1 Campus Wind Resource Assessment Project Summary BACKGROUND The Northwestern Campus Wind Resource Assessment is a project undertaken by the Clean Energy Project (CEP) of Engineers for a Sustainable World (ESW) beginning in Fall CEP is a team devoted to increasing the energy sustainability of campus. ESW - NU supports projects aimed at improving education and implementation of sustainable practices at Northwestern, in the local community, and around the world. By conducting a wind resource assessment, CEP hopes to obtain the technical data necessary to evaluate available technologies for wind power generation on campus. Our findings, in conjunction with local regulations, installation costs, and community feedback, will allow us to present the university with options for the successful, productive, and cost-effective installation of wind turbines. A successful wind turbine installation on campus can add to the university s portfolio of renewable energy sources and help demonstrate Northwestern s commitment to renewable energy. Throughout this project, CEP also intends to publicize this effort through public outreach programs that inform the community about the benefits of wind energy and CEP s efforts in bringing it to campus. METHODS The Northwestern Campus Wind Resource Assessment project aims to generate detailed data for analysis of wind power feasibility. The study has three phases: a planning and preparation phase, an initial survey of four campus rooftops, and a year-long monitoring of the most viable sites. Phase Zero: The initial phase of the assessment included gathering materials for the wind survey, developing wind survey methods, evaluating which roofs to survey (with the help of Facilities Management), and training team members in data collection. This phase took place in Fall quarter With the help of Professor Beddows (EPS) our team identified the Kestrel 4500 Weather Meter as a cost-effective and convenient tool for developing initial wind maps of campus rooftops. The team also worked with Professor Beddows to develop a rooftop protocol for measuring wind resources on each roof. Four 1.5-meter anemometer stands were built to hold our weather meters at a consistent height throughout the study. All purchases during this phase were made possible by the ISEN grant our team received. The roofs to be surveyed were determined with the help of FM. Four rooftops were chosen: Norris University Center, the Jacobs Center, Tech, and SPAC. These locations were ideal because each has an existing lightning ground, adequate unobstructed rooftop space, relatively easy access, and unobstructed wind from the Northeast and Northwest (the primary wind directions as determined by data from the weather station on Scott Hall). Phase One: Each roof was monitored once per week throughout winter quarter from approximately 3:30-4:15pm. Each roof was surveyed on a different day of the week due to FM time constraints and
2 the number of CEP team members available to participate in surveys. In each case, temperature, humidity, and wind speeds were measured on each roof. Wind speeds were measured at 7-11 locations on each roof for 4-5 weeks*, then at the 6-8 locations on each roof which had shown the greatest wind speeds up to that point in the study. At each station, average and max wind speed were recorded. The number of locations was decreased after the first half of the survey in order to increase the length of time that could be spent sampling each location. Initially, average wind speeds were taken over a one-minute interval. During weeks 4-5, eddy variance was assessed on each roof. At one station per roof, average wind speeds were recorded at 15-second intervals for a total of 3 minutes. This data showed that the regular variance in wind due to eddy effects occurs over a timescale longer than one minute. To account for this for the remainder of the study, we extended our sampling times to two-minute averages at each location and decreased the number of locations sampled per roof (based on data collected the previous 4-5 weeks). *Some roofs were not monitored on particular weeks due to unsafe weather conditions. Phase 2: Phase 2 of the assessment, scheduled to begin in Fall 2013, was to choose the most viable rooftops for wind power generation and to install permanently-mounted anemometers on those buildings in order to collect a full year of wind data and make recommendations regarding wind power generation capabilities. This phase was begun this spring, with the installation of an anemometer on the West roof of SPAC. A UGE 1st Step Weather Station (pictured below) was donated to CEP by an Urban Green Energy sales representative in Winter This weather station is intended for long-term installation and weather monitoring. Through discussions with Facilities Management and evaluation of the data collected during winter quarter, SPAC was chosen as the ideal location for installation of this weather station. The appeal of the SPAC roof is largely due to its proximity to two new construction projects - the parking garage to the West, and new athletics facility to the North. Both of these projects hold the potential for wind power to be incorporated into their designs. Therefore, by monitoring wind patterns on SPAC, we could make recommendations regarding the design of wind turbines on either of these new structures. After receipt of the weather station, permission and materials for