Students build solar home that's no gimmick

MEDFORD, Mass.--To build a home powered entirely by the sun, students here drew inspiration from Boston neighborhoods rather than the futuristic lifestyle of "The Jetsons."

College students from Tufts University and the Boston Architectural College on Thursday cut the ribbon for the opening of the Curio House, a building that will run entirely on solar energy. It's the New England region's entry into the Solar Decathlon, a U.S. Department of Energy-run event where 20 teams compete for the best solar-home designs.

Student teams, who have spent up to two years preparing, will disassemble their buildings and put them back together on the National Mall in Washington, D.C., in less than three weeks. The homes, which will be open to the public, will compete over 10 days on design, market viability, and other technical aspects.

A no-fuss solar-powered building

The winners of the 2007 competition were Germany's Technische Universitat Darmstadt, which produced a home said to cost more than $1 million to make. By contrast, the Boston team's budget has been about $200,000. Its goal is to produce a home that could be sold for about that much as well, although it would likely have fewer solar panels at that price.

To keep costs down, the building uses almost entirely off-the-shelf products available in building-supply stores. The construction techniques, too, are meant to be relatively straight-forward, using a modular and simple design, students said.

"We want to show people on the National Mall that they can do this now, not get excited about something that they can have in five or 10 years," said Matt Thoms, the project director for engineering and photovoltaics at the Curio House and a Tufts student. Other students said they wanted to avoid "gimmicks" that would be built only for the competition.

While most of the building materials can be bought at a Home Depot, the solar panels powering the house are top of the line. There are 28 SunPower photovoltaic panels able to produce 6.4 kilowatts of electricity and five solar thermal panels which will provide hot water and heating.

That's far more than a house this size--800 square feet--would need if it were connected to the grid. But competitors need to operate for 10 days while at the Mall, performing a number of jobs, such as doing 10 loads of laundry and hosting a "movie night" where they show off their in-home entertainment system. Batteries will store energy in case it's cloudy or for night-time use.

Teams will also be judged on how much excess electricity they generate. The overall energy load of the Boston house will probably be about a third of a typical home the same size, as it will be well-insulated (lowering the heating and cooling system load) and it will use energy-efficient appliances and LED (light-emitting diode) lighting.

Community living
The building design was done with an eye toward densely populated communities, rather than only for people who can afford to buy land to live "off the grid," students said. The back porch and front deck both have privacy screens, a feature that would allow for many similar buildings to be placed closely together.

The one-story home itself is small at 800 square feet, meant for a couple or a couple with a young child. Residents will also need to "manage" the home's climate to a certain degree as well: south-facing outdoor blinds need to be adjusted to let in sunlight for lighting and heating. The outdoor blinds, along with a planned pull-down bed, are meant to maximize the indoor living space.

But the home will have high-tech touches and modern conveniences. It's wired with Ethernet and will have a simple energy-monitoring display for the residents using technology developed at the Massachusetts Institute of Technology, according to students.

The competition starts on October 9 in Washington, D.C., when students will start assembling their buildings to prepare for the judges, the media, and public viewings. Although it's not part of the requirements, the Boston team thought about the energy that's needed to put the Curio House together. Instead of hiring a heavy-duty and very polluting crane, the entire house can be assembled with people and forklifts.

In focusing on affordability, the Boston team has already tackled one of the trickier problems of green building adoption. The Curio House may even see people living in it someday: the team has lined up a buyer for the home at a "green community" housing development planned in Cape Cod.

For more technical details on the house, see this photo gallery.

[rwm72]

This is a great competition! Practical applications for solar panels need to be pushed along to spur innovation and ultimately mass market adoption. As the panels improve over time, they will help change the power landscape, and with any excess going back into the grid, no matter how small, well, that is a major contribution, even if only in principle.

[Hey_Radar]

I would like to see all wiring jacks have a DC jacks, that you plug all your devices into, so you don't have to have all these AC to DC "bricks". Imagine a very efficient converter installed in your breaker box that feeds your entire house electronics. That would save a lot of money. Even devices such as DVD players, etc. wouldn't need their own AC to DC converters. Thus they could be made cheaper.

[i-arman]

On the other hand, you'd need hundreds of plugs on an outlet - take a look at your devices. Laptop? Somewhere between 14 and 18 volts. Cell phone? Anywhere from 6 to 12 volts. Rechargeable flashlight? 5 volts. Printer? 24 volts. And don't forget that in a standard desktop PC, you need 12 volts, 5 volts, and 3.3 volts, simultaneously. Different devices need different voltages, and if you're going to step the voltage up or down for a few things, you might as well do it for everything, and only do it once.

Standardizing to a specific voltage isn't a good idea. Even if you manage to take care of the majority of devices with just a few voltage ranges, there will always be some device that needs something more, and will thus need to convert that voltage a second time, which throws any efficiency right out the window.

