Hybrid Solar Energy Systems

Commercial Systems


By Maarten de Haas, PHYSEE, The Netherlands

Product Description

Brief Concept Description

PHYSEE SmartSkin is an innovative solution for façades that consists of a fully transparent window capable of generating clean electricity and collecting environmental data (SmartWindow), joined to an intelligent grid connection (EESY). This solution stores and distributes power, communicates data and calculates ideal room settings to increase the comfort level and energy efficiency of buildings. SmartWindows integrate strips of c-Si solar cells in the window-spacer that harvest solar radiation and produce electricity that can be transferred through a nano DC-grid to multiple 3rd party façade applications such as ventilation, integrated sun-blinds, dynamic shading glass units and others. The window-spacer also hosts a set of sensors that collect internal and external environmental data (including temperatures, sunlight, CO2 concentration) and transmits it to EESY where it is interpreted, analysed and communicated to the connected devices that control the conditions of the room. The result is a façade composed by connected SmartWindows that locally produce and consume clean energy, providing the users with a unique experience of comfort.

Figure 72. Concept design of SmartSkin on the left and picture of SmartWindow on the right.

Architectural and Technological Integration into the Envelope

The PHYSEE technology is implemented in the window-spacers of regular double or triple paned windows. Therefore, SmartWindows look just as normal fully transparent windows except for the small strips of solar cells, which are not visible from a distance greater than 5 meters. As a result, PHYSEE technologies are integrated without affecting transparency, functionality or aesthetics of the glass. SmartWindows can be assembled by all large glass manufacturers.

Integration into the Building: System and Comfort

SmartWindows generate both sustainable electricity and data. All of that information is stored and communicated by EESY, which connects this data and power to façade applications. For instance, the sensors in the SmartWindows measure environmental data (sunlight, temperature, CO2 levels and more), in- and outside the building and communicate the obtained information to EESY. Façade applications such as air ventilation systems, sun blinds, lighting and HVAC systems receive inputs from EESY and operate to optimize the indoor climate conditions in each room separately according to the users’ preference. When needed, it is also possible to upload the data on the cloud and connect to the building’s management system.

Figure 73. Installation of SmartWindow in EDGE Technologies headquarter in Amsterdam, The Netherlands.

SWOT Analysis


  • SmartWindow is the first fully transparent window capable of generating clean electricity
  • Good economic figure: low CAPEX and OPEX for building owners
  • It is included in Energy Performance Certificates (EPC) calculations
  • It is a viable option for every glass composition and size
  • Generate additional revenue by including SmartSkin in their buildings


  • The amount of electricity generated is lower with respect to traditional solar panels for the same area


  • The target of reducing energy consumption in buildings and specifically the shift towards zero energy buildings will impose to adopt more efficient and energetically sustainable solutions
  • Green energy and sustainable innovation are hot topics at the moment
  • The construction industry is on the rise at the moment in Europe
  • There are no market-ready competitors in the field of transparent windows generating electricity


  • General global expansion can be jeopardized by external political issues (Brexit, United States/China trading agreements)
  • The usage of alternative solutions to reach EPC/BREEAM levels (BIPV, solar panels on roof, WKO system, etc.) is competitive with SmartSkin
  • Contractors may be sceptic at first sight

Lessons Learned

Keep the product as close as possible to established solutions to prevent resistance due to conservative thoughts of the construction industry. This means that our product should comply with all safety regulations and industry wide guarantees. Thanks to through product development and engineering, we have fully certified window technology which passes all durability tests at glass manufacturers.

Further Reading

Company website