EVALUATING AND COMPARING THE SUSTAINABILITY OF NATURAL GAS VERSUS ACTIVE SOLAR ENERGY TO HEAT THE PHYSICAL ACTIVITIES COMPLEX POOL

FOR: IAN ROWLANDS ERS 218 DECEMBER 7,1998

BY GLYNYS JONES SHERRI FLEGEL CHRISTY HUGHES CORA SHEPPARD REBECCA EARL

TABLE OF CONTENTS 1 .O INTRODUCTION ..........................................................................................

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2.0 BACKGROUND/DESCRIPTION/CASE STUDY............................................

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2.1 BACKGROUND/DESCRIPTION - NATURAL GAS ....................................

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2.2 BACKGROUND/DESCRIPTION - SOLAR ..................................................

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3.0 DETERMINING SUSTAINABILITY OF NATURAL GAS HEATING.. ........... .7 3.1 SOCIAL .......................................................................................................

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3.2 ECONOMIC ................................................................................................

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3.3 ENVIRONMENTAL .....................................................................................

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4.0 DETERMINING SUSTAINABILITY OF SOLAR HEATING ........................... 8 4.1 SOCIAL .......................................................................................................

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4.2 ECONOMIC ................................................................................................

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4.3 ENVIRONMENTAL .....................................................................................

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5.0 COMPARISON .............................................................................................

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6.0 CONCLUSIONS ..........................................................................................

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1 .O INTRODUCTION To date, there has been much contemplation regarding whether the University is using sustainable energy sources. It is important that the University continue to examine new methods to ensure sustainability of energy systems on the campus. The purpose of this report is to evaluate and compare the sustainability of heating the Physical Activities Complex (PAC) pool with natural gas versus solar energy, specifically a flat plate solar thermal energy collector. The system examined in this report is the PAC pool at the University of Waterloo and the energy used to heat the pool water. Sustainable development can be defined as “development that meets the needs of the present without compromising the ability of future generations to meet their own needs” (World Commission on Environment and Development, 1987, p.43). To work towards this ideal, the criteria on which the current and suggested systems are to be examined are not only environmental, but also take into account economic and social considerations. Our report will compare these two types of energy sources to determine which has a greater sustainability. The more sustainable option will be recommended for the PAC. Currently, the University of Waterloo depends on natural gas to fulfil1 its heating needs. In working towards a more sustainable system, the current method of heating and the suggested method of heating are compared in relative terms. Natural gas is not deemed unsustainable because, compared to oil, it may be more sustainable, burning more efficiently and “producing one-third less carbon dioxide per unit of heat energy and fewer pollutants overall” (Draper, 1998, p 363). However, natural gas is a nonrenewable fossil fuel so compared to renewable energy resources, particularly solar energy, it may be less sustainable environmentally. Solar energy produces no emissions and its annual incident energy is equal to more than 15,000 times the world’s annual use of hydro power, fossil fuel and nuclear fuels (Rowlands, 1998). The goal of this report will be to determine which system is more sustainable.

2.1 BACKGROUND/DESCRIPTION - NATURAL GAS Natural gas use in the world has grown substantially in the past decade. In 1984, “natural gas accounted for eighteen percent of the world’s annual energy budget” (Myers, 1984, p. 103). Ten years later, in 1995, the figure grew to “nearly twenty - five percent of the world consumption of energy” (Fellman, 1995, p.286). Natural gas is preferable to most other types of fossil fuels as it produces fewer pollutants.

It has been

called u the nearly perfect energy resource; it is a highly efficient, versatile fuel that requires little processing and is environmentally benign” (Fellman, 1995, p.286). Unfortunately, due to natural gas’ “uneven distribution and difficulties in transporting, it is likely to remain of use only in a few nations” (Myers, 1984, p. 103). At the University, the gas is received at the central boiler stack which burns the natural gas to produce steam (see figure 1). This steam is sent throughout the university to heat the various buildings. In the PAC, the steam is used for heating domestic hot water, the pool’s make - up water (water added to replace the water lost through evaporation), air temperature in the building, and the dryers in the PAC laundry facilities. The PAC pool uses 250 000 U.S. gallons of water which the control room keeps at a temperature of eighty to eighty-two degrees Fahrenheit. Initially, the water at the PAC comes in from the City of Waterloo’s water supply at sixty degrees Fahrenheit and then is heated to eighty-one degrees Fahrenheit. Once this is done however, the eighty-degree Fahrenheit water is filtered and circulated through a heat exchanger to keep the temperature at eighty degrees Fahrenheit. The heat exchanger allows the steam to heat the pipes in which water is being circulated.

The only heat loss is

through surface evaporation; therefore, the only heat required is to heat the make-up water. Rick Zalagenas believes that the system, on a whole, works well (Zalagenas, 1998).

