There is a lot of talk in the news nowadays about “smart grids”, those 21st century products of electronic technology and cutting-edge engineering that will facilitate the tie-in of hundreds of thousands of small, renewable energy sources like solar energy arrays mounted on residential roofs.
We all know what the electric, or utility, grid is; e.g., the transmission and distribution systems that deliver electricity from the power plant to homes and businesses. But what, exactly, is a smart grid?
According to one energy expert, it is the conversion of an analog system to a digital system. Another defines it as the expansion of utility company monitoring and control devices to provide two-way communications – not just from the utility to the customer, but from the customer back to the utility.
The U.S. Department of Energy (DOE) – never one to do things in a small way – has prepared a 48-page booklet that defines the term, but its simplest explanation is a sort of Internet interaction applied to America’s electrical system.
The DOE is also conducting a series of forums to discuss the various issues surrounding eventual smart grid deployment, and a federal smart grid task force – created under the auspices of the 2007 Energy Independence and Security Act – will attempt to coordinate smart grid activities across the federal government sector.
The real vision, a communications network that delivers on-demand information about grid performance (who needs more electricity, and where it is available), interconnection rates (is it cheaper to buy from the Eastern Interconnection, the Western Interconnection, or the Texas Interconnection?), and even substation failures, is a work-in-progress that could both save energy and protect America from cyberattacks which could seriously hamper business and communications, and leave whole cities at the mercy of inclement weather.
One of the disadvantages a smart grid will overcome is the difficulty of connecting renewable but intermittent sources of energy like solar and wind to the existing grid. This will require not only ramping up the existing transmission via a “highway” of extra-high-voltage lines (EHVs), but coordinating and balancing the generators (which must be brought on- and off-line very carefully to prevent overload and consequent blackouts). Other possibilities for integrating renewables safely into the grid include battery storage, and solar technologies like molted salt which store energy as heat overnight.
Currently, the U.S. transmission system is a hodgepodge of power lines and interconnects running on outmoded software to balance loads and determine peak capacity. A true smart grid would allow renewable tie-ins and deliver electricity from any point on the grid to any other, even across the continent, as needed, without diffuse and confusing feed-in tariffs and interconnection fees, or other regional regulations that favor one form of electrical generation over another. In a smart grid, 1 kilowatt of solar from a rooftop would have the same incremental value as 100 megawatts from a nuclear plant, and both could literally go anywhere.
The second-most important feature of a smart grid, and one currently active in Boulder, Colorado thanks to Xcel Energy’s foresight, is a grid that allows customers to regulate their own use based on peak electric needs, turning thermostats up or down in extremely cold or hot weather via programmable thermostats, smart meters and software connected to the utility company.
This – putting control of energy usage directly into the hands of ratepayers – would reduce utility bills and save utilities from having to build more power plants by reducing U.S. electricity consumption by about 16 percent, since homes and buildings currently account for almost 40 percent of all U.S. energy consumption.
It would also create an intelligent that grid that could “heal” itself in the event of regional power disturbances, and optimize power-producing assets like solar by creating a more efficient and equitable distribution.