Great Ideas in Energy
- Thursday, Nov 08, 2012
In its latest issue, The Alcalde featured 22 Great Ideas on Energy — nearly a half of which showcased research from the Cockrell School of Engineering. A century ago, The University of Texas was built on energy. Some sources may have changed, but as these brilliant innovations prove, the university is still charging ahead. Read the full story on The Alcalde's website.
Spray solar panels on
The sun pours enough energy onto the Earth in an hour to supply all our energy needs in a year, if we could harvest it. Silicon-based solar cells are still pricey, largely because manufacturing them eats up a lot of energy. For energy users on a budget — and that would be most of us — the numbers still favor fossil fuels. But what will future solar panels, or photovoltaics, be like?
Think ink on a plastic sheet. Brian Korgel, professor of chemical engineering and a nanotechnology expert, is among a group of scientists who are reimagining photovoltaics. Steering away from silicon in favor of copper, indium, gallium, and selenium (a combo he calls CIGS), Korgel is using extremely small crystals of these elements to form a liquid that can collect solar energy. This "nanocrystal ink" can be used to make photovoltaics at far lower temperatures than silicon requires, and low temperatures in turn allow for more delicate and multilayered devices. Much like traditional ink, it can be printed or even sprayed onto flexible surfaces.
"We're trying to create a process like a printing press for making solar cells," Korgel says. "One thing that I think could be possible would be to have a solar panel that's almost like a carpet you unfurl on the top of your roof."
There are many alternatives to silicon, and lightweight CIGS-based photovoltaics aren't new. But Korgel hopes that painting with nanocrystals will allow solar cells to be mass-produced quickly and cheaply while remaining efficient enough to compete with other energy sources. How efficient do newfangled photovoltaics need to be? To succeed on the market, the magic number is 10 percent. A few years ago, Korgel's group proved that CIGS inks could work at 1 percent efficiency; they have since pushed that to 3 percent with low-heat and 7 percent for high-heat manufacturing methods. (By comparison, silicon solar panels are about 15-20 percent efficient.) "There's no reason to believe you couldn't get to 10 percent," Korgel says. "It's just a challenge of figuring out how to do it."
While Korgel says his group is one of many around the world working on more cost-effective solar cells, he's optimistic that somebody will invent photovoltaics that hit "grid parity," meeting or beating the cost of grid power, in the next decade. "The pace and progress in the area of photovoltaics has been really, really impressive in the last four or five years," he says. "It's the kind of problem that if you solved it would really change the world." — Jenny Blair
Use nanoparticles to find oil
One hundred nineteen billion barrels. That's one estimate of how much oil could be recoverable from American oilfields — including some judged no longer worth pumping. That's because the more oil you pump out of a reservoir, the harder it becomes to get what’s left.
Now professors Steven Bryant and Keith Johnston have devised nanoparticles of silica and iron oxide that can be mixed into that fluid. These tiny particles could help us tap into that 119 billion barrels — and tuck greenhouse gases underground in the process.
After fluids are injected into an oil well, they flow back out to production wells, bringing oil up. That's called sweeping the reservoir. Carbon dioxide is a popular "broom" because it's a great solvent for underground oil.
The trouble is that under typical temperatures and pressures of oil reservoirs, CO2 is buoyant and runny, so it can find shortcuts back up rather than herding oil up through the reservoir’s porous rocks while remaining underground. Engineers can make the CO2 better able to push oil up by mixing it with brine and surfactants to form a stiff foam. The downside is that these foams are quick to separate into their component liquids.
That's where Bryant and Johnston’s nanoparticles come in. The tiny particles attach to CO2 bubbles, preventing them from coalescing. "Once you get [the nanoparticles] there, it's difficult to knock them off," Bryant says. "You get this inherent stability." As a bonus, the stabilized foam is likelier to stay put underground, taking atmospheric CO2 out of circulation. — Jenny Blair
Develop the next generation of lithium-ion batteries
UT scientists have repeatedly pushed boundaries when it comes to batteries. In the 1970s, Cockrell School professor John Goodenough pioneered lithium-ion technology to power the vast array of small electronics we rely on today. Now his colleague Arumugam Manthiram, director of UT's Texas Materials Institute and the Materials Science and Engineering Program, has taken Goodenough's discoveries to the next level.
Manthiram is innovating how to use lithium-ion technology to power cars and store electricity produced by renewable sources. Cost, cycle life, safety, energy and power are major barriers. Manthiram is developing safe, nano-engineered alloy anodes to replace the unsafe graphite anodes now used, in addition to new high-energy cathode materials.