2.2 BACKGROUND/DESCRIPTION - SOLAR

The alternative energy source that will be compared to natural gas in order to assess relative sustainability is solar energy. Solar was chosen because it has been used for a longer period of time as it has “gained most of its strength . . . in the late 1970s” (Draper, 1998, p.371). This translates into more accessibility to suppliers and a wider variety of available technologies, which usually lead to lower costs for the system. In the long run, it may be better economically to use solar energy because there is no need to pay for the fuel, which is the sun’s rays. The environmental benefits of using solar over non-renewable energy sources are seen as a positive step towards sustainability under the environmental criteria. The energy is readily available as the amount incident on the earth each year is “equivalent to 160 times the energy stored in the worlds proved reserves of fossil fuels” (Rowlands, 1998) and its “extraction” has little, if any impact. The specific type of solar energy system that is most effective in this case is Active Solar Collection by means of a flat plate solar collector (see figure 2). The flat plate array consists of cells, a cover, a frame and a supporting structure for the array. The cell is comprised of the absorber plate, upon which the sun’s energy is converted to heat. All absorber plates conduct the heat generated on their surfaces to a site for transfer of the heat to the liquids or air - in this case the pool water. The pool water is piped up to the collector system, is heated by the absorber plates as it passes through them and is then brought back to the water storage tank. The water temperature is regulated by the rate of flow of the water through the system, so there is never too much heat gain, for example, on a very sunny summer day, and the water temperature remains at a constant set temperature which is controlled by the control box (Hilker, 1998). Different types of absorber plates exist and differences between them include efficiency of heat transfer, fluid flow capability and weight (Ametek, 1984, p.80). Heating a swimming pool is a relatively simple project so the absorber plate can be comprised of rubber and plastics with carbon black. The cover’s purpose is prevention of convection loss, reduction of thermal radiation loss and protection of the absorber plate from UV radiation, thermal expansion and soil and fungal accumulation (Ametek, 1984, p.79). The absorber plate has a transparent cover backed with thermal insulation to keep heat loss to a minimum. The frame holds the collector in place with the Physical

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Activities Complex in this case acting as the supporting structure. If the weight bearing capacity is not great enough or of satisfactory structural soundness, modifications may be necessary which would increase the economic cost of installing the collector. Building location is also an issue as this system cannot track the sun. Additional costs would be associated with the purchase, installation and maintenance of an orientation system and is not considered in this report. Therefore the collectors need to be facing south. It is not expected that this system would provide all the heating needs for the pool, as this would not be possible in this area due to the lack of incident sunlight in the winter months. During the winter, solar power would be used only when there is enough sunlight, which would vary each winter. The natural gas should be considered as an auxiliary heating unit to be used mainly in the summer. 2.2.1 Case Study: Breithaupt Recreation Centre (taken from interviews with Peter Beaudry, 1998 and Wayne Hilker, 1998) The Breithaupt Centre is a community centre located in Kitchener, Ontario. The centre contains one, twenty-five by ten yard pool and a smaller, hot exercising pool. The centre uses Active Solar Energy to heat the large pool which is kept at a temperature between eighty-two and eighty-six degrees Fahrenheit. Solar heating of Breithaupt’s pool began in 1985 as a joint venture between the federal, provincial and municipal governments. At this time, the federal government was looking for sites where they would be able to initiate working examples of solar heating. The Breithaupt Centre was an ideal location for the project because of its location and the structure of the building. The centre is located in a clearing so the sun is able to strike the panels from a southerly direction. As well, the roof of the building was built strong enough to be able to hold the weight of the solar panel structure. In order to bear the costs of the implementation of the panels, the federal, provincial and municipal governments split the costs three ways. The total cost of the venture was $120, 000 and the project has paid for itself approximately ten years after implementation. After the initial costs of installation, the panels have proven to be an excellent investment. There was no need to train or hire staff who would be familiar with the technology because little maintenance is required. Due to the fact that less sunshine is received in winter, natural gas is used as an auxiliary source of energy at Breithaupt Centre. This helps to keep costs low because the City of Kitchener owns their own gas company. Since the City of Kitchener also runs 5

