Going Green

E-mail Melanie Martella

Considering some of the conversations I had at Sensors Expo last week, I read this recent release from ON World with a great deal of interest. It seems that wireless sensor networks (WSNs to those in the know) are increasingly being tapped for energy saving endeavors.

Measure to Control
I touched on some of these themes when I talked about the growing emphasis on the smart grid and how utility companies are investigating WSNs for the creation and implementation of demand response networks (Smart Power). The utilities are interested in WSNs to help them create a far more responsive approach to load management. Similarly, those in the building automation field have been interested in WSNs for a while now. For starters, it's significantly easier (and cheaper) to place sensors in a building if you don't have to run wire to each one. WSNs typically use a mesh topology, so they are self-assembling, meaning if you add a new wireless node (or ten) or move another one, the network will manage the reshuffling for you. Some of the wireless products are standards-based, such as ZigBee and IEEE 802.15.4 which means that compliant products from manufacturer A will work with compliant products from manufacturer B, allowing you to mix and match.

Fundamentally, this drive is about finding out what's really happening inside the buildings by achieving a clearer, more detailed sensory picture. Once you know what's happening, you can control it. You can use less energy by only lighting the areas where people are and adjust the heating and cooling on a room by room basis—which means that you need sensors in each and every one of those areas. I used to work in a building with a laughably bad central HVAC system. Too warm in winter, the office was reliably freezing cold in summer. No amount of thermostat tweaking and selective vent opening/closing ever achieved a comfortable indoor environment and we opened the windows as an act of self-preservation, confusing the HVAC system even further. I suspect that I am not alone in these experiences.

As the ON World report observes, it's not just about energy savings—although, with rising energy prices, I suspect more and more building managers are going to hop on the energy conservation bandwagon. It's also about being visibly Green. Considering that Johnson Controls, Siemens, and other huge names in the building automation space are shipping commercial WSN products, it looks like this is a trend that's here to stay.