Stakeholder Costs and Benefits of Distributed Energy Resources on Distribution Networks

Distributed energy resources (DER), such as rooftop solar and combined heat and power (CHP), create a unique opportunity to reduce transmission and distribution network capacity requirements, decrease electrical losses, and potentially improve reliability, resiliency, and other operating metrics. This dissertation examines how DER benefit different stakeholders in the electric power sector: DER owners, ratepayers, utilities, and society. In Chapter 2, we investigate how increasing commercial CHP system peak penetrations may affect net emissions, the distribution network, and total system energy costs. We find that small commercial CHP, due to low and inconsistent heat loads, can increase emissions relative to the bulk grid. We suggest policy options to encourage CHP operation during times of high heat loads. In Chapter 3, we develop metrics based on existing best utility practices that characterize how much solar can reduce peak demand on distribution network feeders. We conclude that solar can act as a capacity resource, but the size of the resource depends on the geographic region. Energy storage or an allowance for occasional overloading within a transformer’s tolerance can increase the capacity resource of solar. Chapter 4 is a value of solar and rate impact study for the Pennsylvania Public Utility Commission (PUC). The Pennsylvania PUC can use it to decide whether the environmental benefits of solar are worth the relatively small rate impact caused by rooftop solar. In Chapter 5, we assess the ability of rooftop solar and storage to reduce peak loads and defer distribution capacity projects in the PECO service territory. We find that targeted placement of solar can increase the total deferral value up to fourfold, but capacity deferral opportunities are rare and large administrative efforts to manage deferral projects, such as markets, are probably not warranted