solar

APSC 400 PEC SolarPrepared for Physical Plant Services Report Prepared by: James Baillie Stephanie Chu Esther Ng Jeffrey Reid i EXECUTIVE SUMMARY The Physical Education Centre (PEC) at Queen’s University provides service to over 18000 students, staff and faculty members. In 1983, a team of Engineers and professors designed and implemented a solar heating system to provide heated water for showers. Due to a malfunction in the system, the piping in the panels burst and the system has not been in use since 1990. This report represents an economically and environmentally sound system to replace the current equipment. Using RETScreen and WATSUN simulation software the required system components and performance criteria were established. Once all the components were defined, contractors and distributors were contacted to obtain pricing quotes. The proposed closed loop system will integrate many components from the previously used drain-back system to reduce costs. The mounting structure on the roof, the panel casings, the building piping system, and the water storage tank will all be reused. implemented. Currently, there are 150 glazed solar thermal panels on the roof of the PEC. Keeping the existing panel casings, and retrofitting new solar absorbers will reduce costs. A Delta-T control system is specified, and is designed by Heliotrope Thermal Inc. Implementing the Delta-T control system will require integration into the PEC’s main control system. A 50/50 propylene glycol/water solution is used to circulate through the panels to collect thermal energy. Once the solution has circulated through the panels, it flows through a heat exchanger where the energy is transferred to water. Two pumps are needed in the system, one at the panels to circulate the propylene glycol solution through the solar array and another at the storage tank to circulate water between the heat exchanger and storage tank. The existing building piping will be used in the new system, with minimal refurbishing to accommodate a closed loop system. Renewing this system has great economic and environmental benefits. Approximately 640GJ of energy will be saved annually, and 6.24tons of CO2 emissions will be reduced. This translates into a monetary value of $8 200/yr. In addition to the economic value of utilizing solar energy, renewing the system in the PEC will result in ii In addition, a heat exchanger, solar panel absorbers, a control system and pumps will have to be displaying a conscious effort to use clean energy in one of the highest traffic buildings on campus. It is also important to consider other added benefits to renewing this project. It was a unique project at the time and promoted clean At the time of its inception, Queen’s University garnered much attention from the installation of this system. energy and helped advance an emerging technology. Financially, the total cost of the project is projected to be $71 780 with a 9-year payback period. The Net Present Value (NPV) of the project is $16 390 with an Internal Rate of Return (IRR) of 10.57%. These numbers show that the project is financially viable and is a sound investment for Queen’s University. iii .................................0 2...0 WATSUN ......Financials iv ......................... 17 5.............................................................Detailed Calculations Appendix B ..... 3 3............................................................. 18 5............. 28 References........... 10 4........... 27 Acknowledgments....................... 19 6................................................0 Recommendations................ 19 5......................................................................................................................7 Pipe Data................... 17 5............................................................................8 Load Data...................................................................................................................................................... 14 4........4 Collector Data for Group B.........................4 Pumps.......................... 18 5...........................2 Collector Data for Group A ...........................RETscreen Output Appendix G.....................................................................1 Solar Energy........................................................................................... 16 5........................................................................................1 Load Determination ......... 14 4.................................................Controls Data Sheets Appendix E ...................2.......... 10 4..........................................0 Conclusions........................................................................................................ 4 3................................0 System Components....1.................................. 18 5....................................................... 10 4...............................................WATSUN Output Appendix C ....................................................................................................0 Environmental Benefits .3 More Collector Data ...............................................................................5 Tank Data................................................................... 5 3............................................. 17 5...................................... 21 8.. 19 5............5 Piping System ........................1 Simulation Data ....................................... 29 Appendix A ............3 Heat Exchanger....................................1 Panel Design and Function ..0 Financial evaluations ..........................................................................................2 Design Parameters ........ 26 9...........................................................Pump Data Sheets Appendix F ............................................................................................................................. 1 The Existing System ............................................................SWEP Software: Selection of Heat Exchanger Appendix D .................................1 Solar Panels............................0 Introduction...............................2 Control Systems ........... 