BrightBuilt Barn: a Super Green, Prefab, LEED Platinum Net-Zero Building

Yesterday’s New York Times contained an article on German “PassivHaus” construction

Passive Houses use superinsulation and strict air tightness to reduce the heating energy requirements of a building by 70% – 90%. BrightBuilt Barn has used some of these same concepts to create its own approach to sustainability.

The Wikipedia entry explaining the history and background of Passive Houses is here:

http://en.wikipedia.org/wiki/Passive_house

The PassivHaus concept grew out of a collaboration in the late 1980s and early 1990s between two professors of architecture, Professor Bo Adamson of Sweden and Dr. Wolfgang Feist of Germany. Over time, their ideas were codified into a standard of building performance, as described on this English-language page of the PassivHaus Institut’s webpage (most of which is in German)

The UK branch of the PassivHaus movement has an English-language website with more information.

It’s gratifying to see advanced but pragmatic approaches to sustainability in building design and construction begin to get recognition in the mainstream press.

Keith Collins

Veteran eco-activist Bill McKibben appears to be the guiding force behind a new social networking approach to advocating for sustainability.

Check out the web site for his newest initiative, known as “350″ (for the 350 parts per million  concentration of CO2 in the atmosphere that is deemed to be sustainable – current level is 387 ppm):

http://www.350.org/

The 90-second animation explaining global warming without narration is worth the visit.
Current efforts seem focused on raising awareness of global warming, through social activities ranging from traditional rallies to postcard mail-ins to craft competitions.

Skeptics may question if there is any “there” there, the movement seeming to be all awareness and no action, but the 350 message is spreading globally at an impressive pace.  Definitely a space to keep watching, to see if this global network of enthusiasts turns into a force to reckon with.

Keith Collins

Today BrightBuilt Barn received a nice review at Treehugger, a leading eco-tech and sustainable lifestyle blog.

Keith Collins

There are lots of new ideas circulating about how to reduce the cost of alternative energy. In our previous  post, we linked to sites explaining how inexpensive kites can be harnessed to produce wind power cheaply.

In today’s story, we learn about how balloons can decrease the cost of solar energy. The balloons are cleverly made with a reflective back surface and a transparent front. They act as concentrators of the sun’s rays, and focus their high-energy beams on a photovoltaic (PV) solar cell. This allows a small PV panel to produce as much electrical power as a much larger one. Since the balloons are light and cheap, and can be held in place with light and cheap wires rather than the heavy and expensive steel frames required by metal concentrators, the total cost of solar energy production is much reduced.

Read the article at TreeHugger

Keith Collins

Dutch researchers have demonstrated a prototype wind energy generator that uses kites, rather than wind turbines. The kites can ascend to heights a half mile or more above the ground, where the winds are much stronger and more reliable than those that drive the near-earth wind turbines.

Scientists from Delft University in the Netherlands have developed a 10 square meter kite (ca. 100 square feet), that in tests produced 10 kilowatts of electrical power when tethered to a generator – enough to serve 10 homes. They say that the idea can be easily scaled to produce megawatts of electricity at prices comparable to coal fired electrical generators – far cheaper than wind turbines.

Last year Google invested $10 million in an American company with a similar idea, called Makani.

Read the article in the Guardian

Read the description of the project on the website of the Delft University of Technology

Read an article on a similar scheme from Italy, from Wired News

Keith Collins

In the July 31 issue of the premiere scientific journal Science, a team of MIT scientists reveal a new method of producing hydrogen from electricity. This new method uses cobalt and phosphorus, both being abundant and widely available minerals, to dramatically lower the energy required to split water into hydrogen and oxygen.

The proposed application of this technology is to store energy from solar electric panels for use during the hours when the sun isn’t shining. The scientists suggest that this will make it feasible for each household to produce its own energy, with no need for the present system of transmission lines from central power generators. The household will use solar energy directly during the day, and use the stored hydrogen energy at night, in a fuel cell or other hydrogen powered energy generator.

The scientists predict that the technology could be in widespread use within 10 years.

Read the MIT News Office release

Keith Collins

One of the remarkable differences between conventional construction and the Barn’s offsite construction method is the speed of the build.

On Monday morning, July 7, the barn was still just a hole in the ground, as it had been since the foundation was laid last November.

At 11:15 AM that day, the truck arrived with the first of the structural panels from Bensonwood. By 7:15 PM on Wednesday, July 9, we had a complete weathertight shell in place.

Floor, walls, roof, windows, doors – all assembled in just 56 hours from start to finish. (Actually, since no work was performed at night, it was only 32 working hours.)

Contrast that with the weeks it would take to attain the same result with conventional construction.

Check out the pictures below to see the process unfolding.

Having seen it in person, I’m now a believer – this needs to be the future of homebuilding.

Keith Collins

Today’s edition of the Rockland Courier Gazette/Village Soup has a nice article on BrightBuilt Barn written by Dan Dunkle, the paper’s business/enterprise reporter. Dan has long covered the environment/green technology beat, and his expertise shows.

The link to the article is here:

http://knox.villagesoup.com/Community/story.cfm?storyID=121489

Dan also includes lots of pictures showing the barn raising in progress – so enjoy.

Keith Collins

Green technology is generating more media buzz by the day. Two recent articles have caught my attention, both because of their content, and because they are in mainstream publications aimed a general, albeit upscale, audience.

