A Tale of Two Cities

Abstract:

Reanalysis data on a range of events such as cyclones, storms, rainfall, etc. are freely available from many different sources. Reanalysis provides an accurate estimate of the climate since it combines observations from satellites and other sources with an environmental model. These data can be found with good temporal and spatial resolution. They can be used to study extreme weather events and applied to analyze usage of solar panel and battery storage to avoid power outages in residential homes.

In this study, reanalysis data from 1998 to 2018 for two cities, Bethesda, Maryland and Denver, Colorado are analyzed. The data were obtained from the NASA’s reanalysis product, Modern-Era Retrospective Analysis for Research and Applications, version 2 (MERRA-2). MERRA-2 data for extreme weather events (extreme wind speed and temperature) in Bethesda and Denver are analyzed to assess severity of these events. The 95^th percentile of wind speeds in Bethesda is 8.0 m/s, lower than the 8.4 m/s observed in Denver. This indicates that Denver has slightly higher extreme wind speeds than Bethesda. The median temperature in Bethesda for the period is 13.5 °C, which is significantly higher than 9.5 °C in Denver. The extreme weather phenomena for these two cities are then connected to power outages for the same time period.

Specifically, the study focuses on analysis of battery storage that may be useful to reduce the extent of power outages. A function from existing literature relating the wind speeds to the probability of power outage is applied to the hourly wind speed data for Bethesda and Denver. This function gives the expected loss of power for each hour during the 21-year period, as well as the total power loss estimations for the entire duration.

The results shown in Figure 1 are for a single year where the variability of the wind is highest. They demonstrate that installing solar panels offsets a significant portion of the loss of load due to severe winds disrupting power supply and installing even 0.1 kWh of battery eliminates the majority of power outages.