Both solar PV and Battery Energy Storage Systems (BESS) alone can provide savings to public sector and C&I building owners. For example, a solar PV system can produce energy for use onsite at a per-kWh rate that is lower than the local utility rate, while a BESS can deliver tariff-specific demand charge savings. To date, most of these types of systems have been deployed separately. However, when the two technologies are paired together, the potential savings and return on investment can be much greater than each on a standalone basis. A combined solar + storage system can firm and smooth the energy used onsite, reducing demand charge risk due to solar intermittency, and results in more reliable reduction of energy and demand charge-related electricity expenses. Additionally, a combined solution can enhance the resilience of a building’s power supply, a key consideration for critical facilities in the face of increasingly common power outages in some areas. The advantages of solar + storage systems are expected to increase as the electrical grid decentralizes over the coming years and as new opportunities emerge for flexible distributed energy systems to participate in grid operations.