MITIGATING VARIABILITY OF HIGH PENETRATION PHOTOVOLTAIC
SYSTEMS IN A COMMUNITY SMART MICROGRID
Mohammad B. Shadmand and Robert S. Balog
*
Department of Electrical and Computer Engineering, Renewable Energy & Advanced Power
Electronics Research Laboratory, Texas A&M University, College Station, TX 77843, USA
*Presenting Author (Ph: 979-862-4985; Email: rbalog@ece.tamu.edu)
ABSTRACT
Interest in renewable energy generated electricity continues to gain popularity. However, two fundamental limitations exist that prevent widespread adoption: variability of generation and cost of the equipment. Distributed grid-tied photovoltaic (PV) systems with centralized battery back-up have been proposed for community-scale microgrids. In addition to improving electricity reliability for the microgrid, this concept also mitigates the variability of the renewable resources as seen by the utility. Thus a neighborhood designed with distributed PV and centralized battery storage is an attractive technology solution for communities to "go green” without compromising reliability of the electric utility. The downside is the cost of the equipment needed for the PV and battery grid interface. Optimization of generation, storage, and mitigation of variability is imperative to the financial feasibility of such microgrid systems.
The focus of this project was to develop design methodology that minimized the variability of a high-penetration PV scenario using the microgrid concept. The case study was a
27.6 kW PV system installed on Texas A&M campus, a system configured as five residentialscale arrays. Electricity generation data is sampled every 10 seconds which provides a dataset with far greater temporal resolution than used in most PV sizing and economic studies. The result shows that the variability of high penetration PV is not as large as if the PV was centrally located and that only a small amount of community energy storage is needed to arbitrarily mitigate this variability as well as reduce energy intensity through demand reduction including peak shaving and demand shifting. The presentation will explore these concepts by examining the optimization methodology and discuss the dataset and results of the study.
The campus PV array was a Department of Energy sponsored collaboration between the PI and the TAMU Athletics Department. The location of the array, adjacent to Kyle
Football Stadium and visible to 83,000 game day spectators, is strategic to support the community outreach mission of the project to educate the public about the science behind renewable energy. The presentation will also showcase how the PV array is incorporated in the classroom to teach interdisciplinary students about renewable energy technology.
Keywords: photovoltaic energy, solar energy, optimization, community outreach, smart grid