George Longstreth’s dreams of a solar home started nearly a decade ago, when he had a crude off-grid system installed for a seasonal beach cottage on Baker’s Island, MA. “It was basic, just four small panels, but it was enough to run the microwave for a few minutes or brew a pot of coffee. It got me thinking about how this technology could be applied for a normal home.”

This thinking process lead him to Yestermorrow Design/Build School in Warren, Vermont, where he learned the basics of green building and passive solar design. Then, he scoured Northern New England for an ideal location to build his solar home, a search that took him from Southeast New Hampshire to Portland, Maine, before he found the property of his dreams in Kennebunkport.

“It was a beautiful property with good access to solar south,” he says, “That’s when I started assembling the best team of local contractors to make the project happen.”

His search for a solar contractor brought him in contact with a number of companies in Southern Maine, but he chose ReVision Energy because “you knew what you were doing.” After a preliminary meeting with engineer Geoff Sparrow, ReVision worked with George and his architect, Hans Warner, to design a 8.28kw solar electric system to be mounted on the home’s south-facing roof along with 2 flat plate solar hot water collectors for his domestic hot water supply.

Solar PV + Geothermal = Synergy

Solar is just one part of the renewable energy systems in Longstreth’s new home. George also contacted Dr. John Logan of Water Energy Distributors for advice on installing a geothermal system. Dr. Logan connected George with New Energy Solutions of Standish who designed and installed a geothermal system consisting of two heat pumps, one for 1st floor radiant heat, and another for cooling and 2nd floor heating.

“It was great when I got all these smart people in the room together to talk about the synergy between renewable energy systems,” George says, “Our predictions are that the solar will provide around 50% of the electricity used for geothermal heating during the heating months, and 100% of my household ‘plug’ loads the rest of the year.”

Designing a home that is mostly renewable-powered requires being very conscious about energy use, and Longstreth’s home takes this concept to heart. His home is heavily insulated, consisting of a double-framed 2×6 + 2×4 wall system filled with compacted cellulose insulation, for a R40 rating in the walls and R60 in the ceiling. His home takes advantage of its south-facing orientation to incorporate passive solar features, such as windows installed for optimum solar gain and a special 1 1/2″ slab to collect passive heat.

Investing in Solar

As his project nears completion, George looks forward to a life of minimal energy bills. “The new home uses no oil whatsoever, very little electricity and very little propane. We bucked the attitude of ‘fly now, pay later’ to ‘pay now, fly later.’ The tight-fisted Yankee in me can’t let this bountiful renewable energy go to waste while we purchase oil from our enemies overseas.”

George estimates that his mechanical systems made up about 25% of his overall project budget, and that with state and federal incentives, his renewable systems were cost-competitive with installing a traditional heating system. “It’s a no brainer, and we’re already seeing results. After our first month, our electric bill went from around $80 to -$10! We can’t wait to see how it performs long term.”

Thought you couldn’t build an apartment building in Maine without depending on fossil fuels? Think again! Paul Ledman proves with his new 3-unit dwelling in Portland that exceptional insulation and smart mechanical systems can work to make a home that requires no source of energy other than the sun… even in Maine! Even with tenants!

We’re proud to have this exceptional building in our backyard and thank Paul for taking the time to talk to us about this exciting project.

Tom Southworth’s BEYOND net zero home will sell power to the grid each year!

Tom Southworth’s commitment to sustainability runs deep. Since 1974 he’s owned and operated a water-powered sawmill in Lancaster, New Hampshire, around which he built the successful Garland Mill Timberframes business. Tom imparted his passion to his son Ben, whose work includes turning a 1970s ranch house into a LEED Platinum, Net Zero showcase. So when it came time to build a home to retire in, Tom set his sights high: he wanted a house that would not only generate all of the electricity it uses each year, but also produce a surplus to sell to the grid.

New Hampshire Ups the Ante

“What got me started in this direction is when New Hampshire went beyond net billing and offered to write me a check if I produce more power than I use,” Tom says. “I took a hard look at my energy usage and determined that 8,000 kWh/year would allow us to meet all our needs and be a net exporter of electricity.”

