The process of converting AC
to DC to run electronic devices involves inefficiency that is multiplied by the
millions of devices that require them. What if this process could be made much
more efficient? That's the promise that new materials used in power conversion
may offer.
Commonly used electronic
devices such as laptops, computers, cellphones, hybrid cars, and industrial
motors make use of DC power that is converted from the AC power coming from
your wall sockets. In the process of converting AC power into DC power, a lot of
electricity is wasted. In fact, a significant percentage- about 10 percent- of
the total power generated in the United States is wasted during conversion from
alternating current to direct current.
To tackle the problem of
reducing the waste of energy during power conversion, Transphorm, a startup
backed by Google Ventures, Kleiner Perkins Caufield & Byers, and other
investors, has introduced a power conversion module that makes use of the
mechanical properties of gallium nitride, a compound used in LEDs, instead of
traditionally used silicon.
Inefficient power conversion
not only results in monetary loss, but also harms the planet. These new power
conversion modules include devices such as circuits, transistors, and modules,
including all the components required for power conversion.
Let's have a look at this
wonder element gallium.
Gallium is not found
naturally, but occurs in trace amounts in zinc and bauxite ores and is obtained
by the process of smelting. Classified as a poor metal, it has a silver hue.
This is known as a poor metal because it becomes brittle at
lower temperature and liquefies at even slightly high temperatures. Though it
is stable in air and water, it reacts with acids and alkalis. Gallium is never
used in its pure forms; instead, its compounds are used for various
applications. For making these new, more efficient power conversion modules,
gallium nitride is used.
Owing to its unique material
and electronic properties, gallium nitride is set to replace silicon in these
power devices. Any power device having gallium nitride shows five main
characteristics including high operating temperature, high dielectric strength,
high current density, high-speed switching, and low on-resistance. When
compared to silicon, GaN show ten times higher electrical breakdown,
exceptional carrier mobility, and three times the bandgap.
Gallium nitride has a property
of inherent negligible charge storage, and it allows the designing of power
switch circuits of extraordinarily high efficiency in compact sizes that permit
very low heat losses.
Gallium nitride has the
potential to replace silicon in all future electronic devices due its wide
bandgap characteristic. The advantages of use of GaN include lower voltage drop
in unipolar devices, increased power output, reduced heat sink requirements,
increase transient characteristics and switching speeds, low electrical noise due
to 10x lower recovery charge, high voltage capability and up to 100x the power
density of Si devices.
The basic claim by the company
is gallium nitride can help systems become 90 percent or more efficient. This
technology is at its nascent stage and is not fully implemented. Once it is
implemented, the company claims, it will reduce hundreds of terawatts of energy
loss.