Frequently Asked Questions

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How is the view to the outside?
The ‘unobstructed view factor’ is 2 to 4 times higher than automated horizontal blinds (depending on location on earth and facade orientation). For example in Amsterdam the ‘unobstructed view factor’ is 41% compared to 11% for horizontal blinds that track the sun. Horizontal blinds that do not track the sun like traditional ‘Luxaflex’ perform even worse.
How is the LumiductTM attached to a building?
The LumiductTM is integrated into a double skin glass facade with single pane clear glass in front and insulated glazing at the back. The LumiductTM and the single pane glazing will be attached to the outside of a building on the head ends of the structural floor slats.
How is heat generated? And how can it be used?
Heat is generated at the solar cells and is dissipated to the air inside the cavity of the double skin facade. This heat can be extracted from the air by a heat-exchanger to be used directly or stored in a seasonal heat-storage. Furthermore the heat can be used directly for natural ventilation by creating a natural draft by the upside moving hot air.
What is the energy performance?
The energy performance of the system is highly dependent on the specific location on earth and the orientation of the facade. We are monitoring the energy performance in the Netherlands right now, expected electricity yield is similar to a crystalline PV panel mounted to a vertical facade. In addition heat is generated and energy is saved on lighting, heating and cooling. Please contact us to help you specify the energy performance for your project.
How efficient are the solar cells?
Wellsun uses solar panels that concentrate perpendicular light on GaAs triple junction solar cells. These cells are originally developed for space applications and have an efficiency of over 40% compared to conventional crystalline silicon cells with an efficiency of max 25%.
Why are DC grids an important development?
We see a trend towards local DC networks for buildings that apply local energy generation. Energy generated from sunlight, as well as the storage of energy in batteries and the usage of most of our common electronic appliances, are all DC based. Our central grids, however, are still AC base. Therefore, sun generated energy normally needs to be converted to AC to be fed into an AC grid and then to DC again to power buildings. This creates substantial conversion losses (up to 20%). Realizing local DC networks prevents these losses but requires the generation of a high volume of locally generated solar power. The LumiductTM generates enough power to make this possible. Furthermore copper can be saved because all the wires can be much thinner. Applying the LumiductTM to a full facade creates the right volume of locally generated solar power for a DC grid to be feasible.
Is the Lumiduct easy to service?
The LumiductTM can be serviced from inside the building. It is a modular system, individual parts like the solar panels or the motors can be replaced easily.
What is the lifespan?
The LumiductTM is functioning in a well-conditioned environment, without excessive moist, dust or external forces. In combination with the limited number of cycles the LumiductTM is highly reliable over the lifetime of the building. Every day the system performs one cycle by following the sun and returning to its starting position. This is very little compared to most mechanical systems. And if broken, parts can be easily replaced.
What are the control features?
The basic mode of the system is to track the sun, regardless of weather and sky conditions. Building users can overrule this mode at any wanted moment in time and move the system to any wanted fixed position. For instance, the system can be fully opened with cloudy weather or fully closed into a privacy position.
How is glare controlled?
A primary functional requirement of the LumiductTM is to prevent glare on desks or computer screens. The modules are positioned in such a way that no direct light, responsible for heating and glare, can pass through.
Why does shading not affect the electricity generation?
This has no negative effect on the power output because the LumiductTM has a specific electronic circuit design that accounts for shading. Therefore the electricity production of a module from the LumiductTM that is shaded by 20% is only reduced proportionally by 20%.
How noisy is the Lumiduct?
The LumiductTM is slow and quiet. In contrary to most automated shading systems, people inside the building will not notice the movements of the LumiductTM.
How much daylight can pass?
Our partner Eindhoven University of Technology developed a simulation model to quantify the daylight conditions with a LumiductTM facade. The LumiductTM allows 1.5 to 3 times more daylight inside a building compared to automated blinds that will close at irradiance levels above 200W/m2 (depending on the location on earth and orientation of the facade).