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

Original Article ↗ Hacker News Discussion ↗

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.