• Energy Research

This factsheet gives an overview of the Photovoltaic (PV) Technology Incubator Awards and the Solar America Initiative (SAI).

This factsheet gives an overview of the Photovoltaic (PV) Technology Incubator Awards and the Solar America Initiative (SAI).

Photovoltaic (pv) devices are encapsulated in polymeric materials not only for corrosion protection, but also for mechanical support. Even though ethylene-vinyl acetate (EVA) suffers from having both glass and melting phase transitions at temperatures experienced under environmental exposure, its low cost and good optical transmission made EVA the most commonly used material for PV modules. These transitions, however, cause EVA to embrittle at low temperatures (~ -15 deg C) and to be very soft at high temperatures (>40 deg C). From mechanical considerations, one would prefer a material that was relatively unchanged under a wide temperature range. This would produce a more predictable and reliable package. These concerns are likely to become more important as silicon based cells are made thinner.

Photovoltaic (pv) devices are encapsulated in polymeric materials not only for corrosion protection, but also for mechanical support. Even though ethylene-vinyl acetate (EVA) suffers from having both glass and melting phase transitions at temperatures experienced under environmental exposure, its low cost and good optical transmission made EVA the most commonly used material for PV modules. These transitions, however, cause EVA to embrittle at low temperatures (~ -15 deg C) and to be very soft at high temperatures (>40 deg C). From mechanical considerations, one would prefer a material that was relatively unchanged under a wide temperature range. This would produce a more predictable and reliable package. These concerns are likely to become more important as silicon based cells are made thinner.

The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its photovoltaics subprogram.

The fact sheet summarizes the goals and activities of the DOE Solar Energy Technologies Program efforts within its photovoltaics subprogram.

Documentation of the energy yield of a large photovoltaic (PV) system over a substantial period can be useful to measure a performance guarantee, as an assessment of the health of the system, for verification of a performance model to then be applied to a new system, or for a variety of other purposes. Although the measurement of this performance metric might appear to be straight forward, there are a number of subtleties associated with variations in weather and imperfect data collection that complicate the determination and data analysis. A performance assessment is most valuable when it is completed with a very low uncertainty and when the subtleties are systematically addressed, yet currently no standard exists to guide this process. This report summarizes a draft methodology for an Energy Performance Evaluation Method, the philosophy behind the draft method, and the lessons that were learned by implementing the method.

Documentation of the energy yield of a large photovoltaic (PV) system over a substantial period can be useful to measure a performance guarantee, as an assessment of the health of the system, for verification of a performance model to then be applied to a new system, or for a variety of other purposes. Although the measurement of this performance metric might appear to be straight forward, there are a number of subtleties associated with variations in weather and imperfect data collection that complicate the determination and data analysis. A performance assessment is most valuable when it is completed with a very low uncertainty and when the subtleties are systematically addressed, yet currently no standard exists to guide this process. This report summarizes a draft methodology for an Energy Performance Evaluation Method, the philosophy behind the draft method, and the lessons that were learned by implementing the method.

This paper presents a brief overview of the status and accomplishments during fiscal year (FY) 2005 of the Photovoltaic (PV) Exploratory Reliability and Performance R&D Subtask, which is part of the PV Module Reliability R&D Project (a joint NREL-Sandia project).

This paper presents a brief overview of the status and accomplishments during fiscal year (FY) 2005 of the Photovoltaic (PV) Exploratory Reliability and Performance R&D Subtask, which is part of the PV Module Reliability R&D Project (a joint NREL-Sandia project).