Renewable Energy – March 2019

Zvi Baum, Ruslana Rachel Palatnik and Ofira Ayalon, University of Haifa; David Elmakis and Shimon Frant, Israel Electric Corporation

This paper presents and evaluates a novel demand response method for households, designed for mitigating intermittency in smart grids with a high share of renewables. The method, named Dynamic-Active Demand Response (DADR), is based on an innovative paradigm of offering multiple electricity service levels and a dynamic-active demand response scheme. It provides the grid operator with the ability to influence consumption patterns in real time, so that responding to renewables intermittency is more effective in terms of reliability, predictability and response time. DADR's performance is evaluated using a Monte Carlo simulation model (implemented in GoldSim), which assesses the method's intermittency mitigation potential and estimates the expected economic value of implementing it in the Israeli residential sector.

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12th International Conference on Applications of Statistics and Probability in Civil Engineering, ICASP12 – July 2015

Adiel Komey, Qianli Deng, Gregory Baecher, P. Andy Zielinkski and Tyler Atkinson

The reliable performance of a spillway system depends on the many environmental and operational demand functions placed upon it by basin hydrology, the hydraulic conditions at reservoirs and dams, operating rules for the cascade of reservoirs in the basin, and the vagaries of human and natural factors such as operator interventions or natural disturbances such as ice and floating debris. These systems interact to control floods, condition flows, and filter high frequencies in the river discharge. Their function is to retain water volumes and to pass flows in a controlled way. A systems simulation approach is presented for grappling with these varied influences on flow-control systems in hydropower installations. The river system studied is a series of four power stations in northern Ontario. At the head of the cascade is a seasonally-varying inflow. The remaining three dams downstream have little storage capacity. Each has two vertical lift gates and all four structures have approximately the same spillway capacity. The problem is to conceptualize a systems engineering model for the operation of the dams, spillways, and other components; then to employ the model through stochastic simulation to investigate protocols for the safe operation of the spillway and flow control system.

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Sandia Report SAND2012-10342, Sandia National Laboratories, Albuquerque, New Mexico – December 2012

Steven P. Miller, Jennifer E. Granata and Joshua S. Stein Sandia National Laboratories

Most photovoltaic (PV) performance models currently available are designed to use irradiance and weather data and predict PV system output using a module or array performance model and an inverter model. While these models can give accurate results, they do so for an idealized system. That is, a system that does not experience component failures or outages. We have developed the Photovoltaic Reliability and Performance Model (PV-RPM) to more accurately model these PV systems by including a reliability component that simulates failures and repairs of the components of the system, as well as allow for the disruption of the system by external events such as lightning or grid disturbances. In addition, a financial component has also been included to help assess the profitability of a PV system. This report provides some example analyses of three different PV system designs using the PV-RPM.

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2011 International Applied Reliability Symposium, North America: San Diego, California – June 2011

Damien Willans

The design, construction and operation of large-scale resource projects are now subject to extreme levels of competition and cost, with many projects running into billions of dollars. For this reason, resource companies, bankers and every participant in the design train are now compelled to understand every aspect of risk to be undertaken, usually well before the project becomes a reality. A key element of the design process is knowing if the plant can actually produce the required output – along with a clear understanding where the areas of potential risk might be. Rather than ignoring the reality of failure effects or, more commonly, de-rating the entire design by some “accepted” operating availability number and trying to justify it, companies are now turning to plant reliability modeling up-front to prove more efficient designs, even with the uncertainties of failures well before plant startup. The concept of calculating “throughput” provides an absolute plant (design) model output for given inputs, by directly linking plant flows and consequences to the equipment availability. This presentation describes a project recently undertaken, including the project background, modeling stages and processes, and the successful outcomes provided for one client who is currently undertaking a very large-scale resource investment.

This presentation describes how GoldSim and the Reliability Module were used to simulate the throughput of an alumina refinery, accounting for failures and preventive maintenance schemes, to support facility design.

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25th European Photovoltaic Solar Energy Conference, Valencia, Spain – September 2010

E. Collins, S. Miller, M. Mundt, J. Stein, R. Sorensen, J. Granata, and M. Quintana, Sandia National Laboratories

A reliability and availability model has been developed for a portion of the 4.6 megawatt (MWdc) photovoltaic system operated by Tucson Electric Power (TEP) at Springerville, Arizona using a commercially available software tool, GoldSim™. This reliability model has been populated with life distributions and repair distributions derived from data accumulated during five years of operation of this system. This reliability and availability model was incorporated into another model that simulated daily and seasonal solar irradiance and photovoltaic module performance. The resulting combined model allows prediction of kilowatt hour (kWh) energy output of the system based on availability of components of the system, solar irradiance, and module and inverter performance. This model was then used to study the sensitivity of energy output as a function of photovoltaic (PV) module degradation at different rates and the effect of location (solar irradiance). Plots of cumulative energy output versus time for a 30 year period are provided for each of these cases.

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25th European Photovoltaic Solar Energy Conference, Valencia, Spain – September 2010

N. Robert Sorensen, Michael A. Quintana, Michael J. Mundt, Edward V. Thomas, Steven P. Miller, and Samuel J. Lucero, Sandia National Laboratories

A program is underway at Sandia National Laboratories to predict long-term reliability of photovoltaic (PV) systems. The vehicle for the reliability predictions is a system performance model, currently being run under a simulation software called GoldSim™. The model includes inputs for module performance, irradiance, and degradation. In order to be truly predictive, physics-informed degradation processes and failure mechanisms need to be included in the model. This paper describes accelerated life testing of metal foil tapes used in thin-film PV modules, and how tape joint degradation, a possible failure mode, can be incorporated into the model.

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