How to configure photovoltaic inverter energy storage

The optimal configuration capacity of photovoltaic and energy storage depends on several factors such as time-of-use electricity price, consumer demand for electricity, cost of photovoltaic and energy storage, and the local annual solar radiation.

When the electricity price is relatively high and the photovoltaic output does not meet the user's load requirements, the energy storage releases the stored electricity to reduce the user's electricity purchase costs.

In the PV system, the PV string configuration must meet the inverter configuration requirements for different inverters to achieve optimal energy yields. This configuration solution lists some common configuration principles for reference. 1. For the same MPPT input, configure PV modules of the same model, direction, and quantity.

The photovoltaic installed capacity set in the figure is 2395kW. When the energy storage capacity is 1174kW h, the user's annual expenditure is the smallest and the economic benefit is the best. Fig. 4. The impact of energy storage capacity on annual expenditures.

The outer objective function is the minimum annual comprehensive cost of the user, and the decision variable is the configuration capacity of photovoltaic and energy storage; the inner objective function is the minimum daily electricity purchase cost, and the decision variable is the charging and discharging strategy of energy storage.

When the benefits of photovoltaic is better than the costs, the economic benefits can be raised by increasing the installed capacity of photovoltaic. When the price difference of time-of-use electricity increases, economic benefits can be raised by increasing the capacity of energy storage configuration.