Vertical Solar Panels Are Out Standing

Original Article ↗ Hacker News Discussion ↗

Performance & Orientation Confusion

  • Some readers misread the graph:
    • ~77% is annual output of vertical vs optimally-tilted.
    • The 131% bar is a single snowy winter day, where snow reflection boosts vertical bifacials.
  • Confusion over the line “one side South, the other North… Down Under do the opposite”; several point out this is mostly a joke, though bifacials often do have a “better” side.
  • Backside generation comes from reflected light, sky diffuse light, and especially snow; not direct sun.
  • One commenter notes vertical N/S bifacials did best only in specific winter conditions and were the worst overall annual producer in the referenced tests.

Why Vertical/Bifacial Can Still Make Sense

  • Goals aren’t just annual kWh: winter adequacy, reduced maintenance, land use, and production timing all matter.
  • Vertical panels:
    • Shed snow and dust better.
    • Stay cooler, helping efficiency.
    • Produce more in mornings/evenings (anti–duck curve), especially when oriented E/W.
  • In snowy, high-albedo climates, vertical bifacials can significantly increase winter energy, when demand is often highest.
  • Vertical arrays can coexist with agriculture and livestock, or double as fences or privacy walls; “suboptimal but feasible” is emphasized as often better than “optimal but impossible.”

Economics, Hardware & Layout

  • Several argue that with cheap panels, it’s often better to add more fixed panels (including vertical/E–W) than to pay for trackers or complex mechanics.
  • Bifacial “rule of thumb” mentioned: ~35% more production for ~10% cost premium.
  • Labor and structural costs (frames, foundations, wind loads, snow/hail, roof geometry) can dominate over panel cost.
  • Microinverters are suggested for DIY, incremental installs and shading tolerance.
  • Multiple commenters stress designing for wind loads; vertical panels act like sails and may need serious foundations, especially in cyclone/hurricane regions.

Policy, Grid & Carbon

  • Balcony/plug-in solar is discussed as a growing vertical use-case, with ~800 W limits in some jurisdictions driven by safety and wiring constraints.
  • Many residential systems are grid-tied and shut down in outages; islanding and backup require specific inverters, batteries, and transfer gear.
  • One claim that snowy-region solar “never pays back its carbon” is challenged; others cite life-cycle studies showing net carbon reduction even in cloudy, high-latitude countries.

Other Threads

  • Interest in agrovoltaics, shade-tolerant crops, and using panels instead of fences.
  • Debate over community/remote solar ownership vs rooftop, and over the economics of residential solar financing.
  • Notes on ongoing module efficiency improvements and emerging ultra-light PV materials as context for increasingly “good enough” non-optimal orientations.