Wireless Energy Savings

Energy is abundant in our environment, available in the form of thermal, solar, wind, and mechanical energy. Typically, these sources provide such small quantities of energy that it makes it difficult to provide adequate power on a large scale. When it comes to powering wireless switches and sensors, however, the tiniest amounts of energy from the environment are all that is necessary to help power control devices that can save between 20 to 45 percent energy in buildings.

Energy harvesting is the process of capturing minute amounts of energy from one or more of these naturally occurring energy sources, accumulating them, and storing them for later use. Energy-harvesting wireless sensor technology collects energy where it costs nothing, from the energy existing in our environment. Linear motion, pressure, light, and differences in temperature can be converted into energy that can be used electrically. Combining miniaturized energy harvesters and highly efficient wireless technology creates service-free wireless sensor solutions for use in commercial, residential, and industrial applications.

No Batteries, No Problem
Many sensors, particularly those that form a mesh network, are usually wired or battery-operated, requiring routine replacement and regular maintenance. Furthermore, batteries can be costly in the long run. Needing to continuously replace them can have a negative impact on valuable resources, and is inherently not very “green.”

Buildings — in particular schools, colleges, and universities — are 
benefitting significantly from battery-less wireless technology for automating campus buildings and residence halls. Products and systems can easily be implemented as a standalone system or integrated into any common building automation system, like LON, BACnet, TCP/IP, or Ethernet.

Just because there are no batteries doesn’t mean these products aren’t robust. Wireless transmission distances can reach approximately 900 ft. in open spaces and up to 100 ft. inside buildings. With 850 interoperable products available in the ecosystem and proven in over 200,000 buildings worldwide, energy-harvesting wireless technology is quickly becoming an international standard.

Greening Campus Life
Energy and maintenance costs in all building sectors are coming under increased scrutiny, and educational organizations are no different. A typical 50,000-sq.-ft. campus building in the 
U.S. uses more than $100,000 worth of energy each year, which equates to about $1.95 per sq. ft. spent on electricity. In most colleges and universities, lighting, ventilation, and cooling are the largest consumers of electricity, making these areas the best targets for energy savings. Computers and other electronic devices have become mainstays in campus buildings and residence halls, contributing dramatically to energy consumption. A typical desktop computer, monitor, and shared printer can draw about 200 watts of power.

Campus residence hall life is rarely predictable and students lead busy lives, leaving the residence facilities empty for long periods of time during the day and on breaks from school. A wireless, energy-harvesting system that includes HVAC control, lighting, and plug load can help save 30 percent energy, on average. During breaks from classes, when building systems are typically left in “on” mode, a building control system can save over 50 percent energy. With documented energy savings like this, payback periods can easily be kept under two years.

Wireless and Limitless
Wireless technology can be integrated into building management systems, which can be set up on TCP/IP to enable the use of Internet connectivity. The addition of maintenance-free technology provides for cost-effective and flexible deployments, as well as the ability to control the system from any Internet or networked end device, including smartphones. The visualization of data, including electricity, water, and gas, allows the user to monitor consumption in a building, or across multiple buildings campus-wide, and can immediately recognize energy-saving potential.

In many university settings, computer labs are often overlooked for their energy-savings potential. Typically, computers are either left on 24/7, or they are set up to go into sleep mode. Regardless, they are still consuming energy unnecessarily. Colleges and universities can greatly benefit from wireless, intelligent power strips, which can turn computers on and off automatically. The power strip contains four outlets that can be controlled by occupancy and two outlets that are always on. Computer labs, as well as residence hall rooms, can save thousands of dollars by controlling this otherwise wasted energy.

When it comes to greener educational facilities, intelligent building automation will continue to provide the key to future sustainability advancements. Self-powered wireless sensors and switches will continue to greatly simplify cabling requirements while, at the same time, increasing flexibility. This technology allows devices to be attached, removed, and reattached as the needs of spaces change over time, or wherever they provide optimum benefit. The complexity and cost of retrofitting is greatly reduced with wireless. 

Cory Vanderpool, business development director for North America for EnOcean Alliance, previously served as executive director of GreenLink Alliance, a nonprofit organization dedicated to promoting energy conservation in buildings and tax incentives for building owners. She can be reached at [email protected].