middlebury carbon neutral | space heating and cooling

The primary greenhouse gas emitting activity associated with space heating and cooling is the burning of #6 residual oil in the physical plant. The heat from burning this oil is used to heat steam at a pressure of 200 psi. This steam is then run through a turbine to create electricity and lower the pressure to 20 psi. Running the steam through the turbine (a process called cogeneration) creates electricity, which supplies about twenty percent of the college’s yearly electricity need. After being run through the turbine the steam is then piped to all major campus buildings (excluding college houses and other small buildings). This process is only about 65% efficient, meaning that only 65% of the steam actually reaches the dormitories and other buildings. The low efficiency of the current system implies that the savings on any energy efficient heating technologies that we implement will be magnified by an extra 54%.

The burning of # 6 oil (1.7 million gallons in 2000) accounts for 22,000 metric tons of carbon dioxide equivalent emissions (MTCDE) related to space heating and cooling in the year 2000 and approximately 70% of total campus emissions for that year.¹ In several small houses and buildings across campus, propane is used for heating, but the ratio of propane burned to oil burned on campus is minute. Currently, Middlebury uses a 45,000 lb/hour oil boiler, which is capable of fulfilling the majority of the campus’s space heating and cooling needs. Occasionally, during intensely cold or hot days, a secondary, smaller oil boiler is used as a supplement. One of our four boilers will reach the end of its lifetime within the next 5 years, necessitating the purchase of a new boiler. The fuel choice for a new boiler will impact the College over the next 50 years—the estimated lifetime of a boiler. It is important that we as a College make informed decisions as to how we heat our buildings over the next half-century. If we choose to continue burning #6 oil as our main source of heat, we will be not only remain dependent on a foreign fuel source, but we will also effectively be ignoring our environmental responsibility.

On campus stakeholders would include administrators, such as John McCardell, Ron Liebowitz, and Bob Huth. Facilities Planning staff including Thomas McGinn, Mark Gleason, David Ginevan, Jennifer Bleich, and Doreen Bernier and Campus Sustainability Coordinator Connie Leach Bisson will be part of many changes that could result. Furthermore, individuals in Facilities Management will also play a role, such as Michael Moser, Harold Strassner, Christopher Ayers and Michael Moore. Faculty, staff, and students would also clearly be affected by the changes that are being suggested in this document. Off campus potential stakeholders include Sprague Energy, Biomass Resource Group, Chiptec Wood Energy Systems, Vermont Department of Economic Development, Vermont Department of Forests, Parks and Recreation, Clover State Construction, Vermont Gas, Back East Solar, Vermont Solar, Delta Shower Heads, and the local community.

The heating and cooling sector represents the greatest potential for carbon emission reduction in relation to the other areas of focus (electricity, transportation, etc.). At present, space heating and cooling accounts for approximately 70% of all CO₂ emissions at Middlebury College (approximately 27,000 tonnes of CO₂). Furthermore, 70% of the oil burned is directed towards air space heating and cooling during the winter months, while approximately 20% is spent on hot water heating.² Technologies and strategies designed to reduce emissions associated with air heating are therefore more critical. However, because water heating and air heating are connected (CO₂ emission source is the same), the only true way to reduce emissions is to switch to a cleaner fuel source, particularly a renewable resource. Thus, switching to biomass will make the largest impact of all strategies for both objectives within the sector, as well as all reduction strategies in this report. Policy based decisions, however, will make some gain in reducing emissions include upgrading windows, lowering the thermostat to 68 degrees, requiring new buildings to have passive solar design, and an education campaign.

Middlebury College produces 3,800 tons CO₂ per year for domestic hot water use, as a by-product of oil burning. As mentioned, 20% of our total steam goes toward domestic hot water heating. We can reduce the magnitude of this need through solar water heating and other solar appliances, which will both reduce CO₂emissions and save money. Installing low-flow water heads will also make a small contribution to lowering the amount of water Middlebury needs to heat per day, consequently reducing emissions associated with water heating.

*Summary data*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
12	Immediate	459	$ 70

We have found that the easiest way to begin reducing Middlebury’s CO₂ emissions, while still effecting substantial GHG reductions, is to turn down the thermostats of campus buildings. Even a small change in temperature can greatly decrease the amount of #6 oil burned to heat the buildings. The Minnesota Department of Energy says that for each degree that one turns down the thermostat (in a home), the home saves one percent of heating costs. At Middlebury, we figure a similar percentage applies—that a two-degree decrease in the temperature of buildings heated by the main plant would lead to two percent yearly savings in heating costs. If this were the case, the school would save approximately $30,000-$35,000 per year. Lowering thermostats in Bicentennial Hall, for example, is not an involved process—the building is equipped with over 20,000 sensor points and all temperatures are coordinated electronically. Currently, daytime temperatures at Middlebury are set at 70°F, and nighttime temperatures are set at 65°F. We recommend leaving the nighttime temperatures at 65°, while lowering daytime temperatures to 68°. Summertime air-conditioning temperatures should be raised from 74° F to 76° F.

Such a simple initiative as turning down the campus thermostats would require no waiting period or research period. A small period of time, maybe one to two weeks, could be used to increase student, faculty and staff awareness about the reason for decreasing academic building temperature and the positive environmental consequences of doing so. The college community could be advised to wear an extra layer of clothing beginning on the day of lower temperatures. However, if the college decides to go ahead with lowering thermostats, the timeline for this strategy is effectively immediate.

We envision a revising of the heating and air-conditioning policy on campus as a permanent strategy. Unless the school received numerous complaints of discomfort associated with lack of heat or discomfort associated with lack of adequate air-conditioning, the policy should remain unchanged. Furthermore, the college could provide space heaters if the complaints were relatively sparse. SUNY Buffalo has lowered their temperature to 68 degrees, and provides space heaters when requested.

If we turned campus thermostats down to 68°F, we would burn 35,000-45,000 fewer gallons of oil over the course of one year. This would reduce Middlebury’s CO2 emissions by 400-500 tonnes per year—an approximate 2-2.5% reduction of current emissions associated with heating and cooling.

The Fixed Cost for lowering the thermostats are negligible. All this strategy requires is one person to electronically or manually adjust temperature settings from the heating plant in the service building or in individual buildings. The primary Fixed Cost would be a campus education campaign about the merits of reducing CO₂ emissions by lowering building temperatures. The coordinators of this campaign, members of the faculty, would surely work longer hours and require a pay bonus. There would also inevitably be copying and printing fees for posters and other public education tools. However, we do not anticipate the total Fixed Cost to be very high.

There would be no operating costs associated with this strategy. Once the temperatures are set, the temperatures would remain at that level and would not require constant attention. One negative cost would be the savings Middlebury would accrue from using less oil—as mentioned earlier, approximately $30,000-$35,000 per year of 68°F temperatures.

Social. A “grumbling factor” could arise from the campus population as people cope with lower temperatures, causing mild dissatisfaction among few people. However, we are confident that once the complainers understand the reason for temperature reduction, and once they learn to dress appropriately, the “grumbling factor” will decrease. As a case study example, during the month of January, Room 104 Bicentennial Hall was reduced to 65°F where our class was being held. Although a little uncomfortable at first, we eventually began avoid wearing clothing appropriate to the temperature. In addition, the classroom remained at this temperature for the following class. There were no complaints from these students (they were told of the adjustment in advance, and presumably dressed accordingly).

Public Relations. Consciously lowering our thermostats would be educationally valuable for Middlebury visitors, students, alumni, staff, and faculty. The reduction of temperatures could be a P.R. benefit, as it would display Middlebury’s environmental consciousness and activism.