20 7................................................................................................................................................................................... 6 4...........................6 Heat Exchanger Data ........................................................................... 1 The Proposed System..........Table of Contents 1............................................... 12 4..............0 3............... 3. 3. 3. 6 7 8 9 11 14 16 24 v .2 Monthly water consumption of the PEC.1 Payback period of the proposed system.3 Daily hot water consumption of the showers in PEC.4 Estimated daily hot water consumption distributed for the PEC. 7. Pg.List of Figures Fig. 3.1 Schematic of the solar panel. 4. 4.1 Solar system efficiency.3 Centrifugal pump chart.2 Schematic of the Delta-T programmable dip switches. 4. 10 23 vi .1 Summary of total costs.List of Tables Table 4. Pg.1 Strength of annealed glass and tempered glass. 7. of domestic water. the thermal solar panels used were first generation panels in an emerging technology. At the time of installation. In 1983. a temperature sensor located near the solar collectors would record the temperature and compare it to another sensor located at the storage tank. In this system. a pump would start sending water to the 1 . but has not been operable since 1990. staff and faculty members.000 liters per day during the winter term and 68. summer term. When the temperature difference was greater than 5˚C. Yung. P. environmental and financial view.000 liters per day in the solar panel heating system has many benefits to the university from a technological.E.Eng.. P. 2. A piping system brought water up from the storage tank to these panels where water was heated by solar radiation before circulating back down for use in domestic hot water applications. Strong.T. It was classified as a drain-back type system. the Commercial/Industrial Solar Demonstration Program was installed to aid in the heating The solar panels were designed to heat up to 135. covering the roof of the PEC. Queen’s University.Y. replaced or removed from the PEC. primarily used for showers. due to a The malfunction in the system. The project was composed of 293 m2 of Nortec TD 1000 Solar Panels. in which water circulated directly through the panels. Unfortunately.0 THE DRAIN BACK SYSTEM The previously existing drain back system in the PEC was implemented in 1982.0 INTRODUCTION The Physical Education Centre (PEC) at Queen’s University provides recreational services to over 18. Campus Services Division. During sub zero temperatures. The objective of this project is to determine if the panels should be fixed. This project received a large percentage of its funding from government sources. the system would shut off and the water would drain down to a holding tank inside to avoid freezing.J. C. as it was a unique project at the time of its inception.1. The system was designed by T. the solar panel system has been unused since 1990.000 students. and the cold water line was moved to bypass the storage tank to connect directly with the three auxiliary tanks used for domestic hot water heating. Glycol would evaporate up the risers. At the same time. a temperature sensor may not have registered properly. however. the resulting events from that first failure are more clearly understood. In any case. ice got into the glycol piping in the collectors. the drain-back valve would be closed. the glycol then froze bursting the pipes in the collectors. When the temperature got cold enough. or a manual valve could have been closed when it should have remained open. transferring the solar energy it absorbed. The drain-back tank was connected to the cold water storage tank in the basement which was then used to distribute water throughout the PEC. the ice melted. When the water pipe burst. however. Piping up to the collectors was then sealed off. The propylene glycol solution was contained in a complex piping system that contained risers that led up to a cross pipe that encompassed the water pipe. 2 . the system was left so over time. the system became completely ineffective and the piping in the collectors became unsalvageable. Ultimately. a variety of problems could have arisen leading to the system’s breakdown: a drain-back valve may have stuck. or the temperature difference between the two dropped to less than 2˚C. diluting the glycol in the collectors. and then condense on the water pipe.collectors. When this occurred. The system was designed so that a single water pipe would run through the solar collectors gaining energy from the propylene glycol solution that was heated. The water in the pipes froze causing extensive damage. replacing the one cross flow pipe that contained the water could have saved the system. The precise cause that led to the system’s failure is not exactly known. Initially. water remained in the piping around the collectors when it should have drained back into the tank. Initially. the pump would stop and the drain-back valve opened allowing the water to flow back into the tank via gravity. during sub-zero temperatures. The water would keep circulating between the 1500 gallon drain back tank and the collectors until either the temperature of the tank reached 87˚C. while the remaining two consists of 18. no longer widely in use. which evaporates just 3 . The heated fluid is transported through insulated pipes to a heat exchanger that transfers the energy to the water in the storage tank circuit. Each of six of the arrays consists of 19 solar collectors. A controller specifies when a large pump circulates the fluid through the collector circuit. which if deemed serviceable.3. The system consists of two piping circuits that transfer energy by means of a heat exchanger. which are then filled with the preheated water from the solar collector The drain-back system contained an expansion tank in this loop.0 THE PROPOSED SYSTEM The previous solar collector system was a drain back type system that pumped water through the solar collectors. The cooler water is then pumped back up to the solar collectors to absorb more solar radiation. absorbing the solar radiation energy through the heat exchanger. the water is delivered to three locations: the showers.887 m3 storage tank. When a hot water load is needed. all of which are also in parallel. From the three tanks. cold water enters three 10m3 auxiliary