Beyond the energy bill: integrating climate, health, and resilience into solar plus storage assessments for public buildings
Local governments are increasingly looking to invest in solar and storage to power publicly owned facilities. Typically, investment decisions for these technologies are based on a comparison of lifetime costs to electricity bill savings for each proposed location. However, this approach fails to fully capture the value of these systems to local governments, considering the burden their communities bear from power outages and power plant emissions. In this study, we assess the impact of incorporating climate, health, and resilience impacts into the optimal sizing of behind-the-meter solar plus storage, with a particular focus on public buildings. Our work expands upon the REopt model, which allows for the valuation of resilience, by further incorporating the monetized benefit of avoided climate and health damages from grid electricity, using location-specific marginal emissions rates and costs. To illustrate the use of this new model, we take Ann Arbor, Michigan—a city actively considering investments in solar plus storage—as a case study. We compare the cost-optimal system sizes and net present value of solar plus storage when considering only energy bill savings versus additionally capturing health, climate, and resilience impacts. Our results show that incorporating these value streams results in significantly larger cost-optimal battery systems. When accounting for emissions and resilience co-benefits, the net present value of each investment is also orders of magnitude greater, with benefits being largely dominated by avoided health impacts. These results illustrate how investment decisions would change when the scope of benefits of solar plus storage is expanded beyond bill savings.