Singapore OKs 4,300km subsea cable for importing electricity from Australia

Original Article ↗ Hacker News Discussion ↗

Singapore’s conditional approval of a 4,300 km subsea high-voltage DC cable to import solar power from northern Australia prompts debate over technical feasibility, cost, and reliability. Commenters note that long-distance HVDC is proven and losses are manageable, but question whether the multibillion-dollar investment is economically rational compared with nuclear or local solutions and how often it might fail or be sabotaged. The project’s geopolitical implications loom large, as it lets Singapore tap vast Australian solar resources while partly bypassing closer neighbors and creating new strategic interdependencies.

Scale and Technology of the Cable

  • Commenters note the 4,300 km subsea link is enormous but not unprecedented compared to existing long HVDC and undersea links.
  • The project will use high‑voltage direct current (HVDC), which has substantially lower losses than AC over long distances and avoids severe capacitance issues in long undersea runs.
  • Loss estimates cited: ~3.5% per 1,000 km for HVDC vs ~6.7% for HVAC, with some debate over compounding and other loss mechanisms (e.g., corona discharge).
  • Cables include power for repeaters and emit electromagnetic fields; there’s mention of sharks historically biting undersea cables.

How Long‑Distance Power Transport Works

  • Several explanations emphasize that transmission losses scale with current (I²R), so very high voltage and thick conductors are used to reduce current and resistance.
  • AC transformers are not used end‑to‑end here; conversion relies on power electronics at each terminal.
  • Undersea AC would require many compensation stations due to capacitance, making DC the only practical choice.

Economics and Alternatives

  • Rough cost estimates: ~$4M/km for undersea HVDC, implying ~$17B just for the cable, with other sources citing US$24–30B for the entire project (solar, batteries, local grid, cable).
  • Some argue it may be cheaper and more sensible to build a nearby nuclear plant, possibly on or near Singaporean islands, or consider floating nuclear; others point out land, environmental, military, and political constraints.
  • Back‑of‑envelope calculations suggest transmission could add several cents per kWh, with strong disagreement over whether this is economically rational once financing and time value of money are included.
  • Storage (batteries, other technologies) is raised as an alternative to extreme long‑distance transmission.

Australian and Singaporean Grid Context

  • Mixed reports on Australian reliability: some Melbourne residents claim frequent brownouts and voltage fluctuations; others from Melbourne, Sydney, Perth report rare outages and high reliability.
  • Australia’s main grid has high and growing renewable penetration; South Australia at times approaches net‑renewable supply but still requires some gas for system strength.
  • Darwin’s grid is currently only ~4–10% renewables and is not connected to the main Australian National Electricity Market.
  • Singapore has limited land for solar, is already interconnected regionally, and is pursuing multiple import projects from Indonesia, Cambodia, Vietnam, and now Australia.

Geopolitics and Choice of Australia

  • Some ask why not import from closer neighbors (Malaysia, Indonesia, Thailand). Responses cite:
    • Australia’s vast, sunny, sparsely populated interior for cheap large‑scale solar.
    • Historical friction and contract disputes with Malaysia, making long‑term dependence politically unattractive.
    • Desire to diversify sources so no single neighbor has disproportionate leverage.
  • Others argue this still grants Australia notable strategic leverage and entangles Singapore more deeply in any future regional conflict involving AUKUS countries and China.

Security, Routing, and Vulnerability

  • Multiple comments worry about sabotage or “accidental” anchor damage, noting recent incidents with gas pipelines and data cables.
  • Route choices appear constrained by Indonesian territorial waters; maps show a path that avoids these, adding distance.
  • Some see the cable as a single point of failure; others note it is expected to supply only ~9% of Singapore’s demand, limiting systemic risk.
  • There is skepticism that such a cable could reliably last 100 years without major maintenance; lifespan and O&M costs are seen as key but uncertain variables.