tanks that heat the water by means of steam. three washing machines as well as the ice rink for filling the zamboni and melting the ice. Effectively the system consists of 150 collectors in parallel. The system is driven by pressure supplied in the cold water line from Utilities Kingston. can be utilized in the proposed An expansion tank is also needed in the solar collector circuit to allow for expansion of the fluid. over 100 oC. Using the solar collector system. Currently. Due to the varying Canadian climate. Solar radiation heats the propylene glycol as it is circulated through the collectors. which drained back when the temperature dropped below zero degrees Celsius. system. The storage tank circuit contains water that is circulated by a pump between the heat exchanger and a 4. the cold water would enter the solar collector storage tank and circulate through the solar panel loop. this type of system is It is proposed that the more common closed loop propylene glycol system be implemented for the PEC instead. it is taken from the three auxiliary tanks. The solar collector circuit contains a propylene glycol solution that is circulated through eight solar collector arrays in parallel. 5 and 5.6 to 0. In a thermal solar collector system. and absorb heat from the solar radiation of the sun. A glazed collector has insulation on the Typically. The thermal cells are much more efficient than the photovoltaic ones. in turn transfers the energy to any heat retainin substance for various applications. Fr (tau alpha) is a parameter used to characterize the collector's optical efficiency [dimensionless].storage tank through a mixing valve. and are therefore used in most domestic hot water applications. A temperature sensor would be located in the outlet pipe directly next to the solar collector array. 3. back to limit thermal losses to the environment. G is the global incident solar radiation on the collector [W/m²]. Fr UL is a parameter used to characterize the collector's thermal losses [(W/m²)/°C]. another would be located at the inlet pipe to the solar collector storage tank. With the proposed system.8. (Eq. One method utilizes photovoltaic cells to convert the solar radiation directly into electricity. The parameters Fr and Fr UL vary depending on the manufacturer of the collector. Fr. fluid is pumped through the collectors. The mixing valve adds cold water when the temperature of the water is above 50 oC to avoid sending scalding water to the loads. and DT is the temperature differential between the working fluid entering the collector and the outdoors [°C]. but 4 . The Fr UL parameter in general ranges between 3.1) where Q is the energy collected per unit collector area per unit time [W/m²]. the performance of a glazed thermal solar collector is modeled by the following equation: Q = [ Fr (tau alpha)]*G . 3.5.[Fr UL]*DT . the other uses thermal cells to heat a conductive fluid which.1 Solar Energy Solar energy is harvested by two main methods. should be as high as possible for maximum efficiency. whose typical values range from 0. and the use of the solar energy is maximized. there is never a shortage of hot water. The controller sends a signal to the two pumps to circulate the fluids when the temperature difference between the two sensors is greater than 8 oC. the optimum flow rate through each collector was determined to be 0.07 kg/s. The reason for this is that the flow becomes turbulent near this point. determined by the climate.2 Design Parameters All other parameters are Although many different variables determine the efficiency of the system. 5 . causing the flow losses in the pipe to increase. This occurs in parallel through all 150 panels for an overall flow rate of 10. For this reason. most values were given due to the already established infrastructure of the drain-back system. and panel area of the drain-back system should be left unchanged. 3. 3. Therefore there is an optimum flow rate that maximizes the net energy gained by absorbing a large amount of solar energy and expending only a tiny amount.it should be as low as possible to limit the thermal losses. which in turn increases the pumping power required. design parameters such as storage tank size. The main variable parameter that To get this determines the overall system efficiency is the mass flow rate through the collectors. the pumping energy required increases significantly after approximately 30 kg/s.5 kg/s as shown in Fig. Other losses in the system include tank heat losses and piping heat losses but both are relatively independent of the flow rate. Through an iterative process. Increasing the flow rate will increase the amount of solar energy collected. using up a fraction of the solar energy collected. The cost benefit of using components of the old system outweighed the benefit of changing certain features that would increase the efficiency. pipe size and insulation.1. As shown in the graph. using WATSUN simulation software. increased flow rate. the pumping power of the fluid would also need to be increased. because of the incidence angle of the sun. consumption of hot water for September is calculated using the amount of steam used in that month (based on the average of the previous three years). daily and even hourly distribution determine how much a solar collector system can reduce the energy If peak hot water consumption occurs at midnight. as opposed to mid day. and the final temperature of the water as shown in Appendix A. the total hot water consumption is not given directly from that information alone. Therefore. then it is evident that a Even if most of the hot water is needed early in Therefore solar collector would be of no benefit. consumption.2. the initial temperature of the water. From utility bill information.1 Load Determination One of the most significant parameters in specifying the size of the solar collector system is the hot water load.1 Solar system efficiency. the total water consumption and the total steam consumption for the past three years was obtained. determining the load and the distribution of the load is extremely important. 3. The load and its monthly. the morning. when the sun is directly overhead. very little energy is being absorbed. September was chosen as the representative month because it is a month of full load operation 6 . 