Cross-cutting areas and synergies. By burning less oil on campus we would inevitably affect our cogenerative electricity production. It is unknown at this point how much of an effect lowering the thermostats would have on cogeneration.

We do not anticipate any funding necessary for this strategy, either at the present moment or at any point in the future. In older buildings with less advanced controls, the thermostats may have to be adjusted manually, but this can be done with minimal cost. Upgrades are not necessary in these buildings.

All faculty, students, and staff of Middlebury College—especially staff such as Tim Wickland, building manager of Bicentennial Hall, Michael Moser, central heating plant manager, and George McPhail, staff engineer of the service building, and Campus Sustainability Coordinator Connie Leach Bisson.

The institutions of higher learning mentioned above all have their own policies on heating and air-conditioning temperatures. Most schools heat their dormitories to the same temperature as academic buildings, but allow for individual room adjustment. Williams, for example, sets its thermostats at 69° F but allows individual rooms to be heated to as high as 74° F. With regards to thermostat settings during periods when a building is not being used, the schools also have different policies. University of Buffalo has one of the best policies in this regard, where during off-hours, weekends and holidays, the temperature is reduced to 55° F in the winter and central air-conditioning is shut off during the summer.

We compared Middlebury’s temperatures to those of these schools, and found that, in general, Middlebury maintains its buildings at a warmer temperature than most other schools in the winter, and cooler than others during air-conditioning months (Figures II.1 and II.2). If students, faculty and staff at schools like ours live at 68° F, then why shouldn’t we Vermonters be able to do the same thing?

Figure II.2. Average summer air-conditioning temperatures in respective New England area schools. A lower temperature signifies greater fuel consumption by the air-conditioning system, and hence greater CO₂ emissions associated with space cooling.

As previously stated, lowering the temperatures of academic buildings represents a simple and effective way to reduce our ecological footprint through reducing carbon emissions. The process is not difficult, but a discussion should ensue between Facilities Management (spokesperson Michael Moser) and College administration. Students, faculty and staff would benefit from and appreciate an awareness campaign that spells out what’s happening to building temperatures and why. After that, Middlebury would immediately begin to see the positive economic and environmental impact of the reduced campus demand for heat and air-conditioning.

*Summary data (full switch to biomass)*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
9	2.8	22,000	$ 27

*Summary data (partial switch to biomass)*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
11	5.7	11,000	$ 25

The construction and operation of the McNeil Power Plant in Burlington, Vermont has shown Burlington Electric Department’s commitment to using biomass as a renewable energy resource. There are zero net carbon emissions associated with biomass burning, because although CO₂ is released into the atmosphere during the burning process, it is quickly sequestered back when trees are replanted in the same place- therefore being rotated within twenty years in the earth-atmospheric cycle. In contrast, when oil is extracted, it is taken from the atmosphere-geologic cycle, and therefore the carbon released when oil is burned will not be sequestered back into the ground for hundreds of thousands of years. Thus, by relying less on oil, which has associated high emissions, and relying more on biomass, with zero net emissions, the college will significantly reduce the amount of its emissions.

Through a process called gasification³, wood chips are burned to produce the necessary steam to heat and cool buildings, as well as turn the turbine to produce electricity identical to the process used when oil is burned and electricity is co-produced (cogeneration). Several Vermont government buildings have switched to biomass, and the State assisted the switch in 24 public schools throughout the Vermont. The wood chips to fuel biomass boilers often come from low quality trees and harvest residues, as well as wood waste from sawmills and lumber companies, consequently decreasing the amount of wood waste going into landfills. Aside from lowering emissions and saving money, if Middlebury chose to switch to biomass as its main energy source, the College would likely be recognized throughout the state as a model of the benefits associated with this technology. Furthermore, it is certain that as the climate change problem becomes imminent to national decision makers, much like the ozone layer crisis forced policy makers to make particular choices, there will be increased pressure to switch to cleaner sources of fuel in the US and throughout the developed world where energy demands are high.

Within this strategy, we outline two scenarios. One entails switching completely from #6 oil to biomass, while the second strategy involves using biomass as a supplement. It should be noted that in 5 years the College plans to buy a 50,000 lb boiler, which will be the main provider of air heating and cooling for the entire campus for the next 50 years.

Strategy 1: Instead of purchasing a new oil boiler, the College could choose instead to buy two 30,000 lb biomass boilers. These boilers would supply the College with all of its energy needs. To store the chips necessary to fuel these boilers, the College would have to build a storage facility of approximately 30,000-40,000 cubic feet, as well as make the current service building accessible to large trucks that would deliver approximately 26 tons of green chips/week. Currently, seven oil tankers deliver to Middlebury per week. The storage facility could be built adjacent to the service building, where they already intend to prohibit parking in the near future. Some storage models are in part underground, which minimize undesirable aesthetics of the facility. Another option, which would be far more massive, could be to move the entire service building to a new location, such as the area next to the graveyard, across from the athletic center. It has been noted that the current location of the service building is not ideal due to the smoke stack in the heart of campus, but also in part to the poor aesthetics of the building design. This move would clearly involve much more effort and require re-venting the main duct to the new location. However, if the College chose to switch completely to biomass, the payback would be approximately 15 years (assuming the price of moving the facility would be approximately 7 million dollars).

Strategy 2: Instead of purchasing one new boiler, the college could purchase a 30,000 lb biomass boiler, in addition to a 30,000 lb oil boiler, using the former as the primary source of steam for heating and cooling and supplementing this source with oil only during months of extreme hot or cold. In this scenario, fewer trucks/week would be needed to provide the necessary chips for burning and oil delivery, and the storage facility necessary to house the chips would also be smaller (20,000 cubic feet). The length of each side of the two story building would therefore be approximately 35 feet, which can feasibly fit in the nearby parking lot space. The building could even be designed to look like a barn or a silo to mimic Vermont architecture and reduce possible negative aesthetic effects of the building. The environmental sustainability of the project would also be less questionable, because half the amount of wood would be needed.

Middlebury College is planning to replace the current 45,000 lb boiler with a 50,000 lb boiler in 5 years. Thus, it is within this time frame that the College should seriously consider changing fuel sources. Biomass is the fourth largest source of energy in the United States preceded by coal, oil and gas. The average lifespan of a biomass boiler ranges from 20-75 years depending on the model, how well the boiler is maintained, and the type of chips burned. In the following analysis, we assumed the lifetime of the boiler to be 50 years.

Strategy 1: Middlebury should commit to this source of energy for at least this 50 year lifespan. Unless new technology is developed to exceed the environmental and cost effectiveness of this source, the College can rely on this strategy indefinitely provided wood suppliers continue to harvest sustainably.

Strategy 2: Similar to strategy 1, the biomass boiler could be relied upon for at least 50 years before replacement, as would an oil boiler.

Strategy 1: Switching to biomass for all of Middlebury’s space heating and cooling needs based on 2000 data would lead to a 60% reduction in CO₂, (22,000 tons of CO₂equivalents/ year).

Strategy 2: If Middlebury chose to rely solely on biomass for half of its energy, the total CO₂ reduction would be a 30% reduction (11,000 tons of CO₂/ year). This estimate is based on the notion that the 30,000 lb biomass boiler would be operating at full and that the current oil boiler or its 30,000 lb replacement would be operating at half.

These numbers were attained using 2000 data on number of gallons of #6 oil Middlebury used assuming there was no net emissions associated with biomass burning (0.013 tonnes CO₂/gallon of #6 oil).

