Cohan analyzes Texas' future power options

Rice atmospheric scientist Daniel Cohan found through a new study that Texas has some breathing room as it considers its energy future, but he warned that the state needs to make wise decisions to assure the supply of electricity meets increasing demand and does so in a green manner.

In a white paper produced for a think tank called Texas Business for Clean Air, or TBCA (co-founded by Rice alumnus and The Container Store founder Garrett Boone ’66), Cohan and his co-authors argue that Texas is positioned well for the anticipated growth of its population over the next few decades.

With sufficient generation of electricity to handle its current needs and more renewable resources coming online, the state is acting aggressively through a $5 billion investment to add transmission capabilities, Cohan said. “Our analysis shows that cost-effective efforts to promote energy efficiency, renewable energy and demand response could offset virtually all projected growth in peak demand through the year 2023 and beyond,” he and his co-authors wrote in the paper, “Policy Options for Clean Air and Sustainable Energy in Texas.”

Cohan, an assistant professor in civil and environmental engineering, is the recent recipient of a prestigious National Science Foundation CAREER award. A native of Dallas, he came to Rice from the Georgia Environmental Protection Division, where he served as an air quality expert. He noted with pride that both his grandparents were graduates of Rice, members of the Class of 1942.

TBCA Executive Director Margaret Keliher said, “We had talked to some economists about doing this study, but when we learned about Dan’s expertise in this area, he was clearly the right person. Nobody else we talked to understood this market the way he did.”

The former Dallas County judge said the paper prompted her organization to file eight bills with the Texas Legislature for energy and environmental initiatives.

The paper was co-authored by Rice postdoctoral research associate Birnur Buzcu-Guven and undergraduate Daniel Hodges-Copple, along with Dan Bullock and Ross Tomlin, both of the Houston Advanced Research Center.

Cohan spoke to Rice News about his findings and what everyone should do to keep Texas powered up.

Q: Refitting coal power plants to make them cleaner is a big-ticket item. Will this happen?

A: The problem is we’ve created a system rigged in favor of the oldest, dirtiest power plants. We’ve set stringent standards for new plants, and yet we’re willing to have much higher levels of pollution from our existing plants.

Those old plants have paid off most of their capital costs, so they offer the most affordable form of electricity, and yet they’re being held to a much less rigorous environmental standard. But even with the cost of putting state-of-the-art controls on old plants, they could still be extremely affordable providers of electricity. They might only add to the price by a cent per kilowatt-hour or less.

Q: Is “clean coal” possible?

A: Everyone has a different definition of what clean coal is. Certainly any new coal power plant being built in this country is many times cleaner in terms of air pollution emission than in the past, but we’re not doing anything yet to capture the carbon dioxide emissions that contribute to global warming. Some people wouldn’t define it as clean coal until you go that next step.

There are technologies being studied that could help bring down carbon emissions dramatically. But they take a huge amount of energy, they could raise the amount of coal you burn by a third, and they could raise the cost by a significant amount. You don’t really get a free lunch.

Q: What is being done about that?

A: President Obama’s economic stimulus contains funding to support carbon capture and storage research, and coal power plants that would take that next step of removing CO2 from their emissions.

The United States has had a fitful approach to this. Large amounts of planning went into the FutureGen plant that was supposed to be the big demonstration of how carbon capture and storage technology was going to work. President (George W.) Bush touted it in his last State of the Union address in 2008, and the next week Department of Energy announced they were canceling the program. Admittedly, the program had a number of problems. (Editor’s note: Secretary of Energy Steven Chu said recently the Obama administration is taking a “fresh look at FutureGen. We want to go forward with it in some sort of modified way.”)

There’s been a lot of interest in moving toward a national policy to put a price on carbon emissions. Whether that comes through cap-and-trade or through a tax, it could revolutionize decision-making about how we generate electricity in this country.

One of the things we quantified in the paper was what would happen if power plants had to pay the CO2 prices anticipated under cap-and-trade, which could add enormously to the cost of coal generation.

We run the risk of choosing an option that’s both dirtier for the environment and will cost us more as ratepayers in the long run. It’s extremely shortsighted.

Q: You conclude in the study that wind power has reached parity with coal. When did that happen?

A: Wind reached cost parity with fossil fuel sources over the past five years or so. Its real challenge now, as we scale it up, is to be sure it’s a reliable source of energy.

Texas is making enormous strides in transmission. It’s been a model for the rest of the world. Texas committed last year to $5 billion in investments in new transmission capacity. That’s going to enable wind power to be transmitted from our windiest areas -- in the panhandle and West Texas -- to the population centers that demand it the most.

Texas can handle large amounts of wind power because we have huge generating capacity from natural gas, which has this great feature: It can be turned off and on -- and adjusted. Nuclear and coal plants are on and off. It’s all or nothing with those; they can’t be turned on in a matter of minutes if the wind slows down.

Q: What about solar?

A: Solar hasn’t reached cost parity yet. That might happen in the intermediate future, but there’s still some uncertainty. Where it’s coming close is in solar thermal (in which the sun heats water to drive turbines).

We think about solar as being on a rooftop, but that’s a pretty expensive way to get power, because each kilowatt of capacity takes its own installation, its own connection to the grid. It would be difficult for our existing transmission system to handle.

West Texas has areas that are extremely well-suited to solar thermal generation, and the costs are about half that of photovoltaic cells.

Q: Citizens are getting all kinds of messages about energy. How do we know what to believe?

A: A couple of false choices have been presented to Texans. One is that we have to choose between what’s best for the environment and what’s best for ratepayers’ pocketbooks.

It may be that the most cost-effective, long-term solution could have the least impact on the environment. You could have some real clear win-win situations that catalyze new industries and generate jobs.

The founding of TBCA was originally motivated by business leaders who opposed (Texas power producer) TXU’s plans for 11 new coal power plants in Texas. The plants were being presented as this dire need — at the time the state was projected to hit up against its electricity supply limits and be at risk of brownouts within a few years.

But if you look at the latest updates from the Electric Reliability Council of Texas, which manages most of the state’s grid, the projections show we’ve easily got enough generation capacity to last us well into the next decade. We really do have some time to make the right choices.

One thing that stands out is that the most cost-effective way to help is through energy efficiency. That doesn’t get talked about nearly enough. Most studies show efficiency can save roughly half the cost of any of the options we have for generating new capacity.

Q: So changing out your incandescent lightbulbs to compact fluorescent bulbs really is significant?

A: Right, and more efficient heating, cooling and building design are huge.

Mike Williams, Rice News