The consulting firm Arthur D. Little reports that PCs waste $5.5 billion of power every year. The average desktop/monitor combination consumes up to 2000 kilowatt-hours (kWh)of electricity per year, of which 500 to 1000 kilowatt-hours can be cut with simple power The consulting firm Arthur D. Little reports that PCs waste $5.5 billion of power every year. The average desktop/monitor combination consumes up to 2000 kilowatt-hours (kWh)of electricity per year, of which 500 to 1000 kilowatt-hours can be cut with simple power management.