Giving the Exterior a Second Job
Research notebook · September 26, 2026 · Established solar-cell processes and tandem research; proposed integrated exterior.
The roof already spends its day in the sunlight. I would like its design to begin with that fact. The challenge is making a surface that collects electricity while also being a good roof or wall, with a sensible manufacturing and replacement process.
There are several routes worth investigating. They do not all involve printing the same thing.
What can we borrow?
Deposited silicon thin films are an established research and manufacturing direction. For example, United Solar’s 2007 DOE program presentation describes amorphous and nanocrystalline silicon cells and modules. This historical evidence supports the material route, not a claim about its current market position or suitability for every building surface.
Printing also already has a job in silicon-cell manufacture: Fraunhofer ISE describes screen and stencil printing for metallization. Those printed contacts collect current. That does not mean the complete crystalline silicon cell was printed.
Perovskite-on-silicon tandems combine absorbers suited to different parts of sunlight. A 2024 primary study of tandem-cell passivation reported small devices with encouraging efficiency and accelerated stability results. The DOE research overview explains why durability and scaling remain central development questions. Laboratory tests are progress; they do not establish decades of performance as an exposed building skin.
Three candidate manufacturing routes
| Route for the proposed house | Main attraction | Question to settle first |
|---|---|---|
| Robotically place finished cells or small modules into prepared regions | Begin with controlled device manufacture | Can the integration simplify sealing, connections, inspection, and replacement? |
| Deposit thin-film devices on compatible prepared surfaces | Follow geometry with relatively little active material | Can the substrate, process conditions, and complete layer stack deliver useful yield and lifetime? |
| Integrate tandem devices where their extra output is worthwhile | Use more of the available solar spectrum | Does the installed energy benefit justify the protection, manufacturing, and recovery costs? |
These are proposed development choices, not claims that all three can already be carried out on a freshly printed house. Different faces of one building might justify different choices.
The cell is only part of the surface
For our exterior, we also need to design optical protection, water exclusion, electrical connections, insulation, heat flow, shading response, and service access. A local damaged patch should have a defined isolation and replacement route. If an active formulation contains lead or another material requiring containment, its recovery plan belongs in the initial design.
I would avoid assuming that everything should be permanently fused together. We can manufacture an aligned, integrated exterior and still arrange for the photovoltaic region to be renewed without destroying the weather barrier. One-piece construction is valuable where continuity helps; it should not make updating an aging solar layer unnecessarily expensive.
A useful first experiment
Build a small exterior panel with a declared solar-device route, encapsulation system, connections, and access method. Compare it with a conventional module and mounting arrangement serving the same area. Measure usable output, operating temperature, leakage or ingress under the chosen exposure tests, and the labor involved in replacing a damaged region.
Record the whole manufacturing sequence and material inputs. Track output after exposure rather than reporting only the best first measurement. Later experiments can add curved geometry, local shading, adjoining wall materials, and material recovery.
The result we want is a better piece of a building that also generates useful electricity. A beautiful efficiency number is one part of that story.
Related pages: graded transitions, energy storage, and the development path.