Roll-to-roll fabricated perovskite solar cells under ambient room conditions

Original Article ↗ Hacker News Discussion ↗

Economics and Cost Comparisons

  • Current perovskite module estimates are ~$0.5–1/W, still above mass‑produced silicon modules (<$0.30/W).
  • Some commenters note residential installs in certain regions are still heavily panel‑cost‑dominated; others say labour, land, wiring, inverters, and grid connection now dominate.
  • Retail panel prices for consumers are often far above utility/module spot prices; finding $0.25/W panels in small quantities is difficult.
  • Several anecdotes show rapid price drops in Europe for 10 kW home systems, partly driven by “balcony solar” rules and kits.

Perovskite Advantages and Challenges

  • Appeal: potentially higher theoretical efficiency than silicon, simpler low‑temperature processing, lightweight and flexible form factors.
  • Main drawback: severe stability and degradation in sunlight and ambient conditions; lifetime is the central unsolved issue.
  • Some see perovskite primarily as a tandem top cell over silicon (lab tandems ~33% efficiency, theoretical ~43%).

Manufacturing: Roll‑to‑Roll and Flexibility

  • “Roll‑to‑roll” means printing long sheets on flexible substrates, akin to newspaper printing.
  • The paper’s claim of ambient, roll‑to‑roll fabrication is viewed as important for scaling and cost reduction.
  • Lightweight, flexible modules could open niche uses (space, portable, certain building surfaces) if durability improves.

System‑Level Costs and Deployment Models

  • Debate over “cheap but less efficient” panels:
    • One view: panel cost is now minor; lower efficiency just increases BOS and labour.
    • Counterview: if panels become extremely cheap, new deployment modes (fences, vertical walls, ground‑laid arrays) become viable and can partially offset labour/land costs.
  • Integration into shingles/siding is criticized as maintenance‑heavy and connection‑dense; conventional roofs plus bolt‑on panels are seen as more practical. Metal roofing with integrated PV may be somewhat more promising.

Materials, Rare Earths, and Lead

  • Confusion around “rare earths”: mainstream silicon PV does not rely on rare earth elements; some rare metals and lab‑scale dopants can appear, especially in experimental perovskites.
  • Lead in perovskite absorbers is flagged as an environmental concern; commenters advocate limiting or eliminating lead before mass deployment.
  • Tin‑based perovskites exist but are currently less efficient and less stable.

Solar Adoption Trends and Limits

  • Installed solar capacity has grown roughly exponentially (~3‑year doubling), with 2023 outpacing historical trends.
  • Some caution against naïvely extending the exponential, invoking S‑curve dynamics and eventual “carrying capacity,” but most agree we’re still early on that curve.

Practical Output Estimation

  • Thread walks through using NREL solar maps: daily kWh/m² × panel efficiency × area gives a reasonable upper bound.
  • Real‑world losses (orientation, tracking, temperature, dirt, inverter losses) reduce output by ~10–20% in typical examples.