The development of photovoltaic (PV)-based renewable energy generation systems and energy storage systems (ESS) is a key approach to achieving decarbonization of the power grid. PV power generation, connected to the grid via power electronics, typically operates at the maximum power point (MPP) and, unlike traditional synchronous generators equipped with governors, cannot participate in primary frequency control during frequency disturbances. As the share of renewable energy increases, the frequency regulation capability of the power system declines, necessitating enhanced utilization of renewable energy for frequency control. To address this challenge, this chapter establishes the mathematical models and characteristics of PV-ESS hybrid systems. Independent primary frequency control strategies for PV and ESS are established. Initially, the operational principles and output characteristics of PV and ESS are analyzed, and equivalent generation models are formulated. Primary frequency control strategies for PV and ESS in grid-connected systems are subsequently developed. A variable reduction rate control is proposed for PV, which dynamically adjusts based on system frequency deviations. Additionally, an adaptive control strategy for ESS is presented, which adapts according to the state of charge (SOC) to extend lifespan. A collaborative strategy is also proposed to align PV reduction rates with ESS SOC, optimizing frequency regulation and economic efficiency. These strategies are validated through simulations.