Project Examples

Feasibility Study for Photovoltaic Energy System for Greater Lowell Technical High School GLTHS

Course: 22.504 - Energy Systems Design
Semester: Fall 2005
Instructor: John Duffy
Partner:Greater Lowell Technical High School (GLTHS)

Brief Description:

Students partnered with Environmental Science teachers at the Greater Lowell Technical High School (GLTHS) located in Tyngsboro and serves primarily Lowell high school youth (which represents a very diverse population base). Two UML graduate engineering students, Jorge Barrientos and Tanya Martinez, worked with GLTHS faculty and administration to develop a feasibility study. GLTHS partnered with the UMASS Lowell Graduate Engineering Program’s Energy Engineering Workshop course in pursuing the Large Onsite Renewables Initiative (LORI) grant available from the Massachusetts Technology Collaborative (MTC).

Full Description:

Students partnered with Environmental Science teachers at the Greater Lowell Technical High School (GLTHS) located in Tyngsboro and serves primarily Lowell high school youth (which represents a very diverse population base). Two UML graduate engineering students, Jorge Barrientos and Tanya Martinez, worked with GLTHS faculty and administration to develop a feasibility study. GLTHS partnered with the UMASS Lowell Graduate Engineering Program’s Energy Engineering Workshop course in pursuing the Large Onsite Renewables Initiative (LORI) grant available from the Massachusetts Technology Collaborative (MTC). GLTHS serves approximately 2100 students and was interested in conducting a feasibility study for PV, but desired to first prove that it would be a practical investment for the school both economically and educationally. A preliminary PV analysis was conducted that was geared toward maximizing incentives eligible for through the LORI grant. A preliminary design proposal was generated based on recommendations, site, structure, and cost.

This study included: (1) Site analysis; (2) Energy analysis; (3) Hardware analysis; (4) Cost analysis; and (5) Additional Recommendations. Highlights from the study and report follow next.

Gas heating provided by Keyspan; electricity provided by the National Grid for the GLTHS are under consideration for changes over the next fiscal year. GLTHS recently converted 80% of their electric heating system to gas; the remainder will be converted over the next five years. A feasibility study was conducted for a cogeneration plant and was deemed not feasible because the payback time calculated was 10 years and required a substantial initial investment.

The HVAC systems were modified about 10-12 years ago; they have a SEER rating of 10. The café, testing center, guidance office area, and at least a dozen classrooms are heated by univent heat pumps; yet the heat pumps are constantly being replaced. There is no HVAC available in the plumbing and electric rooms. The most attractive system to the school committee was the 28kW awning system; it is a decent sized system for the school, and the total energy contribution would increase as the energy efficiency of the building improves. The following is a summary of all recommendations made for the school and committee:

  • PV system size of 28.8 DC kW
  • Installation areas selected that all face south:
  • Pitched roof facing
  • Directly above classroom windows
  • The Flat roof over the gymnasium
  • 96 PV modules ASE-300-DGF/50 in End-Mount (Landscape) configuration.
  • Orientation: tilt angle of 45º for the pitched roof, 35º awning sub arrays, and tilt angle of 15º with 0º azimuth facing south for the flat roof sub array.
  • Electrical distribution: twelve 8-module string
  • Physical distribution: four 8-module string in the pitch roof, one 8-module string as awnings and seven 8-module string in the flat roof.
  • 1 inverter of 15 kW for the pitch roof and awnings, and 1 inverter of 20kW for the flat roof
  • Energy production of 39.726 AC MWh per year.
  • Annual energy savings of $4648.00

An Energy Monitoring and Data Acquisition System was also recommended to track the electrical performance of the system and to allow student interaction with the system. GLTHS could incorporate the PV system into their courses related to electrical, mechanical, environmental or energy sustainable topics. A comprehensive report and presentation was provided for the school and committee. The report was also used as the basis for funding requests from MTC LORI grant. The school committee was so impressed with the study and report that they are considering funding aspects of the study recommendations.

Community needs met:

The report was used as the basis for funding requests from a Massachusetts Technology Collaborative (MTC) LORI grant program.