The Energy and Atmosphere category is the most heavily weighted in the US Green Building Council's rating system, and with good reason. The amount of energy people consume and where that energy comes from -- and everything that goes along with those decisions -- arguably have the greatest impact on the the planet and society.
A typical American home gets most of its power from a mixture of petroleum, natural gas, coal and nuclear. Nationally, 98% of our energy comes from these non-renewable sources, which have significant environmental and social costs.
Petroleum and natural gas are the leading sources of greenhouse gas emissions in the United States. About 68% of New York State's power comes from these sources.
Coal plants give off nitrogen oxides (contributors to smog), sulphur dioxide (a main component of acid rain), mercury and lead (potent elements that damage the nervous system, brain and kidneys,
especially in children). These emissions travel with the wind and rain. The Hudson Valley suffers some of the worst air quality in the nation partly due to pollution that makes its way here from coal power plants in the Midwest.
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Indian Point Energy Center, a nuclear power plant on the Hudson River in Buchanan, NY
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Nuclear power provides 28% of New York's energy and has its own consequences, including the killing of millions of fish each year due to the discharge of heated water (used to cool the reactors) into rivers. The Indian Point nuclear plant alone will have produced 2000 tons of radioactive waste by 2030.
Power plants tend to be disproportionately located in poor communities and communities of people of color, and radioactive waste is disproportionately shipped to Native American lands.
More than 65 new power plants have been proposed for New York, primarily along the Hudson River estuary, the New York City harbor area, and in Long Island.
The good news is that Americans are so vastly inefficient in their use of energy that we can make immense reductions in the amount of energy we consume without changing much at all the way we live. Of course, given the direction things are going, particularly related to global warming, we are indeed going to have to make more significant changes. But the best place to start is certainly where the change is the easiest. And green building strategies that are already widely available definitely fall in that "easy and significant" category.
Getting to Net-Zero -- Reducing Energy Consumption & Creating Clean Energy On-Site
The Common Fire Housing Co-op will be a net-zero energy building. This means it will produce as much energy on-site as it consumes using clean, renewable energy.
There are two factors that go into being a net-zero energy building -- or into making any building as green as possible in terms of energy consumption. The first part is reducing enegy consumption (increasing efficiency) and the second is increasing the amount of energy that is produced on-site from clean, renewable sources.
The Common Fire building will use less than half the energy of a comparable building (while causing a proportionate reduction in pollution). This is thanks to a whole range of energy-saving design strategies and products, both old and new.
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The first step in creating an energy-efficient building is looking for ways to work with nature to take advantage of free or cheap opportunities to heat, cool, and light your building.
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The southern exposure
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The most important place to start is to think about the building's placement and orientation to take advantage of passive solar. By orienting a building toward the south (running it east-west), and creating significant southern exposure, you can take advantage of the sun's energy to heat a building in the winter ("passively", not using anything mechanical like solar panels, etc.). When sunlight hits a building or enters it through windows it heats the building and the air inside -- free heat!
The placement of windows is intimately related to a "passive solar" design strategy. Using a good number of them in the south allows the heat in while using few of them on the north, with its exposure to winter winds, minimizes heat loss through them.
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Through the door, a winter view of the overhangs
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All of that free heat is great in the winter but not so great in the summer. There are a variey of strategies that can then be used to limit the heat gain in the summer when the object is to keep the building cool. The Common Fire building has eaves -- roof overhangs -- designed specifically to block direct sunlight from entering the windows during the hottest hours of summer when the sun is high, while allowing the sun to enter the entire day in the winter. The planting of deciduous trees to the south of a building can also help to block sun in the summer while letting it through in the winter after the trees have dropped their leaves. |
- A passive solar design goes hand in hand with another key energy-efficiency strategy -- daylighting. Thanks to significant use of windows in the south, plus the strategic use of skylights, people in the Common Fire Housing Co-op will rarely have to turn on a light during the daytime in any of the main rooms. This reduces the need for electrical lighting and enhances the sense of spaciousness and connection with the outdoors.
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Solatube skylights on the roof
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Solatubes bring light down to the ground floor lounge
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And Common Fire is not just using ordinary skylights, we are using Solatubes. The Solatubes are hands-down one of the features of the building that wows people the most. Innovative skylight designs by Solatube have helped expand the possibilities for daylighting dramatically. Solatube's Daylighting System captures sunlight on the rooftop, redirects down a highly reflective tube and diffuses it in the interior of the building.
