How much energy storage should be provided for 1 MW of photovoltaic power generation

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 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.

This paper considers the annual comprehensive cost of the user to install the photovoltaic energy storage system and the user's daily electricity bill to establish a bi-level optimization model. The outer model optimizes the photovoltaic & energy storage capacity, and the inner model optimizes the operation strategy of the energy storage.

Said another way, with a fixed amount of solar PV (if you are land-constrained, for example), you can provide more firm capacity with the same amount of storage if you are willing to charge from the grid sometimes [see Figure 1]. Figure 1. Solar capacity, in MW, required to create a 100 MW renewable peaker.

The key to optimally sizing the storage system probabilistically is understanding the tradeoff between marginal cost of additional solar or storage and the penalty for being unavailable to meet a peak in a rare situation.