Towards Smarter Buildings and Homes
Besides these improvements, energy management technologies can strongly contribute to optimizing energy use in buildings. Energy management “active controls” are designed to operate real-time and as close as possible to user requirements to lower energy waste. They usually operate on lighting, heating and air conditioning, but often also accommodate other services such as security, video surveillance, access control and fire detection. As an example, “active controls” will tie the lighting of a room to occupancy and daylight level, preventing lights from remaining on if daylight is sufficient or if the room is unoccupied. These controls are called “active” since they operate in real time and automatically, as opposed to “passive” solutions such as insulation works, heating and appliance efficiency.
Savings from such controls will obviously vary with the type of building and its use. Some buildings have spaces with different usage (offices, hotels, homes, etc.), while others are more homogeneous (retail, logistics, restaurants, etc.). The more fragmented the building, the more opportunity for savings. Space fragmentation is a key factor of energy waste. Also, some buildings are used continuously (hospitals, data centers, etc.), while others are used intermittently (hotels, sport facilities, theatres, etc.). The more intermittent the operation, the more the opportunity for savings. Time fragmentation is another key factor of energy waste.
The efficiency of the control will depend on the granularity of space and time monitoring. For example, an energy management system in a building can consider the entire building as one zone, or split the building into multiple zones (staircase, offices, corridors, facilities, etc.), or control individual rooms as zones. Up to 60% of energy can be saved when “active controls” operate at the lowest granularity level both in terms of space and time fragmentation. Time granularity alone offers the highest efficiency independently from space fragmentation. With no split per zone, time granularity leads up to 35% energy savings (Schneider Electric 2014). The higher the granularity of control, the more precise the “active control”, and the more the energy savings.
Schneider Electric headquarters, located in Paris, France, is a very good example of such type of “active” building. The building was the first in the world to receive ISO50001 certification. It consumes only 80 kWh/m2/year, four times less than in the previous headquarters of the group, using an advanced building management technology (Schneider Electric 2014). Such building management systems are traditionally deployed in large tertiary buildings (commercial centers, offices, hotels, etc.), where it is easier to control energy efficiency. One of the main challenges faced by the industry is deploying similar technologies to small and mid-sized buildings (such as small bank agencies or shops) which have simpler needs and represent a much wider physical and energy footprint. In the residential segment, new information and communication technologies (ICTs) allow the user to measure in real time his energy consumption per main item (heating, cooking, lighting, etc.) and to optimize the use of his energy (regulating temperature, turning on/off equipment) by remote control over the Internet (Schneider Electric 2014).
“Active controls” deployment is progressing rapidly, particularly in new constructions. The technology is equally applicable to existing buildings, where it can lead to important energy savings. Payback calculations show that investments in “active controls” break even within 4 to 5 years, faster than “passive” solutions which payback is rarely reached before 10 years. This is due to the cost of installation. Typical insulation works cost between 30 (internal insulation) and 300 Eur/m2 (window/double glazing) for energy savings in the range of 15%. “Active controls” cost from 20 Eur/m2 (simple solution in residences) to 50 Eur/m2 (room control and monitoring in tertiary buildings) for benefits ranging from 10 to 60% (Schneider Electric 2014).
Smart building and smart home solutions thus form a cornerstone of energy efficiency in the buildings sector.