In 2002 the U.S. Department of Energy launched the Solar Decathlon, an international college competition where students refine and present their best ideas in solar-powered home design. The Solar Decathlon’s interdisciplinary challenge requires students to design, build and operate a cost-effective, energy-efficient home from the drawing board up.
The Solar Decathlon challenges participating students to break new ground, figuratively and literally, on sustainable home design. Held every two years, a top contender at the 2013 Solar Decathlon was Stanford University's Start.Home, leading the pack in market appeal, affordability and engineering.
Led by Derek Ouyang, the 50-member Stanford team built the Start.Home around the idea of the Core, a modular unit designed as the nerve center of the building, around which a customized home is built. A Core includes the kitchen counter and appliances, one or two bathrooms, a laundry room and a mechanical "engine" room integrating electrical, HVAC and plumbing with automation and monitoring systems.
"It's not just about engineering the perfect home,” says Ouyang, “it's about designing a product that people love and empowering people to actually lead more sustainable lives.”
A home built for sustainability includes lots of good things: net-zero energy use, sustainably-sourced materials, passive heating and cooling, graywater recycling and automation system to manage energy use. That's all well and good. But at the end of the day what you've created is a couple thousand square feet of sustainable habitat. If Donald Trump lived in it, what would you have? A sustainable house with a clueless man living inside, with no notion of how his slovenly ways impact energy and resource use inside the house. A nice, energy-efficient house, but with no real impact on human behavior.
Building for agency puts the power back to the people living inside the house (we'll drop our Donald Trump analogy for now). Creating a home system that relies more on information and flexible human interaction than simple automation gives homeowners the knowledge and "nudge" they need to truly understand their energy use and therefore act on it. They then go out and impart this awareness to their friends and neighbors, spreading the idea of sustainable living through agency and active engagement, not through home automation systems running unseen in the background.
“…our philosophy,” Ouyang says, “was that in the end, it's not about smart homes; it's about smart people. And with good design we can actually empower homeowners to make the decisions instead of the house making decisions for you. This, over the lifetime of the homeowner, can actually change behavior”
“Home automation systems today are difficult for the homeowner to implement because they typically require multiple integration of multiple products from multiple companies, few of which are designed to work together effectively.”
Ouyang's team designed and built what they call "Pods," built on the Raspberry Pi and Arduinos platform, to link up various off-the-shelf and custom built devices. Each Pod can control up to 14 different switchable elements, eight dimmable elements and one HVAC element. “We designed our own relay panels with custom PCBs that could turn low-voltage signals into relay commands, and could handle dimming and HVAC protocols," says Ouyang.
Using the low-voltage protocol of the Pods allowed for designing beyond physical switches. Homeowners can control elements based on programmable swipe-based gestures we already use on our tablets and smartphones. A tap could turn on a light, a swipe right could turn a dimmable fixture up, a circle motion could turn on a ceiling fan - it’s up to whatever the homeowner is comfortable with.
Instead of inadvertently leaving the lights on all evening as you rush out the door, a simple three-fingered gesture down could turn off all the lights. This is the sort of human-based interaction with automation that Ouyang and his team believes can empower people to easily adapt habits of sustainability.
Like the Core, Pods are modular, and can be distributed throughout the house in locations where they are most relevant to what is being controlled. In this way, tracing wiring back to the core is reduced. Pods are easily added if more are needed. The structure and control of the Start.Home grows and adapts to the user.
The point is to make monitoring energy use and net-balance production flexible, seamless and intuitive, keeping in mind the concept of human agency, not just sustainability. Changing human behavior was the goal. Maybe even Trump would turn off his lights if he saw exactly how it would save him money. Now that's changing human behavior!
The team intended on installing water flow meters, but ran out of time. Nonetheless, this is easily included in future iterations of Start.Home
Start.Home is Stanford's answer to a largely stagnant home construction industry, creating a "smart, adaptable residential system that cuts up-front and use-phase energy emissions" built on an "energy-efficient framework that is modular and scalable, and does not sacrifice the freedom of the homeowner to build a custom home."
Ouyang envisions a variety of Core configurations, varying in size and equipment specification based on end-use needs and location (the prototype was based on Stanford's Palo Alto Mediterranean climate). Once fully developed, modular home Cores will be produced in an assembly line process and shipped as efficiently as possible to construction sites.
At every point in the design process the team employed a full suite of Autodesk BIM modeling and visualization tools, including the Autodesk Building Design Suite, Vasari for conceptual design, Simulation CFD for fluid flow and thermal simulation, and Green Building Studio for environmental analysis.
"...from high-end residential (think the kind of people who buy Teslas) all the way to disaster-relief and temporary housing," Ouyang says. "I think it just goes to show how simple yet important the idea of a Core is, and I am confident that in the future they will solve lots of problems."
All image credit: Dept. of Energy Solar Decathlon, courtesy flickr
Tom is the founder, editor, and publisher of GlobalWarmingisReal.com and the TDS Environmental Media Network. He has been a contributor for Triple Pundit since 2007. Tom has also written for Slate, Earth911, the Pepsico Foundation, Cleantechnia, Planetsave, and many other sustainability-focused publications. He is a member of the Society of Environmental Journalists