The cost declines of solar and storage technologies have led to concerns about customers disconnecting from utility service and self-supplying electricity. Prior research addressing this issue focused on average electricity tariffs, solar profiles, and demand without considering detailed customer heterogeneity. This paper fills the gap by analyzing how electricity tariffs that shift cost recovery away from variable charges towards fixed charges influence a customer’s decision to disconnect from utility service. A linear optimization model is developed to size an off-grid solar/storage system. Technology cost and reliability parameters of the optimization model are then adjusted to calculate a range of off-grid costs. Unique rate structure information for over 2000 utilities in the United States is then used to compare grid costs to off-grid costs. The results show limited ability for solar/storage systems to economically substitute for grid services. However, 1% of households might disconnect from utility service in a scenario that accounts for future off-grid costs and updated tariff designs. We find that 3% of households in the Southwest and California have private economics that favor defection in this scenario, rising to as much as 7% in Hawaii. Grid defection could increase from 1% to 7% of United States households in a slightly reduced reliability scenario. These results indicate that utilities and regulators seeking to limit rooftop solar adoption by lowering variable charges face a significant possibility that the corresponding increase in fixed charges could lead to inefficient grid defection.

太阳能和储能技术的成本下降已引起人们对客户断开公用事业服务和自备电的担忧。先前针对此问题的研究集中在平均电价，太阳能分布图和需求上，而没有考虑详细的客户异质性。本文通过分析将成本回收从可变费用转变为固定费用的电价如何影响客户断开公用事业服务的决定来填补这一空白。开发了线性优化模型来确定离网太阳能/存储系统的大小。然后调整优化模型的技术成本和可靠性参数，以计算一系列离网成本。然后，使用美国2000多个公用事业公司的唯一费率结构信息来比较电网成本与离网成本。结果表明，太阳能/存储系统在经济上替代电网服务的能力有限。但是，在考虑了未来离网成本和更新的电价设计的情况下，有1％的家庭可能会中断公用事业服务。我们发现，在这种情况下，西南和加利福尼亚州有3％的家庭拥有私人经济，有利于叛逃，而在夏威夷，这一数字上升至7％。在可靠性略有降低的情况下，电网不良率可能会从美国家庭的1％增加到7％。这些结果表明，公用事业和监管机构试图通过降低可变收费来限制屋顶太阳能的使用，面临着很大的可能性，即固定收费的相应增加可能导致低效率的电网缺陷。