Perovskite solar panels on everyday roofs

How far are perovskite and perovskite-silicon tandem solar panels from being sold for everyday roofs?

Tandem cells that stack a perovskite layer on silicon have reached certified efficiencies above the 33.7% single-junction limit, in laboratory devices. Oxford PV has shipped its first commercial tandem modules to a US utility-scale project, with a stated module efficiency of 24.5%. Panels sold for rooftops need proof that they last for decades outdoors, that they hold lead safely, and that they can be made in volume. The sources reviewed show early steps on all three, not yet the full picture.

AI illustration · Illustrative scene, not a photograph of the specific device or experiment.
WHERE WE AREPilots

Close. Early pilots are running in the real world.

Certified tandem cells exist, and one commercial shipment of tandem modules has been announced, so this is past laboratory-only work. The stage is pilot rather than scaling: the first shipment was to one customer, with volume, warranty and lifetime not disclosed, and outdoor durability has been shown only over short tests. A full-size research module has been calibrated at 25% by Fraunhofer ISE, but the sources reviewed contain no certified efficiency for a full-size commercial product.

The tech tree

Everything recorded on Vrulum that this future needs, oldest foundations at the top and the goal at the bottom. Lines show what each step requires.

What it takes: Perovskite solar panels on everyday roofs Unlocked Being researched Locked
  1. 2015Perovskite-silicon tandem solar cellsPilot and early commercial Unlocked.
  1. 2021Outdoor field data over long periodsIn progress Being researched.
  2. 2022Lead containment after damage and at end of lifeIn progress Being researched.
  3. 2024Certified tandem cell above the single-junction limitDone Unlocked.
  4. 2024First commercial shipment of tandem modulesDone Unlocked.
  5. 2025Certified tandem cell at 60 square centimetresDone Unlocked.
  6. Date not recordedCertified efficiency for a full-size tandem moduleIn progress Being researched.
  7. Date not recordedQualification testing to IEC 61215In progress Being researched.
  1. GoalPerovskite solar panels on everyday roofsGoalRequires: Perovskite-silicon tandem solar cells, Certified tandem cell above the single-junction limit, Certified tandem cell at 60 square centimetres, First commercial shipment of tandem modules, Certified efficiency for a full-size tandem module, Qualification testing to IEC 61215, Outdoor field data over long periods, Lead containment after damage and at end of life. Locked.

The road so far

3 of 7 steps done, 4 in progress.

  1. Done · 5 Sept 2024Certified tandem cell above the single-junction limit

    Liu and colleagues report in Nature a perovskite-silicon tandem cell with a certified stabilised efficiency of 33.89%, and describe it as the first reported certified two-junction tandem above the 33.7% single-junction Shockley-Queisser limit. LONGi, a manufacturer, reports an NREL-certified 34.85% in its own announcement dated 21 April 2025. Both are laboratory cells. The LONGi announcement does not state the cell area or test conditions. [3][2]

  2. Done · 30 Sept 2025Certified tandem cell at 60 square centimetres

    Artuk and colleagues report in Nature Communications a certified 28.9% efficiency for a perovskite-silicon tandem with a 60 cm² active area. The abstract also reports a certified open-circuit voltage of 2 V for a 1 cm² device. These are research devices, far smaller than a rooftop panel. [4]

  3. Done · 5 Sept 2024First commercial shipment of tandem modules

    Oxford PV announced on 5 September 2024 that its perovskite-on-silicon tandem modules were entering commercial use, with a first deployment at a US utility-scale installation. Each 72-cell module has a stated 24.5% efficiency. The company says the panels can produce up to 20% more energy than a standard silicon panel, but does not state test conditions. Customer volume, warranty and lifetime were not stated. [1]

  4. In progressCertified efficiency for a full-size tandem module

    Fraunhofer ISE reported in January 2024 a full-size research module built from Oxford PV perovskite-silicon tandem cells, measured by its CalLab PV Modules at 25% efficiency and 421 W over a 1.68 square metre area, with certification of the module still in progress at the time. A 2025 peer-reviewed paper from Fraunhofer ISE sets out how such large tandem modules are calibrated. Oxford PV's own announcement cites a module efficiency record of 26.9%, but gives no certifying body or test conditions. The sources reviewed contain no certified result for a full-size commercial tandem product. [8][9][1]

