Forum for Science, Industry and Business

Switch2Save: smart windows and glass façades for highly efficient energy management using novel switching technologies

Climate change is a topic now on everyone's lips and climate targets are being discussed at all levels. Solutions such as the use of natural resources for energy generation and energy recovery in existing cycles are currently of high research interest.

Effect of an electrochromic window

© ChromoGenics AB

Picture in printable resolution: www.fep.fraunhofer.de/press

Versions of the integration of switchable modules from the Switch2Save project

© Fraunhofer FEP

Picture in printable resolution: www.fep.fraunhofer.de/press

One building block for a sustainable future is the EU Energy Performance of Buildings Directive that targets a full zero-emission building stock all over Europe before 2050.

Glazing in buildings account for up to 60% of energy transfer through modern building envelopes. In winter, heat is emitted to the outside, while in summer, solar radiation heats the building interior which increases the demand for air-conditioning and cooling. Large windows and glass façades – a common design element in modern and large buildings – worsen this effect.

Today, mechanical window blinds and jalousies are used to control solar radiation dependent on the time of day, temperature and sunlight intensity. However, they strongly affect (or impair) comfort and light conditions inside the building. In glass façade buildings, such window blinds – if installed at all – disturb the architectural design and require heavy mounts and profiles.

Smart and switchable glass solutions have the potential to replace mechanical window blinds in the future. However, they are currently optimized towards aesthetic requirements, and not energy saving, are very expensive and hard to come by.

The EU-funded initiative Switch2Save aims to overcome these limitations by combining and maturing EC and TC systems to create lightweight Energy Smart Insulating Glass Units (IGUs) suitable for large windows and glass-façades. EC switching relies on materials that change their light transmitance by applying a low electrical voltage; TC cells are based on materials that change their infrared reflection properties with increasing temperature.

The Switch2Save consortium includes leading universities, research institutes and industries from six EU countries. Within the next four years, the partners will collectively develop a combination of EC and TC cells – with optimized maximum energy saving potential – based on a switchable total energy transmittance (g-value).

They will scale the manufacturing technologies for increased availability and cost effectiveness, assess the performance of the innovative IGUs, and demonstrate the heating and cooling energy saving potential and the lighting comfort in two operational buildings in Greece and Sweden.

Project coordinator Dr. John Fahlteich, Fraunhofer FEP, explains the potential of the technology: “Experts estimated that energy demand for air-conditioning and cooling of buildings will more than double by 2050! Furthermore, large glass façade buildings (e. g. shopping centers, airports, office buildings) require as much as 35% more energy for heating and up to five times more energy for cooling than modern buildings with small windows.

The Switch2Save solution will be able to reduce the total annual heating and cooling energy demand of such large glass buildings by up to 44%. This will be achieved through smart switching protocols based on local, real-time weather and temperature data and the illumination conditions in the building”.

The Switch2Save EC and TC modules are based on nanoscaled thin film stacks that are applied to plastic webs or ultra-thin glass films by using large area vacuum and atmospheric pressure deposition techniques. The modules have a specific weight of less than one kg per square meter – much less than even a single glass pane in a window.

They are easily integrated into IGUs by a lamination step to allow window and glass façade manufacturing with well-established processes – a key requirement for acceptance of the novel technology by construction companies. The integration of wireless switching and standard interfaces directly into the building automation systems will satisfy the needs of building owners and provide maximum energy saving when in operation.

Switch2Save will demonstrate the potential in two representative buildings – Greece’s second largest hospital in Athens and an operational office building in Uppsala, Sweden. The Switch2Save consortium will replace 50 windows and 200 m² glass façade area with the smart glass solution and will perform a full “before-after” comparison of the energy demand for a one-year cycle in both buildings. The findings will accelerate the widespread implementation of energy smart glass and significantly contribute to the goal of a CO2-neutral building stock in the EU before 2050.

During the conference "pro flex 2019 – Roll-to-roll coating of flexible materials" (November 5-6, 2019, Dresden), Dr. John Fahlteich, the Switch2Save project coordinator, will be available with other scientists from Fraunhofer FEP to provide information about the project, vacuum-coating possibilities and plant technology. The conference, with focus on a "Technology Cross-Over", offers the possibility to get information about the numerous possibilities of roll-to-roll technologies for film and ultra-thin glass coating on site.

