storage facilities in operation (
List of power stations in Tasmania).

The Tarraleah Power Station was the first pumped hydro facility built in Tasmania and has been operating since 1934. It has two 80 MW reversible pump-turbines with a total storage capacity of 5 GWh (Our power stations – Hydro Tasmania).

The Poatina Power Station located near Poatina village in the Central Highlands was commissioned in 1968 with six 115 MW pump-turbines and a storage capacity of 300 GWh, making it the largest pumped hydro facility in Australia at the time (Category:Hydroelectric power stations in Tasmania).

The Waddamana Power Station built in the 1960s has four 30 MW pump-turbines with a total storage capacity of 15 GWh (
Our power stations – Hydro Tasmania).

Proposed Pumped Hydro Projects

There are several new pumped hydro projects in development in Tasmania as part of the “Battery of the Nation” initiative to expand the state’s pumped hydro capacity [1]. This includes:

The Lake Cethana Pumped Hydro Project, which will add up to 750MW of new capacity. This project involves building a new upper reservoir and underground tunnels connecting it to the existing Lake Cethana Power Station [2].

Upgrading the Tarraleah Power Station on the Nive River from 110MW to 190MW. This $700 million project will increase the power output without requiring more water [3].

Several other potential pumped hydro sites are being investigated across Tasmania to further boost energy storage for renewable power sources like wind and solar.

Benefits of Pumped Hydro

Pumped hydro provides many benefits for energy grids and supporting renewable energy. One key benefit is providing grid stability. Pumped hydro acts like a giant battery, able to store large amounts of energy and release it quickly when needed to meet demand and stabilize the grid, as noted in an analysis by the National Renewable Energy Lab (NREL) [1]. This makes pumped hydro ideal for balancing variable renewable sources like wind and solar.

Pumped hydro is one of the most cost-effective ways to store large amounts of energy [2]. The economics are highly favorable compared to alternatives like batteries. Pumped hydro facilities can operate for decades, providing excellent returns on investment. Their storage capacity, quick ramp rates, and longevity make pumped hydro beneficial and profitable for grid-scale energy storage applications.

By enabling greater renewable energy integration and grid reliability, pumped hydro provides environmental and sustainability benefits. The storage it provides can reduce reliance on fossil fuel peaker plants, supporting decarbonization goals. Pumped hydro’s strength at bulk power management complements other storage options like batteries for more distributed, small-scale storage needs [3].

[1] https://www.nrel.gov/news/press/2023/news-release-nrel-analysis-reveals-benefits-of-hydropower-for-grid-scale-energy-storage.html
[2] https://www.enel.com/media/explore/search-news/news/2014/01/benefits-pumped-storage-hydropower
[3] https://pumpedhydro.com.au/education/pumped-storage-hydropower-advantages-and-disadvantages/

Environmental Considerations

One of the key environmental considerations of pumped hydro relates to the ecological impacts. The construction of major dams and reservoirs necessary for pumped hydro can lead to widespread habitat destruction and loss of biodiversity. For example, Hydro Tasmania has built many dams across Tasmania which has affected local ecosystems and threatened species such as the Tasmanian Devil and Giant Freshwater Lobster (source).

In addition, the flooding of land to create reservoirs leads to the loss of vegetation and impacts local wildlife populations that depend on those habitats. The changes to water flows downstream can also negatively affect aquatic ecosystems. Environmental groups have raised concerns about the impacts of proposed pumped hydro projects on areas like Tasmania’s Tarkine wilderness (source). Careful site selection, impact assessments and mitigation measures are needed to minimize ecological damage.

Pumped Hydro Costs

Pumped hydro energy storage can require substantial upfront investment and ongoing operating costs. According to one report from Thunder Said Energy, a typical 0.5 GW project with 12 hours of storage duration can have capital expenditures (capex) around $2,250 per kW of capacity^[1]. The U.S. National Renewable Energy Laboratory (NREL) estimates pumped hydro capex ranging from $1,999 to $5,505 per kW, with fixed operations and maintenance (O&M) costs of $18 per kW-year and variable O&M costs around $0.51 per MWh^[2].

Compared to other storage technologies like batteries, pumped hydro can have relatively low costs per unit of energy storage capacity. One study found pumped hydro and compressed air energy storage to have the lowest cost per kWh of storage capacity at $165/kWh and $105/kWh respectively, compared to $285/kWh for lithium-ion batteries^[3]. However, batteries can have lower costs per unit of power capacity. Overall, pumped hydro tends to be most cost-effective for large-scale, long-duration energy storage applications.