To bring these ideas to market, Manthiram partnered with Cleantech entrepreneur Bill Ott. They co-founded ActaCell, a company that got early support from the Austin Technology Incubator's Clean Energy division and seed funding from the Texas Emerging Technology Fund. ActaCell is now developing high-power lithium-ion batteries based on the technology developed in Manthiram's lab. — Maria Arrellaga
Save energy by wasting less food
While waiting tables as a college student, now UT professor Michael Webber was struck by the amount of food tossed out because restaurant patrons didn't clean their plates.
"I worked at restaurants for six years and saw lots of food waste. Wow," Webber recalls. "Food's relatively cheap in America, so we don't value it as much." (By conservative estimates, the U.S. wastes roughly 27 percent of its food, and some researchers believe that figure is closer to 50 percent.)
So years later, Webber, a mechanical engineering professor, and his former research associate, Amanda Cuéllar, set out to study exactly how much energy was lost when Americans chucked all those uneaten nachos or unwanted veggies in the trash.
In their 2011 study, Webber and Cuéllar calculated that if Americans clamped down on food waste, the U.S. could decrease its annual energy consumption by roughly 2 percent.
That may seem like a small percentage, but it equates to saving around 350 million barrels of oil annually. That's more than enough energy to power Switzerland for a full year, Webber says.
"As a nation, we're struggling with energy issues," he adds, "and reducing food waste is not the only answer to the problem, but it might be one of the easiest to implement."
The amount of energy embedded in the food we throw away is more than all the energy we get from the corn ethanol we produce in a year, Webber says.
Webber hopes to further his research on energy and food waste to influence policymakers and society.
The UT campus has taken Webber's findings seriously and is doing its part. In the last five years, the Division of Housing and Food Service has successfully reduced food waste in two dining halls from 112 tons to 59 tons per academic year by adopting smaller food portions, going tray-free, and investing in a marketing program.
The key to reducing food waste is educating every new freshman class, says Scott Meyer, director of food service.
"Anything we save, we put back into our plates," Meyer says. "We might have steak more often or sushi. It's a win-win." —Sandra Zaragoza, with contributions from Melissa Mixon
Use algae as biofuel
Slimy and scummy, algae is a nuisance to many. But to UT scientists, it's a gold mine. Locked deep inside algae is oil. What if instead of costly, hazardous drilling, we could grow our own oil by farming algae?
The Alcalde wrote about this prospect three years ago. But even more exciting developments have cropped up since: not only does UT now boast the nation's largest algae demonstration facility, but it also is among a handful of research hubs worldwide that can already produce oil from the stuff.
"We are one of just a few places, if not the only place in the world, that can do it end-to-end," says professor Bob Hebner, director of UT's Algae Science and Technology Facility, "and we've partnered with more than 30 companies worldwide on algae research."
Hebner says it's the economics that pose a challenge. "Currently, the cost of extracting the oil is very high," he says, "but we've found that, theoretically, you could get 500 times more energy out of algae than you put into it."
He has reason to hope: in 2005, the oil cost $5 per gallon to produce. Today it's a few cents per gallon and expected to go lower. But other costs, such as vital nutrients like phosphorus and nitrogen, remain prohibitively high.
At UT, more than 25 scholars are working at the Algae Science and Technology Facility to find solutions. And the UTEX Culture Collection of Algae is constantly growing new strains for them and global collaborators to study.
Hebner is cautiously optimistic about the biofuel's potential. "We're in the very beginning of this business, but it holds a lot of promise," he says. The airplane industry is a likely first frontier. Continental, Virgin Airlines, Lufthansa, and Air New Zealand have all flown trial flights powered by algal fuel.
Deriving oil from algae, Heber says, is like fast-forwarding the conventional method of getting oil from plant matter buried in the Earth. "Right now, we get our oil from plants that died millions of years ago," he says. "Now we're trying to do in two weeks what Mother Nature does in a few million years." — Rose Cahalan
Use less water in fracking
Hydraulic fracturing is a process in which fractures in rocks below the earth's surface are opened and widened by injecting liquids and chemicals at high pressure to extract natural gas and oil. One of the concerns about what is often called "fracking" is that the process can use a tremendous amount of water. For example, Texas' Barnett Shale requires 2.7 million gallons of water per well. As Texas remains drought-ridden, Professor Mukul Sharma and grad student Lionel Ribeiro are devoting lab time to developing water-saving techniques that will not only decrease dependence, but also enhance natural gas production.
Sharma, who leads the world's largest academic research group on the subject, saw that no one else was addressing the issue head on, so his team dedicated itself to discovering solutions.
"We want to reduce the environmental foot- print of hydraulic fracturing, and there are three areas that we are working on that provide the best means of meeting that goal," Sharma says. "These include safe-produced water disposal, reducing fresh water use in oil and gas production, and fracturing water reuse and recycling."
Armed with this knowledge of what will have the most impact, Sharma and his research group developed a tool to address fracking issues.