3. but also to heat the building. Steam is used to heat a percentage The monthly of the water for the hot water loads.System Efficiency 2000 Net Solar Energy (GJ) 1500 1000 500 0 -500 -1000 Flowrate (kg/s) Solar Energy Created Pumping Energy Required 0 10 20 30 40 50 Net Energy Fig. This gave us a percentage of the total water consumption that is heated for hot water use. Initially. Readings from the water meter. applications in the PEC: showers. a water meter was installed in the PEC. PPS did not have a water meter that was big enough to measure the total water coming out of the hot water tanks and were unable to purchase one in the limited timeframe.) M J J A S O N D J F M A Month Fig. and for melting the ice and running the Zamboni in the arena. 1 Estimated (hot water) 7 . so a smaller water meter was installed in a pipeline that runs to the men’s showers. Unfortunately. but it is warm enough that none of the steam would be used for heating the building. Monthly Water Consumption 9000 8000 7000 6000 5000 4000 3000 2000 1000 0 Water Consumption (m3) Cold Hot (Est.(during the school year). 3.2 Monthly water consumption of the PEC. are taken to give an hourly distribution as shown in Fig. because of the limited resources. This line feeds 36 of the total 80 showers in the PEC.1 To arrive at a more accurate weekly and daily distribution of the load. three washing machines. The data is shown in Fig 3. it was thought that the majority of the load came from the showers.2.3. This fractional value was then used to determine the hot water consumption in all the other months. this meter did The hot water is used for three separate not read the total output of hot water consumed. adjusted to represent all the showers. 3. 3. This accounts for a huge amount of hot water since during peak times. the amount only represented approximately 10% of the total hot water use. the ice rink and the washing machines accounted for a majority of the load. 3. In other words. throughout the day indicating an even distribution. Given the approximated total daily hot water use along with the shower load distribution and the fact that the ice rink and washing machine have a fairly even distribution. 8 .Projected Daily Shower Hot Water Distribution 2000 1800 1600 1400 1200 1000 800 600 400 200 0 Shower Hot Water Consumption (L) 8:30 10:30 12:30 2:30 4:30 Time 6:30 8:30 10:30 Fig. installing two more water meters and taking daily readings of the hot water consumption of the zamboni and the washing machines was not feasible. but it was also used to melt the ice in it afterwards.3 Daily hot water consumption of the showers in the PEC. it was discovered that hot water was not only used to fill the zamboni at Jock Harty Arena. the hourly distribution was adjusted as shown in Fig.4. Unfortunately. when the total daily consumption was tallied. Due to time Talking to restrictions. PEC employees. it was determined that the washing machines are used fairly consistently Talking to the PPS maintenance crew. Again the load was determined to be evenly distributed. the ice is flooded every 50 minutes throughout the day. 4 Daily hot water consumption distribution for the PEC 2 5:30 7:30 9:30 11:30 2 Estimated 9 . 3.Daily Hot Water Use Distribution 8000 Hot Water Consumed (L) 7000 6000 5000 4000 3000 2000 1000 0 7:30 9:30 11:30 1:30 3:30 Time Fig. shallow stipple pattern ingrained in the glass.1. The goal was to mounting structure would be a huge expense.000 psi 60 ft/sec differences of 200°F .300 ° F iron content and ensures high transmission with low reflection of sunlight and results in To prevent thermal loss. as the old system. Annealed Glass Typical Breaking Stress (large light 60 sec. 10 . Table 4.0 SYSTEM COMPONENTS 4. keep as much from the drain-back system as possible to reduce costs.1). This reduces reflectance and gives the Tempered glass is used because of its durability against the It has low elements like hail and rain while maintaining transmissivity (see Table 4. glass a frosted appearance. The new system. impact normal to surface) Resist Temperature Differences 6.1 Solar Panels The solar panels are at the heart of the water heating system.1 Strength of annealed glass and tempered glass. The mounting structure supports two rows of panels totaling 150 panels connected to form an array with a total area of 293 m2. load) Typical Impact Velocity Causing Fracture (1/4" light 5 gm missile.4.000 psi 30 ft/sec Tempered Glass 24. 4. the rest of the case used to house the panels is constructed of aluminum with fiberglass insulation behind and on the sides of the panel. One attribute of glazed thermal The glazing has a panels is that the cover of the panel casing is made of tempered glass. Specialists were contacted to examine the existing mounting structure on the roof of the PEC. an increase in collector efficiency. will have panels installed facing south at an angle of 45° where optimal sunlight could be achieved. They concluded that this component of the system was still in good condition This greatly reduces the cost as replacing the and should be kept in the new system.1 Panel Design and Function The PEC panels are glazed solar thermal panels. diameter of 3/8 of an inch. Fig. Copper tubing with a The innards of the panels are constructed of copper tubing in a serpentine configuration (see Fig. Ontario and its yearly average sun exposure. due to the geographical location Kingston. However. Typically.They will be retrofitted with rubber gaskets all around the case.1) bonded on a stainless steel backing.1 Schematic of the solar panel. 4. copper tubing in serpentine arrangement is considered inefficient because the temperature of the solution in an average collector will be higher due to the repeated passages through the collector. The panels will also have headers on the top and the bottom of the panels for the glycol solution to feed through panels. 