Basslink
| Company type | Private |
|---|---|
| Industry | Electricity transmission |
| Founded | 2000 |
| Founder | Hydro Tasmania (initial agreement) |
| Headquarters | Australia |
Area served | Victoria and Tasmania, Australia |
| Products | High-voltage direct current (HVDC) interconnector cable, telecommunications services |
| Owner | APA Group (since October 2022) |
| Website | www |
Basslink
The Basslink interconnector is a 370-kilometre, 500 MW high-voltage direct current (HVDC) cable that links the electrical networks of Victoria and Tasmania in Australia. Spanning the Bass Strait, it connects the Loy Yang Power Station in Victoria with the George Town substation located in northern Tasmania. This bidirectional link enables Hydro Tasmania to deliver peak load power to the mainland and import surplus electricity from Victoria when generation exceeds local demand.
From a financial perspective, Basslink has facilitated reductions or delays in investments for base load generation while allowing profits through the sale of peak power in higher-priced markets. The interconnector also plays a vital role during drought periods by supplying power to Tasmania, which relies predominantly on hydroelectric generation. A government review conducted in 2011 revealed that although direct costs associated with Basslink exceeded revenues by approximately $130 million in nominal terms, factoring in indirect advantages such as enhanced energy security resulted in an average net positive benefit of over $40 million annually between 2006-07 and 2010-11. Nevertheless, economist John Lawrence estimated that the outage experienced from 2015 to 2016 led to losses for Hydro Tasmania ranging between $140 and $180 million.
Ownership of Basslink transferred to APA Group following its acquisition in October 2022.
History
Hydro Tasmania's Board initially signed a preliminary agreement to develop Basslink in 2000, with an estimated cost of A$500 million. However, additional requirements including corrosion prevention measures increased the final construction expenses to roughly A$800 million.
Built over the period from 2003 to 2005 as an asset under National Grid Australia Pty Ltd (a subsidiary of UK-based National Grid plc), Basslink first transmitted electricity during testing on 1 December 2005. It officially began commercial operation on the National Electricity Market at midnight on 29 April 2006.
On 31 August 2007, CitySpring Infrastructure Trust—a fully owned subsidiary of Temasek Holdings—purchased Basslink Pty Ltd along with its associated entities for an enterprise value of AU$1.175 billion. CitySpring later rebranded as Keppel Infrastructure Trust, listed on the Singapore Stock Exchange, where Temasek retained a one-third stake and public investors held two-thirds. Temasek is Singapore’s sovereign wealth fund managing assets valued at approximately $350 billion.
Basslink’s main source of revenue derives from a 25-year Basslink Services Agreement with Hydro Tasmania that commenced on 28 April 2006. Under this agreement, Hydro Tasmania pays an annual interconnector facility fee close to AU$70 million, which includes a variable portion linked to prevailing interest rates.
While power typically flows from Tasmania toward mainland Australia, this reversed in 2020 due to drought conditions reducing hydropower output.
2015–2016 outage
On 21 December 2015, Basslink was disconnected because of a fault in the interconnector located about 100 kilometres off Tasmania’s coast. Initial repair estimates targeted restoration by 19 March 2016; however, service did not resume until 13 June 2016. Subsequently, another failure unrelated to the cable occurred on 22 June, with power being restored after nearly 36 hours on 23 June.
2021-2022 Receivership and Contractual Conflict
On 12 November 2021, the entities responsible for owning and operating the Basslink undersea electricity cable entered voluntary administration, carrying a debt of A$40 million owed to the Tasmanian government and Hydro Tasmania stemming from the 2015 service interruption.
Subsequently, on 10 February 2022, Hydro Tasmania terminated the Basslink Services Agreement (BSA). Despite this, the interconnector continued functioning while discussions with Basslink’s administrators aimed at revising contract terms during the receivership period. Hydro Tasmania proposed a temporary one-month extension of critical BSA provisions; however, this offer was declined by Basslink on 16 February 2022.
2022 Acquisition by APA Group
On 7 September 2022, APA Group (Australia) was chosen as the preferred purchaser of Basslink. The transaction was finalized on 20 October 2022, with APA Group acquiring Basslink for A$773 million.
Technical Overview
Basslink operates as a monopolar HVDC system featuring a metallic return conductor, functioning at a standard voltage of 400 kV DC. Its nominal capacity is , with the capability to deliver up to for limited timeframes from George Town to Loy Yang.
Key infrastructure components consist of:
- A submarine power cable extending from McGaurans Beach near Giffard, Victoria to Five Mile Bluff close to George Town, Tasmania. This cable weighs 60 kg per meter and was previously ranked as the world's fourth longest submarine power cable.
- An overhead transmission line leading to the Victorian coastline
- Underground cabling within Victoria
- An overhead line segment reaching the Tasmanian coast
- Underground cable installations within Tasmania
Basslink’s transmission towers are designed with two asymmetric crossarms: the longer upper crossarm carries the high voltage line, while the shorter lower crossarm supports the electrode line extending in the opposite direction.
Basslink Telecommunications
Integrated within the Basslink system is a 12-core fibre optic telecommunications cable, marking the first non–Telstra fibre optic crossing beneath Bass Strait. Commercial operations for Basslink Telecoms commenced on 3 July 2009, with an official launch occurring on 16 July. The Tasmanian Government incorporates this asset into its Connect Tasmania Core network to enhance competition within the state's telecom sector. Additionally, this link was intended to serve the now-defunct OPEL Networks.
Facilities
- LoyYang Static Inverter Plant:
- Victorian Cable Terminal:
- Tasmanian Cable Terminal:
- Georgetown Static Inverter Plant: