uninterrupted direct current

A new direct current (DC) technology from the Indian Institute of Technology Madras (IIT-M) is being tested in four south Indian states. If successful, researchers say it could eliminate the country’s disabling power cuts.

The so-called ‘uninterrupted direct current’ (UDC) will provide a minimum of 100W per household per day, even at peak demand times and when grid power is cut.

It works by separating alternating current (AC) and direct current (DC) to power different home appliances. A low-voltage AC line from a substation is converted to DC power by a home device. The current is fed into its own meter and through to lights, fans and other low-power devices like mobile chargers and televisions. The remainder of the building is run on AC power, which is metered separately.   

According to the researchers, the resulting amount of DC power is too low to be shut down, except to repair technical faults. Thus, instead of a blackout, a region could have a brownout, with minimal power remaining.

A UDC unit will cost around Rs1000 ($16.7). Consumers will also need to buy LED light bulbs and fans that run on DC power. Homeowners can also connect a solar panel to the device.   

"I think it's a very simple idea but real huge gains are possible,” said electrical engineering professor Ashok Jhunjhunwala, a member of the prime minister's Science Advisory Council and one of the project’s researchers.  “So I think if we do it right, India has a game changer technology.”