What are the advantages and disadvantages of a watt-meter?

A watt-meter provides precise measurements of electrical power consumption, allowing for effective energy monitoring and management. This can help in identifying inefficiencies and optimizing energy use, which is beneficial for both cost savings and environmental impact. However, disadvantages include the potential for higher costs and complexity in installation and calibration, as well as the need for user expertise to interpret the readings accurately. Additionally, some watt-meters may not be suitable for all types of electrical systems, limiting their versatility.