- First in the World with Self-Sufficient Apartment Buildings
Vätterhem, Jönköping Energi, Skanska, and Yellon are building two fully self-sufficient houses on Öxnehaga, with no connection to any networks. The decisive decision for the project is made in October by the Swedish Energy Agency and the municipality of Jönköping.
Off-grid houses comprising 44 apartments become fully self-sufficient in terms of energy, water, sewage, and ventilation. The project is unique in that nothing like it has ever been done in a multi-dwelling house.
Four equivalent houses, of which two are off-grid
A total of four seemingly similar energy-efficient houses, two of which are connected to municipal networks and two are off-grid. This means that exact comparative figures can be obtained when measurements are taken in different houses. Vätterhem invests long-term through this project, as reduced energy consumption in the long run leads to lower costs.
“Through this research project we want to reduce our climate footprint and learn from new technology and innovative solutions that are applied in the off-grid houses so that we can then use parts of this in our existing housing stock, ” says Thorbjörn Hammerth, CEO of Vätterhem.
Collaboration between several actors
Vätterhem will own and manage the apartment buildings for the Slåttertiden neighborhood that Skanska has been commissioned to build. Jönköping Energi is responsible for the operation of the energy system and the storage of energy in the houses whose basic idea with the combination of different systems is devised by Yellon.
Here how it works
The Base is solar energy and hydrogen produced by electricity from solar cells, for example, which in turn cleaves the water in an electrolyser to hydrogen and oxygen. The hydrogen gas is then stored until needed (winter time) and then turns into electricity and hot water in the fuel cell.
“Finding efficient ways of micro-production, storage, and energy-efficient properties is part of future housing. Jönköping Energi wants to be there to contribute knowledge and experience that both develops us and property owners in our region, says Fridolf Eskilsson, CEO Jönköping Energi.
Drinking water is taken from our own drilled well while other water supply comes from the rain which is trapped in ponds and then purified and recycled. Behind this lies many innovations and the management of food and hygiene water is done in different ways.
The sewage is cleaned and recycled via forced purification and in the case of ventilation, termite ventilation that uses the soil’s cooling and heat depending on the season should be tested.
What does this cost?
The total additional cost for the two off-grid houses is approximately SEK 50 million. Support of SEK 25 million has been sought from the Swedish Energy Agency, the remaining cost is divided between Vätterhem and Jönköping Energi. The production cost of the 44 tenants in the self-sufficient houses is estimated to cost SEK 160 million. Thanks to lower operating costs, Vätterhem expects to collect the extra investment within 10 years so that it will then generate a surplus.