4. multiple passes through the collector would benefit the system and increase the average temperature of the glycol solution. This will be custom made by the installers and will provide a decreased potential for failure. The stainless steel backing of the panel is selectively coated with a solution to maximize heat 11 . is used in the panel and it is a very good conductive material. industry standard panels of dimension 4 ft by 8 ft. prevents water temperatures at the showers from scalding users. The materials used in constructing the panels will help Panel design and manufacturing is a product of Enerworks Inc. A collective agreement was reached to retrofit the old cases instead of creating new cases with This would ensure that the panels would all fit in the mounting rack and the area would be maximized for solar radiation 4. When the differential temperature between the tank and the glycol solution at the panels is greater than 8°C the system is then turned on. maintain durability. As mentioned earlier. one taken at the water storage tank and one at the solar panels. Since the drain-back system used panels with dimensions of 3 ft by 7 ft. One of the challenges for this project was deciding what existing equipment could be reused in the new system.absorption and retention. is mixed with the maximum temperature hot water before going to the showers. This Monitoring these 12 . the number of casings fit perfectly into the mounting rack. ON. the casings for the panels are still in good condition. The cost of retrofitting custom panels into the existing casings and using industry standard cells in new casings was investigated. was to determine the condition of the existing panel casings. One is the ORCA control system by Delta Controls and the second is Delta-T model Differential temperature thermostat by Heliotrope Thermal. been unused since 1990. absorbtion. The measurement at the tank The cold water also ensures that if the water leaving the tank exceeds a maximum temperature of 50°C a 3-way valve is turned on and cold water in introduced into the system. from Dorchester. In the PEC system we are only concerned with two temperature readings. the mounting rack was the first The second challenge Although the panels have piece of equipment that could be brought into the new system.2 Control Systems Two types of control systems were investigated for use in the PEC solar heating system. These two elements were kept to reduce costs as well as to make sure the new panels would accurately fit onto the mounting structure. control wiring would have to run from the differential points to the basement panel. the control system would need to feed through the building from the control points (storage tank and panels) to the basement of the PEC where there exists a control panel capable of monitoring the system. to implement this into the PEC ORCA control system for The Delta-T is easy to implement and requires little to no monitoring. is all inclusive and is However. The ORCA system is the control system currently used to monitor all systems in the PEC. monitoring would cost $800-1000 as the Delta-T would have to have a feed into the main The cost of installing and purchasing the Delta-T is highlighted in the financial section of 13 . located in the basement is simple to wire into the system. The control point on the roof where the panels are would require cables to feed from the roof. programmable dip switches (see Fig. For the ORCA system to be implemented. 4. through a panel in the mechanical An additional panel would have to be added to the existing control panel and the two differential points would have to be programmed into the system. system to turn on or off. Mike Finn from the existing control system in the building. control panel. The Heliotrope Thermal Delta-T is designed specifically to monitor solar heating systems. ORCA was investigated because it use into the PEC system would conform to After consulting with Mr. Currently the ORCA system used in the PEC is no longer available by its manufacturer Delta Controls. this report. It is a compact module and can be attached right to the water tank and controls The Delta-T has the system based on the two temperature differential points. The storage tank. Physical Plant Services.points will also ensure that the system is shut off at the appropriate times as to prevent freezing of the system. This would cost the project approximately $1000 to implement. room and into the basement.2) that can be set at a certain temperature for the This control system is easy to implement. cost effective. it is likely that the flow rate is reduced and fouling. occurs.3 Heat Exchanger The heat exchanger was selected using the SWEP SSP CBE simulation software. which is well within normal heat exchanger operating parameters. along with the SSP CBE simulation software data. is assumed in specifying the heat exchanger that minimizes the heat exchanger 4. array and the heat exchanger. with the pipe sizes and lengths of the drain-back system. 4. Product specifications are shown in Appendix C. a process where minerals and impurities clog the heat exchanger inhibiting the flow and heat transfer. and the pressure loss per 14 . taking into account the flow rates and desired effectiveness. When using an undersized heat exchanger. both of which are obtained using simulation software called WATSUN. an average temperature and the heat transfer coefficient will also be reduce. The heat exchanger selected is a SWEP B65H X150. It is recommended that the Heliotrope Thermal Delta-T be used in the PEC system.4 Pumps Using a flow loss analysis in the piping system. the pressure loss increases Therefore. Specifying a heat exchanger is difficult When utilizing an because it relies on the values of the inlet and outlet temperatures to optimize operation. which consists the power needed for two pumps. inefficiency. these temperatures vary over a wide range. The first one is to pump the propylene glycol solution through the circuit that contains the solar collector A basic pressure loss of 30 kPa is assumed for the heat Along exchanger.2 A schematic of the Delta-T programmable dip switches. For solar panels. 4. the pumping power required is approximated.Fig. oversized heat exchanger. the specific design parameters for the pumps are specified which include pump size.7 kW or 5hp (at an efficiency of 60%). impeller size and efficiency. Using these charts. Appendix E. When sourcing heat exchangers. the input parameters. and the centrifugal pump charts. The second pump is to pump the water in the storage tank up to the heat exchanger and back With the same heat exchanger pressure loss. two Goulds Pumps are selected. power used. the pumping power is found to be 650 W or about 1 hp (at 60% pump efficiency). This flow rate and piping loss method calculates the In reality. which is calculated to be 20 kPa from the design data. Product specifications and pump charts are shown in 15 . a pump must be found which matches theoretical pumping power required. The two pumps recommended are Goulds 3656/3756 S Group models 4BF1J1H0-5 Hp and 4BF1H1k0 3Hp. as shown in Fig.3. the flow rate for the second pump is adjusted to 8 kg/s with negligible performance effects. lengths and sizes of pipe from the drain-back system. 