Solar System Performance Evaluation Research Articles

Review of an innovative thermal and economic model of a thermal solar source

This paper presents an innovative calculation method that simplifies the present calculation in the existing Romanian solar methodology, but also brings a new approach to the problem of determining the actual efficiency of a heating system using solar panels during the actual hours of sunshine. This new method will also make better economical estimations by including a new calculation method that is adapted strictly to solar panels applications. Both proposed methods, include a new approach of determining the thermal and economic indicators faster or more precise. The results shown in this article, validate the new calculation method and offer new perspectives on real-time hourly solar system performance evaluation. Those results show that although the actual hourly efficiency of the solar panels increases over a small period of time, daily system efficiency that includes the consumer’s heating needs, decreases due to the limitation of the required thermal energy over a longer period of time that exceeds those sunshine hours. This paper provides a new vision regarding the way solar systems are treated and suggests some adjustments that need to be made in calculating the solar systems. Thus, due to a considerably higher heat input over a given period of the day, it is concluded that these systems work much better in the case of extra storage of this energy (larger storage tank) or by adjusting the indoor temperatures (through automation) during this solar charging regime.

Long-term stability and performance of solar system instrumentation

SYNOPSIS In an attempt to improve the quality and reliability of methods used for long-term performance evaluation of solar systems, detailed information is provided about the long-term (typically 2 years) performance and stability of a relatively large number of instruments used in the performance monitoring of a well-instrumented solar heating project. The calibration methods are also described. The instruments include resistance temperature detectors, several types of flowmeters, wattmeters, pyranometers, wind anemometers, a humidity meter, a barometer, differential temperature solar system controllers, and an automatic data acquisition system used to scan, convert and store the data. Recommendations for good instrumentation of solar systems are also provided. It was found that the critical instruments for performance evaluation, and most of the instruments overall, have performed very well over the long term, allowing thermal performance evaluation with an accuracy better than 3% with only one calibra...