Beyond on-off

Smart power grid promises efficiency, consumer options

By Gargi Chakrabarty
Globe Correspondent / February 1, 2010

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Imagine an electrical power network that talks to customers - and listens to them.

Or one that practically heals itself, that can sense when a fallen tree has severed a power line and reroute power so the fewest number of customers possible lose electricity.

Or one that gives customers control of their own energy use through the Internet, remotely turning off appliances or running the washing machine at night, when demand is low.

Those are the promises power companies and the state are exploring in new technologies known collectively as the “smart grid.’’

Under state laws passed last year, every utility in Massachusetts is required to investigate such technologies.

National Grid, NStar, Western Massachusetts Electric, and Unitil have all filed plans with the state Department of Public Utilities for smart grid pilot programs, budgeted at a combined $80 million. NStar recently received $7.6 million in federal stimulus money for two smart grid projects.

Some projects probably will begin in 2010, provided they receive the nod from regulators. But at least one observer said the plans are just part of the continuing development of the nation’s electrical system.

“We don’t use the term smart grid, because it is not a clearly defined term,’’ said Gary DesGroseilliers, executive director of the Future of the Grid study underway at the Massachusetts Institute of Technology’s Energy Initiative. “The electric grid has existed for more than 100 years, and it has continuously been improved. . . . No doubt the grid will continue to evolve to include new features that improve reliability, safety, and security.’’

The first step is the so-called smart meter. Unlike the simple counter of kilowatts now in most homes and businesses, smart meters allow two-way communication with the utility company. Customers can see how much power they are using, hour by hour, on home displays or secure websites, much as online banking allows account holders to view their spending.

Customers could then remotely adjust their appliances to cut down power consumption and save money. For example, they could lower the thermostat from work when nobody’s home, or shut off the washer and dryer during peak demand hours.

Eventually, they will be able to plug electric vehicles into the grid and use them as storage devices for emergencies. Plugged in, electric cars could charge their batteries at night when power is cheap, and feed electricity back to the grid in the afternoon when demand is high and power is expensive.

The evolution of the grid will reach beyond the home. Part of the plan is to install sensors along power lines. The devices will be able to predict whether nearby homes are drawing too much electricity and a transformer in the grid is being overloaded to the point where it might shut down. The system would be able to shuttle the load off to another transformer down the line.

If a cable is cut, say if a tree falls during a storm, the sensor would show electricity is not passing through. It could immediately signal the utility, which could then pinpoint the location of the outage and dispatch a crew to fix it, without having to wait for customers to complain.

The system will even have the power to heal itself, using devices known as reclosers. A recloser is a switch that works much like an automatic circuit breaker that protects main lines from an outage. It can reopen power lines in some cases of minor interruptions.

In April 2008, Colorado’s biggest utility, Xcel Energy, launched a $100 million smart grid pilot program in the university town of Boulder.

Thousands of customers were fitted with smart meters, hundreds of miles of fiber-optic cable were laid, and dozens of sensors were installed.

The results came in 18 months later. Customer complaints about voltage fluctuations had dropped to zero from 60 a couple of years earlier, and there were not any unplanned transformer failures, down from six in the previous year.

“The distribution side of the technology works,’’ said Sandy Simon, director of utility innovations and smart grid strategy for Xcel. “We put in 20 new IT applications and integrated it into the system. The applications helped us remotely monitor the substations and the transformers.’’

Newer technology is also being tested to enable the grid to handle huge amounts of renewable energy, such as from wind and solar power facilities, much of which is produced intermittently - the wind doesn’t always blow, and the sun doesn’t always shine.

The smart grid is coming, but slowly.

For one thing, the technologies involved are expensive - in some cases, exorbitantly so. Also, the regulatory framework - geared to set one fixed electricity rate for, say, a month or a year - will need an overhaul as utilities begin to charge different rates during the day to manage peak demands.

And there’s the human element. Utilities will depend on customers to become more involved in managing the power they use.

“Getting customers to understand and embrace smart grid is a challenge,’’ said Bill Pratt, a project manager at National Grid.

“The challenge is to make energy conservation your second nature, so 20 years from now, you just do it like you recycle - without thinking about it.’’