College of Engineering News • Iowa State University

A U.S. Energy Road Map

On a warm spring day after the end of classes, Jim McCalley ponders the fate of America’s electric grid, the lumbering, patchwork system that in 2003 was brought to its knees by a few trees overgrowing transmission lines in Cleveland.

Just that morning the New York Times had run a feature on the early 20th-century inventor Nikola Tesla’s project to build a “global system of giant towers meant to relay through the air not only news, stock reports and even pictures but also … free electricity for one and all.”

Tree-proof electrical power. McCalley chuckles at the notion—but then checks himself.

“I was just reading,” he says, “an article that said Pacific Gas and Electric out in California—a company I used to work for—is supporting a start-up that wants to put solar cells in space, pick them up, and transfer the power back to earth.”

Critical questions

Jim McCalley is no Nikola Tesla. And, lucky for us, his funder isn’t J. P. Morgan, the financier and industrialist who yanked his support from Tesla, shuddering at the specter of “free electricity for one and all.”

Still, McCalley’s latest project, the 21st Century National Energy and Transportation Infrastructures Balancing Sustainability, Costs, and Resiliency—or “NETSCORE-21”— seems at least as ambitious as Tesla’s doomed dream. Over the next four years, NETSCORE will lay out nothing less than a national road map for energy production, transmission, and consumption over the next forty years, with special focus on the increasingly integral relationship of the electric grid to America’s transportation sector.

Supported by a nearly $2 million grant from the National Science Foundation, McCalley and his collaborators are developing software that will help policy makers, utility regulators, fleet managers, and others implement optimal solutions to critical challenges. Which paths will we take? How much of what kinds of technology will we build? And where will we build it? When will we build it?

There’s no single “right” answer to any of these questions, McCalley insists, but rather a number of potentially good answers. In fact, he says, a given question can be divided into 8 or 10 different trajectories, each having its own unique characteristics.

“Those trajectories will provide society the ability to talk,” McCalley says, “to be informed. How much will it cost? What will it buy in terms of grid strength and reliability and resiliency? And what’s it going to buy us in terms of environmental impacts or relief from those impacts, including carbon?”

Still, McCalley is quick to emphasize that, while the work is all about fostering interdependent energy and transportation sectors that are sustainable, NETSCORE isn’t necessarily a “green” project.

“What we do has three very clear objectives: low cost, low environmental impact, and a resilient infrastructure,” McCalley observes. “Those are the pillars, and we want solutions that are good in each of those areas. It’s pretty clear that some level of green or renewable needs to be in each. But how much?“

Strength through diversity of resources

That’s a question Nadia Gkritza, an assistant professor of civil engineering, will play a big part in answering. Although a relatively new PhD, Gkritza brings to the project significant training and practical experience in economics and statistics, transportation planning, and the bioeconomy, knowledge that partners well with each of McCalley’s focus areas.

The first order of business, she says, involves taking stock of current use and resources, and then projecting changes to the overall national energy portfolio as new technologies and alternative resources come online. However, a core assumption of the project is that, regardless of the ultimate sources of energy, the most efficient means of transmitting energy will be through America’s electric grid, and that the increasing profile of electrified transportation, from high-speed rail to plug-in electric hybrid vehicles (PHEVs), will make extraordinary demands on that grid.

“Resiliency,” in this sense, goes beyond the simple ability of the physical grid to survive attacks by terrorists or even trees. It demands as well that the nation not overly rely on a given source of energy, as we still do today on oil for transportation and coal for electricity—that’s a 20th-century model, says Gkritza—but instead develops a variety of energy resources.

“We recognize that only one renewable source will not be enough to generate the energy we need,” Gkritza observes. “So we’re seeing different areas that have potential, some for biomass and wind like the Midwest, some for solar and geothermal, probably on the West Coast.”

Likewise, Gkritza acknowledges, there is no one-size-fits-all solution to the question of transportation. While many experts assume an increasing presence of PHEVs on American roads, gas- and diesel-powered fleets will have a dominant presence for years to come. Further, much long-haul freight in the United States still ships by truck, and few are proposing hybrid (let alone purely electric) technologies for those fleets.

Optimizing our energy future

While Gkritza favors a much higher profile for electrified rail for both passenger and freight in the United States, these face significant economic and political barriers in what is, after all, a largely deregulated market. Unlike Europe, she notes, rail right-of-way in the United States is largely privately held. Short of nationalizing railroads, significant subsidies and other incentives would be required to encourage an industry that runs on diesel and makes its money shipping coal to move toward a more diversified—and electrified—business model.

That’s where Lizhi Wang of the Department of Industrial and Manufacturing Systems Engineering comes in. With a background in using optimization techniques to solve problems in electricity markets, Wang came to Iowa State in 2007 with a view to applying his knowledge to PHEVs in particular, but agreed to take on the expanded task of developing algorithms to include the total scope of NETSCORE’s long-term challenges across a range of possible scenarios.

Simply stated, “optimization” doesn’t prescribe a specific outcome so much as it first defines the relationships of all known factors in a problem set, then determines the most effective means of directing resources toward any given objective. In a two-dimensional optimization problem, Wang notes, you determine your objective, assess your resources and constraints, and then decide which approach in a field of possible solutions will take you furthest toward achieving that goal.

“But consider,” says Wang. “with NETSCORE, we have a thousand dimensions, and we want to get as far as we can toward a specific direction: the optimal solution is not that obvious. So I’m designing algorithms to achieve the optimal solution as quickly as possible.”

