A lot would depend on the location of this store room in relation to the existing power supply circuits. Most store rooms only have provision for low wattage lighting, and the wiring may not be suitable for running high wattage appliances. There would be a lot more involved than simply hooking up a meter to the existing installation. In our block, each car space and store room has its own light circuit connected to the relevant unit’s meter, but the wiring has a very low power rating.