3.collector. The two parameters used for pump selection are flow and head The flow was determined previously and the flow loss analysis determines the Using this information head loss (the values were then converted to pumping power). loss.5 kg/s as before. the overall pumping power for the first pump is found to be down. 4. and a flow rate which at first is assumed to be 10. 4. 4. 16 . The original piping will be slightly altered to accommodate the proposed two-loop system.5 Piping System It is decided that the existing pipes that were used for the drain-back solar system will be used for the proposed system.Fig. Slight alterations must be made in order to run glycol from the collectors through a heat exchanger and also to run water form the storage tank to the heat exchanger.3 Centrifugal pump chart. which incorporate variables assigned by the user. along with weather data obtained from a weather file to create an output file that displays the energy absorbed.” with eight sections which require different input variables.5. area per panel. The output can be set to display yearly. The PEC Project arrangement contains eight groups of solar collectors in parallel. the year analysed and length of detailed analysis. The weather file used in the simulation for the PEC project was the 1994 readings taken in Toronto.6 m2. Ontario by 2005. 292. 5. the simulation ran with a detailed analysis for 365 days.1 Simulation Data This section contains the initial parameters for the simulation such as simulation length.95 m2 giving a total area of Due to the limitations of the software. indicating the overall energy savings and efficiency. the simulation for PEC had to 17 The main data includes the solar collector arrangement and orientation. Its purpose is to evaluate the performance of thermal systems that incorporate solar panels by determining the economical feasibility of such projects. and the pumping . mass flow rate through the collectors. Ontario. and lost from the particular system. The following describes each of the sections. consumed. six of these groups contain 19 solar panels each. Mines and Resources Canada. For the PEC project. The program uses the simulation data. power required. The simulation for the PEC project was run with the system type “Domestic Hot Water System With Storage and Heat Exchanger. monthly or hourly performances of the system. 5.2 Collector Data for Group A This section contains the information used to calculate how much energy the solar collectors absorb from the sun. As previously mentioned. Every panel has an area of 1.0 WATSUN WATSUN is a DOS-based simulation program developed by the University of Waterloo with the support of Energy. the other two each contains 18 solar panels. There is a set of predefined system types. which is assumed to be a fair projection of the weather in Kingston. approximate the arrangement as eight groups of solar collectors in parallel. The PEC currently has three auxiliary tanks and one storage tank. This gives a total area of 296. This includes the collector parameters. 45o. 5. The eight collector groups are all orientated so that the panels face the east and have a tilt angle of The flow rate was altered to find the optimum position. contains information used to calculate the amount of energy the collector absorbs from the sun. the more energy is absorbed by the panels and expended by the pumps.3%. It includes the sizes and heat loss factors for the storage and the auxiliary tank as well as the maximum temperature values for the tanks. The PEC project will only utilize one collector type therefore this section is not applicable. head loss during flow through the system. Since the proposed collectors are custom-made. approximated values were used. The auxiliary tank temperature is a standard value set by Queen’s University. pumping power required was found using a piping loss spreadsheet that approximated the 5. a supplier of propylene 5. These parameters are ideally determined by manufacturer test results. with 19 solar panels per group. 18 . like the last. incidence angle modifiers and specific heat of the collector fluid. the higher the The flow rate. an error of 1.4 Collector Data for Group B This section contains data for another collector type for systems that use more than one collector type. The heat loss coefficients were found based on the standard values of well-insulated pipes and tanks.4 m2.5 Tank Data This section contains the information used to determine the amount of energy stored and the heat loss from the tank.3 More Collector Data This section. The propylene glycol solution was obtained from Dowfrost. and the storage tank maximum is simply set to the point before evaporation occurs. The collector parameters were based on standard values obtained from other products. glycol-based heat transfer fluids. Generally. collector outlet surface area. a rough estimate of the hot water consumption was determined for the PEC. The heat loss coefficients were assigned as common values for insulated pipes indoor and outdoor. The Surface area of the pipe was calculated using the known pipe diameters and lengths from the system schematics. It includes variables such as the collector inlet pipe surface area. It accounts for monthly. the cost of the heat exchanger and the pressure loss must be considered to find the optimum effectiveness. and the temperature of the water. and the indoor and outdoor heat loss coefficients. With meters and utilities information. 