Date of Graduation

12-2014

Document Type

Thesis

Degree Name

Master of Science in Microelectronics-Photonics (MS)

Degree Level

Graduate

Department

Graduate School

Advisor

Ajay P. Malshe

Committee Member

Gregory Salamo

Second Committee Member

Alan H. Mantooth

Third Committee Member

Kenneth G. Vickers

Keywords

Energy, LCA, Life cycle, Photovoltaic, Renewable energy, Solar

Abstract

With increasing clean-energy demand, photovoltaic (PV) technologies have gained attention as potential long-term alternative to fossil fuel energy. However, PV research and manufacture still utilize fossil fuel-powered grid electricity. With continuous enhancement of solar conversion efficiency, it is imperative to assess whether overall life cycle efficiency is also being enhanced. Many new-material PV technologies are still in their research phase, and life cycle analyses of these technologies have not yet been performed. For best results, grid dependency must be minimized for PV research, and this can be accomplished by an analytical instrument called Life Cycle Assessment (LCA).

LCA is the study of environmental impacts of a product throughout its life cycle. While there are some non-recoverable costs of research, energy is precious, and the PV research community should be aware of its energy consumption. LCA can help identify options for energy conservation through process optimization.

A case study was conducted on the energy demand of a test-bed emerging PV technology using life cycle assessment methodology. The test-bed system chosen for this study was a new-material PV cell. The objective was to quantify the total energy demand for the research phase of the test-bed solar cell's life cycle. The objective was accomplished by collecting primary data on energy consumption for each process in the development of this solar cell. It was found that 937 kWh of energy was consumed for performing research on a single sample of the solar cell. For comparison, this energy consumption is 83% of Arkansas's average monthly residential electricity consumption. Life cycle inventory analysis showed that heating, ventilation, and air conditioning consumed the bulk of the energy of research.

It is to be noted that the processes studied as part of the solar cell test-bed system are representative of a research process only. Life cycle thinking can identify energy hot-spots and help a new lab be set up in a more energy-efficient way. Proactive action based on the results can lead to higher energy return on investment, making emerging PV technologies truly energy-competitive.