Wang is not talking about a spatial model—that’s just a metaphor—but rather the multiplicity of factors in a problem set, each of which exponentially increases the difficulty of optimizing the other factors; e.g., a given decision regarding electrical production or transmission can have an immediate effect on the transportation side of the equation, and vice versa.

“We have to consider both sides,” Wang reminds. “To the extent we use electricity to power our transportation needs, we increase our burden on the electric grid and have a decreased demand on biodiesel and gasoline.”

‘The problem with planning’

That’s not to suggest that NETSCORE seeks to model the totality of American energy production and consumption; nor does it presume to prescribe universally valid solutions at all levels of social and economic activity.

In evaluating current infrastructure, McCalley observes, there’s a level of “granularity” below which it doesn’t make sense to go. For example, he says, NETSCORE may factor in all transmission lines at 230 KV and above but is unlikely to include the 69,000-volt line running from the City of Ames power plant. Likewise, while the Eisenhower Interstate Highway System and major state roads will factor into transportation models, city-level street grids may not.

“But for those levels we do want,” McCalley asks, “how do we get the information? That’s an issue, because there’s a critical infrastructure thing here that the homeland security people are concerned about.

“We concluded that we need to get halfway there, not 100%,” McCalley continues. “And if you get halfway there with respect to the integrity of your data, it’ll probably be enough to illustrate things that would be very effectively used in follow-up.”

But modeling the current infrastructure—even only half of it—isn’t even half the battle. More than the availability of hard data, what makes optimization especially difficult is the educated guesswork that goes into projecting, over the next 40 years, trends in technology, the economy, and social and political stability, both domestic and international.

While McCalley and company would like nothing better than to beam electrical energy directly to consumers wirelessly from space or even Tesla’s terrestrial towers, the grid of tomorrow is far likelier to involve the construction of massive new transmission lines, along with the inevitable resistance from communities whose paths they’ll cross. An unforeseen technological breakthrough—say, cold fusion in your garage or a thousand-mile PHEV battery—could render their models obsolete. Or, more prosaically, gasoline could cost $10 a gallon—or $2.

And, of course, there’s the greatest variable of all in the looming shadow of global climate change.

“That’s the problem with planning,” Gkritza concedes. “You cannot validate most of the assumptions you make about what will happen in the future until it happens. But we’ll run different scenarios based on different policies—a cap-and-trade, a carbon tax, subsidies for plug-in vehicles.

“The plan is likely to have some high- and low-range scenarios,” she adds. “There are more aggressive things that might happen if the political will is there, and some less aggressive, more incremental changes.”

Farewell to the dinosaurs

The task before them inspires nothing if not humility, and team members are quick to emphasize that NETSCORE does not pretend to offer an “ultimate” solution to the nation’s energy crisis, only some perspective on what some of the solutions—that’s plural—might be. Or, as McCalley would have it, not so much a “master plan” as a tool for master planners to gain perspective and longer-range vision as they make critical choices.


Yet it’s not that NETSCORE engineers don’t share some core convictions about energy in America by mid-century. One bedrock principle, simply put, is that you don’t use energy to move energy—think of those endless rail cars shipping coal from mines in Wyoming and West Virginia to midwestern and eastern power plants, or vast fleets of trucks transporting stocks of gasoline from distribution centers to retailers.

For McCalley, that means two things: First, electricity must be produced at the source of its feedstock, whether coal, wind, solar, or geothermal. And, second, internal combustion engines inevitably must go the way of the dinosaurs whose fossils fuel them, to be replaced by PHEVs and, eventually, totally electric vehicles.

Together, these twin imperatives demand an electric grid that is more robust, resilient, and, yes, smarter than the one we have today. And “smart” means a grid with communications capabilities among producers, distributors, and consumers of electricity that can compensate for the variability of generation from intermittent sources such as solar and wind.

“We’re going to hit a barrier with wind,” McCalley says, “because it doesn’t do a good job following the load. But that barrier tends to go away if you build in the ability to control load at the customer level.”

A smart grid, he adds, demands not only smart consumers and producers, but also smart appliances—everything from air conditioners to swimming pool heaters to auto rechargers—that can shut down automatically for brief periods at minimal inconvenience to compensate for that portion of the power supply dependent upon intermittent sources. And it will mean two-way communication between smart car batteries and home recharging stations, whereby homes can temporarily draw power from a charged battery to compensate for minor fluctuations in supply from the grid.

“These offer some level of controllability to modulate the load to match generation,” adds McCalley. “We’ve always matched the generation to the load, and that’s where wind has a problem.”

‘The will is there’

But that’s just a technical challenge, one the NETSCORE team feels electrical and computer engineers such as McCalley can eventually meet. More formidable are the human factors, along with the assortment of carrots and sticks that policy makers will have to deploy in order to encourage cooperation among the producers, transmitters, and consumers of energy whose individual short-term perspectives don’t always match their collective long-term interests.

McCalley, for one, is both confident and optimistic. No, NETSCORE won’t realize Tesla’s techno-fantasy (and Morgan’s economic nightmare) of “free electricity for one and all.” But it can, he feels, prod the nation toward a different kind of freedom from dependency on foreign oil and ecological anxiety.

“The political will, the social will, the economic will is all there today to make the change,” McCalley reflects. “It’s never been there before for energy like this.”

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