"We have built the first fully compositional hydraulic fracturing simulator that is used for fracture design," Sharma says. "It accounts for three important aspects of the problem critical to accurately predicting the fracture: changes in fluid density, temperature and fluid composition during fracturing."
Ribeiro focuses on the reduction of water usage through CO2 and nitrogen foams. These foams reduce the need for water by about 70 percent, and the use of pure CO2 gas almost completely eliminates water from the equation.
"Beyond the environmental impact, the inter- actions between the rock and the injected water can hinder production," Ribeiro says. "The CO2 and nitrogen foams outperform water fractures because they don't cause as much damage to the fracture and the rock maintains its permeability to gas, so overall it is a win-win scenario."
Sharma and Ribeiro are testing the model in the field and getting positive feedback. If the technique becomes an industry standard, it will take a weight off of Texas' water sources, allow for more efficient gas production, and provide more abundant natural gas. — Katharine Grieve
Create a futuristic transit system
Texas' capital city ranks among the country's most gridlocked, 2012 could be the costliest year ever at the pump, and our carbon footprint grows ever larger.
The chairman of UT's Petroleum and Geosystems Engineering Department, Tad Patzek, proposes a solution: podcars.
Podcars are driverless vehicles that run on electricity-powered guideways suspended over existing highways. The concept may seem futuristic, but such cars have already been launched in countries like Sweden and England.
"Podcars cost 10 times less to operate and are 11 times more energy-efficient than today's vehicles," Patzek points out. "Also, photovoltaic panels can be installed on the guideways to augment power supply."
Patzek is moving the concept forward in the U.S. by collaborating with Ron Swenson, one of the scientists leading the charge on podcar development. They both serve on the board of the Association for the Study of Peak Oil, which examines the issues around fossil fuel production.
Podcars are already transporting people at one of the world's busiest airports, Heathrow in London. Given that, Patzek says, "there is no reason why they couldn't move people between the main UT campus in Austin and the Pickle campus 10 miles north. This would be a convincing demonstration project for the city." — Katharine Grieve
Fuel up with natural gas
The U.S. Department of Energy wants to put more natural gas-powered cars and trucks on the road to take advantage of cheaper, cleaner fuel and a near 100-year U.S. supply of natural gas.
And it's betting that UT researchers have the know-how to make natural gas cars and at-home fueling easier for consumers.
The problem for some would-be natural gas car buyers is that at-home fueling appliances are costly, and natural gas isn't available at many U.S. gas stations. That's unlike countries like Brazil, where they are commonplace. Of the 13 million natural gas vehicles on the road worldwide, only 120,000 are in the U.S.
In an effort to solve the domestic natural gas car quandary, the DOE awarded researchers at UT's Center for Electromechanics a $4.3 million grant to advance technology that could reduce the cost of a residential fueling appliance by more than 80 percent.
In the next few years, UT researchers will take their ideas from concept to prototype. On the drawing board: an at-home fueling appliance that can compress natural gas using a linear motor with a single moving piston.
"Eliminating the many moving parts in a traditional compressor will help improve the life and durability of those compressors, and make it cheaper," says Michael Lewis, a senior engineering scientist with the Center for Electromechanics.
Researchers are envisioning a 50- to 70-pound wall unit that plugs into a standard outlet and dispenses natural gas from the same pipelines that bring heat to homes. They hope to begin testing in a real-world environment by 2013.
"It's fulfilling to know that your research is good for the U.S. Widespread adoption of natural gas vehicles will reduce our dependence on foreign oil," Lewis says. "Natural gas vehicles are also better for the environment. They have fewer greenhouse gas emissions than gasoline or diesel vehicles." — Sandra Zaragoza
Use automation to improve drilling efficiency and safety
For 20 years, Eric van Oort worked at companies like Shell, seeing the struggle of oil and gas companies to meet their safety goal of zero people hurt on the job. Now a UT petroleum engineering professor, van Oort saw a solution: automate drilling.
"Drilling is potentially dangerous, with rig staff and heavy machinery operating in the same tight space," he says. "So why not let machines do the hazardous work?"
On its face, automation for safety isn't a new idea. Airplanes have autopilot; cars have airbags. Now van Oort is on a mission to help oil and gas catch up. As the industry works overtime to ensure that a disaster like the 2010 Deepwater Horizon spill never happens again, automation is crucial. Algorithms can detect changes in rig data consistently and quickly — preventing problems early.
There's also a pressing challenge to drill more efficiently. The low price of natural gas, says van Oort, pushes operators to be more efficient. Automating best practices can help reduce waste and improve speed. Van Oort is cautious but confident.
"The oil industry is known for being conservative, but it's changing rapidly, and for the better," he says. "This is the future."— Rose Cahalan