In 2011 Alex Barajas, Zion Environmental Protection Specialist, and Matt Mackay, Zion Electrician, attended an Introductory PV class at the Grand Canyon. After learning of the installation class conducted at Glen Canyon in early 2012, Alex pursued bringing a class to to Springdale, UT. Zion is a Climate Friendly Park and their Visitor Center was constructed in 2000 through a partnership between the Department of Interior and Department of Energy using the most energy-efficient technology available. Neighboring cottonwoods have grown over the past decade, shading some of the VC’s solar panels and Alex’s plan for a class project was to move the system to increase the system’s production.
A second project involved installing a small PV array to power trail lights leading to the concessionaire’s transportation facility. The conventional wiring had failed and rather than tear into the pavement to replace the wiring, it was decided to take the lighting off-grid. As a temporary measure, a solar-trailer usually used at back-country ranger’s quarters was brought in to power the lights.
There were two participants from Zion; the other eleven trainees were from other Intermountain and Pacific West parks and all received travel scholarships from Learning and Development, which totaled $6,600. Dormitory housing was made available and L&D also paid all associated housing costs.
Six of the class participants hadn’t attended a previous introductory class and instead took part in an inaugural online training conducted by Coconino College.
Alexandra Wright, Director of Corporate and Community Learning, provided a brief welcome and orientation to the class. After introductions and a review of students’ expectations, Joe Costion reviewed many different applications and installations for photovoltaic technologies.
After lunch the group moved out to get an overview of the week’s projects and to assess potential sites for future arrays using a Solar Pathfiinder. Barajas is developing a “shovel-ready” project to install another array on a shade structure at the shuttle bus parking area and it provided a practical application for site and designDan talked about the fundamentals of site analysis. A sun chart for a specific location can be created at http://solardat.uoregon.edu/SunChartProgram.html
Kirk Rose, ZION HVAC technician, provided an explanation of the Visitor Center’s unique design which utilizes a combination of trombe walls, cooling towers, passive solar and natural ventilation which allows the VC to remain at 74 degrees when outside temperatures are well over 100 degrees. A building automation system monitors the conditions and responds to keep the building comfortable while using minimal energy to do so.
A quiz first thing in the morning provided a review of all of the concepts covered the previous day, including understanding siting issues (azimuth, angle of incidence, polar south vs. magnetic south), and comprehension of series vs. parallel wiring to achieve specified voltage and amp hours. Lecture covered creating a line-diagram for a grid-tied system. Components were discussed in depth looking at the Park’s 25kW array and at CCC’s PV trailer.
The class divided into two groups and went through the process of planning the grid-tied system and the off-grid system. Some of the resources utilized were:
NREL Renewable Resource Data Center provides access to an extensive collection of renewable energy resource data, maps, and tools.
PV Watts Site Specific Data Calculator to estimate annual energy production and cost savings for a PV system
Fronius Configuration Tool for determining possible system configurations based on inverters and environmental conditions
PV Watts Viewer to view a map and easily locate geographic and energy usage data.
Inclement weather forecasted for later in the week prompted the instructors to alter the schedule and do the project installation a day early. Before going out in the field the students reviewed their job plans, completed a Job Hazard Analysis and reviewed the GAR factors of operational leadership.
Nine students and two instructors worked on the grid-tied system: the posts were cut to proper height to ensure the optimal angle for energy production. The students measured and installed the mounting struts, pulled the wires from the AC disconnect to the inverter and installed and connected the 12 panels and the inverter by the end of the day.
The group of four students working on the off-grid system determined the correct angle for the 2 panels, prepped and mounted a battery box, connected the panels to the inverter.
The group debriefed the previous day’s work and reviewed the concepts of line vs. load and how the AC-disconnect as applied to the grid-tie system. Costion presented a session on batteries: types of batteries, maintaining them; safety issues; making battery cables, etc. A variety of training videos are available from Trojan Battery .
The off-grid group completed connecting the charge controller while the remainder of the students continued practical skills development by assembling two different systems provided by the CCC. An afternoon lecture covered mechanically integrating a PV system onto a roof as well as fall protection.
Kelly demonstrated the online monitoring resources provided by one micro-inverter manufacturer, Enphase Energy. Micro-inverters prevent a whole array from going down when some of the panels are in shade and not producing energy. She also reviewed different components and pricing from http://www.civicsolar.com/ David Cain finished out the class with a lecture on electrical theory.
When asked what the greatest benefit of the class was, students responded:
- the hands-on work; seeing and feeling the hardware and components solidified their knowledge
- The positive atmosphere with all the students engaged and eager to learn and the more experienced participants provided additional guidance to those new to electrical work.
- There was a great deal of pride in seeing a quality project completed by NPS employees rather than having to rely on contractors for all the work.
Feedback for the online class was mixed. One person said they felt more comfortable with the information because the online class was immediately before the field training. There was difficulty because work emergencies interfered with their ability to focus on the course.
Another hands-on course will be offered in the spring at Glen Canyon and will have a battery maintenance component.
- Solar Pro Magazine http://solarprofessional.com/home/
- Federal Energy Management Program Webinars http://apps1.eere.energy.gov/femp/training/
- Free Online course in DC Circuit Theory: https://gm2.geolearning.com/geonext/doi/ coursesummary.CourseCatalog.geo?id=88511
- Sustainable Historic Preservation: http://www.wbdg.org/resources/ sustainable_hp.php
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