John Harrison may have retired in 2007 from his position as the environmental coordinator at University of Hawai'i at Manoa's Environmental Center, but his predilection to educate and impart the benefits and necessities of energy efficiency and sustainability still take precedence in his life. There's only one difference: his classroom is now his home. Harrison, who continues to work as an energy and environmental consultant through his company 3E Advisory Services, frequently entertains small groups of people to tour his energy-neutral home.
On a particularly wet December afternoon, seven curious energy-minded homeowners mill around a wooden table in the family room, the center of an open floor plan beset by the den and the naturally well-lit living room. It's covered with pamphlets and books on birds, sustainability and the environment. John's wife, Anne, is showing a few of them around the grand and spacious remodeled living area as John talks rainwater catchment systems with one of the guests. He's been giving the two-hour tour of his home for the last three years and anxiously looks forward to getting started.
Finally the last guest arrives and John invites everyone to have a seat in the living room. He is tall with a crop of white hair, a calming smile and a gentle, articulate voice. He passes out several pages of information about the house and dives head first into the casual seminar.
Harrison bought the Osipoff-designed, Nu'uanu Valley home in 2000. With an ailing roof, John knew a major remodel was in the cards; the 1954 abode was about to get a major facelift that would transform it from an ordinary electricity-dependant residence to a self-sufficient example of energy efficiency and sustainable design and practice. By 2005, working with architect Paul Noborikawa, John Harrison drew up plans to replace the roof, enclose the open lanai with a new roofline to integrate the den, living and family room into the addition, convert their existing laundry into a guest studio, install solar thermal and photovoltaic energy systems, switch to natural gas for heating applications, replace all appliances with Energy Star qualified appliances and to use recycled materials and renewable resources wherever feasible. The ambitious remodel was a tall order indeed, but integral to show that an energy-neutral residence is possible without sacrificing quality of living.
Demand
In John Harrison's vernacular, demand is the energy required to power
one's home and lifestyle. Addressing ways to decrease demand in the home
was his first order of business.
One of the biggest draws on energy in the home is air conditioning and the addition was designed with the overall goal to keep the heat out with insulation and adequate ventilation to do away with air conditioning. Harrison's great room is essentially one complete passive cooling system.
The open beam roof is a dual roof insulation design, using Tech-Shield to create an air space above the sub-roof and ridge vents on every ridgeline of the house to dissipate the trapped heat. Tech-Shield is a recycled wood radiant barrier with a reflective surface designed to keep the sun's radiant heat from entering the home. There are also soffit inlets under the shaded eaves.
¿When the sun shines on the roof, most of the energy is reflected by the Tech-Shield right back out," explains Harrison. "That which is not, heats up the air in that one-inch space between the sub-roof and the Tech-Shield. Heated air has a lower density than the surrounding air, meaning it's lighter, so it has a tendency to rise. It rises up till it gets to the ridge vent, exhausts and as it goes out creates a low-pressure system that draws the cool air in from the soffit vents. So we are air conditioning our roof with no electrical energy."
Harrison also employs the same strategy in the house, using three solar attic fans to pass the rising warm air out through the roof and small, floor-level windows, which are almost always left open, for an opportunity for fresh air to enter. John has taken his passive cooling technique a step further by planting tropical vegetation around the windows and his home, which actually cools the air before it enters the home. For those days when light and variable winds dominate and the sun is intense, he has ceiling fans to help circulate the air, the only appliance in the entire system that uses electricity, and a very small amount at that.
Next up on John's list is mitigating the big demand on electricity used to heat water by switching over to something no home should be without: a solar hot water heater. "Whenever people ask me what they can do, this is the first thing. It's going to pay for itself instantly and the technology is there," says Harrison. According to Harrison, air conditioning units and electric hot water heaters alone comprise 60 percent of the energy consumption in the home.
Once a cool and comfortable home is achieved, the next step to decreasing demand is through employing natural lighting techniques. Harrison designed the roof profile to create east- and west-facing apertures for large trapezoidal windows to maximize natural lighting during the day. At night, instead of using common area lighting, John opted for task lighting: small halogen bulbs in low voltage fixtures that direct light purposefully in a specific area. The lighting is on dual circuit tracks, so each light can be dimmed or brightened accordingly. And of course, all other incandescent bulbs were replaced with CFL bulbs.
Harrison beams with delight as he explains to the group about the extremely inefficient process of electric generation through the combustion of fossil fuels, his main reason for replacing the electric stove and the electric clothes dryer with models that operate on synthetic natural gas. "By the time the electricity gets to the outlet in your house, you're probably looking at something in the order of at most maybe 30 percent, or as little as 25 percent, of the original energy in the barrel of oil that was imported and bought and paid for with money shipped over seas for you to have that electricity," he says with enthusiasm.
Then, like a proud father, he talks about his switch to Energy Star certified appliances: clothes washer, dishwasher and refrigerator. He jokes that the toaster is the only inefficient aspect of the kitchen.
Supply
Energy has to come from one source or another-fossil fuels, solar, wind,
water or wave energy-to power our 21st century lives. It can be produced
by a utility or harnessed by an individual. Either way, our homes require
a consistent supply of energy to function and as we all know, it's not
free. According to Harrison, once you've utilized green building techniques
and energy efficient practices to reduce your demand, the next phase to
the complete system of the sustainable home is creating supply.
Harrison accomplishes this goal through an off-the-shelf photovoltaic system. Obvious to the audience that this is his favorite part of the afternoon seminar, they listen intently as he animates his talk with his hands and wears his excitement with pride.
After some initial calculations based on how much sunlight is available to the location and the average monthly demand, John opted for a five-kilowatt solar array, the catcher's mitt of his power plant. That's big for a single-family residence, but the limited amount of sunlight in the valley required additional panels. Being a sailor as well, having completed two Transpac crossings in his many years at sea, John is familiar with battery back ups and fail safes, and chose to include two 48-volt battery banks with his photovoltaic system.
Even though self-sufficiency is completely attainable with the size of the system, Harrison elected to stay connected to the grid, opting for net metering. "During the day we are producing far more than we are using. The surplus of what we produce goes right back out into the grid," Harrison continues. ¿We have a meter that calculates how much we take off of the grid and how much we put back into the grid. We are net metered with the utility. There is an equal trade off. For every kilowatt we take off the grid, it gets balanced one for one with every kilowatt that we put back into the grid.
"I was disappointed when Hawaiian electric came by and switched out my old conventional spinning wheel meter with a digital one, so I can't go out on a sunny day and watch the meter turn backward, which was one of my recreational activities."
Harrison stresses to the group the importance of working with a solar contractor that is up to date and current on regulations, laws and tax credits associated with installing a photovoltaic system.
Before heading out to the carport for an up-close look at the power plant, Harrison offers one last anecdote to the group, "When we had the earthquake in the fall of 2006, I felt the earth start to move early in the morning, the ground shook, the whole island shook. I immediately turned on the TV to see what was going on, but it was still regular programming. I walked out into the living room to make sure everything was OK. I went back into the bedroom and the TV was off. Island wide the power went out, but the system seamlessly switched over to the battery back up. It switched over so fast that not even the led lights on the clocks started blinking, an instantaneous transfer, we never knew the power was out. We had power all day long. The TV went off because the transmitter station went down. The TV was still on, there was just no signal."
For more information about John Harrison's home or to schedule a tour, please contact the Hawai'i Audubon Society, (808) 528-1432, hiaudsoc@pixi.com