Evaluating Avoided Carbon Emission Benefits at the Santa Rita Jail

Abstract

The Santa Rita Jail, located in the city of Dublin, California, is the 5th largest county jail in the country. The site encompasses approximately 45 ha and the main buildings cover a million square feet. It operates year-round and has stringent requirements for reliable power. To this end, the microgrid and distributed energy resources scientists and researchers at the Lawrence Berkeley National Laboratory have been involved in the Chevron Energy Services lead project to convert the various onsite distributed generation (DG) technologies at the Jail into a true microgrid. Currently, the Jail’s technologies include large-scale batteries, photovoltaics (PVs), fuel cells (FCs), and wind turbines. Several research papers and reports have already analyzed and described the performance, bill savings, and return on investment of the equipment individually or together as a microgrid. This document reports the results of the effort at quantifying the value of avoided carbon emissions by analyzing the PV and FC performance and energy data from 2007 to 2011. Using California’s recent cap and trade allowance auction settlement prices, estimates of the avoided value of carbon emissions from PV and FC during the 5-year period are presented and compared to the counter-factual emissions had the Jail purchased all of its electricity from the local utility. The estimated value of avoided emissions is between $116,000 and $177,000.