Off-grid living can mean living it up in comfort

First energy self-sufficient multifamily house in the world inaugurated in Switzerland

Can you imagine living in an apartment powered entirely by the sun, even when you live in the northern lowlands of Switzerland where temperatures average 1 °C in January and 17 °C in mid July? Sounds implausible I know, but that’s exactly what the Vogts family are doing, along with eight other families, in the first self-sufficient multi-occupancy residential building in the world.

Cutting the cableCutting cable
To mark the opening of this revolutionary building no red ribbon was cut, but instead the Swiss parliamentarian, Doris Leuthard, and the building’s owner, Walter Schmid, cut the last electricity line to the house to illustrate the significance of this landmark achievement.
Now that the grid connection has gone, the only external source of energy for this house is the sun.

Living the ‘green dream’Panels
So have the Vogts family taken leave of their senses? Not at all, because the house is packed with proven technologies and systems that work, combining them in one intelligent arrangement that acquires and stores energy, then uses it efficiently with the enabling products from ABB.
“The Vogt family and all the others living in this building have nothing to fear,” said Roger Balmer, technical Project Manager of the pioneering project. “The daily energy demands of all nine families in summer require just one hour of sunshine thanks to the powerful solar systems installed. The entire building, the roof and façade, are encased in solar photovoltaic panels, with 26 ABB solar inverters to convert the DC power generated to AC.”

What about winter?
Sounds great when the sun shines, but what about during the cold and miserable winters? Won’t the house need a boost from the grid to get it through the autumn and winter months?

Not now there are low-priced energy storage systems available. Several different energy stores are combined intelligently in this house to power-up all year round. Surplus solar energy, not consumed immediately by the residents, is stored for use during the night, during cloudy days and throughout the winter. This is done by combining short- and long-term storage systems; a lithium iron phosphate battery in the cellar, roughly the size of a wardrobe, provides three or four days short term coverage, while two large below ground water tanks, which serve as a heat store, provide the long-term winter heat. 250,000 liters of water is heated to 65°C during late spring, summer and early autumn and released into the house slowly during the winter.

Turning water into fuel
It sounds crazy but it’s true. Using the surplus power in summer, water is split into hydrogen and oxygen, by electrolysis and the oxygen escapes in to the atmosphere through a chimney in the garden. The hydrogen is stored in huge tanks and used as a combustible winter fuel.

Energy efficiency is key
ComfortTo achieve self-sufficiency all household appliances must be energy efficient.
Beyond the energy saving washing machines and refrigerators, the apartments are fitted with ABB’s free@home – a building automation system that helps keep energy consumption to a minimum without compromising comfort.
“ABB-free@home converts your new apartment into an intelligent home,” explains Martin Vontobel, Product Marketing Manager, Building Automation Solutions at ABB. “The building automation system helps control and reduce energy consumption, while at the same time enhancing comfort. An obvious example is the ‘goodbye’ button, a convenient switch that powers-down all standby appliances when leaving the apartment to help save energy.”

With building automation comes control, which means regulating lighting and energy stores through conventional switches or via smartphones or tablets.

A scene for every occasion
Furthermore, different scenes can be programmed – like dimmed lights for dining and bright illumination for reading. The system also recognizes light combinations and offers them for selection. If the residents watch TV with the lights dimmed and curtains drawn in the evening, the building automation system notes this combination and offers it as a selectable scene. All functionalities can be switched on and off, or configured very easily and thanks to indoors and outdoors sensors, the ABB-free@home building automation system responds automatically to internal and external conditions.

If it is too warm in the apartment in summer and if the sun is also shining on the window pane, the curtains will be drawn automatically to provide shade. If a strong wind is blowing that could damage the blinds, they are retracted. In this way, the building automation system ensures not only safety and energy efficiency, but also maximum living comfort.

Breaking the link between comfort and dwindling resources
Quality of life is not compromised just because energy consumption is low, and since the building controller is fully automatic, the building runs with energy efficiency in focus all the time, even when no one is at home.

This pioneering project of the Umwelt Arena Spreitenbach in Switzerland, demonstrates what is possible with the technology of today and sets new benchmarks for residential construction in the future.

“Research and innovation needs lighthouse projects like this. This project demonstrates our innovative technology works,” said Remo Lütolf, Country manager, ABB Schweiz. “There is no need to sacrifice comfort to achieve energy self-sufficiency in an apartment block.”

Useful links
ABBMy Living Space
Living Space
ABB i-bus KNX
Solar inverters
Solar power solutions
Energy storage

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About the author

Mark Curtis

I am content manager for Electrification Products division at ABB Headquarters in Zurich
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