010-011_EETE-VF

EETE DECEMBER 2012

NEWS & TECHNOLOGY Smart home splits over low power By Nick Flaherty DevelopmeNts For NetworkiNg the smart home are diverging over the use of energy harvesting and low power technologies. As the process technology drives down the power consumption and cost of wireless devices, so the cost of the energy harvesting elements and the power management de- vices becomes more critical. this leaves the leading european companies at odds on the best approach. Dutch chip designer greenpeak technologies is pushing into smart home via the set top box and Zigbee protocol. this is initially using r4Ce as a more reliable remote control but then using the set top box as the hub to control a network of sensors around the home. “we started with energy harvesting but we found other ap- proaches“, said Cees links, founder and Ceo of greenpeak. “it’s very expensive because you need a storage element and power management and on a per device basis it is consider- ably more expensive. We see a battery factory as a very efficient energy harvester that’s distributing the energy. that gap is so The low cost Raspberry Pi computer has been used as the large we moved from energy harvesting to making the battery hub for EnOcean wireless sensor links. life exceed the lifetime of the end product and that represents a 10-fold reduction in the power consumption.” one of the key ways of driving down the cost is with high the company has recently launched a dual mode low power volume shipments, but this relies on having a single standard Zigbee chip to link the low power r4Ce protocol to a wide frequency worldwide says links. the split between the Us and Zigbee network and teamed up with Bosch security systems, europe on sub 1gHz ism band frequencies is a key problem Us cable operator Comcast and sony on smart home systems. he says. “our team developed wiFi at Bell labs and we found “my bet is that in the next ten years there will be at least 50 Zig- that big companies hate different power cords and different bee devices in the home if not 100,” he said. “this is happening frequency settings. this needs one frequency and an open now.” standard – that’s the lesson Apple taught us in 1992 when they adopted wiFi.” german energy harvesting pioneer enocean is moving from its initial in-building automation market to the consumer and home with two thirds of the interest coming from consumer now, according to laurent giai-miniet, Ceo of enocean. giai-miniet also sees the sub 1ghz bands providing longer range for sensors and lo lower power to support energy har- vesting. “the deployment of 2.4gHz has issues with range and functionality that doesn’t apply to the sub gHz bands,” he said. He also doesn’t see volume as an issue. “one frequency for the world is not what most customers are requesting,” he said. “in the ism bands there are more shipments worldwide in chips and modules in sub-ghz bands than there are in 2.4gHz.” one key example he points to for energy harvesting is having a radiator valve powered by peltier effect sensors capturing thermal energy. “when we talk to telcos and msos they see the value of having the radiator talking to the window so that if the window is opened the radiator automatically switches off. that’s a real saving, and you don’t want to do that by sticking a battery in a radiator,” said giai-miniet. Using the kinetic energy in the light switch to power a wireless link is another example of where energy harvesting has a real advantage, he says. “the cost of the peltier element is good but you still have to boost the voltage, and customers really want solutions now with self powered thermal power,” he said. the company has Laurent Giai-Miniet, CEO of EnOcean. signed up with rohm to drive the energy harvesting technology into Asian smart home developments. “out of 300 members, we have 95 companies in the enocean Alliance which are making “Out of 300 members, we have 95 companies in the EnOcean good traction in Japan,” he said. Alliance which are making good traction in Japan” energy micro is also pushing down the power consumption 10 Electronic Engineering Times Europe December 2012 www.electronics-eetimes.com


EETE DECEMBER 2012
To see the actual publication please follow the link above