Larger stand-alone PV systems are called Solar Residential Systems (SRS). They usually provide electricity to large individual installations like hotels, hospitals, schools, factories etc. and offer a wide range of applicable loads. They generally include an inverter allowing the use of AC loads. The use of AC power has certain advantages, but should be primarily reserved for larger systems and/or if the loads needed can only be operated with AC power (e.g. larger working instruments and machines). With a typical range from 500W to 4000W output power, SRS usually integrate 12V and 24V battery voltage, even if bigger systems work with higher voltage (48V).