A Swiss solar house is ready to conquer the West!

Following two years of development and construction, the Swiss Living Challenge project’s NeighborHub is ready to cross the Atlantic Ocean to Denver, Colorado, where it will compete against twelve other contenders in October 2017. The Swiss team worked assiduously to pack its solar house with winning ideas.

An open solar building
While most entries to the Solar Decathlon are designed as solar homes for one family, the Swiss entry audaciously ups the ante, proposing instead a modular community center that lives up to its name: the NeighborHub. Ultimately, the building’s aim is to become an environmentally friendly place for neighbors to meet, encouraging them to strive, together, toward a more sustainable future.

The students selected seven topics (energy, mobility, choice of materials, biodiversity, food, waste management, and water management) that will be showcased in the building using colorful design and humorous, catchy phrases. The Swiss team stands alone in its choice of developing a community center that highlights these seven topics. And no other team has taken its concept as far. Also, with its flexible architecture, its mobile and collapsible furniture, its storage spaces with tools at anyone’s disposal, and its entire interior design, the NeighborHub can adapt to a multitude of activities: a Repair Café, urban gardening, yoga classes, eco-responsible cooking classes…

Harvesting all its energy on the facades
The NeighborHub has 29 solar panels, all installed on its facades. With this choice, the team demonstrates that it has now become feasible to rely entirely on wall-mounted solar panels. The building produces more than enough energy, even considering the risk of shade in urban environments. The key to achieving this is the creative use of power optimizers on each solar panel that continuously monitor and fine-tune the performance of the photovoltaic cells. Solar panels on the building’s east and west-facing facades produce power earlier in the morning and later at night when consumption peaks. Consequently, production is smoother than with only south-facing panels. The doors of the building’s outer skin open upwards, ideal for letting in air in the summer, exposing the integrated solar panels to sunlight at the optimal angle for energy production. With its bold strategy of concentrating power production on the facades, the Swiss team stands out starkly from its competitors. (To learn more, read: “A self-sufficient home with solar panels installed only on its facade”)

Every raindrop counts
The NeighborHub’s water management scheme seeks not only to curb consumption but also to limit environmental impacts by restoring nutrient cycles. Water is separated into different types based on its properties and is either reused or treated in an environmentally friendly way. Dry toilets make up an independent, water-free system, and composting excrement with straw and worms provides nutrients for crops. Water from the washing machine, the shower, and sinks is treated naturally in a phyto-purification tank using reeds and gravel. The closed water cycle is one of NeighborHub’s strong suits in the competition. (To learn more, read “Switzerland's NeighborHub is going to shine in Denver,” chapter: “A closed water cycle“)

A blooming NeighborHub
Preserving biodiversity is one of the objectives the Swiss team set for itself beyond the ten challenges imposed by the competition. Free of solar panels, the roof can largely be covered with vegetation. Melliferous plants that attract bees to the roof and the phyto-purification tank create a habitat for flora and fauna. Additionally, vertical greenhouses integrated into the façade structure will contain local plant sprouts. Graetzel cells, named after their inventor, are integrated into these vertical greenhouses to demonstrate that solar energy can also be produced using a process inspired by photosynthesis. Among Graetzel cells’ advantages are their translucency and the fact that they are colored. Orange-red was chosen for its growth-promoting properties that would benefit the plants cultivated behind them.

As a demonstrator of high-potential solar technologies, the NeighborHub includes aquaponics, a cultivation system that combines aquaculture and hydroponics, with which extra food can be produced at the very location where it is consumed. The house includes three aquaponics units, each comprising a vertical greenhouse built into the façade and a fish reservoir under the floorboards. In the reservoir, the fish enrich the water with their droppings. The water is then pumped up to the grow trays containing the crops, where it flows in contact with the plants’ roots. These take up the natural fertilizer and the purified water flows back to the fish. This technique takes up little space and requires neither fertilizer nor soil.

Students, the floor is yours!
In closing, we asked the students to define the project in one word. Margaux Peltier from EPFL chose the work Sharing, by which she means “sharing knowledge and experiences! You learn a lot. Sharing not only among students but also with the partners.” Florian Meyer, who graduated from HEIA-FR couldn’t make up his mind between Incredible and Difficult. “Incredible because we have the opportunity to go from the start to the finish with the interdisciplinary team. But also difficult because there are so many constraints, and we always have to find the best compromise,” he explains. Laure Christinat from HEAD opted for the word Exchange, thinking of “exchanging know-how, support, communication… The project is teaching us so much. Personally, I have never worked with people from so many different backgrounds.” Salma Derouiche from EPFL described the project as a Challenge, “because it really isn’t straightforward and you constantly come across new challenges you have to face.” Asli Sevcan Ozkan from HEAD chose the word Multifunctional, “because you have to take into account multiple things at once and be multifunctional,” she explains. Elena Zambelli from EPFL presents her point of view: “I’d like to say Convivial, but there is more to it than that. More in the sense that it’s also about being part of a team. The team spirit gives rise to the project.” Sébastien Bielmann, an apprentice at Group E Connect, who perfectly fit into the student team chose the word Complementarity: “It’s quite unusual to work on a construction site with young people that are not professionals and are doing whatever they can to transform their ideas into reality. They know more in theory than in practice, which is why we are very complementary.” Finn de Thomas Wagner from UNIFR found the project to be Rewarding, “not only rewarding because it offers this unique learning experience to the students, but also rewarding to our country, as we are contributing to addressing some of the most pressing social and environmental problems of our time.“ Guillaume Gruet from EPFL chose the word Adventure: “It isn’t just a student project or a course you go to once a week to work on. It takes much more time in my life than it would were it just a simple project. On top of that, the project extends over a long time and is demanding. That is why it is an adventure.”

With support from experts from the four schools (EPFL, HEIA-FR, HEAD, and UNIFR) and their partners, with Groupe E and the Landold & Cie SA private bank most strongly involved, the students demonstrated their determination to overcome any challenge to meet the construction deadline.

The NeighborHub will open its doors to the public next Saturday, June 10. Shortly after, it will be disassembled into modular components that are meticulously designed to fit into a shipping container, before embarking on a more than two-month long journey to the competition venue.

Swiss Living Challenge's major partners:
Public Sector Partners: Swiss Federal Office of Energy, Canton of Fribourg, City of Fribourg and Smart Living Lab
Diamond Partners: Groupe E, Landolt & Cie SA
Gold Partners: JPF-DUCRET, Regent, la Mobilière, Setimac
All the partners on: http://www.swiss-living-challenge.ch/fr/partenaires