Vail Valley solar specialists explain the ‘smart grid’ |

Vail Valley solar specialists explain the ‘smart grid’

Bill Sepmeier and Matthew Charles
Vail, CO, Colorado

Our nation’s electric grid is not designed to carry large amounts of intermittent renewable energy in proportion to the relatively fixed demand we place upon the grid’s supply each day.

We’ve talked about how a new generation of plug-in hybrid vehicles might provide a source of reserve power to the grid, even as they charge their batteries using grid energy. And we’ve mentioned something called the coming “smart grid” as a requirement in solving the problems increasing proportions of wind, solar and other renewable-energy supplies will present to us and our power systems.

Today’s grid

A definition of smart grid depends on who you ask, but the common denominator seems to be that it is an electric grid that is artificially intelligent; a grid capable of a tremendous amount of systems-level interactive communications and real command and control interaction with the appliances and machines connected on the load side and the generation systems producing the power at the supply side.

Today, system operators literally guess what their demand will be each hour and day based on a number of factors, ” historical use and the weather factor in a lot ” but when loads increase unexpectedly, system operators know this primarily by observing the frequency of the system drop a bit. This happens because electricity is primarily generated by rotating armatures and as load increases, armature speed slows down, exactly like what happens when you push your lawn mower into tall crabgrass.

When system frequency drops, system operators have to bring in reserve generation capacity, which spreads the additional load across more armatures, allowing all of them to speed back up.

The system works well now, most of the time, and will until a significant proportion of the generation capability becomes intermittent which, by definition, “natural” power is.

When a lot of the grid supply is intermittent, the system operators have to provide reserve power for not only the load but these portions of the supply. As the grid is managed today, in a purely reactive mode, situations will get out of hand often. The only option today is cutting off large sections of load. Rolling blackouts, when a power failure can cost a company such as Sun Microsystems $1 million a minute, are not acceptable.

Smart Grid Australia, a new group of governments and energy producers, defines the

smart-grid concept by saying, “The coming decade will be defined by a rampant growth in new intelligent-energy technologies, just as computers and communications devices have defined the recent past. Making our energy systems ‘smart’ holds the key to protecting our planet and to fueling our global economy …

The developers of the smart grid must empower the user to actively participate in this process through a range of interactive intelligent home appliances, allowing them to save energy and assisting them in addressing the inevitable price increases for electricity.”

Tomorrow’s power

The first step in development is the standards of communication used with new smart electric meters that tell system operators how each customer uses energy throughout the day. These meters are already becoming available to some customers, especially local solar system owners using net-metering. These meters are, literally, computers out on the former “meter box” ” but the smart grid doesn’t stop there.

Most industrial process controllers, modern appliances, high-end home lighting systems and other consumer electronics already contain microprocessor controllers. The smart grid will provide standards allowing the capability to “talk” to all of these individual loads, and they will talk back, negotiating power and energy availability constantly.

It’s mind-boggling, but consider this: In a renewable-energy smart grid, when the wind changes 500 miles from here, your electric oven soon will begin switching on and off several hundred times a minute in order to take advantage of rate savings for you during these suddenly created peak demand times, as it shares tightening supplies with thousands, even millions, of other grid-fed “smart” home appliances ” in real time.

As the wind speed drops across western Kansas, reducing the available energy supply, the smart grid will lighten its load in proportions that, since they are shared, will be un-noticed by the people using their appliances. It might take an extra minute to cook a roast, but no natural gas plants would have to be brought on line to make up for the supply variation with a smart grid.

Simultaneously, hundreds of homes and small businesses with solar battery back-up power systems might be told to feed power from their small batteries into the system or to briefly switch their owners to backup power to help offset the reduction in

Kansas wind power.

Thousands of next-generation plug-in hybrid cars, sitting idle at the office or at home, could be asked to send power to the grid briefly. Other sources of wind energy might be imported automatically from areas where the wind is blowing in excess, perhaps California or the plains of central Canada, mixed with solar power imported from vast solar farms in Nevada or Mexico.

The smart grid will not happen spontaneously, but, like the Internet, it will happen rapidly, since without it, the nation’s reliable electrical supply will fail without large numbers of new nuclear, coal and gas generators needed to back up renewable supplies.

Bill Sepmeier is chief technical officer and Matthew Charles is the design and sales manager for Grid Feeders in Eagle-Vail. Contact them at 970-688-4347.

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