- Besides getting the sun on your side, it can be extremely helpful to get the earth working for you as well. There are a range of ways both simple and advanced that you can use the earth's year-round stable temperature to both cool and heat a building that are super energy-efficient.
For starters, a new building can be set partially into the ground. This helps to cool the building in the summer, and in the winter it can feel cooler underground, but once you get below the frost line the temperature is constant year-round and tends to be warmer than the air outside. In the Mid-Hudson Valley it is about 54 degrees, which means you are battling 54 degrees outside versus the 30 degrees or cooler throughout the winter.
"Our children ... should enter adulthood with a basic knowledge of how to store food over winter without the cooperation of a nuclear power plant a hundred miles away. Every animal in the forest is taught this skill; we owe our children no less."
-- Jerry Minnich, as quoted in Root Cellaring by Mike and Nancy Bubel
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Apples being stored for the winter
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Root Cellars have been around just about as long as humans have been trying to store their food. Basically a root cellar is a storage space or room set into the ground that uses the earth's cool temperature to preserve food. The Common Fire building has a large three-room root cellar connected to the building for easy access. This will allow the residents to store a lot of food without using a fridge. More importantly, it will allow them to buy significant amounts of local fruits and vegetables in the fall and store them through the winter when they would otherwise have to buy food shipped a long distance. That supports local farmers and saves massive amounts of gas (and pollutions, and corruption, and violence, and other oil-related illnesses!).
In the US food travels an average of 1,500 miles before it reaches its final destination. Almost 50% of food transported is lost to spoilage.
Geothermal heating and cooling is the most energy efficient and cost effective way to heat and cool your building, and it can take care of all your domestic hot water needs at the same time. Geothermal systems use the heat of the earth underground to heat water that is in turn used to heat the building, or in the summer to dump the heat from a building underground to cool it.
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Our geothermal circulation pumps
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About four feet below the frost line of the earth the ground maintains a constant temperature year-round. In the Mid Hudson Valley it's about 53 degrees Fahrenheit. Geothermal systems come in different flavors, but the core premise is that pipes are run underground so the water piped through them comes out the other end at 53 degrees, whether it was cooler or warmer going in. The water is brought into the house to the geothermal unit. In the winter the unit extracts energy from the water, reducing its temperature down to about 34 degrees. That energy is then transfered to water that is running through pipes in the building to make it really hot. In the Common Fire building that's about 115 degrees. That hot water is then circulated through the building and used to heat it. In our building we have "fan coil" units that blow air over tiny fins with the hot water going through them and that air is blown out into the room nicely heated by the fins. In some buildings pipes are set in the floor and the heat radiates through the floor ("radiant heating").
In the summer the process is reversed. The geothermal unit extracts heat from the water circulating through the building and dumps it into the water going into the earth, heating it. That water is cooled by the earth and re-enters at 53 degrees. Meanwhile the water in the building has been cooled, is circulated through the building where it absorbs heat. Again, in the Common Fire building the water goes through small fins that have air blown over them, chilling the air and heating the water.
The Common Fire building is so well insulated that in the summer the building stays about 10-15 degrees cooler than outside. We simply open the windows at night to let cool air in (assisted by a whole house fan that pulls air through the building, completely flushing the building in about 5 minutes), then close the windows in the daytime. On top of that we have ceiling fans in every room, reducing the need for cooling further. So only once in a while in the summer do we need to turn the geothermal cooling on. And even then we have one large central fan coil unit that is not even attached to the geothermal unit, it simply pulls the 54 degree water in directly from underground and uses it, rather than using the geothermal unit to chill it further. Only if the house is still too humid or hot do we turn on the geothermal cooling.
Radiant Heating - Good for the Environment?
In a radiant heating system, hot water is distributed through pipes in the building's floor structure, heating rooms from the floor up. It heats evenly and avoids all the dust issues associated with forced air heat. Radiant heating is a really nice feature to have in one's home, but it is not necessarily a green technology. It is often combined with geothermal heating, but it is a separate system. We do not have radiant heat in the Common Fire building because it was an additional cost and would have made it challenging to have separate zones, so that the temperature of each room could be individually controlled.
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As wonderful as it is to use nature as an ally to help heat and light your home, that will only get you so far and then the goal becomes trying to keep a more desirable climate inside while the elements are doing their thing outside!