Most impressive is that Tom both exports power to the grid and heats his home with electricity. While conventional wisdom is that electric heat is expensive, 21st century building standards challenge that assumption completely.

“While it’s not official yet, we built this house to meet German passivhaus standards,” Tom says. “This means an extremely well-insulated building envelope consisting of 12″ exterior side walls packed with cellulose sheathed with 2″ foam, and 40″ of cellullose packed into the truss system. We moved in on April 1st and so far have not used any heating whatsoever.”

Tracking Results

Tom Southworth’s solar thermal storage tank is tied into its own electric meter to track run time of the backup electric element

To keep track of his goals, Tom uses a decidedly analog but very effective method of monitoring his systems – an extra electric meter dedicated to tracking photovoltaic production, and a second dedicated to his hot water tank. In addition to the photovoltaic system, Tom had us install a solar hot water system tied into an existing 120 gallon storage tank with electric backup.

“Since we don’t really know much electricity our backup tank will use in the winter, we added the second meter so we could really understand it,” Tom says, “We expect to use only solar-heated water from May through September and will be closely watching how much the electric element is needed in the other months.”

Power While the Sun Shines

Now that everything is up and running, Tom says the system is so far “on target” for photovoltaic production.

“I’m 100% pleased with the system,” Tom says, “I look forward to enjoying my years of retirement knowing my energy comes from the sun.”

The new home of Susan Turner and Karl Karnaky will be net-zero, meaning it generates as much energy as it consumes during the course of a year. It was constructed using the “rammed earth” method and features numerous recycled/repurposed materials.

Although Maine is still the most oil dependent state in the U.S., a Bar Harbor couple is proving that people can live comfortably year round at our latitude with virtually no fossil fuel energy.

Rammed earth involves packing a mixture of sand, gravel, and cement into a form, which then that solidifies into walls. This dense material is an excellent thermal mass for passive solar applications, and practically soundproof.

The home also features numerous recycled/repurposed elements including a recycled aluminum and steel roof, a soapstone farm sink from a cabin found on the property, and plank flooring and beams recovered from an 1836 house in Dexter.

Going Solar

Turner and Karnaky’s sustainable mindset applied to their choice of mechanical systems, as well.

“Deciding to go with solar was the easy part,” Susan Turner writes. “We found that we could get a system that would cover the entire winter’s [radiant floor] heat. Knowing that the panels are creating our electricity leads me to consciously decide how I will use electricity and to be aware of not wasting it.”

Turner and Karnaky were so impressed with the installation that they opened their home up this past October to be on NESEA’s Green Building Open House Tour. Approximately 50 people visited to see the “striking” house which the MDI Village Soup said combines “the earthen feel of an ancient construction technique, the intriguing attractions of vintage elements reanimated by new use and the aesthetics of a contemporary sensibility.”

Enjoying the Sunshine

The new home should be “net zero,” meaning that it will generate as much energy as it consumes throughout the course of the year, required no fossil fuel inputs!

The 5kw grid tied photovoltaic (PV) system will produce roughly 6,000 kilowatt hours of clean, renewable electricity annually. Electricity will be used for normal household loads as well as a Thermolec electric boiler which supplies radiant heat, and a backup element to the solar hot water system.

From May through September, the evacuated tube solar hot water collectors will provide nearly 100% of the home’s domestic hot water supply. Combined, the two systems will offset roughly 11,600 lbs of C02 emissions each year.

“We hope our home will inspire more folks to decide that solar is the way to go,” Turner says, “We are excited about ‘free’ heat without using non-renewable energy, and we love the hot showers provided by the sun!”

Passive homes such as the GO Logic model house in Belfast, Maine, are still rare in America, but forward-thinking homeowners, builders, and architects are increasingly incorporating the strict German standard in new homes.

This weekend the New York Times highlighted the growing effort of architects, builders, and homeowners to create houses that meet the strict German Passive House standard.