Strategy 1: The startup costs of this project would be high (3.8 million dollars). The building of a storage facility to house the chips would cost approximately $45,000 (assumes a facility that is two-stories high, 40,000 cubic feet, costing $18/square feet, housing three days supply of chips). The cost of the storage and delivery system would cost approximately $750,000. In addition, the installation and purchase of two new 30,000 lb biomass boilers would range between 2 and 3 million dollars. In comparison, a new 50,000 lb oil boiler would cost approximately 1.5 million dollars.

Strategy 2: The startup costs for this option would also be high (2.52 million dollars). A storage facility (20,000 cubic feet) would cost approximately $23,000, and the storage and delivery equipment for this facility would cost about $500,000 (same assumptions as strategy 1). The installation and purchase of one 30,000 lb biomass boiler would cost approximately 2 million dollars. It would probably not be necessary to purchase a supplemental oil boiler. Recently, the College purchased a 45,000 lb boiler, which must be utilized so the College can maximize its investment on the purchase. Thus, the biomass boiler could be the primary source of energy supply, while the recently purchased boiler could act as a supplement during extreme hot and cold days.

These high-end estimates were provided by Brad Noviski at Chiptec Wood Energy Systems (brad@chiptec.together.net), Burlington, VT.

According to Chiptec Wood Energy Systems, the operating costs would be approximately the same as current cost for oil. ($250,000/year). However, one must anticipate some increase in costs associated with ash disposal and chip handling. The price of wood chips would be on the high-end approximately $25/ton, the current price of oil is $0.69/gallon, however in the year 2000 the price was $0.80/gallon.

Strategy 1: The price difference in cost of fuel based on 2000 oil prices would result in an annual savings of $631,300. The payback time would be approximately 5 years, and would result in a total savings over a 50-year period of 31.6 million dollars. Other potential costs and benefits are related to the way Middlebury would choose to dispose of the ash. Brad Noviski at Chiptec estimates that one 30,000 lb boiler would result in 150-200 lbs of ash per day using green chips or approximately 0.7 tons/week. If Middlebury chose to landfill the ash, it would cost an additional $11,000/year, assuming the cost/ton for trucking and disposal was equivalent to $150/ton. Composting the ash would be less expensive, approximately $3,600 /year ($50/ton), although the College would need to expand the current composting site, because it is currently operating at maximum.⁴ However, if the College chose to sell the ash as fertilizer to local farmers, the net benefit would be $1800/year ($24/ton).⁵ Another option for ash disposal is to spread it along icy walkways during winter months. The operating cost of this option would likely be null, in fact, the College would no longer need to purchase sand and therefore this could be a possible financial benefit.

Strategy 2: The annual savings of supplementing oil burning with biomass would result in an estimated annual savings of $309,300 based on 2000 figures. The payback time would be approximately 7 years, and would result in a total savings over 50 years of 15.4 million dollars. To landfill the ash, it would cost an additional $5,500/year, assuming the cost/ton was equivalent to $150/ton. Composting the ash would be less expensive, approximately $1,800 /year ($50/ton), although the college would need to expand the current composting site because it is at present operating at maximum. However, if the College chose to sell the ash as fertilizer to local farmers, the net benefit would be $900/year ($24/ton).

In addition: The cost of oil has traditionally been unstable in comparison to wood. Figure II.3 illustrates this difference. Using biomass for fuel will stabilize energy costs at a reasonable level, often lower than current oil costs. In addition, Middlebury currently plans for the construction of several new buildings associated with the implementation of the Commons system, which by default will increase the demand on heating and cooling at the College. As space heating and cooling demands rise, the fluctuating oil prices will tend to have a greater impact on the energy costs of the college.

Environmental. Forest and mill residues release methane into the atmosphere, which has a greater impact on climate change than CO₂ emissions. According to the Vermont Agency of Natural Resources, mills are able to market 46% of wood wastes in Vermont for biomass energy. Creating a market for low-quality wood would provide incentive for local forest landowners to thin and utilize other forest stand management practices that normally would not be affordable. Switching to biomass would also contribute to the creation of early successional habitats in a cost-effective manner. Inevitably, there are also potential negative effects on the ecosystems of Vermont forests. However, if forests are harvested sustainably, this impact would be minimal. The current estimate of the necessary wood chips needed is 26 trailer trucks per week for a full biomass conversion, and 13 tractor trailer trucks of chips for a half biomass supplement. This amount is equivalent to 3-4 tons of chips/hour for the former strategy, and 1-2 tons/hour for the latter option. Currently, the McNeil Power Plant uses 76 tons of chips/hour and has received much acclaim for attaining chips from harvesters who meet strict environmental standards, therefore suggesting that Middlebury’s impact should be minimal by comparison. The Vermont Department of Forests, Parks and Recreation is committed to ensuring the sustainability of biomass suppliers as overviewed in their strategic plan outlining objectives and goals between 1999-2004. Paul Frederick and Bob DeGeus at the Vermont Department of Forests, Parks and Recreation are two important contacts to discuss the sustainability of the project.⁶ David Brynn, Addison County Forester and Executive Director of Vermont Family Forests would also serve as an important resource.

Social. This project would have an educational value for Middlebury visitors, students, alumni, staff, and faculty. However, it should be expected that the initial reaction by some individuals would question Middlebury’s ability to use a wood chip supply that is harvested in a sustainable manner. It would therefore be Middlebury’s responsibility to first develop a definition of forest sustainability, and then only purchase chips from suppliers who harvest wood accordingly.

Public Relations. The use of local companies to supply and deliver wood chips, will increase the number of local jobs. The plant will be far ahead of other colleges and universities in making a true commitment to renewable types of energy. Vermont has led the nation in biomass production through the installation of the McNeil plant in Burlington. By choosing biomass, Middlebury will be recognized as an institution committed to sustainability and shifting the region to greater dependency on local renewable energy sources.

Cross-cutting areas and synergies. If the ash were composted, the solid waste sector would be affected. The cost of increasing the composting site to accommodate the load increase was not included in the calculation. The campus fleet would also likely increase its travel, due to biomass burning, because of the additional transport needed for ash disposal. The electricity that the storage delivery system would require may result in a minimal increase in CO₂ emissions.

Vermont Energy Investment helped sponsor the installation of a biomass boiler in Barre, VT in Green Acres, a 50 family apartment complex (granted $105,000). It is possible that they might be a financial supporter of this project. Contact: dhill@veic.com (802)658-6060.

Biomass Energy Resource Center is unclear at present on its ability to provide any funding for this project, although they are extremely interested in working with Middlebury College at every stage of the implementation process. Their ability to provide financial assistance is pending on receiving more federal funds for which they have applied and waiting for a response. Contact: Timothy Maker, Director of Biomass Energy Resource Center, (802)223-7770, tmaker@biomasscenter.org.

Efficiency Vermont currently works with Middlebury as an energy consultant. They occasionally can provide funds for energy savings projects, and could be a potential resource.

Staff: Facility Panning, Campus Sustainability Coordinator, boiler operators/engineers, general administrative staff, upper administration, compost facility manager

Vermont Department of Forests, Parks, and Recreation: Bob DeGeus and Paul Frederick

Mount Wachusett Community College. Mount Wachusett Community College is located in Gardner, Massachusetts and has a 405,000 square foot campus. The College, in collaboration with the Forests & Wood Products Institute, has changed from an all-electric fuel source to a hydronic wood chip fuel that will supply the campus with space heating and cooling, as well as hot water. The College estimates that its annual savings will be approximately $280, 000. The initial cost of the project is estimated at 3.5 million dollars, which will be paid back in approximately 9 years. The project received $1,000,000 in federal support by the US Department of Energy under the FY01 Energy and Water Development Appropriation Bill. The college will serve as an example and an educational tool for all nearby institutions within the Commonwealth, as well as throughout New England.⁸

Future potential: University of Iowa. The University of Iowa has been collaborating with Quaker Oats on a project that would entail using oats as part of the University of Iowa’s fuel source. The University has a massive biomass research initiative in their environmental sustainability division.⁹

Chiptec has installed 125 boilers in the Vermont area in the past 17 years including public schools and government buildings.