Keeping the summer heat out and the winter heat in requires a well-insulated "envelope" -- the exterior shell of the building.
Windows again play a key role. 1/3 of a building's total heat loss occurs through windows and doors. Inefficient windows and doors cost Americans $40 billion each year in higher utilities costs and waste as much energy as the US gets from the Alaska Pipeline.
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Living room windows
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PellaWe used triple pane windows (Pella Designer Series), which can save as much as 28% in energy costs. (Ours provide a U-value of .25, the equivalent of R-4. Our French doors provide U-.26 and a few small windows in the north offer U.27.)
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Blowing cellulose
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Cellulose is shredded paper -- mostly recycled newspaper, which is treated with a fire-retardant and blown into a space and used as insulation. Cellulose arguably has a higher insulation value than fiberglass, it takes about 6 times less energy to produce as fiberglass because it is about 85% recycled material, and its manufacture produces nearly zero emissions. Fiberglass insulation is listed as a potential carcinogen, containing respirable glass fibers and most likely formaldehyde. Cellulose also doesn't itch and fits the shape of irregular spaces!
Adding insulation is one of the most cost-effective and dramatic ways you can increase the energy-efficiency of your building. And cellulose plays a central role in Common Fire achieving its outstanding insulation values (measured in "heat resistance" values -- "R values"):
- Between R-80 and R-100 at the peak of the attic
- R-80 in the attic dormer walls
- R-45 to R-50 in the attic knee walls
Common Fire also had cellulose sprayed in the floor above the downstairs bedrooms for sound-proofing.
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EcoCon crew installing the SIPs from Murus Company
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For the upstairs walls Common Fire used Structural Insulated Panels. SIPs are prefabricated walls composed of a Polyurethane core sandwiched between OSB (Oriented Strand Board). They use significantly less lumber than traditional framing and have much higher insulative properties. With them we achieved:
- R-45 in the upstairs walls
The downstairs is 40% underground with the rest having southern exposure and shielded from the northern winds. So we didn't need as high an R-value down there, but by spraying cellulose into the pre-cast concrete walls downstairs we achieved:
- R-38 in the downstairs walls
We used two inches of foam insulation (extruded polystyrene) under the concrete slab downstairs, yielding:
- R-12 in the downstairs floor
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Once you've taken care of climate control, it's time to make sure that you're as efficient as possible with your building's other energy needs.
Energy Star Appliances: Energy Star is a government-backed program helping businesses and individuals protect the environment through superior energy efficiency. Their energy and water efficient appliances can save families about a third on their utility bills while reducing greenhouse gas emissions.
Kenmore is the exclusive supplier of Common Fire's Energy Star-rated home appliances. With nearly 75 years of experience, Kenmore is the No. 1 selling brand of appliances, at work in one out of every two homes in America today.
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Common Fire's induction cooktop
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Perhaps the most amazing Kenmore appliance is an induction cooktop. Induction cooktops use half the energy of gas and conventional electric stoves and can boil water in half the time -- using magnets! Rather than heating the surface of the cooktop, each 'element' (induction coil) on the cooktop generates a magnetic field that creates heat in steel or iron cookware placed on top of it -- directly heating the cookware, saving all of the heat that would otherwise just go up and around the pot or pan. This means the heat response is quicker as well, allowing very accurate control. It's also safer because the cooktop doesn't get nearly as hot. It does mean you have to use stainless steel cookware or cast iron, because they are ferrous metals (can become magnetized). We use stainless steel cookware donated by Demeyere. Induction cooktops are more expensive than other stoves, but Kenmore is helping to make them more affordable for the average person.
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Casablanca ceiling fans are in every room in the building
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Casablanca has provided all of Common Fire's Energy Star-rated ceiling fans. Ceiling fans use about the same energy as a 100-watt light bulb, costing pennies a day, and can reduce cooling costs by 40% and heating costs by 10%. In the summer ceiling fans create a breeze, causing a wind chill effect that makes you feel up to eight degrees cooler. In the winter the fans can be run in reverse, moving warm air from the ceiling back to the center of the room. Casablanca offers a range of Energy Star fans in different styles.