5.6 Heat Exchanger Data This section contains parameters used to determine the amount of energy transferred from the solar panel loop to the storage loop. 19 . fraction of outlet surface area outside. and even hourly distributions. storage fluid.7 Pipe Data This section contains the parameters used to determine the heat losses associated with the transportation of fluids delivered to the storage tank. It includes the heat exchanger type. its effectiveness. fraction of inlet pipe surface area outside. The effectiveness is varied to find an optimum point.5.8 Load Data This section contains the information to calculate the amount of hot water needed. weekly. While increasing the effectiveness will increase the energy the collectors transfer to the domestic hot water load. the flow rate in the storage tank and the specific heat for the 5. 24tons of CO2 a year. Of the systems included. It is available for free at the RETscreen International Renewable Energy Decision Support It uses a variety of tools to allow users to better analyse the technical and financial possibilities of projects.cleanaircanada. REDI is a $24 million program run by the government. up to a maximum refund of $80. RETscreen is an international renewable energy project analysis software. From an environmental standpoint the new solar panel system will lead to a reduction in 20 . Having the solar panels on top of the PEC refurbished will promote Queen’s University and the city of Kingston as leaders of renewable energy. The basic idea behind the emission credits is to achieve a A company can bank or sell to other companies the However. but CleanAir Canada is continuing to review and to register these types of emission reduction projects. requirements for incentives.org). Emissions Trading Regulation does not include reductions of CO2 or other greenhouse gases. CleanAir Canada is an organization which promotes the reduction of emissions in Canada by “assisting business and government in the validation. Centre and seeks to promote the deployment of renewable energy systems. the Ontario set limit of emissions in Canada.6. amount of emissions that it has under its target emission. A complete RETscreen financial summary is found in Appendix F which projects a reduction of 6. using solar energy to provide some of the energy needed reduces emissions of greenhouse gases and other pollutants.000. active solar hot water systems such as that of the PEC meet the Though Natural Resources Canada is currently re-evaluating the program and its objectives. verification and registration processes required to transact offsets in Canada against required obligations” (www.0 ENVIRONMENTAL BENEFITS Not only does solar thermal power make use of a renewable natural resource which is readily available. designed to stimulate the demand for renewable energy systems for space and water heating and cooling. funding details for future years depend upon the results of an independent review which are expected by the end of April of 2004. businesses are eligible for a refund of 25 percent of the purchase and installation costs of a qualifying system. To encourage the private sector to gain experience with active solar and large biomass combustion systems. which translates to $8 260/yr. financial calculations can be made to determine if this is a worthy investment from a quantitative standpoint. Rick Rooney is an Energy Systems Specialist from Quantum Renewable Energy Inc.0 FINANCIAL EVALUATIONS The control system we recommended to purchase is from Heliotrope Thermal. Sensor Wire. They supply the following items: Differential temperature control. inflationary expectations and approximated rises in energy costs have not been included in the calculations. this will generate yearly savings of 643 GJ.model number 3656/3756 S Group. this effort will help position the university in the minds of the public as being dedicated towards improvement and sustainability. however this figure is in US dollars. Regarding technology. Rooney has quoted a price for the installation of $35 200. This brings this project. 7. Using an exchange rate of 24. The impact these attributes have to our result is negligible. Standard project costs to be added include the need for scaffolding.15. With the total installation costs now finalized.40. When converting to Canadian funds our costs increase to $2 365.44 The heat exchanger being recommended can be found and $1 972. and Repair These items from Heliotrope total $331. the total cost to install this project is $71 780. and Queen’s can boast an environmentally friendly conscious to the public.75 respectively. For simplicity.99 and $1 482.00. disposal and acquiring a plumbing permit. barring an extreme economic 21 . a company based out of Richmond California. The pumps selected (Goulds Pumps.88% these costs will increase to the costs of equipment and installation to a total value of $52 950. After adding a 10% contingency and a 15% tax rate for purchase of goods and services. With the assumption of a 25 year project life for the new system.99 USD. Brass Check Valve. It is a local firm based in Kingston and has submitted a bid for the installation of Mr. models 4BF1J1H0. $441. Sensors. locally at a cost of $8 046. Physical Plant Services has quoted a price of $4 500 for these expenses based upon past experience. items for Draindown Valve.greenhouse gases. and 4BF1H1k0) are also purchased from the US at prices of $1 776. 25 years.57% over the same time period. and internal rate of return for our investment that is well recommended from a financial standpoint. payback period. Given the above data concerning our initial investment and the amount saved each year. IRR = 9. $100 today is worth less a year from now. 8 months). Due to inflation. All figures still represent this as an attractive investment. if NPV is equal to zero then one will have to consider other reasons to make the investment as this is a point of indifference.crisis.75%. the Net Present Value (NPV) of that venture must first be evaluated. Two other calculations of interest are the payback period and internal rate of return. and when an NPV is negative the Accordingly. potential investments. NPV is defined as the present value of an investment's future net cash flows minus the initial investment. This is used as a comparison tool with other The IRR for this project is currently an astounding 10. It is clear that after considering the net present value. This means another investment would have to be located in the market that generates a return of 10. N. Expected annual maintenance costs for the system have been estimated at $500. The internal rate of return (IRR) is defined as the rate of return that would make the present value of future cash flows plus the final market value of an investment equal the current market price of the investment. investment results in a positive NPV it should be made. Payback Period = 9.57%. This calculation (NPV) takes into consideration the time value of Anytime an money and helps us to understand if it is a worthwhile investment. this investment is very much worth our while from a financial standpoint when using a net present value approach. we are presented with the following results: NPV = $11 044. Should this figure be subtracted from our annual energy cost savings. it can be found that the payback period is approximately nine years (8 years. When deciding upon any investment. in order to consider reallocating the money. 