Near Net-Zero on a Community Scale

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Half the ecovillage
Twenty-two of the 36 high-efficiency homes in the Belfast Cohousing & Ecovillage already have PV systems that provide most of their energy needs.
The other half of the ecovillage
Twenty-two of the 36 high-efficiency homes in the Belfast Cohousing & Ecovillage already have PV systems that provide most of their energy needs.
Homes are clustered, leaving much of the property as open space; wide vehicle-free pathways for walking, biking, playing, and socializing connect the houses.
Eco-village community event
Traditional folk music and arts are embraced by many in the community and create lively social gatherings.
New members are eagerly greeted by volunteers to help unload the moving truck.
Through a community effort, paths are being beautified with fruit trees.
Builders from GO Logic erect the 8.25-inch structural insulated panels that form part of the exterior wall.
Interior of SIP wall panel
Inside the SIP wall is a 2-by-4 framed wall filled with blown-in cellulose, bringing the total insulation value to R-45.
One of the ecovillage homes
All of the homes are duplexes and share a common wall, which reduces heat loss through the building envelope. While the styles and details vary slightly from building to building, each was constructed on a strong premise of energy efficiency and livability. This made achieving net-zero-energy achievable, even with relatively small solar-electric systems.
One of the ecovillage homes
All of the homes are duplexes and share a common wall, which reduces heat loss through the building envelope. While the styles and details vary slightly from building to building, each was constructed on a strong premise of energy efficiency and livability. This made achieving net-zero-energy achievable, even with relatively small solar-electric systems.
One of the ecovillage homes
All of the homes are duplexes and share a common wall, which reduces heat loss through the building envelope. While the styles and details vary slightly from building to building, each was constructed on a strong premise of energy efficiency and livability. This made achieving net-zero-energy achievable, even with relatively small solar-electric systems.
All but one of the PV systems installed on BC&E homes use Enphase microinverters, which were mounted on the racking prior to installing the PV modules.
Installing the PV array
BC&E community members and a Capital City Renewable crew member (also a BC&E member) install a 5-kilowatt PV system of Axitec 250-watt PV modules on the author’s home.
Installing the PV array
The first 11 systems at BC&E were installed by ReVision Energy, using Canadian Solar modules (see the schematic above, which reflects a typical system).
PV modules arrived in bulk
Kiril Lozanov organized the bulk PV module purchase to help keep costs down.
Half the ecovillage
The other half of the ecovillage
Eco-village community event
Interior of SIP wall panel
One of the ecovillage homes
One of the ecovillage homes
One of the ecovillage homes
Installing the PV array
Installing the PV array
PV modules arrived in bulk

In December 2013, an ice storm caused an extended power outage in Maine, leaving many residents scrambling to keep their pipes from freezing. But even with no utility electricity for five days, below-freezing temperatures, primarily overcast conditions, and no supplemental heat, the homes at Belfast Cohousing & Ecovillage (BC&E) lost only 2°F a day, on average, for a total drop of 8°F to 10°F. Nearby homes, by contrast, were below freezing after 24 hours.

How did they do it? Passive House design, passive solar orientation, and a small building footprint.Small, Smart Design

The super-efficient ecovillage homes are heated largely by passive solar gain. Despite Maine’s cold winters and relying on electric space and water heating, a 900-square-foot BC&E home can approach net-zero energy with a 3.5-kilowatt PV system, and a 1,500-square-foot home can zero out with a 4.5 kW system.

Although the homes aren’t certified, the Passive House Institute US standards guided the design process. A southerly orientation; generous south-facing glazing; triple-pane windows and doors; lots of insulation; airtight construction; and a compact footprint resulted in a 90% reduction in the energy used for space heating compared to the average house. The homes share walls, reducing the exterior surface area and heat loss to the outside.

When designing the ecovillage homes, architect Matthew O’Malia of GO Logic used the Passive House Planning Package (PHPP), a spreadsheet-based design tool for architects and designers. “The Passive House standard is revolutionary in that it has spawned a new way of thinking around high-performance buildings,” says Gibson. The PHPP energy model spreadsheet is used to determine a building’s energy gains and losses. “You have a section of wall with certain properties, and the program can calculate how much heat is going to move through that wall over time. If you determine every way a building can gain or lose energy, you come up with a comprehensive model for how a building is going to perform.”

However, Gibson points out, PHPP has its limitations. The software was designed in Europe and has been very accurate in predicting how the building will perform, but doesn’t accurately model household electricity use in U.S. homes. “We use a lot more electricity than Germans do,” he says. “And you can’t predict occupant behavior, such as how someone might set their thermostat.”

Comments (2)

Sarah Lozanova's picture

That's a great question David. We joined Belfast Ecovillage during the development phase, after a core group was established. The community resonated with us because the mission is in line with our values. We visited or met with several communities, both established and forming, and this one seemed to be the best fit for us. I was more interested in joining an established community because it can often take 5 years or more to form an intentional community.

Conflict is inevitable, but I think what is more important is if it can be worked through productively. Belfast Ecovillage is experimenting with the use of dynamic governance, with distributed leadership. This is helping to reduce the time spent in general meetings, while striving to make create more productive meetings.

Before joining Belfast Ecovillage, I read a couple books on intentional communities. I recommend:

Creating a Life Together: Practical Tools to Grow Ecovillages and Intentional Communities by Diana Leafe Christian and Patch Adams

Finding Community: How to Join an Ecovillage or Intentional Community by Diana Leafe Christian

Visiting communities is a great way to get started. IC.org has a directory of forming and existing communities. You can also advertise that you are forming a community, to help attract potential members.

All the best in your endeavor!

david congour's picture

Thanks for the great article on your community, I wish you all success!

I'm starting to think about starting an ecovillage in Colorado, and was wondering how you managed to get together a group of people that would be compatible, and also, how you manage to resolve the inevitable conflicts/disagreements that arise in a community?

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