  5. In progressQualification testing to IEC 61215

    IEC 61215-1:2021 sets design qualification requirements for terrestrial photovoltaic modules intended for long-term outdoor use. The standard states that its test results are not a quantitative prediction of module lifetime, so the qualification results do not show how long a perovskite panel will last. [7]

  6. In progress · 2021Outdoor field data over long periods

    Liu and colleagues report in Joule (2021) a perovskite-silicon tandem with 28.2% independently certified efficiency that kept about 93% of its performance over 43 days in a hot, humid outdoor setting. The publication also reports about 87% retention in an 85/85 damp-heat test over 500 hours. The page says a carbazole precursor additive suppresses halide phase segregation under moisture and light. No multi-year outdoor dataset for a commercial tandem module was found in the sources reviewed. [5]

  7. In progress · 15 Dec 2022Lead containment after damage and at end of life

    A 2022 review by Torrence and colleagues compiled published leaching data and found that lead from a broken perovskite module may exceed safe limits unless a lead sequestration layer is included. The authors say that encapsulation does not mitigate lead leaching, and that once water gets under the encapsulation, leaching is similar to unencapsulated cells. They say testing is needed to determine whether lead sequestering layers last for the life of the module. [6]

Why it matters

Solar panels with higher efficiency would give more power from the same roof area. Whether that matters depends on how long the panels last, what they cost and how they are recycled. Most perovskite formulations contain lead, and the highest-efficiency ones do too, so their safe use at the end of life matters as much as their output.

What stands in the way

  • Long-term outdoor durability is not shown. The longest outdoor test in the sources reviewed is 43 days, and IEC 61215 results are not a lifetime prediction.
  • Lead in the perovskite layer must stay contained after breakage and at end of life. A 2022 review found lead leaching from a broken module may exceed safe limits without a sequestration layer.
  • A full-size research module has been measured at 25% by an independent calibration laboratory (Fraunhofer ISE CalLab), but the sources reviewed contain no certified efficiency for a full-size commercial tandem product.
  • Factory yield and uniform large-area deposition are not shown. Making good cells at volume is a different task from making one good cell in the lab.
  • Volume, price, warranty and field performance of the first commercial shipment were not disclosed.

Signals to watch

  • A certified efficiency result for a full-size commercial tandem module, with the area and test protocol stated.
  • Multi-year outdoor data for tandem modules from independent field tests, with the methods published.
  • Warranty terms or delivered volumes published by a manufacturer selling tandem modules.
  • Lead containment shown after breakage tests and in recycling trials on full-size modules.
  • A published perovskite-specific extension to module qualification standards such as IEC 61215.

Sources

  1. company announcement
    20% more powerful tandem solar panels enter commercial use for the first time in the US
    Oxford PV, 5 Sept 2024.
  2. company announcement
    34.85%! LONGi Breaks World Record for Crystalline Silicon-Perovskite Tandem Solar Cell Efficiency Again
    LONGi Green Energy Technology, 21 Apr 2025.
  3. peer reviewed paper
    Perovskite/silicon tandem solar cells with bilayer interface passivation
    Jiang Liu, Yongcai He, Lei Ding et al.. Nature, 5 Sept 2024.
  4. peer reviewed paper
    60 cm² perovskite-silicon tandem solar cells with an efficiency of 28.9% by homogeneous passivation
    Kerem Artuk, et al.. Nature Communications, 30 Sept 2025.
  5. peer reviewed paper
    28.2%-efficient, outdoor-stable perovskite/silicon tandem solar cell
    Jiang Liu, Erkan Aydin, Jun Yin et al.. Joule, 2021.
  6. review article
    Environmental and health risks of perovskite solar modules: Case for better test standards and risk mitigation solutions
    Christa E. Torrence, Cara S. Libby, Wanyi Nie et al.. iScience, 15 Dec 2022.
  7. standard
    Terrestrial photovoltaic (PV) modules - Design qualification and type approval - Part 1: Test requirements (IEC 61215-1:2021)
    International Electrotechnical Commission (IEC), 23 Feb 2021.
  8. other
    Oxford PV and Fraunhofer ISE Develop Full-sized Tandem PV Module with Record Efficiency of 25 Percent
    Fraunhofer ISE, 31 Jan 2024.
  9. peer reviewed paper
    Traceable Efficiency Determination of Large-Area Perovskite on Silicon Tandem Modules: Insights From a Calibration Laboratories Perspective
    Chojniak, Schmid, Hohl-Ebinger. Progress in Photovoltaics: Research and Applications, 21 May 2025.

Last reviewed 21 Oct 2026.