Australia's most bankable geothermal play

[Sparty]

TASMANIA'S BASS STRAIT BONANZA : THE SHALLOW HEAT SOLUTION

The Underwater Energy Jackpot
Beneath the stormy waters of Bass Strait lies an energy paradox. While Tasmania exports renewable electricity via submarine cables, a largely untapped geothermal resource sits just kilometers from these vital interconnectors - one that could transform the island into Australia's first 24/7 renewable powerhouse.

Unlike South Australia's deep, radiogenic granites, northeast Tasmania offers:
✔ Shallower heat (150-200C at just 3-4km depth)
✔ Natural fracture networks from ancient rift systems
✔ Plug-and-play grid access via Basslink and Marinus Link

This installment investigates why geologists call this zone "Australia?s most bankable geothermal play" ? and why it remains dormant.

Section 1: The Maritime Anomaly: A Geologist's Dream
Heat Flow Hotspot
The Numbers:

Surface heat flow: 92-112 mW/m2 (vs. Tasmanian average of 65 mW/m2)

Gradient: 33-42?C per km (compared to 25 Deg C/km in mainland EGS targets)

Predicted reservoir temps: 180'C at 3.5km (modelled by Geoscience Australia, 2022)

Geological Origins:

Failed rift system: When Tasmania tore from Antarctica 100 million years ago, it thinned the crust near today's Bass Strait

Fracture inheritance: Northeast-trending faults from the Parmeener Supergroup create natural fluid pathways

Sedimentary bonus: Overlying sandstone layers may act as natural heat exchangers

Case Study: The Fingal Bore - A 1980s water drill unexpectedly hit 82C at 1.1km depth, proving convective heat transfer exists.

Section 2: The Grid Advantage: Why Location Trumps Depth

Basslink's Secret Opportunity
Existing Infrastructure:

500MW Basslink cable (operational since 2006)

1.5GW Marinus Link (under construction)

<10km distance from Scottsdale anomaly to cable landings

Economic Edge:

Cost Factor Tasmania Cooper Basin (SA)
New transmission $0 (uses Basslink) $320M (needed 300km line)
Water access Abundant rainfall Arid, costly sourcing
Drilling depth 3.5km for 180?C 5km for 200?C
Real-World Proof: The United Downs project in Cornwall (UK) succeeded by targeting shallow (3km), grid-proximal resources ? now powering 3,000 homes.

Section 3: The Hydrogen Handshake - Doubling Down on Heat
Geothermal's Hidden Superpower: Industrial Heat
While most focus on electricity, Tasmania's 180-200C resource is ideal for:

Green Hydrogen Production

High-temp electrolysis (SOEC) achieves 30% higher efficiency at geothermal temperatures

Pilot potential at Bell Bay Hydrogen Hub (existing $70M federal commitment)

Mineral Processing

Direct heat for lithium carbonate conversion (critical for Tasmania?s mining sector)

Timber drying for Tasmania?s $1.2B forestry industry

Economic Model: A 50MW hybrid plant could yield:

$160M/year revenue (power + hydrogen)

4.7 year payback with proposed state tax credits

Breaking the Logjam - A 5-Point Action Plan
1. Exploration Blitz (2025-2027)
Deploy marine magnetotellurics to map offshore reservoirs

Drill 2 slim holes (<$15M total) at priority sites:

Scottsdale (onshore)

Flinders Island (offshore shallow shelf)

2. Policy Triggers
Amend Tasmania?s Renewable Energy Action Plan to include geothermal baseload targets

Create Geothermal Rights framework (similar to offshore wind leases)

3. First Nations Partnership
Palawa energy co-op model (mirroring NZ?s Ngawha iwi-led success)

Joint ownership of test wells with Tasmanian Aboriginal Centre

4. Tech Transfer
Partner with Cornwall?s EGS experts (UK has 20-year head start)

Adapt oil/gas directional drilling tech from Bass Strait platforms

5. Market Creation
Hydro Tasmania offtake guarantee for first 20MW

Rio Tinto heat supply contract for Bell Bay smelter

Conclusion: The Bass Strait Decade
Tasmania stands at a unique crossroads. With Marinus Link construction underway and hydrogen hubs seeking firming power, geothermal could shift from curiosity to cornerstone. The recipe is clear:

Leverage shallow, fractured reservoirs near cable landings

Marry geothermal with hydrogen for double-value streams

Act before 2030 - when battery costs may undercut development

"This isn't just about geothermal - it's about rewriting Tasmania's role in the NEM. One test well could change everything."

Dr. Pippa Nelson, Geoscience Australia (2023 interview)