Instead, device manufacturers need to put more efficient voltage converters in their devices, which frankly just isn't going to happen unless the consumer demands it.

[kzemach]

Ahhh, slightly disagree with i-armari. Your concern about various DC voltages is valid, but I've seen some real world solutions to this. Seen a GREAT demo of DC and AC hosted on the same lines, with the DC overlaid on the AC via a junction box at the house interconnect. Then, the DC gets modified at the jack with the appropriate, efficient DC buck converter (main DC at 24V as I recall). The real value is that then your solar panels, etc, only have to do a DC-DC to get into the DC system, and any extra power is converted back to AC for the other loads/feedback to grid. It was crazy, but brilliant, and I mean REALLY brilliant. I would put the working demo as one of the top three truly out of the box solutions I've ever seen. Ever. See:

http://www.nextekpower.com/

The solution that I talk about isn't on their website unfortunately. But it does work.

[Seaspray0]

It also depends on the source generating the power. 99.99% of all houses get their energy from a public utility and AC is the best method when doing this. DC is the best method when using solar cells and windmills... but very few have it. Lets also look at the cost of running all that copper inside a house. A 12 Vdc hair dryer (1600 watt) would need a cable the size of what feeds an entire house on 120 Vac. It looks like the inverters and power bricks are here to stay.

[brewster_13]

The only problem with that, is that you have to get all of the DC appliances/electronics to work on a single voltage. Generally for offgrid DC you would have to choose 12, 24, or 48 volts for your wired system. Generally selecting whatever voltage requirement for your available appliances.

Often electronics have way too many different voltage settings (check the fine print on all of your different converters) to be able to use with a single voltage. Unless you go to 12 VDC and can use electronics that provide automobile cigarette lighter plugin options.

[mco7]

i-armon id is not correct. Someone familar with electronics would know that there were be only one DC supply at some high level - say 24 volts. Then each device would have a regulator that would clip the voltage down to what it needs. So this is not an issue at all.
The problem is that since power = voltage x current, if you need, say 300 watts, then you need 5x as much current if you are using 24 VDC compared to 120 VAC. This means the wires have to be much thicker.

[tech_crazy]

@kzemach

The idea is good but not new - superimposing 2 voltages so the AC gets a DC bias instead of return to zero. However, one would have to consider the cost of a buck converter for each outlet. Contrast that with separate wiring to route a DC supply (say 24V) to each outlet.

Also, as another poster mentioned, it would be difficult to run high wattage appliances from the DC jack as the DC wiring would have to be a lot thicker to support the increased current requirements (vs 110/220 VAC)

[Anon-Y-mous]

800 square feet for 2 adults and 1 child is considered adqeuqate? C'mon, you don't need to live in a McMansion to know that is just way too cramped. Yes, it's a sprawl if you're used to a NewYorkCity apartment, but in most suburbs, a typical home needs to be about 1400 sq feet with 2 adults and 1-2 children.

[sanenazok]

Living in Chicago, I know a lot of condo/apartment dwellers who live in sub 1000 sq ft places. However, for a house that's tiny whether it's in the city or burbs. So I guess whoever lives here will need to keep storage space AND there's no room for a home office. This means commuting. Oh well nothing's perfect. For a student project I think this is pretty good.

[rapier1]

Something to keep in mind is that this is a concept house that needs to be transported from the build site to the demonstration site. As such, they don't want to move a 2000 sqft house from Boston to DC. Anyway, the key concepts here are the technology and techniques going into the construction. Getting hung up on the square footage is like complaining that Edison's first light bulb wasn't frosted.

[studiodave56]

With more than a thousand 800-900 sq. ft. houses in my neighborhood I would say yes it's small but adequate for a family of 4. Although I just added 650 sq. ft. to my 850 Ft. house I had other reasons for that, I have too much stuff. My next door neighbor 850 ft. house 2 adults and 3 kids and they are happy because it is bigger than the apartment they were in before.

[ledhead1962]

I absolutely love this! Too small, maybe, but what a great starting point. I really, really want to live in a house like this and think that there should be no new home built in any "first world" country that does not try to achieve these goals. An unrealistic wish it may be, but just imagine.

[archinerd]

One of the biggest impediments to developing this kind of home, believe it or not, has got to be the American Institute of Architects. For the past 25 years, this organization has been redefining 'what architects do' to be 'making art.' Environmental issues are someone else's problem and business, because the architect just makes the package look stylish. Its highest honors and awards are given out for so-called 'advancements' in style, not use.

[DeenaLarsen1]

This is great! I think that living in a microhome (or tiny home) is doable. We are planning one under 250 square feet that will be sustainable and accessible. See our thoughts at http://www.accessahut.wordpress.com

[Alchemist_09]

Sangat menarik, andai saja bisa di aplikasikan di negara saya... :) <b>

<a href="http://www.walkingassistant.com">Walking Assistant</a>

[pratomporn]

The ideas that should encourage more development. For the future of the world.