By Canberra, Australia correspondent Erica Quarterbee on assignment in Launceston

Australian experts have been scratching their heads on how to fix the electrical power link between Tasmania and the mainland since it failed in December but a permanent solution may be at hand from the opposite side of the planet. The Basslink undersea cable has been problematic from the outset and finally failed shortly after Tasmania’s hydroelectric generators tried to use the link to export electrical power to the mainland.

Sweden’s Vattenfall is proposing a sustainable solution that will provide Australia’s eastern seaboard with reliable, baseload, renewable energy capacity.

Bass Strait is a relatively narrow, shallow sea passage that separates Tasmania from the mainland by a few kilometres. It is infamous for its rough seas and high winds.

Vattenfall propose to exploit its experience in wind and hydro-power, deploying a chain of wind turbines, wave, tidal and pumped storage within Bass Strait. The ambitious plan is to build two land-bridges joining Cape Otway in Victoria to Cape Grim in Tasmania, via King and smaller Islands to the East; and Wilsons Promontory in Victoria to Cape Portland in Tasmania, via Flinders, Cape Barren and minor islands.

The enclosed sea is then to be pumped out slowly, lowering the interior’s water level to 60 metres below mean sea level, forming inland lakes; reservoirs to be used for pumped storage when their level is allowed to rise to 30 metres below sea level. Vattenfall’s expertise in hydropower will allow them to deploy several pumped-storage power stations that utilise the volume of the ocean to generate power when wind is not blowing, and to evacuate the reservoirs when wind, wave and tidal power are in excess.

Vattenfall estimates a maximum build-out capacity in excess of 100GW; sufficient reserves to power an energy-hungry Australia into the next century.

The two land bridges will also serve transport needs by means of a very fast train line along each, connecting Victoria to Tasmania, powered by renewable energy. Existing ferry operators have been offered first rights of refusal on a lease of the line, replacing ferry services between Victoria and the North coast of Tasmania.

Vattenfall agreed to rule out a connecting highway along either land bridge to gain key political approval from the Australian Greens. The Greens sought a ban of fossil-fuelled transport over “Bassland” as well as a restriction of settlement of the new territory beyond existing  human population levels in order to preserve the pristine, natural ecology of the Strait.

Fresh water may also be supplied from the wet West of Tasmania to the drought-prone Victoria by pipeline. Communications cables for the NBN and pipelines which previously operated in a submarine environment, will be at a more maintainable level, reducing operational costs.

Melbourne’s establishment is very excited at the prospect of lowering sea levels to the point of draining Port Phillip Bay. Not only does it remove the threat of rising sea levels, but makes much more land available for development, directly within the Bay and as a result of the necessary relocating Melbourne’s sea port to Portland Bay, West of Warnambool.

Australia’s Turnbull government is in negotiation with the European Commission on the trading of emission certificates to finance much of the work. Europe’s cost for transition to renewable energies is to cost them around 3 trillion Euros by 2022. If Vattenfall is permitted to trade emissions permits between hemispheres, then that money will be available for the Bassland project, while Vattenfall maintains cheap open-cut lignite mines to fuel its power stations in Europe.

The initial construction of walls for the land bridges is projected to take 12 years, simultaneously building “out” from islands and capes. Wind and wave power stations will be installed and connected to the grid progressively. Land bridges will then be strengthened to dam the ocean out from Bassland as pumping stations, powered by wind and wave, pump out the interior.

Vattenfall projects that the if the Bassland project can commence next year, that it will be operational with limited pumped storage capacity as early as 2035 and full capacity around 2050; depending on the weather and consumer power demand. Once fully operational, Australia can shut down all of its fossil-fuelled power stations connected to the national grid, becoming completely carbon-free.

Update:

Vattenfall states that the daily to weekly cycling of pumped storage will sustain the essential environmental flows of water across what used to be the Strait.