We recommend having a luncheon panel with individuals from several key stakeholders to discuss the feasibility of the project. Representatives from Biomass Resource Center, Paul Frederick and Bob DeGeus of the Vermont Department of Forests, Parks and Recreation, George Robson of the Vermont Department of Economic Development, and a representative from Vermont Energy Investment Corporation (perhaps David Hill). David Brynn, as an expert of sustainable forestry in this area, might also be able to provide valuable insight into the sustainability of the project. Prior to this luncheon, the consultant from the Biomass Resource Center, preferably Tim Maker, should review Middlebury’s current system and anticipated needs and be knowledgeable about the benefits and costs of implementing this strategy.

*Summary data*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
15	None	-	$ -

Middlebury College seems to be constantly under construction and has created a new dormitory, a new dining hall, and a large academic building in the last five years. As a result of this construction, there have been large increases in the heating and cooling needs for the school (Figure II.4). This in turn has led to higher energy costs for the school that could have been lessened had the school incorporated passive solar design. The College is in the process of building a new library, dining hall, and dormitory. However, in each of these cases, the College and its hired architects have largely ignored passive solar heating. Solar passive heating consists of an architect incorporating simple architectural designs into the creation of any new building. This could be done on campus without impacting the aesthetics of the building and having minimal or even no extra costs associated with construction. By incorporating passive solar designs in the construction of new buildings the school would save on energy needs for the lifetime of that building.

When a building is designed using passive solar heating, many simple measures are used in the design. The most important and most simple measure used in passive solar design is orienting the building so that the longest walls run from east to west. This design enables the maximum amount of sunlight to hit the building, which provides natural heat in the form of solar radiation. The next step that is directly related to the first is having the majority of the windows facing south. Southern exposure allows the sun’s radiation to provide heating. These windows would be the more high-tech models that allow the sun’s heat in while insulating against the cold. To improve the heating associated with solar heat gain through windows, the building could use concrete, stone slabs, or masonry partitions for the walls and flooring. These materials hold heat and slowly release it at night when heating needs are the highest. All of these methods involve the direct gain of solar heat (“Passive Solar Heating”¹⁰). By using these simple methods in the construction of a building, heating costs will be much less for the building and there will be no noticeable visual differences.

In addition, isolated gain of solar heat can be used to provide heating for a building. This can be done through the incorporation of a system that is isolated from the primary living space such as a sunroom or solar greenhouse. These rooms maximize the amount of solar heat gained by having large windows that face south. These rooms are designed to gain heat and then subsequently ventilate it throughout the building using convective loops (“Passive Solar Heating”). While these systems add another dimension to the construction of the building, they provide more natural heating by harnessing the sun’s power.

Figure II.4.: Increased heating and cooling needs after the 1993 construction and 2000 construction of Bicentennial Hall.

As for passive solar cooling for a building, this can be accomplished using a variety of simple strategies and some more complex strategies. For instance, shading and overhangs will reduce summer heat gained through a window while not excluding winter sunlight. Other more technical strategies used for passive solar cooling have more of a visual presence for the building. These strategies include adding wing walls and thermal chimneys. By installing casement or other operable windows for passive solar gain and adding vertical panels (wing walls) perpendicular to the wall on the windward side the natural breeze is enhanced inside of the room. Thermal chimneys on the other hand are built like smoke chimneys but vent hot air out of the building through the roof (“Passive Solar Heating”).

The incorporation of some or all of these strategies into the construction of a new building will help save the College money in a short period of time while taking advantage of the Earth’s largest natural resource: the sun.

Mandating the use of passive solar design could be incorporated immediately into College policy. This would mean that passive solar heating would not become a reality until the design and construction of the next new building.

The magnitude of potential CO₂ reductions would vary from building to building depending on its size, location and which strategies the school decided to incorporate into the construction. Obviously, if a building such as Bicentennial Hall used passive solar heating to reduce energy cost, the reduction of CO₂ needed to light and heat the building would have been much greater than if LaForce Hall had been constructed with passive solar techniques, due to the simple difference in size. Also, the impact of passive solar heating could be compromised if the sunlight reaching a new building was obstructed due to the presence of an already existing building. Finally, there are many different measures the school could incorporate into architectural design to utilize the benefits of passive solar “technology.” The more aspects of this design the school embraces, the greater the increase in Middlebury’s overall emissions will be.

In a case study performed by the National Renewable Energy Laboratory in the 1980’s, 19 new and retrofit passive solar commercial buildings were examined. Construction costs for these building ranged from $46-$85/ft² and on average were the same as the costs associated with the construction of a conventional building. When costs for passive solar buildings were more expensive, the increase never exceeded a 10% increase than its conventional counterpart (“Passive Solar Design”¹¹).

Operating costs are less than those associated with conventional heating, cooling, and lighting. Again, in the study conducted by the National Renewable Energy Laboratory, the 19 buildings that incorporated passive solar heating had energy costs that were on average 51% less than the energy costs if the building had been constructed using conventional methods (“Passive Solar Design”).

Social. Passive solar heating has been shown to increase worker productivity in

the work place (“Passive Solar Design”). Perhaps, the brighter atmosphere will have the same effect on Middlebury students, faculty and staff.

Public Relations. This design strategy would show the local community and other schools around the country the benefits of using passive solar heating and would also show that Middlebury College truly is an environmentally conscious campus.

Cross-cutting areas and synergies. Passive Solar Design can lead to lower lighting needs and thus save on electricity use in the building (“Passive Solar Design”).

Since construction costs for passive solar buildings can be the same as conventional buildings, funding would be through the normal channels. Sometimes passive solar design is slightly more expensive than conventional design. Efficiency Vermont rebates money for projects designed to save electricity. In 2001, they worked with 77 commercial and industrial institutions in Vermont in new constructions. Though not for passive solar features, Middlebury has received financial incentives for constructing energy efficient buildings. In addition to the on-going energy savings during the life of the building, Efficiency Vermont’s financial incentives for passive solar design may be enough to cover any additional costs associated with the passive solar design and may even lower construction costs to a level below that of conventional construction.

Oberlin College’s Lewis Center for the Environment-The center has large windows facing the south. These windows allow heat to go into a sunroom as well a greenhouse. The flooring of the sunroom consists of stone slabs and the walls are brick (Figures II.5 and II.6).

Figure II.5. South facing windows at Oberlin Figure II.6. Sunroom at Oberlin

College’s Lewis Center for Environmental Studies. College’s Lewis Center for

17,000 commercial buildings across the United States incorporate passive solar design (“Passive Solar Design”).

In order to incorporate passive solar design, Middlebury College would need to go through the normal channels it uses to construct new buildings. If the architect was not familiar with passive solar design, then they could do some simple research on the Department of Energy’s website (http://www.eren.doe.gov/RE/solar_passive.html) and hire a consultant to assist with this component of the design. However, most architects are familiar with this technology. The most important part of passive solar design is that it is incorporated at the very beginning of a project.

