Sustainable solutions: what it means to be environmentally friendly

29 September 2016

Determined to thwart the impending global energy crisis, Professor Ron Hui (Croucher Senior Research Fellowship, 2013) has pioneered sustainable solutions in the field of power electronics to propel the green energy movement forward.

Hui’s research on power electronics, in particular wireless charging and sustainable lighting technologies, has led to over 55 patents adopted by the industry worldwide, numerous awards, as well as the recent honour of being elected fellow to the prestigious Royal Academy of Engineering (U.K.), an acknowledgement of Hui’s contribution to the field of energy saving and environmental protection.

Tracing his interest in the field back to his days as a PhD student at Imperial College, Hui says, “Reading theology, especially the Book of Genesis, made me realise that we are given the environment to take care of, not to exploit or loot. So, with the effects of global warming drastically intensifying, it became obvious that more needs to be done, which is why I devoted the last 20 years of my research to the reduction of greenhouse gases and electronic waste.”

An important aspect of his research is to devise strategies to apply findings, theories, and inventions into real-world operation. “I do not just tell people that they are wrong, I also come up with practical solutions so that they have an alternative to rely on instead.”

Wireless charging pads

One such study would be his research into wireless charging technologies, of which a group of Hui’s inventions were adopted and written into the first international wireless charging standard called Qi which, in Chinese, means ‘invisible force’. 

The Qi standard was launched in 2010 by the Wireless Power Consortium formed by tech giants including Sony, Panasonic, and Philips. The consortium now consists of over 220 companies worldwide. Hui’s contributions to some of the key features of the standard include the wireless charging pad structure, free positioning, and localised charging.

Having been quite vocal about the damaging environmental effects of company-specific chargers for mobile phones, Hui began working on a charging pad suitable for different kinds of portable consumer electronics such as mobile phones, regardless of their parent company. 

“The mobile phone companies frequently try to promote different versions of their products, including their specific chargers, in order to make more money. They refuse to talk to each other to have a common charging protocol or socket,” he says.

Hui came up with the idea of inventing a user-friendly wireless charging pad to place the phone upon instead of a wire charger. He developed a winding array structure within the charging platform that would respond to the receiver coil inside a mobile phone when the device is placed on it. 

The winding array section closest to the device will detect the device and the mutual magnetic coupling between the transmitter coil in the winding array and the receiver coil in the mobile phone will provide a mechanism for wireless energy transfer, allowing for the user to enjoy free positioning, which is the ability to place the device anywhere within the charging pad.

As for localised charging, this concept refers to the detection of a compatible receiver (i.e. the mobile phone) by the winding array structure. Once detected, only the winding array section underneath the device will be energised. The energy will be transferred through a covered area so that the magnetic flux will be fully enclosed, thus avoiding any human exposure. Any other object, be it a metallic car key or a cigarette lighter, will not be compatible and so no energy will flow through and heat the object up. 

Energy-saving does not necessarily mean environmentally-friendly, unless the product has a long lifetime.

This reduces any health and safety risks caused by the wireless charging flux. It is envisaged that such wireless charging technology will become a norm in the near future, reducing the number of traditional chargers and their associate electronic waste. The environmental implications of this product range from a reduction in the amount of raw materials needed to manufacture the constant supply of chargers for each individual company, to cutting transportation energy costs involved in the mining and manufacturing processes.

Sustainable lighting technology

Another major environmental landmark spearheaded by Hui is his research on sustainable lighting technology. Electronic drivers became more widely-used in the lighting industry in the early 2000s, when they were incorporated into the design of fluorescent light tubes to help conserve energy and be more environmentally-friendly compared to the previously-used incandescent lamps. 

You could replace a 100-watt incandescent lamp with a 25-watt compact fluorescent light for the same amount of light. But while the mainstream viewpoint favours the compact fluorescent light to be an environmentally-friendly alternative, Hui argues against this sentiment. “I think I am the first one to voice out an interesting statement, that energy-saving does not necessarily mean environmentally-friendly, unless the product has a long lifetime,” he says.

