The 'tricky' challenge of storing energy

by Karen Kawawada, Communications and Public Affairs

In some senses, generating sustainable energy isn’t all that hard. The wind blows, the sun shines, waves flow — that’s energy. The tricky part is capturing, storing and distributing the power, especially when renewable sources can be as intermittent as wind gusts.

Linda Nazar, a professor of chemistry at the University of Waterloo, is working on the storage part of the equation. She’s one of the eminent scientists working on a blueprint for the energy future at the Equinox Summit: Energy 2030, underway this week at the Perimeter Institute for Theoretical Physics. Nazar, who is Canada Research Chair in Solid State Materials, is a world leader in research into next-generation batteries that use nanomaterials to deliver far more oomph than even today’s best batteries.

In more scientific terms than “oomph,” old-fashioned lead-acid batteries deliver 35 watt-hours per kilogram, abbreviated as Wh/kg. Nickel-cadmium batteries deliver 45 Wh/kg, and today’s best rechargeable lithium-ion batteries, which probably power your laptop or smartphone, deliver about 150 Wh/kg.

Nazar is working on batteries using new materials such as lithium-sulfur, which could deliver some 600 Wh/kg once commercialized, and lithium-air, which could deliver some 1,000 Wh/kg. Another potential is magnesium-sulfur, which is still “a gleam in people’s eyes,” she said in a panel discussion at the summit on Tuesday (photo at top).

However, developing the next generation of batteries isn’t easy, and it will be 10 to 15 years before they’re available on the market, Nazar warned. “I think it’s safe to say, when people ask: ‘Why haven’t you built a better battery for us?’ Well, we have. It’s just… a complicated process because the chemistry is really tricky.”

The materials Nazar is working on could potentially deliver as much as 10 times the power of current-generation batteries, but she readily admits they will never have the energy density of gasoline, which can deliver 12,000 Wh/kg.

 “I think that one has to remind oneself that chemistry is based on the periodic table. You can’t get around that,” she said. “But nanomaterials can offer tremendous abilities to move beyond the batteries that we have, to a whole new generation of batteries, and if we can even get to five or seven times the energy density of the ones that we have, it could make serious changes in the way that we use energy.”

More powerful batteries, coupled with a smart grid, could make a major difference in how we use renewable energy, as panelists in yesterday’s plenary made clear. Bill Rosehart, a University of Calgary professor who earned his PhD in electrical engineering from Waterloo, talked about the need to change the electrical grid. “Since the 1880s, things haven’t changed … With smart grids, everything’s going to change, everything can change, and that’s going to become a real enabler for making real progress in our emissions.”

Today will bring the release of a communiqué that summit participants have been putting together to start us down the right path to the energy future. There’s more about this week’s sessions on energy distribution and storage, on a special Equinox Summit web page.

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Grant supports better mapping of sea ice

a news release from the university’s media relations office

A Waterloo engineering researcher has received funding to refine a breakthrough technology to more correctly identify sea ice, an important clue in tracking climate change in the North and South Poles. David Clausi, a professor of systems design engineering, has been awarded a $150,000, 18-month grant for key development work on the Map-guided Ice Classification System (MAGIC). The strategic investment initiative is funded by a NSERC Network of Centres of Excellence, known as GEOIDE (Geomatics for Informed Decisions).

MAGIC is designed to read and interpret satellite imagery using ice maps provided by the Canadian Ice Service (CIS), a government agency based in Ottawa.

Clausi said he believes he and his research team are the first in the world to automate the interpretation of the imagery. "It's been the holy grail of the remote sensing problems," he said. "Ever since we've been able to capture this radar data people have wanted to automate the process. We're the first ones to make these big steps. Other algorithms have been evaluated and they’ve been shelved."

Currently, the work of developing ice maps is performed manually at CIS. Clausi said that while CIS staff do a good job in creating the maps, detailed mapping cannot be produced by a human operator and computer vision algorithms are therefore necessary to do such tasks.  

In 2005, he was awarded a $130,000 strategic investment initiative grant to research remote sensing and computer vision technologies in order to better identify sea ice. "The continued funding will let us take the algorithms we've developed in-house and make them part of the operational pipeline at Canadian Ice Services for generating ice maps," said Clausi, whose research interests include computer vision, digital image processing and pattern recognition.

Within MAGIC are a host of algorithms, including one that identifies ice types and their locations in the sea. Ice maps are used primarily for two purposes. First, ice maps are critical for ships and ice breakers moving through ice-infested waters.

They are also used to monitor climate change, because seasonal volumes of ice are key indicators of the impact of global warming. Knowing the extent of open water is critical for climate models, since heat transfer from open water directly to the air is tremendous compared with heat transfer through an insulating ice cover. Since ice covers vast inaccessible ocean areas, only remote sensing and the application of computer vision can be used to effectively study ice phenomena.

As well, the maps assist with mining and oil exploration in the north. Knowledge of the ice types and their distributions provide tools for understanding shrinking polar bear habitats. MAGIC has also been used to interpret radar imagery of lake ice and Brazilian savannahs.

Clausi, who developed MAGIC with a number of Waterloo systems design engineering graduate and post-doctoral students and other researchers, is partnering with Canadian company MDA, which owns Radarsat. Radarsat is a Canadian satellite carrying a SAR (synthetic aperture radar) sensor that produces images that provide unique information compared with visible band cameras.

It’s an excellent example of the university, industry and government synergy that is furthering research in Canada, Clausi said. "We have a group who knows what they’re doing technically, another group that has a vested interest in creating products based on the satellite data, and an academic who is committed to developing systems to automate interpretation of satellite imagery containing sea ice. It’s a very nice fit."

CAR

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