The first article is by Robert F. Kennedy Jr., son of the slain political leader and a prominent eco-activist, writing in Vanity Fair.

RFK Jr. argues for the federal government to underwrite a an alternative energy infrastructure, including building a nationwide High Voltage Direct Current (HVDC) power transmission network. Although HVDC may seem arcane, it actually addresses one of the major impediments to switching to alternative sources of energy, namely that the best places for capturing sun power or wind power tend to be remote from the population centers that use the energy. Alternating current (AC) power lines are cheaper to build and maintain, but over long distances lose much of the energy they transmit. Direct current (DC) power lines are more expensive, but lose much less energy over long distances. A HVDC network could bridge the gap between where sustainable energy is produced and where it is used.

RFK Jr. is putting an important idea out into the public discourse. Time will tell whether the idea gains traction. An alternative to HVDC, of course, is the local generation of energy near the point of use. Solar panels on each roof, wind generators in the back yard, etc. My guess is that we will see some of both strategies implemented over the next several years.

The second article that caught my eye this week was in the New Yorker (I’m addicted to the cartoons). Titled “The Island in the Wind”, the article describes the Danish island of Samso, an island about the size of Nantucket with some 4300 inhabitants, who have become energy independent by switching to wind power.

Actually, Samso Island is a now a small but steady energy exporter, producing more electricity than they use, and selling it to the mainland.

The islanders apparently made the switch to wind power without government support or subsidy of any kind, as a sort of community project. The wind turbines were all erected with private funds raised by the islanders themselves. Each turbine is owned by one or a group of investors, who get annual dividends based on the economic performance of the turbine they own.

A fascinating story in its own right, the achievements of the Samso Islanders make you think, “If a small population of rural, mostly agricultural residents can successfully switch to sustainable energy, what’s our excuse?”

The article is also full of revealing anecdotes about how this small real world community has evolved in its use of energy under a sustainable regime. For example: the Samso Islanders have little interest in energy conservation. The local eco-activist, an island native proud of his neighbor’s achievement of energy independence, becomes indignant when discussing the results of his attempts to persuade the community to conserve energy. Families that insulated their homes better, for example, would then heat more rooms in the winter, so that the net savings were always close to zero.

There is much more to glean from this article, and I will probably return to it for further insights in the future. I highly recommend that you take the time to read it.

Keith Collins

As we try to decrease the carbon footprint of our buildings, we need to consider two distinct, but inter-related issues: reducing the carbon footprint of the building process itself, and reducing the carbon footprint of running and maintaining the structure once built.

Addressing the second issue led us to choose super-insulation (to minimize the energy required to heat the place) and sustainable energy sources such as solar thermal and photovoltaics.

Here I want to say just a few words about the other issue, minimizing the carbon emissions resulting from the building process itself.

First of all, this is to my mind a much harder problem to solve than that of reducing the carbon impact of ongoing energy use. Ongoing energy needs can be straightforwardly addressed by judicious design (to decrease consumption by eliminating waste) and switching to zero-emission sources of energy such as wind or solar. To solve the problem of reducing the impact of the building process itself, we need to consider the carbon load introduced by making, transporting, and assembling each and every component of the building. This calculation quickly becomes extremely complex, requiring detailed knowledge of materials, manufacturing processes, and modes of transport.

To take a simple example: the chemical process by which cement powder is turned into hardened concrete (just add water and stir!) releases CO2 – lots and lots of it, it turns out. So we have tried to use more wood and less concrete, even though concrete has many desirable properties as a building material (easy to shape, high thermal mass). But if the wood is harvested in Indonesia (as much wood is) and transported to us by boat, train, and truck, we have incurred the carbon load of all that transport. So we have tried to minimize transport by local sourcing of wood, to the extent feasible. And on and on.

The underlying concept here is generally called embodied energy: each structure embodies all of the energy (and associated carbon emissions) used to make its constituent parts, transport them to the site, and assemble them into the finished building. On the BrightBuilt team, we usually call it the carbon debt we have incurred by building a structure where there wasn’t one, or the kilowatt hole we have to dig out of by generating zero-emission electricity that displaces high-carbon fossil fuel use.

It turns out that there is no central database containing data on the embodied energy of common building materials. Worse, there is no single, widely accepted method for calculating embodied energy.

We have consulted experts around the globe, from MIT to Australia, in an attempt to calculate the embodied energy of BrightBuilt Barn. While we believe that we have made a serious and intellectually honest attempt, we do not claim to have precise and unassailable results.

Brian, of Opus One Studio, has become our resident expert on the subject. In a future post, he will give some of his findings and methods.

For now, we will only say that the carbon debt incurred by even a small building such as BrightBuilt barn is surprisingly high, and will require years of excess clean energy production to pay back. We are helped here by 1) our commitment to durable materials, which greatly lengthen the usable life of the building, and so give us a longer time frame over which to amortize the carbon debt; and 2) our decision to maximize the excess energy we produce, by using superinsulation to reduce energy demand while covering the roof with solar energy systems despite the reduced need for ongoing energy.

Brian’s Energy Meter will track the energy surplus, both minute-to-minute and cumulative, and we will put the results on the web at the BBB site, so anyone can track the progress we make in climbing out of our “kilowatt hole.”

Keith Collins