the Centre, Breithaupt gets its natural gas at a fraction of what it might cost in another municipality. This auxiliary source is used to ensure that the temperature of the water remains constant and does not fluctuate even if there is a lack of solar energy. This system is used frequently in the winter but never during the summer. The solar heating system in place at the Breithaupt Centre consists of a control panel, piping and collector plates. The control system is located inside and is used to control the amount of water that is circulated through the solar system depending on the water temperature. The pipes carry the water from the storage area up to the roof and through the backs of the solar panels where the water is heated. The solar panels consist of ridged glass in order to catch the sunlight as well as a black coating on the backs to absorb as much heat as possible. Breithaupt Centre has eighty solar panels, which heat the 100,000 US gallons of water in the pool. Since installation thirteen years ago, the Centre has had nearly no problems with the solar panel structure. When the system was installed, the pipes on the roof through which the water flows were made of asbestos. Over time, birds pecking at the pipes had destroyed the insulation around them. A protective covering was added and since then there have been no problems. The only case of a solar panel being broken occurred last year when a golf ball from a nearby field hit the panel and shattered the glass. Because this area receives snow in the winter, there was an initial concern about its weight on the panel system. This has proved not to be a problem because of the black surface of the panels, which creates a constant melting effect so that no accumulation occurs. The solar structure at the Breithaupt Centre was implemented during a time when a significant amount of research was being done on alternate energy forms and the federal government was willing to contribute money to these ventures. This is not the case anymore, but the Breithaupt Centre stands as a reminder that solar energy is a viable, alternate form and perhaps the federal government should consider more projects such as this in the future.

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3.0 DETERMINING SUSTAINABILITY OF NATURAL GAS HEATING 3.1 SOCIAL Only a small number of social issues can be recognized at the University regarding the use of natural gas. The system is sealed and therefore there are no safety problems. Health concerns may be related to emissions from burning the natural gas at the University, but the smokestack is high, dispersing the emissions where hopefully, they will not affect human health. Yet one must also consider the cumulative effects of using natural gas, its contribution the greenhouse effect and the possible health concerns of global warming, such as higher mortality from rising temperatures. In looking at the life cycle of natural gas, consideration must be given to social concerns related to flaring, the burning of unwanted, unprocessed, natural gas “to avoid the build up of potentially explosive levels of gas at work sites” (Draper, 1998, p. 363). The effects on humans from emission exposure are not well understood, as “more than two hundred different chemical compounds produced by flaring, including more than thirty varieties of cancer-causing benzene” (Draper, 1998, p.364 from Francis, 1997). As well, there are dangers associated with piping the gas; leaks may occur, creating the possibility of accidents such as explosions. It is therefore important to consider not only the local effects, but global issues as well. 3.2 ECONOMIC The University buys their natural gas from an Alberta company called “Amoco” through a direct purchase agreement. They pay Trans Canada pipeline and Union Gas for use of their pipelines to transport the natural gas to the University’s Central Boiler Stack. The University receives a constant supply of gas throughout the year. The cost for the gas fluctuates monthly but on average the University pays roughly ten cents per cubic metre. The University pays just over one million dollars a year for gas. Unfortunately, it is impossible to determine the exact amount of natural gas used by the PAC as there is no metering of the gas to individual buildings within the University.

3.3 ENVIRONMENTAL

Natural gas is one of the more environmentally conscientious ways of obtaining energy. Compared to other fossil fuels such as coal, natural gas “emits half the carbon dioxide, one fifth the nitrous oxides, and almost none of the sulfur dioxides” (Kessler, 1994, p. 623). Although natural gas produces fewer pollutants, it still produces substances, which contribute to the enhanced greenhouse effect, acid rain, and other related problems. 4.0 DETERMINING SUSTAINABILITY OF SOLAR HEATING 4.1 SOCIAL

The social concerns that may arise if a solar energy system is implemented at the University of Waterloo’s swimming pool are the issues of vandalism, the aesthetic beauty of the campus and the maintenance of consistent service to the patrons of the pool. Vandalism is a concern that must be addressed if the university is going to spend a great deal of money to implement a solar energy system. The Breithaupt Recreation Centre has not had a single case of vandalism. The centre is not in a very prosperous part of Kitchener and it is proven that in areas where money is an issue, there is a higher rate of vandalism (Henslin and Nelson, 1997, p. 180). There are also University police which will deter any acts of vandalism. Since the roof of the Physical Activities Complex is high and wide few people will probably even know that the panels are there. Vandalism will likely not be a problem if solar panels are used to heat the university swimming pool. People may think that having solar panels will detract from the overall appearance of the university campus. Since the roof of the PAC is very high and wide so it will be difficult to notice the panels. As well, there are many other tall and obtrusive buildings on campus such as the smokestack and the Dana Porter Library. These buildings are much higher and more visible than solar panels would be. The appearance of the campus should not be an issue if the campus is being benefited in other ways. Finally, people may be concerned that the temperature of the pool will fluctuate when the system is being installed as well as at times when there is no sun. The Breithaupt Centre has not had a problem with this as the auxiliary system that is in place 8

is used in order to maintain consistency. The systems work together to ensure that the comfort of all pool patrons is met. 4.2 ECONOMIC

