Texas already churns out more wind energy than any other state, and its solar power sector is rapidly growing — in some cases, pushing high-polluting coal plants out of the market.
Those trends will need to continue if the fast-growing state plans to meet its carbon-cutting goal under President Obama’s Clean Power Plan.
But quickly adding large amounts of renewable energy to the grid carries challenges, particularly since the sun doesn’t always shine and the wind doesn’t always blow.
Texas researchers like Paul Chu, who recently sat down for an interview with The Texas Tribune, are among those trying to address those challenges, examining better and cheaper ways to store intermittent energy and release it when it’s most needed.
Energy storage can come in various forms. That includes a host of different types of batteries, like those built with lithium ion, nickel cadmium or sodium sulfur. For his part, Chu has turned to high-temperature superconductors.
As founding director and chief scientist at the University of Houston’s Texas Center for Superconductivity, Chu is looking for more efficient ways to store excess magnetic energy in a superconducting coil. He is credited with several breakthroughs in the field that have brought the technology closer to the market.
The scientist spoke to the Tribune about how energy storage could revolutionize the grid and how Texas plays a role in advancing the technology.
The following is an edited and condensed transcript of the interview.
Texas Tribune: People often refer to energy storage as a “holy grail” for the electric grid and renewable energy. Why do you consider it so important?
Chu: Burning fossil fuels is the most wasteful way to produce energy. Fossil fuels are very important to our daily life. But energy in all those fossil fuels took hundreds, or close to billions of years to store. And now we burn it in seconds. And when we burn it, it also generates all types of pollutants. So why don’t we use renewables and clean energy? Well, renewable energy doesn’t give you power at a constant rate — it fluctuates, depending on weather or other factors. The grid operates best when the flow of energy is constant. So you want to store energy, and then transmit it when you need it. And there are many ways of storing it.
TT: But we aren’t storing renewable energy on a large scale across the grid in Texas, or elsewhere. The technology, while getting cheaper, still costs too much right now to deploy far and wide. Why is that?
Chu: Right now, the metals are expensive. It’s the processing that’s expensive. When using superconducting material, you have to put it in atomically perfect layers for the super-current to go through. So this is very costly. For superconductors, you have to incorporate the cryogenic capability — in other words, you have to cool it. That adds to the cost.
TT: I know it's hard to predict when storage will become economical, but can you envision some forms of storage helping Texas and other states meet carbon-cutting goals under the federal Clean Power Plan?
Chu: I believe yes. The question is: How much are you willing to pay? What we are doing here is trying to reduce the cost, if we can, and also the improve the design. Our center is working with the National Labs and industry in trying to make this a reality.
TT: A lot of people were excited last year when Oncor, Texas’ largest transmission company, released a study showing that certain energy storage — in this case batteries — could be economical over several years if the company could use them as a backup source of electricity when power lines go down and sell stored excess energy. What do you make of that proposal?
Chu: I think that’s a reasonable suggestion. When you put in this system, capital costs can be huge. It takes determination to do it. Once you can get it up there running, you can recoup the investment.
TT: Which projects in Texas are you most excited about?
Chu: On the battery side, Texas is doing well. For electrochemical storage, they’re doing quite well. And that expertise is spread among several universities. And we all know that John Goodenough at UT-Austin played an important role in the development of the lithium ion battery.
TT: When we’re thinking about a future grid supported by batteries, what other changes might we see?
Chu: One should not forget the transmission part. That’s where superconductivity can come in. You have all this storage — how do you connect it to the grid system? We need improved transmission. The amounts of stored energy could be so large that conventional power lines might not work. If you use superconducting cable, it could be better.
TT: So building those special power lines would add more costs?
Chu: Yes, the up-front costs. But then the savings — it’s huge.
Disclosure: The University of Houston and the University of Texas at Austin are a corporate sponsors of The Texas Tribune. A complete list of Tribune donors and sponsors can be viewed here.