Batteries: How cheap can they get?

Original Article ↗ Hacker News Discussion ↗

Accuracy of the Cost Projections

  • Several commenters recalculate the article’s exponential growth math and find errors:
    • 59% annual growth from 2023 to 2030 yields ~26x capacity, not “eight doublings” (256x).
    • With 25% cost reduction per doubling, reaching ~$8/kWh is argued to be more like 2040 than 2030.
  • Some still see sub‑$10/kWh cells as plausible in the 2035–2040 range; others call $11/kWh by 2030 “optimistic.”

Current Costs and Real-World Pricing

  • Large spread between cell-level cost and end-user systems:
    • Claims of ~$80–100/kWh for cells; DIY LFP rack batteries from China quoted around $90–130/kWh.
    • Turnkey home storage in many markets still ~US$300–500/kWh, sometimes much higher (e.g. ~€400–500/kWh in EU, Powerwall-level systems).
  • Commenters emphasize that cost per kWh delivered (considering efficiency, lifetime, failures) is the relevant metric, not just capacity cost.

DIY vs Installed Systems

  • Many describe successful off‑grid or mostly‑off‑grid setups using cheap LFP cells, used solar panels, and DIY installation.
  • Others report:
    • Install quotes 3–4× DIY hardware costs, heavy sales tactics, opaque economics.
    • Regulatory and insurance barriers to DIY or grid‑charged storage in some regions.
  • Safety and code‑compliance concerns raised; quality of cheap Chinese packs and BMSes seen as variable.

Battery Chemistry, Recycling, and Safety

  • LFP and sodium‑ion favored for safety (no thermal runaway) and low‑cost, stationary storage.
  • Debate over lithium-ion recyclability:
    • Technically recyclable, but lithium recovery often uneconomic; recycling driven more by cobalt/copper.
    • Skepticism that “recyclable” truly means waste is minimized in practice.
  • Other chemistries (iron‑air, sand/thermal storage) mentioned for long-duration grid storage.

Policy, Tariffs, and Grid Interaction

  • US/China tariffs seen as likely to slow cheap battery/solar adoption in the US, though some domestic manufacturing exists.
  • Net metering rollbacks and high grid fees push interest in going off‑grid or using home batteries mainly for arbitrage and backup.
  • Some utilities explore utility-owned or community batteries; others may restrict grid‑charged home storage.

Extrapolation, Hype, and Blockchain

  • Strong optimism that cheap batteries + solar will crush fossil fuels; others caution against naive exponential fits and tech futurism.
  • The article’s brief blockchain/PoS “trustless grid” aside is widely criticized as off‑topic or muddled.