Shehu Dean, Kim Mi-Ok, Rosendo John, Krogan Nevan, Morgan David O, Guglielmo B Joseph
Supply Chain Management, University of California, San Francisco, San Francisco, California, USA.
Department of Epidemiology and Biostatistics, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, San Francisco, California, USA.
Biopreserv Biobank. 2024 Sep 25. doi: 10.1089/bio.2024.0070.
The storage of biospecimens is a substantial source of greenhouse gas emissions and institutional energy costs. Energy-intensive ultra-low temperature (ULT) freezers used for biospecimen storage are a significant source of carbon emissions. ENERGY STAR-certified ULT freezers have the potential to decrease the carbon footprint. Quantify the impact of an institutional-scale freezer conversion program on carbon emissions and energy costs. A ULT freezer energy use prediction model was developed to identify and replace the most inefficient freezers in the research building for this pilot, and eventually institution-wide. Multiple linear regression factors included the number of years of use, storage volume, and ENERGY STAR certification status. Electrical usage and carbon emissions were quantified before and after replacement with ENERGY STAR models. Logistical methods were developed to decrease the risks of exposure of frozen samples to ambient temperature during content transfers. Institution-wide energy costs were derived by converting electrical burden to electrical costs. Carbon footprint assessment from ULT freezer operation was computed using the U.S. EPA Greenhouse Gas Equivalencies Calculator. The pilot project revealed an annual reduction of 310,493 kilowatt hours of electrical usage, equivalent to 134 metric tons of carbon emissions. Annual electrical costs were reduced by $55,889 resulting in an 8-year payback on the initial investment. Using the pilot results, we modeled the benefit of the freezer exchange across the entire institution. The modeling predicted that conversion of the institution's remaining 1119 conventional ULT freezers to ENERGY STAR models would lower annual electrical usage by 7,911,549 kilowatt hours (3423 metric tons of carbon emissions), resulting in savings of over $1.4 million annually. Our methods make a large-scale initiative to replace energy-inefficient ULT freezers logistically possible, reduce carbon footprint, and demonstrate an attractive return on investment while proactively protecting valuable research materials.
生物样本的储存是温室气体排放和机构能源成本的一个重要来源。用于生物样本储存的高能耗超低温（ULT）冰箱是碳排放的一个重要来源。获得能源之星认证的超低温冰箱有潜力减少碳足迹。量化机构规模的冰箱转换计划对碳排放和能源成本的影响。开发了一个超低温冰箱能源使用预测模型，以识别并更换研究大楼中效率最低的冰箱用于该试点项目，并最终推广至整个机构。多元线性回归因素包括使用年限、储存容量和能源之星认证状态。在用能源之星型号冰箱替换前后，对用电量和碳排放量进行了量化。制定了后勤保障方法，以降低在转移样本内容物期间冷冻样本暴露于环境温度的风险。通过将电力负担转换为电力成本来计算全机构的能源成本。使用美国环境保护局温室气体当量计算器计算超低温冰箱运行的碳足迹评估。该试点项目显示，每年用电量减少310,493千瓦时，相当于减少134公吨碳排放。年度电费降低了55,889美元，初始投资的回收期为8年。利用试点结果，我们对整个机构更换冰箱的效益进行了建模。该模型预测，将机构剩余的1119台传统超低温冰箱转换为能源之星型号，将使年度用电量降低7,911,549千瓦时（3423公吨碳排放），每年节省超过140万美元。我们的方法使大规模更换能源效率低下的超低温冰箱在后勤上成为可能，减少了碳足迹，并在积极保护珍贵研究材料的同时展示了可观 的投资回报率。
