Graham Martin, Chairman of EnOcean Alliance explains
For years, energy policy has mainly focused on different sources of renewable energy. Politicians, economists and other commentators still discuss the best performing technologies and the requirements of the power grid. However, recently another perspective is attracting more attention: energy efficiency as a valuable “source” of renewable energy.
The UK’s National Energy Efficiency Action Plan sees it at the heart of the government’s long-term energy and climate change plan for low carbon growth. This includes ambitious goals of reducing primary energy consumption by 20 per cent of the 2007 level by 2020.
Achieving this saving requires rapid action now. Existing buildings provide great potential to improve their performance. They consume up to 40 per cent of primary energy – and therefore are more power-hungry than the industrial sector. However, energy-related renovation, such as new insulation or a more efficient heating system, is costly for businesses and homeowners alike. Despite the potential savings available, most cannot make the necessary investments in the short term. This could hold back the potential efficiency effects for years.
Buildings can control energy efficiency
Does energy efficiency remain a luxury? Not necessarily. In discussions, there is a measure, which is beginning to come to the fore: building automation. With publication of the Building Renovation Strategy as part of the UK’s National Energy Efficiency Plan, it looks set to play a key role in delivering energy efficiency.
Building automation controls areas such as heating, ventilation, lighting or shading in accordance with individual requirements. The goal is to consume only as much energy as is actually needed.
Such systems are already intelligently connected within a building and often learn the occupant’s behaviour automatically. Room sensors deliver data as a basis to analyse a building’s heating and cooling rate as well as its physical fabrics. Besides temperature, sensors also detect open windows or whether the humidity rate of the air is too high. Thus, the system automatically reduces the heating or activates the ventilation respectively. In addition, data on light intensity influence the control of lighting and shading.
Current weather conditions, the presence of people in a room, solar radiation etc. are crucial elements of a control that adapts to changing situations and conditions. Usually, there is an immediate saving effect. The more efficiently the building services are matched to each other, the better the saving rates, which can be up to 30 per cent.
Building automation has a great advantage compared to other energy-related measures: thanks to wireless technologies, such systems can be easily retrofitted in existing buildings, requiring less cabling and at manageable costs. Wireless sensors, which deliver the needed data and execute control commands, can be flexibly placed. This, for example, meets the requirements of flexible office concepts, where partition walls and the floor plan have to adapt to the heterogeneous needs of different tenants. Wireless switches and sensors simply move accordingly whenever the office structure changes.
Today, wireless devices also operate without batteries. They gain their energy from the surrounding environment, such as the press of a button or indoor light. Even differences in temperature between the heating and the room air can power automatic valve actuators. Using batteryless wireless technology, a system’s operating and maintenance costs are low as there is no need for material or staff to change batteries.
Fast return on investment results in immediate effects
In the housing industry with millions of rented apartments, wireless building automation is also an attractive efficiency measure. Owners or housing associations can implement it without affecting the tenants’ quality of life by extensive renovation, noise and dirt for years. In addition, the landlord does not have to bother the tenant with an annual battery replacement.
Besides flexibility, wireless building automation systems offer significant cost benefits. In a new building, they save between 15 and 30 per cent of installation costs; in retrofit projects, the saving rate can be even up to 70 per cent. Combined with reduced energy consumption, such systems pay off after one to five years. In comparison, the return on investment (ROI) of a new insulation is about 10 to 60 years. Consequently, building automation will clearly become the inevitable foundation for energy- efficient buildings.
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