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Glamorous living off the grid: Aktivhaus generates double the energy you need

By Allyssia Alleyne, for CNN

Published 12:20 PM ET, Tue March 17, 2015
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Off-grid living tends to conjure visions of isolated log cabins inhabited by burly lumberjack types with rough hands and an extensive knowledge of edible plants.

But with the launch of Aktivhaus -- a handsome modular and modernist home that generates two times as much energy as it consumes -- that stereotype may soon be consigned to the past.

Conceived by the German designer and engineer Werner Sobek, Aktivhaus positions itself as the next step in sustainable living and architecture, thanks to a series of clever adaptations, design hacks and technological advances.
Courtesy Zooey Braun
The current Aktivhaus prototype in Stuttgart, Germany -- nicknamed B10 -- is powered by photovoltaic thermal panels on its roof, which generate electricity that creates heat as a byproduct. Its components are fully recyclable, and take only a day to assemble; and the fact the modules can be stacked suggests they could be suited to high-density cities. Courtesy Zooey Braun
Sobek first started developing the Aktivhaus concept in 2000, when the design community was forced to consider fossil fuels, global warming and population growth.

"(Design) is not about more efficiency. We need effectiveness," he says. "We need another approach. So I said, 'What's the most radical goal we can define?'"

In this case, it was a house that produced no emissions or waste, and derived no energy from fossil fuels -- three tenets Sobek refers to as the Triple Zero standard.
Courtesy Zooey Braun
Sobek has designed eco-friendly buildings in the past (most notably the four-story R128 in 2000, "the first residential building beyond the mud hut that was completely recyclable"), but B10 is the first to generate not only enough energy to fuel itself, but surrounding buildings too (Sobek calls this the "sisterhood principle").

In fact, B10 is currently powering the neighboring Weissenhof Museum, designed by Le Corbusier in 1927, with its surplus.
Courtesy Zooey Braun
B10 doesn't require as much energy as your typical home, thanks to clever engineering. The most intriguing element: the house is connected to local weather stations so that it can adjust its energy usage based on the forecast.

"The house knows how much energy is produced under which weather conditions, and how much energy it will need under each weather condition, which allows the house to predict the balances, and the overflows of energy in the coming days."
Courtesy Zooey Braun
The inclusion of an underground ice storage tank also cuts down on energy needs by removing the need for traditional heating and air conditioning systems.

"In summer, the ice is used to cool the house. By melting, it absorbs heat energy," Sobek says. "In winter, it gradually freezes. Each time a chunk of water turns into ice, a certain amount of heat energy is released, which is then used to heat the house via a heat pump, which brings the energy to a higher temperature level."
Courtesy Zooey Braun
The house only draws on its energy reserves when direct sunlight can't be counted on.

"Batteries are still expensive and not as effective as we'd like them to be, however we need electricity in the night hours when we have no sun," Sobek says. "We try to reduce the consumption of electric energy over the night hours as much as possible."

To this end, the refrigerator runs especially cold during the daytime before automatically switching off after dark, so that the contents don't spoil overnight. It turns on again when the sun rises.

"In the morning, the temperature may be 8 or 9 Celsius, but it's still fine."
Courtesy Zooey Braun
While the current prototype was imagined for high-density cities, Sobek hopes to bring the concept to all regions. This year, prototypes will be built in southern Argentina and Patagonia, while 2016 will see the Aktivhaus debut in Siberia and Turkey. Courtesy Zooey Braun
It will soon be possible for people to order their own custom Aktivhaus. In the next two months, Sobek and a group of industrial partners will start selling the concept to consumers.

"People will buy a house like you buy a car. You're invited to a certain place, you have a catalog, you have an electronic order, and then we design the house," he says.

A standard model costs €3,000 ($3,500) per square meter, but Sobek says prices can exceed €10,000 ($12,000) per square meter for more luxurious models.

"The technology means the houses -- the skeletons and the muscles -- are always the same, but the comfort and luxury on the inside is adjustable to certain regions or tastes, or environmental specifications."
Courtesy Zooey Braun