The article, Can We Build in a Brighter Shade of Green?, follows the story of one super efficient home built in Vermont.

It notes both the challenges both with designing such an efficient house, and getting the required skills and materials to construct it in America:

While some 25,000 certified passive structures — from schools and commercial buildings to homes and apartment houses — have already been built in Europe, there are just 13 in the United States, with a few dozen more in the pipeline.

“Even though the passive house standard is tried and true, and is used all throughout Europe — we know it works, we know there’s some simplicity to it,” says Mrs. Landau, “here in the United States, we were reinventing the wheel.”

… In Europe, this design-and-construction balancing act has an established manufacturing base to feed it; in the United States, not so much.

“If we were in Europe, most of the materials and equipment would be off-the-shelf and readily available from local suppliers,” says Tedd Benson, owner of Bensonwood Homes, a high-efficiency timber frame builder based in Walpole, N.H., that is constructing the Landau house. “And they would have already been vetted and certified by the Passivhaus Institut, with their performance specifications already linked into the passive-house software.

“Here, we have to invent the systems and try to find the materials, products and equipment that will help us meet the passive-house standards.”

Despite an initial price premium (for additional design time, thicker walls and insulation), over the course of its life a Passive House will return the initial investment many times over. The Landaus (featured in the Times article) expect to have the energy efficiency investments pay for themselves within 10 years.

Here’s a video the Times produced on the project:

Journalist Tom Zeller Jr. went on to write about the general state of green building in a follow-up blog, When Green Building Is Not Green Enough.

In it, he cites design-focused (rather than energy-focused) architecture as one of the problems with building design, stating that “American architects are well schooled in matters of design, they often receive little training in the physics of how a structure breathes, how it consumes energy and how best to elevate its overall efficiency.”

While it is an accomplishment to see that “more than 1 million Energy Star qualified homes, which consume at least 15 percent less energy than conventional construction, have now been built in the United States,” Zeller goes on to say the “lack of [more] ambitious targets may actually be hindering the effort to address pressing problems like global warming.”

Why Code-Built is Not Efficient Enough

To understand why exceeding Energy Star ratings is desirable, Zeller includes a graphic of the HERS Index, a chart that shows the energy consumption of typical homes on a scale from zero to greater than 100, showing how different types of construction stack against each other.

Here’s the graphic, courtesy of Zero Energy Design:

We express the discussion in slightly different terms. Here’s a graphic from our renewable home heating page, where we frame the discussion of mechanical systems for heating a home in terms of btu/hrs required per square foot:

The underlying principle remains this: the more energy efficient a home is, the less heating load it requires. When minimal heating load is required, smaller, modest, and renewable heating options make sense, and monstrous fossil fuel heating systems are unneeded and uneconomical.

Going Passive in Maine

ReVision has worked on a number of high performance homes, here are links to a few:

• The GO Logic home in Belfast, Maine is the state’s first true passive house home. The prototype home has produced more energy than it has used to date and is a model for a new Belfast cohousing community.
• The home of architects Ian and Zofia Weiss uses many passive house principles. It uses radiant heat powered by solar hot water collectors with electric backup, and should eventually have grid-tied solar electric to make it near net-zero.
• The Bright Built Barn is a net-zero home in Rockland that incorporates leading-edge building practices and an innovative LED system to inform you as to whether the home is generating more energy than it is using.

The Bar Harbor Times Soup reports on a unique rammed-earth house constructed in Salsbury Cove this summer. ReVision installed the solar electric and solar hot water system on the home which expects to have net-zero electric use due to high solar production in the summertime.

Laurie Schreiber writes:

Retired professors, Turner and Karnaky wanted their second home to be as energy-efficient as possible. Turner said she learned about the rammed earth technique years ago. After considerable research into alternative building methods in general, she said rammed earth emerged as the best choice for the first story. In 2000, the couple approached Sassaman, whose portfolio ranges from detail work to high-end residential construction, additions and renovations. The design was finalized in June 2008 and excavation began that August.

