The curtain and its forebears, like the tapestry, have been a feature of dwellings for millennia. But our age is seeing the first-ever curtains that can illuminate rooms at night or power your laptop.
Such capabilities, made possible by solar technology designed right into the fabric, represent a key element of the Soft House — a “hybrid house” in which solar textiles collectively generate some 15 kilowatt hours worth of electricity a day, or about half a typical U.S. household’s needs.
The house, realized in a concept prototype for a German design museum, is the brainchild of Sheila Kennedy, an MIT professor of the practice in architecture. And the dwelling’s energy-harvesting curtains are a big part of its promise.
The Soft House’s aim is to lower barriers to widespread adoption of solar energy. Rooftop installation, for one, represents about half a typical solar system’s cost. There are also challenges to using solar energy with, say, household appliances, since you need a conversion device to turn the direct current that photovoltaic systems generate into alternating current.
“Most people don’t want an engineering project in their houses,” says Kennedy. “But what if homeowners could buy an energyharvesting textile curtain and start drawing down clean power for home lighting and other purposes?”
The translucent Soft House curtain fulfills some traditional functions: shade south- and west-facing glass walls in summer, insulate in winter. In its solar role, though, the curtain’s anything but conventional. It harbors semiconducting strips that, together with electrical conductors, make up a photovoltaic system. It also features light-emitting devices (LEDs) — miniature, highly efficient alternatives to traditional light sources that can individually deliver as much illumination as a 60-watt bulb.
Small batteries encased in the curtain’s hem store power to be used by the LEDs at night. That power can be harvested for other needs, too. “The curtains could help charge a range of high-capacity batteries, including those used in hybrid vehicles,” notes Kennedy.
The Soft House itself bypasses many conventions of the building industry, like framing with 2x4s. Instead, Kennedy’s group has created a construction system, based on computer modeling and a technique called parametric design, that uses sheet products like plywood or recycled pressboards to form highly innovative structures.
Though the house’s components are prefabricated, its design does allow for some variation. “Using the Soft House parametric design program, you could input the orientation of your lot,” notes Kennedy, “and the form of the roof could be modified to fit the site.”
The design package could then be emailed to a manufacturer, where the structural elements would be cut using a computer-controlled router. Importantly, those building components could be readily stacked flat for a truck or rail trip.
Kennedy, also a principal at Boston architectural firm KVA, says the house is ready for a real-world trial. “Our goal is to realize a Soft House development anywhere there’s a need for innovative homes that harvest clean energy,” she says.
Kennedy also hopes to form interdisciplinary working groups with Institute colleagues. “If we can get good collaborations among designers, industry, and the engineering community,” she argues, “we can challenge a lot of the conventional thinking in architecture and develop new ways to integrate clean energy into building design.”