Andrew Lau

Net Energy Analysis for Sustainable Energy Production From Silicon Based Solar Cells

A number of detailed studies on the energy requirements on the three types of photovoltaic (PV) materials, which make up the majority of the active solar market: single crystal, polycrystalline, and amorphous silicon were reviewed. It was found that modern PV cells based on these silicon technologies pay for themselves in terms of energy in a few years (1–5 years). They thus generate enough energy over their lifetimes to reproduce themselves many times (6–31 reproductions) depending on what type of material, balance of system, and the geographic location of the system. It was found that regardless of material, built-in PV systems are a superior ecological choice to centralized PV plants. Finally, the results indicate that efficiency plays a secondary role to embodied energy in the overall net energy production of modern solar cells.Copyright

Analysis of the Design and Energy Performance of the Pennsylvania Department of Environmental Protection Cambria Office Building

The Pennsylvania Department of Environmental Protection asked NREL to evaluate the energy performance of the Cambria Office Building to determine if it had met design goals. The focus of this report is the analysis of an integrated design process used to construct the facility and the postoccupancy energy performance. NREL collected energy use and other performance data and compared that data with a standard ASHRAE baseline computer model. NREL used this metered data and analysis to formulate recommendations to further improve building performance.

A SELF-ACTUATING BACKDRAFT DAMPER FOR PASSIVE SOLAR APPLICATIONS

ABSTRACT Natural thermosiphoning of solar-heated air is important for many passive solar applications. It is also important to prevent reverse thermosiphoning at night, often with the use of backdraft dampers. Commonly used plastic film dampers may restrict air flow. Therefore, this project developed a novel backdraft damper that utilizes bimetal coils to actuate a conventional metal damper. Two prototype dampers were tested in the upper and lower vents of a thermosiphoning air panel. The upper damper opened fully on sunny days, but partial opening of the lower damper reduced collector efficiency by 19%. A single upper damper should minimize reverse thermosiphoning. Future efforts will study the performance of plastic-film dampers and a single, bimetal-actuated damper in the upper vent.