Hui says that though the compact fluorescent lamps reduce energy consumption, the electronic drivers implanted in them only have a typical lifetime of one year. This is damaging because the actual tube lasts for about five years, and so consumers are forced to throw away the product without having completely exhausted all of its components, and go buy new light tubes at least once a year. 

Typical compact fluorescent bulbs

The product’s short lifetime is perpetrated by a component inside the driver called the electrolytic capacitor, which is filled with a liquid. When the temperature is increased by ten degrees, its lifetime is decreased by 50%, so most compact fluorescent lamps in the market only last for about a year. 

Furthermore, compact fluorescent lights each contain two to five milligrams of mercury, which is several thousand times higher than the safety level approved for human beings. Since they have such a limited lifespan, the frequent disposing of these lights releases large amounts of highly toxic substances into our environment, causing a detrimental effect overall.

While one aspect of Hui’s research aims to voice out against the misconception that energy saving is equivalent to environmentally-friendly, another aspect studies and promotes the concept of sustainable lighting technologies. Regarding sustainable lighting technologies, the three most important factors that he takes into account are (i) energy saving, (ii) longevity, and (iii) recyclability.

In the past ten years, during which he was awarded the Croucher Senior Research Fellowship as well as several other funding awards, Hui had invented a unique passive LED driver that has a lifetime exceeding 15 years. This LED driver is intended for street lamp use and satisfies the three factors mentioned previously. 

The LED driver has an energy efficiency of 92%, which is higher than the 90% efficiency of an electronic driver, its lifespan of 15 years far exceeds the electronic driver’s three years, and while an electronic driver would just be disposed of in a landfill, 80% of this LED driver is made of recyclable materials.

Prototypes of this passive LED driver have been in the testing period at an actual site trial in South China for two years, and after reports of no failures being recorded, compared to the 17% failure rate recorded for electronic drivers in street lamps, the technology has now been transferred to a Hong Kong-based company for production.

Electric springs

Not one to slow down, Hui is currently researching a new concept called the electric springs. This is analogous to the metallic springs under a bed that are distributed to provide support and absorb vibrations. Hooke’s law or the law of elasticity states that these springs create a force to push back if you compress them, and are pull back into their neutral position when you extend them. “I realised that no one has developed an electrical version of this law in the last 3 centuries, and that such a concept is very important for the future power systems,” says Hui.

He says that if we want to have a higher percentage of our power coming from renewable power sources such as solar and wind power, it is essentially for us to stabilise the voltage and frequency in the power system in order to reduce the effect of the intermittent nature of these power sources and help stabilise the flow of energy. By creating electric springs, we are able to provide the necessary support regardless of the renewable power sources’ dynamic changes.

Hui often makes references to the basic principles of physics when devising any new research study or invention. He says, “Engineering is basically the application of science or scientific principles so, in the beginning stages, I would usually spend some time doing the review, trying to understand what happened in the past, and what technology is available in the present. Then, it becomes easy to point to the future because you can see the trend. You are able to start asking questions as to what should be the best concept or technology for the future.”

Professor Ron Shun Yuen Hui is the Philip Wong Wilson Wong Professor of Power Electronics at the University of Hong Kong, which he joined 2011. He also holds the Chair Professorship at Imperial College London. Hui obtained his Ph.D. at Imperial College London (UK). He previously held academic positions in the University of Nottingham, University of Sydney and CityU of HK. He was appointed Professor of Electronic Engineering at the City University of Hong Kong in 1996, and was promoted to Chair Professor in 1998. In 2001 to 2004, he served as an Associate Dean of the Faculty of Science and Engineering at CityU. Hui is well known for his work on power electronics, in particular the development of novel strategies to manage energy consumption and electronic waste. He has published over 250 technical papers, has had over 55 of his patents adopted by industry and has won multiple awards for his research and contribution to the field of power electronics and sustainable technologies. In 2015, he was the recipient of the IEEE William E. Newell Award and in 2016, he was elected to be a fellow of the Royal Academy of Engineering. Hui was a recipient of the Croucher Senior Research Fellowship in 2013.

To view Professor Hui’s personal Croucher profile, please click here