*Summary data*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
23	Immediate	23	$ 52

One of the easiest and most cost effective ways to reduce energy consumption is through education. Education is fundamental in converting ignorance (of the environmental impacts associated with personal space heating) to knowledge. By teaching people that they can help reduce CO₂ emissions associated with heating, they will become more cognizant of their ecological foot print and may in turn start promoting more environmentally friendly technology. We feel that one of the better ways to educate the Middlebury community is by enticing them into competition with one another and rewarding those who perform the best.

Our plan is to hold a competition on Middlebury campus entitled “How Low Can You Go?” Ideally this competition would be between different dormitories on campus. Unfortunately there are currently no meters on campus that measure the steam flow to an individual dormitory, however some meters are being installed. Nevertheless, we plan on starting the competition in Bicentennial Hall between the different academic departments that are based in the building. From the energy management system computer operated by Facilities Management, the temperature in the different offices can be controlled. Our plan is to first educate faculty on how they can lower heating costs associated with their offices. Since the space is small there are only a few steps that can be taken. First, they can comfortably work in their office at lower temperatures if they were to wear a fleece instead of only a long sleeved shirt. Next, they can inform Facilities Management of their normal office hours so the temperature in their offices can be lowered when not in use. Also, faculty could inform Facilities Management if they will not be in town for a few days, so their office is not heated to such a high degree when they are gone. The competition will start October 1 and will last until the last day of the fall semester. At this time, the average temperature of the offices for each department will be calculated and the department with the lowest temperature will be rewarded with free CO2 Neutral Middlebury College fleeces.

In the future, when meters are installed to measure the flow of steam to each dormitory, the competition will be campus wide. In a dormitory, there are even more strategies that can be implemented in order to reduce the amount of steam needed to heat the building and its water. Students could take shorter showers and not leave the faucet running when shaving or washing their faces. By minimizing these simple daily activities the steam needed per dormitory will decrease. Also, by closing window blinds at night not only will the sun not wake them up, but also there is less heat loss between the cold outside and the warm room due to the added insulation (“How to Save Energy”¹²). Another strategy that could be used is as simple as not opening their windows during the cold winter months. The winning dormitory will be the one that had the greatest percentage of reduction in steam as compared to the previous winter term. Then the winning dormitory will be treated to pizza sticks and Ben & Jerry’s ice cream.

The whole point of this exercise is to show the Middlebury College community that they can still live comfortably while reducing CO₂ emissions associated with heating the campus. While the college may not save a significant amount of money while hosting this competition, the competition will hopefully promote wiser use of heating by the college community.

The competition between faculty departments in Bicentennial Hall could be held in the fall term of 2003.

The competition within the student body will have to wait for a few years because the meters that measure steam flow for a particular dormitory have not yet been installed.

Only minimal reduction of CO₂ will be associated with the faculty competition since the competition takes place on such a small scale.

The student body competition has the potential of reducing a noticeable amount of CO₂ emissions, but these emissions probably will not be a significant part of the total emissions associated with space and water heating.

The prize money in both competitions will be approximately $400, which is enough to supply a fleece for each faculty member in the winning department and ample money to provide a dormitory with pizza sticks and Ben & Jerry’s.

For the faculty competition either the energy management system manager will have to be extremely generous and offer their time to set temperatures for each office or a volunteer running the competition could take over that responsibility. As for the student competition, volunteers running the competition will have to do the calculations on the reduction of steam used.

Environmental. The benefit of this competition is less CO₂ emissions associated with

Social. If people want to be involved in the competition they will need to alter some of

their daily activities. The competition will lead to increased awareness regarding the heating of Middlebury College.

Public Relations. This competition could be used as a model for other colleges and

Cross-cutting areas and synergies. This education may lead to increased environmental awareness across campus in other areas such as electricity, transportation, and solid waste.

Since the funding for this educational project is minimal, Middlebury College could easily cover the costs. In addition, the possibility exists that Ben & Jerry’s would be willing to donate ice cream as part of the prize for the student competition.

The only comparable competition we know of is Tufts University’s “Do It In The Dark” competition where dorms competed against each other on cutting back electricity costs.

In order to get started, someone must present this idea to George McPhail who runs the energy management system on campus to ask for his assistance in carrying out such a competition. Connie Bisson and the Environmental Council should be informed and it is likely they will play a large role in the project. Finally, the space heating and cooling group of the winter term 2003 Carbon Neutral Middlebury class should be contacted if any assistance is needed in running the competition.

*Summary data*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
18	21.4	220	$ 25

The energy savings associated with buying new windows is quite high on a house due to the reduced need to heat and cool. This savings can clearly be applied to a dormitory or academic building. For example, an old wooden framed, single paned window loses approximately 1.2 BTU/hour. Double paned, argon insulated, vinyl framed windows will reduce this loss to 0.34 BTU/hour.¹⁰ Currently, a number of the Middlebury facilities have old windows, including Allen, Stewart, Forest, Munroe, Freeman International Center and Warner, as well as a number of smaller buildings such as both Hillcrest buildings. Middlebury College could commit to retrofitting these buildings with energy efficient windows (U value< 0.35) by a certain time, such as 2008, instead of waiting until the facility is renovated. In addition, when renovating a building, policy should mandate that the windows are updated if old and inefficient. For example, Stewart was renovated the summer of 2000, but all windows still have old, single paned glass. In addition, three years passed from when Battell was renovated to when the windows were replaced. Window upgrades should be a priority during renovations. It should also be noted that historic buildings can have specially made windows that are thermally insulated. For example, Old Chapel, Painter and Star have had most of the their windows designed to maintain the historic integrity of building and save energy using thermal insulation. The following strategy provides the case study of Battell, and outlines the case for Allen, Forest, Stewart, Munroe and Warner.

Implement policy immediately. Plan to renovate all older model windows by 2008. The ISES reports, which reviewed the quality of all buildings on campus in the spring of 2000 (found in the Service Building), outlines which buildings are most in need of new windows.

By switching to new windows from single- paned models with a U value of 1.2 BTU/hour, the CO₂ emissions associated with newer models would be reduced by 75%. Recently, Battell was renovated with new windows, replacing 181 single paned wood sash windows with Harvey Industries double-hung, vinyl, double pane, low-emissivity argon windows. For a building the size of Battell, the CO₂ reduction was calculated to be approximately 40 metric tons/year. Thus, if Forest, Allen, Munroe, Stewart, and Warner were all renovated with new windows, the estimate reduction would be approximately 220 tons/year (see appendix for calculation). Freeman International Center and campus houses needing new windows were eliminated, because of lack of specific data regarding the windows (how many windows in each building, size of the windows etc.).

This past summer Middlebury paid $54,300 for window replacements in Battell. The payback time for this installation will be approximately 21 years (annual savings of $2538/year). However, over a 50-year period, installing these windows will save Middlebury approximately $73,650. If all windows of the five key buildings (Allen, Forest, Munroe, Stewart and Warner: approximately 684 windows) were the same size as the Battell windows (15 sq. feet), and the price per window was fixed at the same price as Battell ($300/ window) then replacement in these 5 buildings would have an estimated cost of $205,200. The payback, however, would be an estimated 21 years, with an annual savings of $9,597. Thus, over a 50-year period, Middlebury will save $278,300.

Social. More comfortable room temperatures for students, faculty, and staff due to thermostat control

Public Relations. Middlebury could advertise that all windows have a U value lower than 0.35 or that they are all Energy Star windows to emphasize environmental awareness and comfortable room temperatures.

Policy makers, such as John McCardell, Ron Liebowitz, and Bob Huth, must commit to window replacements, and create a policy stating that during all renovations, old windows will be replaced. Furthermore, Harold Strassner is the customer service representative at Middlebury, he was responsible for the window replacements in Battell, and he may be helpful in attaining more information about the costs of special design windows.