… Minimum energy use is the order of the day, with the use of low-energy appliances, triple-glazed windows, radiant floor heat, and composting toilets. Turner said she expects that the photovoltaic system will generate enough electricity in the summer to sell some back to their grid provider. In the winter, the house will consume electricity to keep the house from freezing, but the energy usage should zero out, she said.

Read more (PDF Download)

This home in Falmouth served as a model for what a modular green home might look like. In addition to extreme energy efficiency, it uses solar hot water collectors for domestic hot water and supplemental radiant heating.

At ReVision we’ve had the honor to work on several pilot projects for net-zero homes – projects like the Bright Built Barn and GO Home which have proven to produce more energy than they use.

This leading edge building science is starting to move from the realm of demonstration to reality, marked yesterday in the Portland Press Herald’s coverage of new green modular homes developed by Kaplan Thompson Architects and Keiser Homes.

Tux Turkel writes:

To achieve net-zero performance, Keiser looked at a site-built home Kaplan had recently designed in Falmouth. That home, which is 1,680 square feet and has three bedrooms and 2½ bathrooms, served as a prototype for the line. It’s being offered as the Great Diamond model, with a starting price of $235,000.

Each model combines energy efficiency with features that promote healthy indoor living, such as low-emission paint and heat recovery ventilation for fresh air exchange. South-facing windows help warm the homes in winter; roof overhangs block hot sunlight in summer.

Each home will be plumbed and wired for solar. For buyers who choose the option, solar hot water, solar electric systems or both will be installed.

Choosing both systems could add another $40,000 or so, although tax credits could lower the cost. The systems are designed to soak up enough energy over the course of a year to offset electric bills. The extra power generated by the solar electric panels in the summer and fed back into the grid is intended to make up utility costs in winter — resulting in net-zero energy consumption.

What makes the homes remarkable is that they are not being marketed at the top-tier of development, but towards middle class families. “We think this is the direction of the future,” said Josh Saunders, Keiser’s sales manager. “Even more than sustainable, energy efficient is what people are going to gravitate to. That’s where the payback is.”

As we’ve mentioned before, investing in a solar electric system allows you to pre buy electricity for less than today’s grid rates. Add to that a life of minimal utility bills, and net zero starts to mean as much economic sense as it does environmental sense.

More info at Kaplan Thompson’s website.

Receiving the Leed for Homes Innovative Project Award
Photo courtesy Bright Built Barn blog

The Bright Built Barn recently won the prestigious 2009 LEED for Homes Innovative Project Award from the U.S. Green Building Council (USGBC).

The award recognizes projects, developers and home builders who have demonstrated leadership in the residential building marketplace.

Phil Kaplan from Kaplan Thompson Architects and Tedd Benson from Bensonwood went to Phoenix, Arizona to accept the award at GreenBuild, the USGBC Annual Conference, this past December.

A write-up of the event is available on the Bright Built Barn blog.

We also received this report of performance of Bright Built Barn‘s solar systems, one year later:

I’m happy to report that [BrightBuilt Barn] has exceeded all expectations.

On a subjective level, it has been a joy to live and work in – warm in the winter, cool in the summer, light and airy and lovely to look at all year round. I am also delighted to report that I have not had one minute of trouble with any of the systems – high praise indeed from a guy who hates maintenance and repair, and who has had his share of woes while living in a number of conventionally built houses over the years. The solar systems in the Barn are simple, with few moving parts, and highly reliable – so far, they just work.

BrightBuilt Barn Generated a surplus of more than 5000 KW/hrs in 2008-09

ReVision installed the solar hot water and solar power systems in this innovative, net-zero building.

In its first year, the home’s PV system generation a surplus of 5094 kilowatt-hours – or enough energy to power 5 conventional homes for a month.

Building owner Keith Collins goes on to say that “The Barn does, in fact, power my conventionally built main house (over 15 years old and no paragon of energy efficiency) which sits about 100 feet away, and has produced over 60% of that home’s electrical use.”

You can see real-time system performance of the Bright Built Barn online at brightbuiltbarn.com.