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Grid lessons from India

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As MIT’s Technology Review tries to figure out the lessons for the rest of the world from India’s recent power grid failures, there are lessons for India as well:

India, in particular, operates its grid with one very large handicap: insufficient power. … Few, if any, countries suffer the same gaping mismatch between power need and availability. But India’s disaster illustrates the perils of relying on manual control of the grid as these systems get overtaxed and more complicated. To make grids around the world more reliable, operators need to incorporate more advanced control technology, which can help grids recover gracefully from disruptions.

It will take months to pinpoint the root cause of failure in India, but [Arshad Mansoor, senior vice president at the Electric Power Research Institute] suspects it is something fairly mundane, such as a failed relay or a grid operator making a mistake. Grids in other countries are prone to the same disruptions, triggered by events such as falling trees and generator breakdowns.

The primary function of grid operators is to anticipate load and to maintain a steady balance between power supply and demand. The grid signal operates at a set frequency—60 hertz in the U.S. and 50 hertz in India—and when supply and demand fall out of sync, the frequency will either dip or rise. In the U.S., grid operators have “hot” generators on standby to ramp up power in order to keep a close-to-steady frequency, but that’s not the case when generators are routinely maxed out.

More technologies to keep that frequency steady are emerging. Sensors called phasor measurement units are designed for real-time measurement of grid frequency, and can flag potential problems. Grid operators in the United States are increasingly using automation to manage demand-response programs that lower consumption at big power users at peak times.

Still, there’s little doubt that the causes of India’s blackouts have more to do with politics than technology and engineering. Reports from India suggest that northern states have been consistently overdrawing power in response to drier weather over the past few weeks, but federal regulators did not discipline them out of fear of losing political support for the ruling party in Parliament.

The price of electricity is also controlled, which has led to an underinvestment in the grid. “This is an endemic problem, so there has not been nearly adequate investment in transmission and distribution,” says David Dapice, an economist at the Harvard Kennedy School’s Ash Center for Democratic Governance and Innovation. Coal, which supplies the majority of energy in India, is also controlled by a government-owned company, and there is a debate over how and whether to expand mining.

One section of the article has wider implications for planning:

The conflict between water and power, seen in India’s blackout, is poised to become more acute as weather patterns change and fast-growing economies consume more water. A 2010 report from the World Resources Institute, a Washington-based environmental think tank, says economic and population growth are stressing freshwater suppliers in India, Malaysia, the Philippines, Thailand, and Vietnam. With the rapid expansion of thermal and hydroelectric plants and longer dry periods, many countries in Asia and elsewhere will face water-related risks in power generation, the report said.

A different article in Technology Review suggests a small corrective step:

A big part of the solution is obvious: more power plants, more power lines, and an increased supply of coal and other fossil fuels—in India, many power plants don’t operate at full capacity because they can’t get enough fuel. But another part could be technology that’s already starting to catch on in many parts of the developing world: microgrids.

Instead of relying only on large, centralized power plants, microgrids supply a small area with electricity from distributed sources—such as diesel generators combined with solar panels with battery storage. These localized grids can operate either attached to the national grid or apart from it, in many cases allowing businesses and hospitals and other organizations to keep going without a hiccup when the larger grid goes down.

Microgrids are an extension of on-site generators, or dedicated power supplies, sometimes called captive generation. But they have several advantages over the simple backup diesel generators that are keeping many essential services in India going right now. They use a variety of resources for power, not just diesel generators, which makes them more reliable. So they can keep running, at least in a limited way, even if supplies of diesel fuel get cut off.

Microgrids also offer benefits for the larger grid. Utilities can call on businesses running microgrids to disconnect to ease strain during times of peak demand. That could reduce the number of power outages in a country like India.

“Islanding” of cities like Mumbai and Kolkata, already in use, can be thought of as a microgrid.


Written by Arhopala Bazaloides

August 16, 2012 at 4:43 am

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