Clover State Construction in Ferrisburg, VT (Window contractor used for Battell in summer 2002), contact person, Marcel Bumet, 802-877-2102

It is well known that good windows are essential to maximize energy efficiency, therefore it is probable that the majority of colleges and universities use energy efficient windows when remodeling.

All new buildings and nearly all institutions choose energy saving windows due to their cost-effectiveness.

Harold Strassner from Facilities Management facilitated the change in Battell, so he might be useful in coordinating this effort. The window company Middlebury used in the Battell renovation was Clover State Construction Inc (contact person: Marcel Bumet). The sooner Middlebury chooses to replace windows, the sooner it will begin saving money and reduce CO₂ emissions.

*Summary data*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
26	3.2	50	$ 82

Changing a person’s daily habits is extremely hard. Not even effective education can ensure that a person will in fact change his or her behavior and act in an environmentally conscious way. By installing low-flow showerheads, Middlebury College will not only be complying with Vermont Law but will also help students live more environmentally friendly lives. According to Vermont State Law, Middlebury College must install low-flow showerheads in any new construction project, and switch to low-flow showerheads if a conventional showerhead needs maintenance in an older building. Therefore, any construction that has occurred on campus within the last seven years, any dormitories that have been renovated within the last seven years, or any showers that have required maintenance in the last seven years all have low-flow showerheads. These low-flow showerheads translate into an enticing idea. For example, student Joe likes the idea of conserving hot water but feels that cutting his shower time by 40% is not worth the water and energy savings. With low-flow showerheads in his shower, however, he could take his usual amount of time showering and still use 40% less hot water than he would with the old conventional showerhead. This savings in hot water directly turns into savings in heating needs, which means we burn less oil and thus save money. Not only do these savings help finance the state-required low-flow showerheads, but by going beyond the requirement of the law Middlebury College would be showing the community how seriously we take environmental laws, and how we are willing to be environmentally aware.

Currently, all of the showerheads on our campus are low-flow, but many low-flow valves have yet to be installed. Approximately 100 low-flow valves are scheduled to be installed in the next few years.

The college does not wait until a building needs to be renovated or a showerhead needs maintenance. Instead, we are currently replacing these valves in the course of their regular maintenance.

Every three months, according to the Department of Energy, a low-flow valve saves $11 in water heating. There are no operating costs because the low-flow showerheads accomplish the same task as conventional showerheads. In addition, current Vermont law requires the use of low-flow showerheads when an old one is replaced.

Environmental. A large portion of our hot water needs will be reduced indicating that less fuel will be needed to produce steam to heat the hot water. In addition there is less wastewater used per shower.

Social. When low-flow showerheads were first installed in some of the buildings, some students did complain that it took longer to get the shampoo out of their hair, however, since that time the student body has adjusted and no longer complains about the lower flow.

Public Relations. By going beyond our compliance with Vermont State Law, Middlebury College will be showing the state as well as the community that the college takes the state’s environmental laws seriously.

Cross-cutting areas and synergies. Saves on electricity in campus houses that have electric hot water heaters.

Since the school will eventually have to pay to replace each showerhead on campus, then there will be no net loss of money.

Every building that has been built on a college campus in Vermont in the last seven years has low-flow showerheads.

Contact Harold Strassner (x2538) of Facilities Management and he will be able to replace older showerheads with the new low-flow showerheads and low-flow valves from his stockpile and will also be able to order more of these. However, some investigation on identifying the showerheads that need upgrading may still require some work.

*Summary data*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
33	11.1	5	$ 567

Currently most on campus houses are heated using domestic water heaters with an oversized 115 gallon holding tank (ISES).¹³ These water heaters use large amounts of electricity in order to heat the water. Much of this electricity could be saved if a solar water heating system was put in place.

Solar water heating systems use the suns energy to heat an anti-freeze solution running through black, specially designed, panels placed on the roof of a building. This anti-freeze solution is then used to heat water in a storage tank. Since we live in a cold climate that is cloudy for much of the year, solar water heating cannot be relied upon for all of our water heating needs. There is a temperature sensor in the hot water tank, if the water is not hot enough it is heated on demand by a fossil fuel powered backup heater. This system cuts the cost of water heating by 65-70% (Back East Solar¹⁴)

Using Weybridge house as an example, (simply because Weybridge House happens to have a meter on their water heater), we find that each year 13,469 kWh of electricity are used for water heating. This is almost half of the total 31,292 kWh of electricity used by Weybridge House.² Assuming that 7.11e-5 tons of CO₂ are emitted for every kWh of electricity that we purchase,¹⁵ we find that by switching Weybridge House to solar water heating would save 0.94 tons of CO₂ per year. This is lessened by the fact that a fossil fuel heater to make up for the amount of heat that can’t be generated by the solar collectors must supplement solar water heating. This amount varies greatly depending on the amount of heat generated by the collectors. The actual tons of CO₂ saved would be lower than this number. Also, since heating water with fossil fuels is much more effective than heating using electricity, we would recommend upgrading from electric hot water heating to other systems for all units not on the core campus system. Since we have no way of estimating the amount of fossil fuels that would need to be burned to supplement the solar water heating system we can only give a high limit of 0.94 tons of CO₂per year.

There is also a monetary saving associated with switching to solar water heating. Using electricity to heat water costs the college $1373 per year.² If the cost of water heating by the college cut by 65% the college would see a monetary savings of $892.00 per year. The initial cost of installing a solar water heating system would be significantly higher than that of installing an electric water heater. The cost of buying and installing a new electric water heater is between two and three thousand dollars,¹³ while a new solar water heating system costs around eight thousand dollars for parts and installation¹⁴. However, this would pay for itself within10-15 years. This system has a lifetime of over 30 years, so the college would make a net profit by switching to solar water heating.

There are several problems associated with solar water heating. The first is that solar water heaters require direct sunlight and a large southern exposure. This eliminates many of the campus houses (including Weybridge) from consideration for solar water heating, because trees surround the south side of the house. However, there are many houses on campus that do have adequate southern exposure to support solar hot water. It should be noted that the fact that a house may not have a south facing roof does not mean that it can not be equipped with a solar water heating system, because mounts can be installed on an east or west facing roof to provide adequate southern exposure.

It would be best to install solar water heating systems on houses that are used in the summer as well as the winter. Heat collectors work best in the summer months, since there is not a large loss of heat to the surrounding air. Therefore, houses that are only used in the winter months would not be good candidates for this project.

Efficiency Vermont, which we work with on many projects, would most likely be able to supply us with financial incentives based on the amount of electricity that would be saved through this installation of a new solar water heating system. They should be consulted before going ahead with this project.

Dormitories: Currently Middlebury College heats water in most of its dormitories using steam created in the physical plant. This steam is pumped through pipes from the physical plant to the buildings, where it is condensed on a heat exchanger, which transfers the heat into water to be used throughout the building. This process is fairly inefficient (however it is more efficient than the electric water heaters used in the houses). The total efficiency of turning the #6 oil burned in the physical plant to hot water is about 65%.²

We do not currently have an estimate of the cost associated with installing a solar water heating system on a dormitory. We do however have an estimate of the cost savings per year and the total amount of CO₂ saved per year. We estimate that the college will save about $600 per year on water heating costs and 11 metric tonnes of CO₂ per year (see Appendix). The CO₂ savings are considerably larger than the cost savings because the price of oil is low and the CO₂ emissions associated with the burning of #6 oil are very high.

