They do address energy storage in the full plan e.g.:

• The Government is therefore committed to a fundamental and urgent reform of the connections process, as set out in the Clean Power Action Plan. The Plan included connections capacity allocations for onshore wind for 2030 and 2035
• The Strategic Spatial Energy Plan (SSEP) will support a more actively planned approach to energy infrastructure [...]. It will do this by assessing and identifying the optimal locations, quantities and types of energy infrastructure required for generation and storage, including onshore wind, to meet our future energy demand with the clean, affordable and secure supply that we need