The high upfront infrastructure costs and site-specific nature of pumped hydro can present challenges. But government incentives and declining costs could improve the investment case going forward.

^[1] “Pumped Hydro Costs.” Thunder Said Energy, https://thundersaidenergy.com/downloads/pumped-hydro-the-economics/. Accessed [date].
^[2] “NREL includes pumped storage in 2022 electricity baseline report.” Hydro Review, 15 June 2022, https://www.hydroreview.com/business-finance/nrel-includes-pumped-storage-in-2022-electricity-technology-baseline-report/. Accessed [date].

^[3] “Report covers costs of various storage technologies including pumped storage hydro.” Renewable Energy World, 8 Aug 2019, https://www.renewableenergyworld.com/storage/report-covers-costs-of-various-storage-technologies-including-pumped-storage-hydro/. Accessed [date].

Pumped Hydro vs. Batteries

Pumped hydro and battery storage both play important roles in stabilizing and supporting renewable energy grids. However, they each have advantages and disadvantages that make them suited for different applications (http://www.dispatchablerenewables.entura.com/batteries-vs-pumped-hydro-a-place-for-both/).

Batteries excel at quickly delivering bursts of stored electricity over short durations when needed to balance supply and demand. They can respond rapidly to fluctuations in renewable energy generation. However, batteries have limitations in the amount of energy they can store and discharge over longer durations (https://www.csus.edu/college/engineering-computer-science/about-the-college/_internal/_documents/posters/sds/eee192a-pumped-hydro-storage-spring22.pdf).

Pumped hydro can store much larger amounts of energy and discharge it for longer continuous periods when needed. This makes pumped hydro well suited for daily or seasonal storage to balance out supply and demand. However, pumped hydro cannot respond as quickly as batteries to sudden fluctuations (https://www.iea.org/articles/will-pumped-storage-hydropower-expand-more-quickly-than-stationary-battery-storage).

Therefore, pumped hydro and batteries may complement each other in renewable energy grids, with batteries providing short duration grid balancing and pumped hydro providing longer term energy storage.

Future Outlook

Pumped hydro is poised to play a vital role in Tasmania’s renewable energy future. With abundant hydropower resources and plans for more wind and solar generation, Tasmania aims to become a renewable “Battery of the Nation” by using its existing dams and reservoirs for pumped hydro energy storage (Hydro Tasmania, 2023).

Pumped hydro provides a way to store excess renewable electricity generation and dispatch it when needed, enabling high levels of variable renewable energy in the grid. Hydro Tasmania has proposed increasing Tasmania’s pumped hydro capacity from the current 500MW at Wivenhoe to up to 2,500MW across several sites (Hydro Tasmania, 2023).

With the Marinus Link project underway to increase transmission capacity between Tasmania and mainland Australia to 1,500MW, Tasmania’s pumped hydro can serve as a storage solution at a national level. Pumped hydro’s ability to store huge amounts of energy to balance supply and demand makes it well-suited to support further wind and solar penetration on the NEM as Australia transitions to a renewables-based grid (Hydro Tasmania, 2023).

If Tasmania can realize its pumped hydro plans, it will cement its role as the renewable “Battery of the Nation.” Pumped hydro will be key to balancing the NEM and providing clean, reliable electricity to Australia in a future dominated by renewable energy sources.

Conclusion

Tasmania currently has three operational pumped hydro power stations that provide valuable energy storage and grid stability benefits. Several major new pumped hydro projects have been proposed, most notably the Battery of the Nation initiative by Hydro Tasmania. If developed, these could position Tasmania as a global leader in renewable energy storage.

Pumped hydro allows renewable energy to be stored for later use. This helps balance variable wind and solar generation, while reducing reliance on fossil fuels. Pumped hydro can respond faster than most other forms of storage, providing critical system inertia and frequency control.

However, pumped hydro does have downsides. It requires substantial upfront capital investment and suitable topography. Projects may face environmental concerns over habitat destruction, altered river flows, and visual impacts. Operating costs are relatively low but pumping does consume additional electricity.

Overall, pumped hydro will likely play an important role in Tasmania’s clean energy transition. When combined with other technologies like batteries, it offers a proven way to support high renewable penetration. With careful planning and responsiveness to community concerns, pumped hydro can help Tasmania continue its leadership in renewable energy.