In summary we see that a greater cost savings is gained by converting campus houses to solar water heating, and more CO₂reductions are found by installing solar water heating on dormitories. This is because of a number of factors. One is that it is expensive to heat water using electricity, this is because of the inefficiency due to converting the quality of energy. Greater CO₂ saving are found in converting the dormitories to solar water heating because of the large amount of CO₂ emissions associated with the burning of #6 oil. However, oil has been relatively inexpensive in recent years and is a much more efficient way of creating heat energy than electricity. Therefore the monetary savings of installing solar water heating systems on college dormitories is minimal.

In the end it is most likely more effective to install solar water heating systems on campus houses, if not for CO₂ savings, then simply for energy and monetary savings. Their installation on dormitories should be viewed as low priority. Accordingly, for the summary calculations below, we assume that this will be undertaken for five small campus houses with the adequate southern exposure.

Most College owned houses are in need of new water heaters within the next 5 years according to the ISES report.¹³ Instead of simply replacing the old systems with new electric water heaters the College could use this as an opportunity to install a solar water heating system in five small houses.

It is also recommended that many of our current steam to hot water heat exchangers in dormitories be replaced soon.¹³ Instead of replacing the heat exchangers, we could instead install a solar water heating system. This could happen on select dorms within a few years.

If installed in fives houses, the College would reduce its emissions by 5 MTCDE/year. This number can be extrapolated to other houses. Clearly, the more houses on which the College installs solar water heating systems, the more carbon dioxide is saved. Eleven tonnes of CO2 per year could be saved with the installation of a solar water heating system on Hepburn dormitory. This is a much larger reduction than can be found by installing a system on campus houses.

Startup costs would be about $10,000 for a large system for a house. This cost would vary with the amount of water needed. Cost would have to be estimated on a per building basis. Some of this initial cost can be differed by Efficiency Vermont depending on the amount of electricity that would be saved.

No company would provide an estimated cost of installing a solar water heating system on a dormitory. It would likely be high due to the requirement of additional piping and because the system would be massive.

The cost savings associated with the installation of a solar water heating system on one house would be approximately $900 per year.

The cost saving associated with the installation of a solar water heating system on Hepburn dorm would be about $600 per year.

Public Relations. This would be good advertising for our school. Putting solar water heaters on our buildings is a statement. There is the possible negative visual impact, but it is unclear if this would be a problem.

Cross-cutting areas and synergies. Clearly putting solar water heaters on campus houses would affect electricity use and therefore this proposal is cross-cutting between electricity and space heating and cooling.

Efficiency Vermont and other organizations have programs to give financial incentives to institutions planning to purchase green technologies. These incentives are based on the amount of electricity that would be saved and therefore are only a viable option for installation of solar water heating system on campus houses currently using electric water heaters.

Tufts University put up a solar water heating system on one of their campus houses as a part of their climate change initiative.

The first people to call would be one of several solar energy companies in order to get an exact estimate of cost. Back East Solar (www.backeastsolar.com) and Global Resource Options (www.GlobalResourceOptions.com) are excellent places to start. Once an estimate from these or other companies is received, Efficiency Vermont should be contacted in order to investigate the options for financial incentives.

II.4 Future Considerations

*Summary data*
Index rank	Payback time (years)	Annual tonnes CDE	Total (cost) or benefit per tonne
11	1.8	3,000	$ 52

Natural gas is widely accepted as the most environmentally friendly fossil fuel. Relative to burning coal, it produces half the amount of CO₂. When comparing its direct emissions to #6 oil, natural gas produces 35% less emissions. Thus, switching to natural gas would have an impact on the carbon footprint of Middlebury in terms of CO₂ associated with space heating and cooling, as well as a potential offset value if Middlebury were a major player in bringing natural gas to the area. Clearly, there are many stakeholders in this initiative. However, Middlebury could make a political statement that it is committed to using natural gas, if Vermont Gas proposes a plant that could supply the College.

Five years ago, there was a major initiative by Southern Vermont Natural Gas to develop natural gas lines in southeastern Vermont. Two plants were going to be built—one in Rutland, Vermont and the second in Bennington, Vermont. These plants were going to be linked together, as well as to natural gas pipelines in Albany, NY. They would have been capable of providing 1350 MW of energy, which is more energy than the entire state of Vermont needs. Eventually, the plan would have led to a pipeline providing both Middlebury and the Killington area with natural gas. There was major opposition to this project by the local communities.¹⁶ In the future, however, Vermont Gas, which currently provides natural gas as far south as Shelburne, is considering building a plant that might be able to provide Middlebury with this resource. The plant would be much smaller, on the magnitude of 250 MW. Although still quite tentative, the company is searching for investors to fund the project when other energy companies go offline. There is therefore no official time line for making a statement about supporting natural gas, until an initiative has been publicly announced. However, it is important that the Administration becomes informed immediately about the costs and benefits of natural gas, so they have the tools necessary to make an informed decision.

The reduction would be approximately 3,000 tons MTCE, a 10% reduction from #6 oil emissions (0.008 tons/therm). This number is based on a calculation including both upstream and downstream emissions associated with natural gas, and therefore includes the impact of methane and N₂0 on climate change. It should be noted that if Middlebury would choose to draw the line at direct emissions, the associated reduction would be about 35%. It also takes into account that the colleges Vermont Gas currently supplies have interruptible service, which means that during extremely hot or cold days, Middlebury would not be able to access the gas and must burn oil. We hypothesized that this would happen 30 days each year, and also used the calculation for oil that would include upstream and downstream emissions (0.013 tons/gallon).

To retrofit three of the four boilers to burn natural gas would cost approximately $300,000 ($100,000 each).

There would be no additional operating costs associated with a switch to natural gas. There would, however, be an overall savings of 4.5 million dollars over a 30-year period. The cost/ton would be a benefit to the college: -$50/ton (this estimate is based on an estimate of current prices for natural gas, $4-5/therm given by Scott Harrington¹⁷ at Vermont Gas, (802) 863-8899 ext. 338). For oil, the 2000 estimate was used, $0.80/gallon.

Environmental. Two environmental hurdles such a project might face are the aesthetic concern of the pipeline and possible negative effects related to leakage. The solution is temporary, for there are still high emissions associated with natural gas burning, and eventually the College would need to switch to a renewable resource. However, if given the option between burning oil and natural gas as a fuel source, the latter is the choice that has lower carbon emissions and a cheaper price.

Public Relations. Major opposition by local community initially. Overtime, Vermonters might approve of this fuel source.

Many other universities and colleges have far lower emissions associated with space heating and cooling due to the use of natural gas. Examples include the majority of colleges in cities where it is an option, such as Tufts University, University of Vermont, and Saint Michael’s College.

All major cities have the option of natural gas, and therefore utilize this fuel source. It is recognized by major environmental groups as the best fossil fuel available.

Geothermal heating and cooling uses a renewable resource found throughout the world -- the ground. At a depth of ten feet below the surface of the Earth, the soil remains a relatively constant temperature, plus or minus a couple of degrees, year round. In most places around the world this temperature is somewhere between 45°F and 70°F. Geothermal heat pumps (GHPs) take advantage of this temperature range by running plastic pipes underground filled with water or a mixture of water and antifreeze. In the wintertime when the outside temperature is cold, the temperature of the ground is a constant temperature between 45°F and 70°F. To heat the building, the GHPs take the heat from the ground and concentrate this heat in the pumps. This heat is then circulated throughout the building. The reverse process is used to cool a building. When a building is warmed up in the summertime, the GHPs pull the heat from the building and carry this heat through the system where it is cooled in the relatively cool earth, which is then used to cool the building. These systems have an average lifespan of twenty years, but require virtually no maintenance during the span and even pay for themselves usually in less than five years. In addition, the heating and cooling GHPs provide are less noisy than most heaters and every room has its own comfort control. Also, the heating pipes in the walls can take excess heat from the sunny side of a building and use it to heat the colder shady side of that building. The heating pipes used to disperse this heat throughout the building can use heat given off by appliances such as a refrigerator. Finally, GHPs can also provide for the hot water needs of a building (“Geothermal”¹⁸). By using the Earth as a source of heating and cooling, the energy consumption for a building is greatly reduced and thus emissions associated with this heating are also reduced.

