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2017 Issue 3: Science on a small scale

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Power disruptors

Power disruptors

Imagine a time in which electrical energy is generated all around you and the cost of that energy is continuously falling. Imagine that the only place to view electrical infrastructure, like transformers and telephone poles, is in a museum. Imagine that every building in your daily life generates the electricity that powers every device within it and charges a battery to maintain that power at night or when the sun is obscured. Imagine that the mass production of electrical energy does not add to the heating of the planet nor require massive public or private investments in unsightly carbon-producing infrastructure.

[Photo of Praveen Jain and Marko Krstic at the ePOWER lab at Queen's.]

In one of their labs at ePOWER, Praveen Jain, using tweezers, holds a tiny power converter. Marko Krstic holds a traditional integrated circuit board that can be replaced by the single microchip.

That’s the future toward which Praveen Jain and his colleagues are working at the Queen’s Centre for Energy and Power Electronics Research (ePOWER) in Walter Light Hall. ePOWER “brings together academic and industrial researchers to develop a broad range of applications and expertise, from power transmission to alternative energy, to power consumption to power application-specific integrated circuits.” Its mission is to develop the innovative control algorithms and mathematical architecture to facilitate the application of existing and new technology toward cost-effective and efficient energy generation.

Dr. Jain, a professor in Electrical and Computer Engineering and head of ePOWER, is leading a team of researchers from Queen’s, York, Western, and the University of Ottawa in a project – with support from the Ontario Research Fund- Research Excellence (ORF-RE). They are working to develop new technology to capture solar energy that, Dr. Jain predicts, “will enable us to have off-grid energy systems that are reliable and can give you a 24/7 supply of energy.”

In 50 years we will be off-grid … That’s what this project is all about.

The current quest is for more efficient and ever-smaller micro-inverters that convert sunlight into electricity. “The sun is the largest source of energy on Earth,” Dr. Jain says. “We can very efficiently capture the sun’s energy and convert it into electricity, which is the common form of energy that we use in everyday life. Currently we have renewable energy systems feeding power to the grid. We have the traditional system, and we have renewables. But what of the future? The current model hasn’t evolved at all in a long time. In 50 years, what will our energy system look like? I’m of the belief that in 50 years we will be off-grid. I don’t think we will be connected to any sort of power grid at all. That’s what this project is all about."

Solar panels convert sunlight into direct current (DC) electricity. But it’s rough, unstable, erratic, and discontinuous. A solar panel – to be efficient – must operate at the maximum power point. So the challenge is to create the technology to get maximum efficiency out of a solar panel – and do it cost-effectively.

The technological challenge

If anyone can do it, it is Praveen Jain. He is the Tier 1 Canada Research Chair in Power Electronics, and a Fellow of the Royal Society of Canada, the Institute of Electrical and Electronics Engineering (IEEE), the Engineering Institute of Canada, and the Canadian Academy of Engineering. He has authored or co-authored 550 publications. He holds 107 patents and has launched numerous spinoff companies that have translated his research into real-world applications. In 2011, he received the IEEE Newell Field Award, the highest international award in his field. Most recently, he received the Phoivos Ziogas Electric Power Medal from the Canadian branch of the Institute of Electrical and Electronics Engineers (IEEE) recognizing outstanding engineers who have made important contributions to the field of electric power engineering.

So, what exactly is “power electronics” and why is it so transformative? Power electronics is that cluster of technologies that – in a cost-effective and efficient manner – transforms and regulates and stabilizes solar energy to enable us to operate anything that runs on an electric current. It is a fundamental component of the infrastructure of our increasingly wired and wireless lives – such that advances in this domain produce outsized consequences downstream where we register the effects. The more efficient and cost-effective power electronic technology becomes, the more stable and reliable – and ultimately cheaper – electricity becomes, and the more applications we can imagine and devise.

“One of the issues with solar energy is, of course, what do you do at night, or on cloudy days? So we need to address the storage of solar energy. Batteries are the most common form of electrical energy storage. With the development of electrical vehicles,” Dr Jain predicts, “you will see battery technology evolve very, very rapidly. Once that happens, we can do cost-effective energy storage. Now we want to address cost-effective solar energy capture.

The conversion challenge

Currently, Dr. Jain says, “the cost of taking solar energy and converting it into electricity is at par with the traditional energy sources.” But conversion technology – which converts solar or battery direct current (DC) into usable alternating current (AC) – wastes a percentage of energy through dissipation in heat, which also shortens the life expectancy of the conversion technology. One important task – on which the centre is working – consists of designing technology that converts efficiently and cost-effectively without producing surplus heat.