22 . and it can be reasonably expected that the Bank of Canada will continue with its monetary policy of keeping inflation between one and three percent on an annual basis. Based upon a pessimistic discount rate of 8% the NPV for this project is $16 390. which is well into the positive range. Clearly.B. investment should be avoided. 23 .A summary of the total costs as well as a graph of the payback period are found in the following two pages. disposal. refit.000 $2.500 $10.Table 7. Equipment & Installation Costs Panel removal.1 Summary of the total costs.600 $2. equipment rental* Absorbers ($150 each) Internal plumbing* SAS-10 Sensors Sensor Wire Brass Check Valve Repair Items Valve kit.000 $800 $2. model 4BF1J1H0 Pump style 3656/3756 S Group.000 $2.740 $500 * . O-rings.000 $500 $4. Replacement of O-rings Differential Temperature Control Mixing Valve* Monitoring Heat Exchanger SWEP Type B65HX150/1P-SC-S.000 $8. 4x2-1/2" NPT.940 Total Before Taxes and Contingency Tax 15% Contingency 10% TOTAL Expected Annual Maintenance Costs $57.000 $52. P/N 11487-220 Pump style 3656/3756 S Group. and replacement* $75 labour / panel.600 $5.Quoted values 24 . 144 panels Set up. model 4BF1H1k0 Integration Costs with PEC Controls General Installation Costs Total Equipment & Installation Costs Standard Project Costs Scaffolding Disposal Permits Total Project Costs $2.440 $8.000 $30 $40 $50 $130 $190 $1.800 $800 $21.400 $2.100 $1.700 $71. 25 .200000 150000 Savings (Costs) 100000 50000 0 0 -50000 -100000 Years 5 10 15 20 25 30 Fig. 7.1 Payback period of the proposed system. REDI. the major milestones were met during the course of the last eight months. to the project would reduce the cost up-front by a great margin. this task can be made easy by arranging for the PEC exchangers should be further researched and studied in detail. Meters can be If possible. Firstly. more accurate recordings of the loads should be made. solar panels. the selection of the heat Thirdly. since their contribution 26 . analysis in the piping system should also be investigated in depth.8. it is important Some recommendations are suggested prior to the implementation of the the three loads should be made. to confirm the status of the government funded program. installed to track an accurate hot water consumption. the flow loss Lastly. employees to take hourly or at least daily readings. year-long readings of Secondly.0 RECOMMENDATIONS Though time constraint was the main factor hindering the team’s goals as set out in the beginning of the project. over time. especially ones that This can positively contribute to the image of Queen’s. through the results acquired by calculating the net present value. but an attractive investment. internal rate of return. environmental. This is an impressive Few facilities move forward by the university and helps position it in the minds of the public as an institution dedicated towards continuous improvement and sustainability. there are both quantitative and qualitative aspects to consider. Financially. lead to a reduction in greenhouse gases. and technological. Queen’s can expect to receive monetary compensation from the selling of these recently acquired emission credits. and the benefits of such contributions will be seen 27 . Qualitatively. are to be relied upon on a daily basis. This leads to the third aspect which concerns technology. Quantitatively. From an environmental standpoint. the university will be able to boast an environmentally friendly conscious to the public through efforts such as the solar panel system. our studies have shown that This has been determined this is not just a feasible. and payback period. of this size are capable of successfully implementing such systems.0 CONCLUSIONS There are three key aspects to be evaluated before undertaking this project: financial. there is a market being established in the near future As the new solar panel system will for the trading of greenhouse gas emission credits.9. Queen’s University. Queen’s University Physical Plant Services Ms. Physical Plant Services 28 . Larry Dougan – Foreperson. Arena and Stadium. David Moody – Advisor. APSC 400 Mr. Eric Neuman .TEAM Project Instructors Dr. Dale Dilmarter . Stephen Harrison and the Solar Calorimetry Lab . Queen’s University Mr. Barry Jackson.Client.ACKNOWLEDGMENTS The APSC400 PEC Solar Team would like to thank the following individuals for their invaluable contributions to our project over the past year: Mr. Quantum Renewable Energy Mr. Herb Steacy – PEC Facilities/Services Manager. Rick Rooney – Energy Systems Specialist. Mr. Mike Finn. Department of Mechanical and Materials Engineering Mr. Annette Bergeron. Dr. Queen’s University Athletics Mr. Dewitt. from http://www. 2. F. M.Shapiro. H. Swep A Dover Company. 9. Moran. Natural Resources Canada. New York: JohnWiley & Sons.asp. Munson. from http://www.cleanaircanada. 2004.net/ang/menu. CleanAir Canada.. 1998. D.. New York: John Wiley & Sons.org.watertanks.. Water Tanks. 7.swep. 1996. Retrieved March 8. Fluid Mechanics 4th Ed. The Dow Chemical Company. 10. Okiishi. 1986. University of Waterloo. from http://www. 1999. 2004. 8. Fundamentals of Engineering Thermodynamics 4th Ed. B. 29 . Watsun User Manual and Program Documentation. Incropera.. White. Fundamentals of Fluid Mechanics 3rd Ed. 2000. Retrieved February 14. 6. Retrieved on March 15. 2002. New York: John Wiley & Sons. 3. T.REFERENCES 1. Toronto: WBC McGraw Hill. Muson. 4. 2004. Retrieved on March 20. Watsun User Service. Introduction To Heat Transfer 4th Ed. F. 2004.se/.retscreen. from http://www.php. B. Dowfrost Engineering and Operation Guide.com/products/0516-080. 5.