This technology is currently being used in 500,000 buildings ranging in size from homeowners to large institutions such as Fort Polk Army Base in Louisiana, Skunk Creek Conoco station in Sandstone Minnesota, the Georgia Institute of Technology, the Great River Medical Center in Iowa, and other large commercial buildings (“Geothermal”). Therefore, the technology is available and has been proven to work. However, this technology has not yet been developed to its potential. Electricity is needed to power the process and currently has a lifespan that is less than the boilers we use. Due to this increase in electrical demands and the short lifespan, we did not feel that GHPs were a viable solution to provide heating needs for buildings that are already part of a rather intricate heating system. While GHPs are not currently viable for Middlebury College, they should be looked into when a new building of any size is being built on campus. The Department of Energy is excited about this technology and is investing a lot of time into advocating its use throughout the country. GHP technology has recently taken off, and the first quarter of 1998 sales grew by 24% (“Geothermal”). With all of this attention these systems are receiving, GHPs may be a viable option to provide heating by the time designs for a new building at Middlebury College are proposed.

2. These figures were given by Michael Moser, Central Heating Plant Manager, Middlebury College.

“The gasifier itself is a circular steel vessel. The wood chips are fed into the hopper, air is injected and the woodchips tossed around, so they mixed with the oxygen in the air. The wood/oxygen mixture is heated to a high temperature so that the wood gives off moisture and undergoes thermal decomposition. This process produces steam, volatile gases and a tarry substance called char. The volatile gases…(raise) the temperature of the gasifier to 850° C. In the blast tube, the amount of oxygen is limited, this results in a product called syngas (energy value 5.4 MJ per cubic meter), which is mainly carbon monoxide, hydrogen and methane.”

4. Figures for cost/ton for landfill and composting were verified by Norm Cushman, Facilities Management, Middlebury College.

5. $24/ton, ash fertilizer price: www.extension.umn.edu/mnimpact.asp?projectID=3005.

7. George Robson, Natural Products Specialist, Dept. of Economic Development http://www.thinkvermont.com, (802) 828-5241,George.Robson@state.vt.us

10. “Passive Solar Heating, Cooling and Daylighting.” U.S. Department of Energy: Office of Energy Efficiency and Renewable Energy. 25 October 2002. http://www.eren.doe.gov/RE/solar_passive.html 29 January 2003.

15. Figures provided by Lori Del Negro, Visiting Assistant Professor of Chemistry and Biochemistry, Middlebury College, 2003.

17. Scott Harrington, Industrial Account Representative, provided the majority of the information on the future of Vermont Gas Co.: 802-863-8899 x338

Sample calculation: Battell dormitory

Infiltration heat loss/hr = (cfm)(1.08)( Δ T)= (0.1 cfm)(1.08)(30)= 3.24 BTU/hr

CO₂ emissions= 4435 gallons * 0.013 metric tons CO₂/gallon = 57.7 tons of CO₂/ year

Infiltration heat loss/hr = (cfm)(1.08)(Δ T)= (0.05 cfm)(1.08)(30)= 1.62 BTU/hr

CO₂ emissions= 1263 gallons * 0.013 metric tons CO₂/gallon = 16.4 tons of CO₂/ year

For Warner, Stewart, Allen, Forest, and Munroe (assume all windows to be 14.8 ft²) (Note: Munroe has had some storm windows installed, therefore this estimate might be a slight overestimate).

Window # = 684

CO₂ emissions= 16,758 gallons * 0.013 metric tons CO₂/gallon = 218 tons of CO₂/ year

CO₂ emissions= 4767 gallons * 0.013 metric tons CO₂/gallon = 62 tons of CO₂/ year

Difference in showerhead efficiency: 3.5gallons/minute – 2.0gallons/minute = 1.5gallons/minute

Gallons of oil: (5300820 BTU’s/year)(gallon oil/140000 BTU’s) = 37.9 gallons oil/year

Savings of tonnes of CO2: (37.9 gallons oil/yr)(0.013 MTCDE/gallon oil) = 0.5 MTCDE/yr

80 students * 5 minutes/student * 5 gallons/minutes= 2000 gallons of hot water used every day.

-Assuming that the water starts at the ambient ground temperature of approximately 60 degrees F

-Assuming that 70% of the water coming out of the showerhead is at 120 degrees and the rest is unheated.

-Taking the fact that a BTU is defined as the amount of energy needed to heat one pound of water one degree F. Also using the fact that 1 pint of water weighs one pound, and there are 6.66 pounds in a gallon.

2000 gallons/day * .70 * 6.66 pounds/gallon * 1btu/pound degree F * 60 degrees F = 559440 BTU’s per day used for showering in Hepburn.

-Assuming a 65% efficiency rate of the physical plant heating system. (Michael Moser)

-Taking the fact that each gallon of #6 oil burned gives off 150,000 BTU’s of heat.

-Assuming that installing a solar water heating system reduces the cost of water heating by 65% throughout the course of a year, and assuming that since cost is directly related to CO2 emissions. (This is true for Middlebury College since our costs are associated with buying # 6 oil)

559440 BTU’s/day / 150,000 BTU’s/gallon *.013 tonnes CO2/gallon of oil * .65 reduction in CO2 emissions = .0315 metric tones of CO2/day

559440 BTU’s/day * 150000 BTU’s/gallon * $.69/gallon * .65 reduction in cost = $1.67/day

Fuel	#6 oil	#2 oil	propane
Gallons	1,694,233	390,599	40,759
Conversion (tonne CO2/gal)	0.013	0.0128	0.0072
CO2 emission	22025.03	4999.672	293.4648
		Total	27318.17

1)	U value of old windows = 1.2 BTU/hour
2)	U value of new windows = 0.34 BTU/hour
3)	Air infiltration of old windows = 0.1 cfm/ft²
4)	Air infiltration of new windows = 0.05 cfm/ ft²
5)	Window size: 14.8 ft²/ window
6)	Average temperature differential = 30˚F (www.weather.com)
7)	#6 fuel oil = 140,000 BTU/gallon
8)	CO₂ emitted = 0.011 CO₂ / gallon (accounts for upstream, downstream CO₂, N₂0, and methane)
9)	# 6 fuel oil = $0.80/gallon (2000 rate)
10)	$300/window (removal, installation)

1)	Average Middlebury student showers every other day.
2)	Average shower stall is used by 7 students
3)	Average shower lasts 8 minutes
4)	Students are on campus 36 weeks of the year
5)	Conventional showerhead uses 3.5 gallons/minute
6)	Low-flow showerhead uses 2.0 gallons/minute
7)	BTU = heat required to raise the temperature of 1 lb of water 1ºF
8)	1 lb of water = 0.1198 gallons of water
9)	Water must be heated from 60ºF to 120ºF for hot water needs
10)	#6 fuel oil = 140,000 BTU/gallon
11)	0.013 tonnes CO2 = 1 gallon of oil

II.4 Future Considerations

Fuel

Gallons

Sample calculation: Battell dormitory

Window # = 684