Improvements extend from the macro-infrastructure of a continental energy grid to the operation of a nano-scale heart pacemaker for an infant, and all points in between. This is the domain in which Praveen Jain has made his career and toward which his students are making their contribution.

Why is power electronics so potentially disruptive? Because, to take one example, if this technology can be cost-effectively miniaturized and engineered to be more efficient, it can be built into existing construction materials so that a building can be made to generate its own power by turning every window or concrete surface exposed to sunlight into an electricity-producing solar cell. These cells are then networked together and their yield is regulated and stabilized by technology developed at ePOWER to render even a simple family residence energy-independent.

A building can be made to generate its own power by turning every window or concrete surface exposed to sunlight into an electricity producing solar cell.

As PhD student Marko Krstic describes it, “If you can extract more power from solar cells – even one per cent more – that’s a very significant development. For this specific converter [a piece of technology developed for his graduate research], we achieved efficiencies that are up to 20 per cent higher than comparable converters that have been presented in industry and academia.” “The converter structure that was developed can be fully integrated into a single microchip that is only millimetres in size,” Mr. Krstic says. “This is very difficult to achieve for existing power converters, which are typically constructed on circuit boards and made up of discrete components. We are able to achieve this while maintaining high efficiency, which means less wasted power.”

[photo of Marko Krstic holding a microchip]
A closer look at a microchip developed at ePOWER. Photo: Bernard Clark

Furthermore, he says, “sales of solar panels have not plateaued – as was predicted by many in the industry. Solar energy is now competitive with coal in some cases. So a device like this converter” – he is speaking of a microchip so small it would take six or seven to cover your thumbnail – “which can be integrated with the silicon solar cell to extract the maximum power out of them … that’s a big step forward.” Even if solar cells are not as efficient as would be optimal in all circumstances, their prices continue to fall. In time, their efficiency will rise so that it will make more sense to generate electricity autonomously than to connect to a grid. Combine these innovations with improvements in battery technology and the effect is compounded. These will become a disruptive threat to existing energy providers, infrastructure, and systems.

The commercialization challenge

“At this moment,” Mr. Krstic says, “we’re in the process of patenting this technology, which we would like to move through quickly, so we can begin to present our work. It could be a real breakthrough and have an immediate impact.”

“But it’s not straightforward,” Dr. Jain adds. “It requires a lot of complex mathematics, a lot of control theory, a lot of electronics, as well as integration of semi-conductors and complex mathematical functions into tiny transistors. So our collaboration with York, Western, and the University of Ottawa enables us to come up with a common architecture, and then the individual components of that architecture. Our task is to apply the existing science knowledge and mathematics to new applications. In the field of power electronics, most of the innovations these days happen because of the mathematics.”

All very promising, but is Canada positioned to take commercial advantage of these innovations? “That’s the one caution I have,” Dr. Jain says. “In this country, we do a lot of innovation, but we are not able to convert that innovation into wealth. Our innovation is going outside Canada and being converted into wealth elsewhere. We get money for basic research, but we lack the mindset to take on the risk of commercializing that innovation – which is not as true in the United States. “Canadians,” he observes, “are one of the most innovative people I have met. Why? I don’t know. I have been working in Canadian industry for 30 years – they are very innovative – but they end up working in Silicon Valley or elsewhere in the U.S. Being a small country, there needs to be a more proactive role from government in developing basic industry. We can’t depend on our resources – they are consumable things.”

The development of small-scale solar power systems aims to break this dependence on dwindling resources. None of this will happen overnight – it will take decades – and it’s too soon to know how much of the commercial benefits will be captured and retained by Canadians, but the tiny converters being designed and produced at ePower will be the stuff of massive change.

Learn more about ePOWER: queensu.ca/epower.

Photovoltaic (PV) or solar cells convert photons of sunlight into electricity. PV cells are made out of semi-conducting materials like silicon. when sunlight strikes the silicon, electrons are excited from their atomic orbit. the energy created can either be dissipated through heat or captured by an electrode in the form of direct current (DC) electricity. technology currently being developed at Queen’s converts direct current into alternating current (aC). The technology for converting DC into AC and rendering it stable enough to be useful and reliable is on the verge of a major breakthrough – and Queen’s is on the cutting edge of that breakthrough.

[cover graphic of Queen's Alumni Review, issue 3, 2017]

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