The economic constraints of the implementation of a solar structure were a major limitation in this project. To get prices on how much solar energy would cost to heat the PAC pool, specific measurements must be known. These measurements included the surface area of the pool and what the temperature of the surrounding air is. Once this information was obtained companies could be contacted and a request for cost could be made. Unfortunately, many companies did not respond to these requests. In fact, only one company responded with the reply that they needed more information. Fortunately, with the help of a past project done using WatSun requirements needed for a solar facility at the PAC, specific needs for the solar array could be determined. The prices have changed considerably since then, and they were found on a web site for a solar company in Quebec; Laurend’eau. Fifty-eight solar panels, one thousand and twenty-seven feet of piping, various control boards and sensors, glycol, and an automated controller are needed for the complete system (WatGreen, 1992, p.4). The breakdown costs are as follows: Panels

$14500.00

Piping

$8131.79

Controller

$445.00

Glycol

$658.72

Sensors

$1408.00

Total with taxes $28 703.72 (Laurend’eau, 1998) Installation costs would vary depending on the company as some suppliers include free shipping and installation or require the buyers to install it themselves. Such things as glycol would have to be bought on an annual basis (WatGreen, 1992, p. 19). Other than that, most of the costs would only be at the beginning. 4.3 ENVIRONMENTAL

The amount of energy incident on the earth each year indicates sustainability in solar methods. Solar energy is a renewable alternative as opposed to the more conventional methods. Solar energy does not have the emissions of pollutants that the burning of fossil fuels does. In the Kyoto conference, Canada signed an agreement 9

vowing to reduce emissions, the implementation of solar energy and other renewable alternatives is a major contributor the realization of that goal.

Solar energy is becoming

more accessible is a sustainable practice. Perhaps solar energy could help the University of Waterloo meet its Voluntary Challenge that it signed under the Voluntary Challenge Registry. 5.0 COMPARISON Environmental

Economic

Social

Natural Gas -less emissions than oil but still contributes to the enhanced greenhouse effect -exact cost for PAC indeterminable as there are no metered services to individual University buildings

Active Solar Energy -no emissions

-health concerns resulting from burning and flaring emissions -no safety issues at the University

-vandalism of panels is of small concern -appearance is not of concern -no change in water temperature during implementation

-high initial costs - no cost for the actual fuel -virtually no maintenance

6.0 CONCLUSIONS It is evident that both energy sources are effective in maintaining adequate temperatures for pool water. Since very little heat is used to warm the pool water, and as natural gas is used to heat the entire University, the gains made financially by implementing solar panels are not great enough to deem it desirable to use solar collectors to heat the PAC. Instead, the money would be better spent on finding other methods or systems to decrease natural gas use throughout the entire University.

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APPENDIX

HOT WATER RADIATORS

INSULATED HOT WATER STORAGE TANK AUXLIARY FURNACE

FIGURE 6-13 Conventional delivery of solar energy for hot water and space heating with circutatiflg hot water.

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BIBLIOGRAPHY Ametek, Inc. Solar Enerqv Handbook: Theorv and Application. Radnor: Chilton Book Company Radnor, 1994. Beaudry, Peter. Interview, 19 November 1998. Aquatics Manager. City of Kitchener, Kitchener, Ontario. Draper, Diane. Our Environment: Canadian Perspective. Scarborough: International Thomson Publishing, 1998. Fellman, Jerome, Getis, Arthur, and Getis, Judith. Human Geoaraphv: Landscapes of Human Activities. 4* ed. Dubuque: Wm. C. Brown Publishers, 1995. Henslin, James M., and Adie Nelson. Essentials of Socioloav. Scarborough: Allyn and Bacon Canada, 1997. Hilker, Wayne. Interview, 19 November 1998. Head of Maintenance. City of Kitchener, Kitchener, Ontario. Kessler, Jon, Schillo, Bruce, Shelby, Michael, Haspel, Abraham. “Is Natural Gas the Answer?“. Enerqv Policy. Vol. 22, no. 7, pp. 623-628, 1994. Laurend’eau. Http:Nwww.cam.org/-cpsYindex.html,

November 1998.

Myers, Norman. Gaia: An Atlas of Planet Manaqement. New York: Gaia Books Ltd., 1984. Rowlands, Ian, Lecture on Enerqy , ERS 218 - Sustainable Development, University of Waterloo, 7 October, 1998. WatGreen. Thermal Solar Heatina in the PAC. Waterloo: University of Waterloo, 1992. World Commission on Environment and Development. Our Common Future. NY: Oxford University Press, 1987. Zalagenas, Rick. 23 November 1998. Utilities and Maintenance Ma&er. University of Waterloo, Waterloo, Ontario. Interview.