Wireless power has the potential to be very useful, but range is a major hurdle. In a new proof-of-concept project, Ericsson and PowerLight Technologies have demonstrated a technique called optical beaming, using a laser to transmit power to a portable 5G base station.
Most people’s experience with wireless power is for charging devices like phones, watches or earbuds, but that still requires them to be placed on a pad, which limits how useful it can be. Lab setups are experimenting with larger systems that can charge devices anywhere within a room, but how about beaming electricity long distances outdoors?
PowerLight has been developing the technology to do so for years, and has now demonstrated it with a proof-of-concept in partnership with telecommunications company Ericsson. The system is made up of two main components, a transmitter and a receiver, which can potentially be hundreds or thousands of meters apart.
The system doesn’t send electricity directly like a Tesla coil – instead, the electricity at the transmitter end is used to produce a powerful beam of light and send it towards the receiver, which catches it using a specialized photovoltaic array. That in turn converts the incoming photons back into electricity, to power whatever device it’s connected to.
While it might seem dangerous to have a beam of high-intensity light blasting through open air, there are safety measures in place. The beam itself is surrounded by a wider “cylinder” of sensors that detect when something approaches, and shuts off the beam within a millisecond. It’s so quick that fleeting interruptions like birds wouldn’t affect the service, but there’s a battery backup at the receiver end to cover any potential longer-term disruptions.
In this case, the PowerLight system was powering one of Ericsson’s 5G radio base stations, which was not connected to any other power source. The system delivered 480 watts over a distance of 300 m (985 ft), but the team says that the technology should already be capable of sending 1,000 watts over 1 km (0.6 miles), with room to expand in future tests.
Powering these 5G units wirelessly could make them more portable, allowing them to be rolled out in temporary locations of higher demand, such as festivals and events, or during disasters where other infrastructure has been disrupted.
PowerLight’s optical beaming technology could find use in many other applications too, such as charging electric vehicles, making the power grid more adjustable on the fly, and even potentially in future space missions.
This isn’t the only company working towards similar goals though. Last year New Zealand-based startup Emrod unveiled its own vision for long-distance power transmission, but rather than light and photovoltaic cells it beamed microwave energy between antennas. Emrod’s prototypes have so far beamed about 2 kilowatts of power over 40 m (130 ft), and the company claims that it should be able to scale up to send far more power over dozens of kilometers.
Between them all, wireless power transmission could become a key part of electricity grids in the coming decades.
Sources: Ericsson, PowerLight