TCP supplied all of Common Fire's compact fluorescent and cold cathode light bulbs, making it possible to save an incredible amount of energy costs! Compact fluorescent bulbs use 66% less energy and last 500 hours, ten times as long than a regular (incandescent) bulb. Cold Cathode lights use the same energy as compact fluorescents but last an incredible 25,000 hours and can be used outside. They're currently only available to replace regular 20-25 watt bulbs and need to be ordered online.
If every US household replaced just one light bulb with a compact fluorescent or cold cathode bulb, it would prevent enought pollution to equal removing one million cars from the road.
The Other Half of Net-Zero -- Producing Clean Energy On-Site
So you can see that a tremendous amount of thought and effort has gone into reducing the energy consumption of the building. In all the building uses about 50% of the energy of a comparable building.
The other half of being a "net-zero" building is producing clean energy on-site to meet all of the building's electrical needs. In the case of the Common Fire building, we are meeting these needs through solar power. Solar power is a fairly expensive up front investment, but the money you save on electricity will pay back your investment in about 8-10 years, and after that you get free electricity for the remainder of their life span (over 30 years total). And in New York State (and many others), about half the cost of a solar PV system is covered by the State, so long as your system is net metered and you use a certified installer. Check with your installer to see about any other restrictions that apply.
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Our 12.9 kilowatt system
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The Common Fire building has been outfitted with 60 Sunpower solar panels which convert the sun's rays into electricity. These kinds of panels are called photovoltaic, or PV. Over the course of the year the building will produce as much or more energy than it consumes. This does not mean the building will be "off the grid" -- detached from the network of electric lines and energy that supplies most homes. We are connected to the grid. Through a process known as "net-metering", any time our panels produce more electricity than the building is consuming -- which often happens in the summer when PV production is highest -- the extra electricity flows out into the grid, causing the building's electric meter to run backwards. That electricity is then available for anyone else on the grid to use -- most likely our neighbors. Any time the panels are not producing enough to meet the building's needs -- as often happens in the winter -- we draw electricity from the grid like a normal home and our electric meter runs forward. The building is considered a net-zero home not because we always produce all of the electricity we need on-site, but because over the course of the year we produce as much as we consume.
Our panels are not mounted on the roof, as is fairly normal these days. We put them on the tops of steel poles mounted in the field in front of the house. We didn't have enough space to put all we needed on the roof, and we save money to have them all in one place near the meter rather than split up. Also, we are using Direct Power and Water's "Top of Pole" mounts which allow us to adjust the angle of the panels. By going out there and manually adjusting the mounts (we have five of them) so they face up in the summer and south in the winter (and in between in the spring and fall) to follow the sun, we increase their efficiency by 15%! That's alot cheaper than buying more panels.
PV panels produce DC (direct current) electricity, yet almost all homes and appliances run on AC (alternating current), so the sytem requires what is called an inverter. Common Fire went with two SMA Sunnyboy 6000s, very efficient, reliable, and cost-effecitve inverters.
Solar Hot Water
A solar hot water system is the most efficient way to use the sun's power to heat water, rather than using solar panels to make electricity to heat water. Solar hot water systems are straightforward to install to replace existing electric, gas or oil hot water systems as well as in new construction. Cold water is run through a solar collector on the building's roof, heated and then stored in a hot water tank, ready to be used. A backup system of gas, electric or oil is in place in case more hot water is required than is available, though if properly designed a solar hot water system should provide at least 70% of the energy needed for heating water. We did not use solar hot water in the Common Fire building because we used a geothermal heating and cooling system, which already heats water very efficiently.
Choosing Green Power for your Building -- Without Any Installation Costs
Whether you rent or own, in New York you have the right to decide who supplies your electricity. Contact your local utility to find out what your choices are and which ones are using solar or wind or small dam projects that are renewable and cleaner.
And You Can Offset CO2 emissions From your Building, Your Driving, and From Any Flights You Take As Well!
There are independently audited companies where you can purchase enough clean energy, or the planting of enough trees or similar anti-global-warming activities, to offset the CO2 you are producing in any number of ways in your life. Two that Common Fire used and that we highly recommend are Native Energy and carbonfund.org. (Native Energy is majority Native American owned and most of their projects are on native lands, while carbonfund.org is non-profit.) Both of these websites have calculators that help you quickly and easily figure out how much CO2 you are producing in your home or in your travels, and pay to offset that CO2. For the average car, $60 will offset your CO2 emissions for a year.
Continue the tour: Materials
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Energy & Atmosphere
