Sunday, December 8, 2013

Why am I torturing myself with this insane project?

A brief history

My own inspiration to build a passive house came when I met Keith Collins at an MIT Energy Conference in 2009. I was awe struck by Keith’s story of how he built the BrightBuilt Barn, a net zero home in Maine that shockingly doesn’t have a furnace–doesn’t need one, to be precise, even in the winter. What? How is that possible. Amazingly, body heat, residual heat from the lights, and solar gain during the day are sufficient to keep the BrightBuilt Barn warm. For years, I kept the postcard from Keith (above) on my desk and, later, pinned it on my fridge, slowly nurturing the dream of one day building my own BrightBuilt Barn. And here I am, anxiously waiting a building permit from the town of Amherst before it gets too cold and the ground freezes. The Potwine Passive House is a modified version of the BrightBuilt Barn, slightly larger and revised to function seamlessly as a stand alone residence.

Why it’s so compelling

One of my struggles with teaching PHYS/ENVST 104 “Renewable Energy” is that the course material can become overwhelmingly depressing. We, as a society, are observing the slow-motion decay of the world to the point where the next generation will be left with a planet that is barely hospitable to life. Even though many awesome solutions exist that could be implemented right away – high speed trains, bikeable cities, solar panels, wind energy and zero-energy homes (sure, there are enormous challenges) – armies of lobbyists, media figures, politicians and executives are standing in the way, unable to set aside their own small self-interests for the greater good of humanity and the ecosystem. Despite an overwhelming public desire for a healthier environment, we are held hostage by a tiny minority of plutocrats. It feels like there’s nothing we can do about it. I usually don’t go into this sort of editorializing in the classroom, but the implication is there.

When we talk about zero-energy homes, many of the complicated pros and cons fall away and the discussion turns more hopeful. Owning your own home is a mainstay of the American dream. We can all easily picture adding more insulation to the walls, upgrading the furnace to a heat pump, upgrading the windows to triple pane, and replacing the stove with an induction cooktop. The cost savings are modest, but the energy savings are enormous (see my last post). No birds are harmed in the process. There’s no nuclear waste to contend with. Relatively few entrenched interests stand in the way. To me it’s a demonstration that real solutions exist, that they are practical and can have a profound impact without requiring undo sacrifice or shifting the burden elsewhere.

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It’s an insane project, but fun

It’s not necessarily that the project itself is insane. It’s more so that I’m a pre-tenure faculty with absolutely zero time to spare, already overcommitted with professional duties and not enough time to hang out with friends or my fiancĂ©, or even to relax (preferably on a Greek island, see above). For the past year, I’ve squeezed in precious little bits of time to plan the project and make critical–often agonizing–decisions. (Of course, Integrity Construction and GOLogic have done the lion’s share of the work.) Late at night, in the face of utter disapproval from LeeAnn, I’ve worked with irrational zealotry, powered by the notion that somehow this project will spark a massive movement toward carbon-free living.

I have to admit, though, it’s not all personal sacrifice. The project has been super cool and fun; there’s something about a technologically sophisticated house that really captures my boyish imagination: building stuff, doing it ahead of the curve, and with a laudable purpose.

Tuesday, December 3, 2013

Huge energy savings possible with passive houses



A rarely known fact – and one I love to repeat – is that our wonderful modern society uses energy in terribly inefficient ways.  Few of us know how much energy is wasted when you flip on a light switch, but the answer is delightfully instructive, and shocking.  Powering a light bulb from the power grid is only 1% efficient.  A staggering 99% percent of the energy is lost (to heat, specifically), lost at each step along the way: first at the power plant, then in transmission to your home, and then within the light bulb itself as it operates.  Think about it this way: 99% of the pollution emitted from the power plant causes harm to someone (or something, or someplace) without anything to show for it.

If you can tackle poor efficiency, which happens to span all aspects of energy usage, you stand to gain tremendously; doing more with less and, in the process, causing less damage to your surroundings.  The chart below shows the predicted energy usage of the Potwine passive house, compared to that of the typical home in Massachusetts.  The savings are enormous – over an 8 fold decrease in energy usage overall, much of it simply from increasing efficiency and smarter design.  The lion's share comes from reducing the heating load of the house and adding passive solar gain, but switching to LED lights and more efficient appliances also makes an impact.

We'll see if these predictions actually hold true.  If they do, then we've realized a practical, economical, and sacrifice-free way of reducing household energy consumption in the US.