May 18 2009

What's So Smart About Smart Grid?

Posted by: Jonathan Marshall

The hottest two buzz words in the utility industry these days are "smart" and "grid." They became even hotter after Congress earmarked $4.5 billion in federal stimulus spending on smart grid. Utilities are scrambling to come up with eligible projects, venture capitalists are investing hundreds of millions of dollars in the sector, new conferences are being organized almost weekly and consultants seeking a piece of the action are clogging the Internet with PowerPoint presentations.

But just what is so smart about smart grid? After all, electricity grids--transmission and distribution lines connecting generators to customers--have been around for more than a century, and the creators of what the National Academy of Engineering termed the greatest engineering achievement of the 20th century weren't exactly dumb.

The so-called smart grid is really a smarter grid, taking advantage of new technology to enhance efficiency, reliability and environmental sustainability. Here's how many at PG&E describe it:

The Smart Grid will leverage the power of information to transform the operation of our electric network--by integrating sensing, communications, computing and control technology from generation to the customer premise-- in order to give customers cleaner, more reliable and more flexible energy services.

So what does this mean in practice? A few examples might help:

• A fundamental building block of a smarter grid is the "smart meter," which keeps track of energy usage at frequent (say, hourly) intervals and communicates it back to the utility, eliminating the cost and hassle of monthly visits by meter readers. Customers can see their energy usage on the Web, helping them manage it better--for example, they might unplug that freezer in the garage after they realize just how much juice it draws.
• The same meter can be programmed to instruct a new generation of smart appliances in the home, like dishwashers and clothes dryers, to moderate their energy use when electricity prices are highest (on hot summer afternoons). Customers who sign up for voluntary programs like this can save money. For the utility, such control will be essential when millions of customers start charging plug-in electric vehicles.
• To improve service reliability, smart sensors on distribution lines, transformers and other parts of the grid will detect trouble spots, allowing system operators to prevent outages. When an outage does occur, intelligent switches will confine it to as few circuits as possible and identify the location so crews can repair it quickly.
• As utilities add more and more renewable power, they will face the challenge of balancing supply and demand when power availability fluctuates with the winds and available sunlight. A smarter grid will measure varying power output levels in real time and call upon storage devices, including utility-scale batteries, to even them out.
• A smarter grid will also perform that balancing act by adjusting demand automatically. If generation dips for a time, the smart grid can signal participating customers to cut back their usage until power levels are restored. That solution is likely to be much cheaper--and environmentally cleaner--than building new gas-fired "peaker" plants to back up wind farms and solar arrays.

PG&E's Andrew Tang, who heads the utility's "Smart Energy Web" program, recently presented his vision of the future of smart grid at the California Academy of Sciences in San Francisco's Golden Gate Park. Click on the short video clip above to see what all the excitement is about.

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