Session: 19-04: Symposium to Honor Professor Jane Davidson IV

Paper Number: 167451

167451 - Interesting Solar System Simulations in 1990 and 2025 

Abstract: 

Jane Davidson has a remarkable talent for teaching and modeling the simulation of solar energy systems. As an expert in thermodynamics and transport phenomenon, she integrates practical insights into her lessons, breaking down complex concepts and making them accessible for her students. Davidson utilizes advanced simulation software to characterize and optimizee diverse types of solar energy and thermal energy systems.  Modeling and Simulation allows students to develop and understanding of the performance of complex system and allows them to experiment with different configurations and see important results. Her approach not only deepens their understanding of energy system technology but also inspires them to innovate and explore new solutions for sustainable energy. Through her dedication and passion, Davidson is shaping the next generation of renewable energy experts and advocates.  Jane Davidson was my graduate disertation advisor at Colorado State University from 1987 to 1991 on the topic of "Simulation of 2-Phase Self Pumping Solar Water Heating System." That study is interesting in its approach to modeling the heat transfer and thermodynamics of a complicated cycle.  This presentation offers a brief description of that very early modeling project and then offers a brief description of a more recent modeling advancement "Ditstribution Function instead of Steady State Assumption in Time Series Simulation."  The first part of the presentation will cover the thermodynamics and heat transfer processes involved in the operation of an innovative self-pumping solar water heating system. The system utilizes solar energy to heat water, eliminating the need for conventional pumps through the utilization of a heat-engine actuated by 2-phase working fluid.  We analyze the thermodynamic principles governing the pumping cycles and fluid flow. The resulting model allows optimization of system component sizes.  In the second part of the presentation we will focus on the most recent development of time series simulation by replacing the traditional steady-state assumption with a dynamic distribution function that incorporates minimum, maximum values, and curve shape parameters within each time-step. Our method enhances the accuracy and realism of simulations by capturing the inherent variability and fluctuations present in real-world systems. We detail the mathematical framework and implementation of this distribution function, highlighting its advantages over steady-state models in the application of photovoltaic system simulation and more specifically phenomenon of interest to grid integration.  By introducing a more flexible and responsive representation of time series data, we aim to improve predictive capabilities and provide deeper insights into the underlying processes.

Presenting Author: Howard Walker NREL

Presenting Author Biography: Andy Walker received his MS and PhD in Mechanical Engineering under the tutelage of Professor Jane Davidson at Colorado State University. Dr. Walker currently serves as Senior Reseach Fellow at National Renewable Energy Laboratory and teaches solar energy as an adjuct instructor at Colorado School of Mines.