page 5 • Renewable Energy Curtailment: When excess solar or wind energy cannot be used or stored, leading to wasted generation. VGI can help by charging EVs when renewables are abundant. • RIO (Regional Investment Optimization Model): A macro-energy supply model that determines least-cost investment and operation plans across electricity, fuels, and storage while optimizing for emissions reductions. • Smart Charging (V1G): A one-way charging method that schedules EV charging based on grid conditions, electricity prices, or renewable energy availability to reduce costs and support grid stability. • State of Charge (SoC): The battery charge level of an EV, expressed as a percentage of its total capacity. • Time-of-Use (TOU) Rates: A pricing structure where electricity costs vary depending on the time of day, encouraging users to charge EVs during off-peak hours when energy is cheaper. • Vehicle-Grid Integration (VGI): A broad term for technologies and strategies that allow electric vehicles (EVs) to interact with the grid, optimizing charging and potentially discharging power back to the grid. • Vehicle-to-Grid (V2G): A two-way charging technology where EVs not only charge from the grid but can also discharge power back to support grid stability and reduce system costs. • Vehicle-to-Home (V2H) / Vehicle-to-Building (V2B): The ability of EVs to provide backup power to homes or buildings, improving resilience during outages. Glossary of key terms