Project consortium Switch2Save:
Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP
www.fep.fraunhofer.de

Fraunhofer Institute for Silicate Research ISC
www.isc.fraunhofer.de

ChromoGenics AB
www.chromogenics.com

School of Mechanical Engineering @ National Technical University of Athens
www.mech.ntua.gr/en

University of West Bohemia
www.zcu.cz/en

SIA AGL Technologies
www.agltechnologies.eu

FASADGLAS BÄCKLIN AB
www.fasadglas.se

Vasakronan AB
www.vasakronan.se

General State Hospital of Nikaia “Agios Panteleimon”
www.nikaia-hosp.gr

VAN ROMPAEY SARA
www.e2arc.com/team

AMIRES s.r.o.
www.amires.eu

About the project:

The project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 869929.
Project duration: October 1, 2019 – September 30, 2023

Press contact:

Ms. Annett Arnold

Fraunhofer Institute for Organic Electronics, Electron Beam and Plasma Technology FEP
Phone +49 351 2586 333 | presse@fep.fraunhofer.de
Winterbergstraße 28 | 01277 Dresden | Germany | www.fep.fraunhofer.de

Weitere Informationen:

http://www.ordis.europa.eu/project/rcn/224847/factsheet/de
http://www.fep.fraunhofer.de/proflex

Franziska Lehmann | Fraunhofer-Institut für Organische Elektronik, Elektronenstrahl- und Plasmatechnik FEP
Further information:
https://www.fep.fraunhofer.de/en/press_media/14_2019.html

Im Focus: The human body as an electrical conductor, a new method of wireless power transfer

Published by Marc Tudela, Laura Becerra-Fajardo, Aracelys García-Moreno, Jesus Minguillon and Antoni Ivorra, in Access, the journal of the Institute of Electrical and Electronics Engineers

The project Electronic AXONs: wireless microstimulators based on electronic rectification of epidermically applied currents (eAXON, 2017-2022), funded by a...

Im Focus: Belle II yields the first results: In search of the Z′ boson

The Belle II experiment has been collecting data from physical measurements for about one year. After several years of rebuilding work, both the SuperKEKB electron–positron accelerator and the Belle II detector have been improved compared with their predecessors in order to achieve a 40-fold higher data rate.

Scientists at 12 institutes in Germany are involved in constructing and operating the detector, developing evaluation algorithms, and analyzing the data.

Im Focus: When ions rattle their cage

Electrolytes play a key role in many areas: They are crucial for the storage of energy in our body as well as in batteries. In order to release energy, ions - charged atoms - must move in a liquid such as water. Until now the precise mechanism by which they move through the atoms and molecules of the electrolyte has, however, remained largely unknown. Scientists at the Max Planck Institute for Polymer Research have now shown that the electrical resistance of an electrolyte, which is determined by the motion of ions, can be traced back to microscopic vibrations of these dissolved ions.

In chemistry, common table salt is also known as sodium chloride. If this salt is dissolved in water, sodium and chloride atoms dissolve as positively or...

Im Focus: Harnessing the rain for hydrovoltaics

Drops of water falling on or sliding over surfaces may leave behind traces of electrical charge, causing the drops to charge themselves. Scientists at the Max Planck Institute for Polymer Research (MPI-P) in Mainz have now begun a detailed investigation into this phenomenon that accompanies us in every-day life. They developed a method to quantify the charge generation and additionally created a theoretical model to aid understanding. According to the scientists, the observed effect could be a source of generated power and an important building block for understanding frictional electricity.

Water drops sliding over non-conducting surfaces can be found everywhere in our lives: From the dripping of a coffee machine, to a rinse in the shower, to an...

Im Focus: A sensational discovery: Traces of rainforests in West Antarctica

90 million-year-old forest soil provides unexpected evidence for exceptionally warm climate near the South Pole in the Cretaceous

An international team of researchers led by geoscientists from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) have now...