Roll-to-roll fabricated perovskite solar cells under ambient room conditions
Roll‑to‑roll fabrication of perovskite solar cells under ambient conditions is prompting debate over whether this emerging technology can compete with today’s ultra‑cheap silicon PV modules. Commenters note that while perovskites promise higher theoretical efficiencies, flexible lightweight form factors, and potential in tandem cells or niche uses (e.g. space, fences, vertical or building‑integrated PV), they currently suffer from faster degradation, lead content concerns, and still‑uncompetitive cost per watt. The exchange situates these trade‑offs within a broader trend: panel prices have fallen so far that installation, labor, and grid integration now dominate project costs, shaping which innovations are likely to matter in practice.
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.