EMS systems based on blade servers occupy a fraction of the space previously required. For instance, a blade rack of 20 servers occupy much the same space as that previously occupied by a single MicroVAX server. Other meanings Energy efficiency In a slightly different context, EMS can also refer to a system designed to achieve energy efficiency through process optimization by reporting on granular energy use by individual pieces of equipment. Newer, cloud-based energy management systems provide the ability to remotely control HVAC and other energy-consuming equipment; gather detailed, real-time data for each piece of equipment; and generate intelligent, specific, real-time guidance on finding and capturing the most compelling savings opportunities. Home energy management system Home energy management (HEM) enables domestic consumers to take part in demand side activities. But, it confronts some problems resulted from the uncertainties of renewable energy resources and consumers' behaviour; while, the domestic consumers aim at the highest level of comfort that should be considered by minimizing the “response fatigue” phenomenon. Automated control in buildings The term Energy Management System can also refer to a computer system which is designed specifically for the automated control and monitoring of those electromechanical facilities in a building which yield significant energy consumption such as heating, ventilation and lighting installations. The scope may span from a single building to a group of buildings such as university campuses, office buildings, retail stores networks or factories. Most of these energy management systems also provide facilities for the reading of electricity, gas and water meters. The data obtained from these can then be used to perform self-diagnostic and optimization routines on a frequent basis and to produce trend analysis and annual consumption forecasts. Energy management systems are also often commonly used by individual commercial entities to monitor, measure, and control their electrical building loads. Energy management systems can be used to centrally control devices like HVAC units and lighting systems across multiple locations, such as retail, grocery and restaurant sites. Energy management systems can also provide metering, submetering, and monitoring functions that allow facility and building managers to gather data and insight that allows them to make more informed decisions about energy activities across their sites. The global energy management system market is projected to grow exponentially over the next 10-15 years. See also Energy accounting Energy conservation measure Energy management Energy management software, software to monitor and optimize energy consumption in