With 25 billion connected Internet of Things (IoT) devices expected to come online by 2020, finding an adequate and efficient way to power each device is critical to the success of this emerging technology.
A “connected thing” could be anything from a smartphone and laptop, to a wireless sensor network, medical and military equipment. Connected things are also found in electronic signage, digital merchandising and even inventory tagging. And each of these “things” can contain a multitude of sensors.
According to Sandhi Bhide, Intel’s director of innovative IoT solutions, the energy required to power these devices and their internal sensors is “huge,” and demand for energy is outstripping supply. Bhide believes the next wave of IoT devices will not be able to rely entirely on batteries and wired power.
Bhide extrapolated the following example: in 2012 there were approximately 75 million vehicles shipped with an average of 80 sensors in each vehicle, equaling 6 billion sensors total. If the average wattage of power per sensor is 1 watt, this means that 6000 megawatt-hours are consumed by these sensors. By 2020, an expected 110 million vehicles will ship that year with 200 sensors per vehicle, which equates to 22 billion sensors in automobiles alone consuming an estimated 22,000 megawatt-hours. Bhide puts this into easier to understand examples: 6000 megawatt-hours equals approximately 4.8 million customers consuming energy (the population of Lebanon); and 22,000 megawatt-hours is equivalent to 17.8 million energy customers (the population of Shanghai) – just to power sensors in automobiles.
As greater quantities of connected devices and sensors push the total energy consumption meter higher, advances in chip and sensor design as well as energy harvesting technologies need to evolve in order for the ecosystem to be sustainable.
“Energy harvesting technologies to allow devices to power themselves—even 1 milliwatt saved across 50 billion devices translates into a lot of power,” say Intel Labs leader Wen-Hann Wang.
Energy generation, or more accurately energy loss prevention, comes in all sizes and forms, such as photovoltaic (solar), thermal and mechanical (vibration or electromagnetic).
Using light energy from the sun is already well-researched and advanced to the point where PCs can run directly off a solar panel.
Racing down the tracks to energy generation
Many electric and hybrid vehicles use friction to generate power – actually capturing energy being lost through regenerative braking systems. Greenrail, an Italian startup, has developed a system that can be retrofitted into railways that incorporates a piezoelectric (vibration) system that generates electricity as trains pass over.
Similarly, walking or running shoes outfitted with piezoelectric generators can generate enough electricity to power small devices such as GPS sensors, receivers and perhaps even a smartphone.
But energy generation by vibration or friction depends on external movement, so researchers are also turning elsewhere to capture potentially lost energy.
The waves are all around us
Another source of energy could be scavenging radio waves already in the air. This harvesting method looks so promising it compelled Joshua Smith, an associate professor at the University of Washington and former principal investigator at Intel Research Seattle, to form an energy-harvesting start-up.
“Moore’s Law, in addition to giving us more transistors and cheaper transistors, is also giving us more energy efficient computing,” says Smith. “If you compare energy efficiency of computing in 2010 to 1940, it’s improved by a factor of a trillion, and it’s continuing to scale.
“Now we can start thinking about powering certain workloads wirelessly, even using pre-existing radio waves that are already in the air. The amount of power in the air hasn’t really changed that much since 1950.”
Smith is referring to radio and TV broadcast transmissions, which is the focus of his research into wireless ambient radio power. He believes this ambient energy can be captured from the air without changes to the existing infrastructure. According to Smith, all that you need to capture radio frequency (RF) power are antennas and circuitry, which many devices have already.
“I think wireless power is the best solution because…our devices are already built to transfer information using electromagnetic waves and so just adding the capability to do power through that same antenna, form factor and housing is attractive,” explains Smith. “We are already using electromagnetic signals for communications so if we use it for power as well, everything can be consistent.”
Vital for a connected future
While there are various methods to capture energy, as well as new chip designs to make the capture, usage and storage more efficient, considerable advancement is needed in this area to support the billions of sensors coming online in the coming years.
“If we don’t find a comprehensive solution to this energy problem, then there is no way that we will be able have an Internet of Things,” declared Smith. “It just won’t be feasible.”
This content was originally published on the Intel Free Press website.