A BESS tolling agreement is a contractual arrangement in which the toller (asset owner) grants the off-taker (service provider) the right to utilize the battery energy storage system (BESS) in exchange for a tolling fee. The off-taker provides the charging energy and dispatch instructions, and the toller operates the BESS accordingly, while retaining ownership of the asset. The tolling fee compensates the toller for making the storage capacity available and covering aspects such as energy throughput, degradation, and operations and maintenance (O&M) services. The off-taker typically assumes the market risk and captures revenues from activities such as energy arbitrage, ancillary services, or capacity sales.