mounting it on SPAC were obtained, and the setup was constructed in June The weather station is accompanied by a small tablet which also serves as its data storage device. Testing showed that data transmission was inadequate when the tablet is located inside SPAC. Therefore, the tablet was secured alongside the weather station in a weatherproof container on the roof. Data collection will require a CEP team member to access the tablet approximately once per month in order to download the files and Weather Station donated by UGE clear the tablet s memory. We have been granted permission to be accompanied by Facilities Management personnel onto the roof on a monthly basis for this purpose. The last part of Phase 2, to take place at the beginning of Fall 2013, will involve the installation of two more identical weather stations on the roofs of both Tech and Norris. Due to its relatively high wind speeds as measured in Phase 1, the roof of Tech seems to be one of the best spots on campus for wind energy generation, warranting further data collection. On the other hand, we chose Norris as the third site for installation of a weather station because of the possibility of the
3 construction of a new student center at that location. Further data collection at this site will allow us to make recommendations regarding the inclusion of wind turbines on a new structure. The new student center would be an excellent location for the generation of wind power, publicly displaying the commitment of both Northwestern and its students to renewable energy. RESULTS/OUTCOMES: The measurements taken during Phase One of this study allowed our team to draw general conclusions about relative wind exposure on various roofs, and to determine the best location for wind power on each rooftop. The four rooftops that we surveyed are shown below and marked by a red star. *Tech pictured without B-Wing in-fill. Our measurements were taken on this in-fill. Average and maximum wind speeds for each location were averaged over the 6-8 sampling periods, and compared to evaluate the most viable section of each rooftop for wind power generation. The location with the highest mean average speed was chosen as the preferred location for each roof. The values for the best location on each roof can be found in Table 1 below. Average Wind Speed (m/s) Max Wind Speed (m/s) Tech SPAC Jacobs Center Norris Table 1: Average and maximum wind speeds for the best locations on each rooftop, presented as an average over the course of the study.
4 These results reflect our team s general experience in recording data on these roofs. Tech typically had the greatest wind speeds, followed by SPAC, and both the Jacobs Center and Norris received significantly less wind at the locations tested. There are a few potential reasons for this. First, the section of the Norris roof that was sampled was surrounded by a railing that extended approximately one meter above the level of the rooftop. This likely obstructed the wind at our measurement height (1.5 meters). Additionally, Norris and the Jacobs Center have sections of roof that are higher than the level on which we were able to measure. Therefore, walls blocked wind from at least one direction in each case. In contrast, the measurements taken on Tech and SPAC were not obstructed on any sides. Based on this information, we chose an ideal location to place our first permanent anemometer on SPAC. We also determined that a second anemometer should be installed on Tech, based on consistent and relatively high wind speeds. Lastly, we are exploring the possibility of installing the third anemometer on the highest roof of Norris, which we did not have access to during our initial study. On this roof, the wind would be less obstructed and may display significantly greater wind speeds than those gathered in Phase 1. The completion of Phase Two of this study will include an assessment of seasonal and diurnal wind speed variations on all three roofs. This information will then be used to calculate a realistic value for energy generation and payback times for various potential turbine systems. While this study has served as an excellent opportunity for our team members to learn about wind data collection and analysis, it has also allowed us to share our knowledge about wind power with the greater Northwestern community. During Earth week, CEP passed out pinwheels with facts about wind turbines to educate students and faculty about wind power generation and to promote awareness of our study on campus. CEP has also teamed up with a summer SESP course to encourage learning about wind power as a renewable energy source. We shared our data from the Phase One surveys with the course instructors and are acting as advisers on wind data collection and analysis during this upcoming summer. Lastly, with our Phase One data, we are exploring the possibility of developing an on-campus wind map using GIS software. This map could then be used as an educational tool at Northwestern. CEP will continue to gather wind data as we strive to promote wind power as a renewable energy source for Northwestern University through wind studies and campus outreach.
5 Appendix 1: ISEN Grant Budget Grant Received-Fall 2012 $2,000 Anemometers ($897) Year 1 Expenses (Fall 2012-Spring Pinwheels ($37) 2013) Mounting Supplies ($99) Current Funds $967 Year 2 Expenses (Summer Spring 2014) 2x Weather Stations ($250) 2x Mounting Supplies ($200)