You are travelling through a desert in your hybrid diesel-electric car. Suddenly, you realise that you've veered hundreds of miles away from your intended destination. Your fuel gauge reads almost "empty" and there's no prospect of topping up your fuel tank. But then, a few clicks on the dashboard mount a receptor on the hood of your car, which taps into wireless electricity generated from the local grid, helping you recharge your car and drive away.
To put it simply, wireless electricity is the conduction of electrical energy without wires. The idea was proposed way back in 1891 by Nikola Tesla, who suggested it could be an alternative to power distribution through transmission lines.
So imagine a world without wires, where household and portable electronic devices like cell phones, mp3 players, and laptops can be charged wirelessly without being plugged in. Sounds incredible? Think again; as the technology to support this is already here, albeit in its infancy. Start-up companies are also working on emerging technologies that can efficiently transfer power over long distances through the air, using a magnetic field and specially designed magnetic resonators. This could potentially impact the support infrastructure for electric cars.
Typical components in wireless power transmission include a microwave generator, transmission antenna, and receiving antenna and electricity can be relayed over short, moderate, or large distances. Microwave signals sent over a larger area can be received through a rectenna (rectifying antenna), which extracts microwave energy and converts it back into electrical energy.
Another widely documented area of research is the use of space-based solar power (SBSP) satellites for wireless power generation. These satellites can be placed in a geosynchronous or high Earth orbit, enabling them to receive solar energy throughout the year. The energy would be transmitted back to Earth stations, where a large rectenna array facility would collect incoming microwave signals and convert them back into electrical energy.
This technology could eliminate the need for a capital intensive array of cables, towers, and substations especially in hilly areas where it is a challenge to erect communication towers. Also, according to the World Resources Institute (EIA), electricity transmission and distribution losses average about 7% of the electricity that is transmitted annually within the United States. The main reason for losses worldwide is the resistance of wires used in the transmission grid. This problem can be solved by a wireless power transmission system, which will not only improve efficiency and lower transmission costs, but also eliminate power thefts.
The technology around electricity transmission and distribution is continuously evolving, and under favourable conditions, the day is not far away when people will start receiving wireless electricity just like a cell phone call!
Are you excited about the idea of wireless electricity? Share your thoughts with us in the comments section below.
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