By Rebecca Fields Green, CELT Graduate Research Fellow
A technological system that saves money, the environment, and the pain of power outages may sound too good to be true. Yet this dynamite combination is precisely what so-called “smart grid” technology—now being tested in projects around the nation—could offer.
Though people often mistakenly assume a “smart grid” is merely one that incorporates renewable, clean energy and is environmentally friendly, in reality, smart grid technology encompasses a range of devices to address the technological, economic, and environmental concerns facing the electrical grid in the twenty-first century. Much of the infrastructure currently in use is already at least fifty years old, which means that decades of population growth—plus the advent of electricity-intensive computers and the internet—is increasingly putting intense pressure on the system to produce enough electricity to meet peak demand.
In this post I will introduce one facet of smart grid technology—two-way communication—and show how it can enhance the American grid by improving efficiency and integration of renewables.
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Coal-fired power plant in Michigan. From Wikimedia Commons, author Cgord: http://en.wikipedia.org/wiki/File:DTE_St_Clair.jpg.
The driving force behind smart grid development is the desire to enhance grid capacity, reliability, and efficiency—a goal with potential benefits for both the economy and the environment. With two-way communication between consumers and producers of electricity, smart grid technology can eliminate some of the inefficient uncertainties of the grid today, particularly the problem of balancing supply and demand within the electrical grid. Achieving supply and demand balance is more complex for electrical utilities than for other industries; at any second the amount of electricity used in a region—called “load”—must equal the amount generated, but utilities cannot currently build up “inventories” of stored electricity.
At the same time, American utilities remain in many ways “in the dark” about how much electricity they will need to produce to meet load requirements, particularly during peak periods. For this reason utilities often have to bring “peaker” electricity-generating assets into service when they anticipate especially high demand (usually during summer air-conditioning months) so that they can be certain of meeting their requirements. These peaker plants are often older, more inefficient, and very costly to operate, plus they generate substantial additional greenhouse gas emissions.
Smart grid technologies can help remedy the uncertainties of load and electricity production by enhancing the “granularity” of the operator’s knowledge of current and future demand with two-way communication between consumers and producers (DOE, 13-14). With devices attached to consumer appliances, to the infrastructure of local distribution systems, and to the larger regional transmission system, smart grid devices facilitate communication—essentially in real time—about local demand and regional supply conditions. With a more nuanced view of the trajectory of electricity supply and demand at any given second, utilities can make more informed decisions about when and where to bring additional power-generating assets online.
Two-way communication does not necessarily entail reducing electricity demand (although it can do that if hot water heaters and other appliances are programmed to stop drawing electricity when there is great demand pressure on the grid). Two-way communication does, however, allow utilities to react to changing conditions faster and more precisely instead of firing up more power plants as an insurance policy for uncertainty. Simply increasing utilities’ information can help save energy and benefit both our pocketbooks and the environment.
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Installing solar panels in Arizona. From: http://energy.gov/articles/top-6-things-you-didnt-know-about-solar-energy
Two-way communication can also make it more feasible for utilities to integrate renewable sources of power like wind and solar, whose output varies from day to day and even from hour to hour with changes in weather. In today’s grid, demand is the primary variable for utilities; electricity production is largely within their control. As utilities begin incorporating wind and solar assets into their system, however, they must determine how to cope with the natural variability in sunshine and windy days (PNSGDP). Ideally, two-way communication in a smarter grid would give utilities more complete knowledge of whether wind turbines or PV panels are pumping electricity into their region so they can react accordingly. With lightning-fast, two-way communication in a smarter grid, the expanding integration of renewable energy sources becomes more viable.
Designed with a range of objectives in mind, smart grid technologies are not a panacea for reducing energy use and carbon emissions in the US, nor are they intended to be. But by making greater efficiency and the integration of renewables possible, the smart grid can play a significant role in a national strategy for reducing greenhouse gas emissions (Pacific Northwest National Laboratory, v-vi). Since there are several different ideas for how to make the grid smarter, in my next post I will give these technologies a closer look.