Waste not, want not

Handan Tezel, Vice-Dean (Research) of Engineering, is developing technology to store excess heat generated by power plants and solar installations for future use. M.Sc. student Burcu Ugur (opposite), who is assisting Tezel in her research, holds zeolites, a key element in the storage process.

 

Commercializing the technology for use by power utilities, solar farms and buildings with their own solar systems would allow excess heat to be stored and used to create energy during peak periods.

As far as Handan Tezel is concerned, steam puffing out of power plants as they generate electricity is a wasted resource. The chemical engineering professor and Vice-Dean (Research) for the Faculty of Engineering is working to turn her research on storing energy from waste heat or solar panels into a commercially viable technology.

Although it is possible to trap and use excess heat from power plants and solar installations when electricity demand is high, Tezel explains that storing that energy for future use is still a major challenge. Most storage systems are designed to release heat within a few days of generation. Moreover, zeolites, a critical element in the storage process, are expensive. Resembling white peppercorns, they are made up of microporous minerals used to adsorb, or separate a substance from a fluid. Key to lowering the cost, says Tezel, is either increasing the energy density or reducing the price of the zeolite material.

“We’ve increased the density to 200 kilowatt-hours per cubic metre, but need at least five to 10 times greater energy density,” she says. This sort of energy storage conundrum must be solved if many alternative energy generation methods are to catch on.

In Tezel’s laboratory, solar or waste heat is used to remove the water vapour from a column packed with zeolite adsorbent. This energy can be released at any time by introducing moist air into the column of zeolites that adsorbs the water vapour, creating heat in the process. This heats up the air that is carrying the moisture, which can then be used for space heating.

Commercializing the technology for use by power utilities (including nuclear plants), solar farms and buildings with their own solar systems (schools, apartment buildings and big box stores, for example) would allow excess heat to be stored and used to create energy during peak periods.

Tezel says the technology would significantly reduce carbon emissions by putting to good use what is now being wasted. Since the energy would be produced on-site, there would be no need to transport it elsewhere, thereby cutting fossil fuel use.

“It could be sold as well,” says Tezel. “In theory you’d just need a pipe underground to sell it to a neighbour. The closer the better, of course, in terms of the carbon footprint.”

The next step in Tezel’s research is to secure funding to build a prototype many times larger than her current lab’s set-up, to confirm lab results, allow modelling of storage capacity under varying conditions, look at applications for air conditioning and translate results into economic projections.

In the meantime, as she juggles research, teaching and duties as Vice-Dean, Tezel is buoyed by the increasing interest in alternative energy from both students and the private sector. Solar energy companies and utilities in particular have approached her, looking for a solution to improve heat storage. With such interest in her technology, the road to commercialization may not be too distant.

 

Following a research dream far from home

Burcu Ugur left her native Turkey to pursue studies in Ottawa because, she says, research opportunities in sustainable energy are greater in North America than in Europe. The Master of Science in Chemical Engineering candidate was attracted to the University of Ottawa principally because of engineering professor Handan Tezel’s research on energy storage.

“I came here because I heard about Dr. Tezel because she is also from Turkey, and many of my professors knew about her research,” says Ugur, a graduate in chemical engineering from Middle East Technical University in Ankara. “I’ve always been interested in clean energy technologies, and during my bachelor’s degree in Turkey, I became aware of the environmental and health risks of using fossil fuels.”

Ugur began her studies at the University of Ottawa in September 2011. After a semester spent working on a literature search and a crash course from Tezel on zeolites, the key element used in energy storage, she now conducts experiments on heat storage under her professor’s supervision.

Given the opportunities in her field in North America, Ugur expects to stay for some time to come, but plans to apply her knowledge in Turkey some day.

“After my graduation, I would like to continue doing research on renewable energy,” she says. “It could be in the private sector or doing a Ph.D. I would like to go back to Turkey as my family lives there, but the research in North America is more advanced.”

 

by Celeste Mackenzie

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