Aluminium smelting

The problem:
Converting aluminium oxide into pure aluminium is hugely expensive. In a large bath, a powerful electric current is passed through the oxide to smelt out the pure aluminium. Each year, this process uses three per cent of the world’s electricity and costs in the region of US$10 billion. Energy and money could be saved if the baths were bigger. But in bigger baths, the process is destabilised and interrupted as rotating waves start to form in the bath.

The solution:
Professor Sergie Molokov, Director of the Applied Mathematics Research Centre at Coventry University has figured out a theoretical way to suppress the unstable waves with an alternating magnetic field. With colleagues at Warwick University, the theory is being tested in a table-top bath. “The very early results look promising,” says Professor Molokov, “but there are some technical issues to overcome.”

The outlook:
If the team is successful, the electricity consumption by aluminium smelting could be reduced. “Even a one per cent reduction would save a huge amount of carbon and money,” says Professor Molokov, “but it could be more than that.”

Cost-effective kilns

The problem:
Kilns provide us with many objects for everyday life, from the toilets we sit on to the crockery we drink from, in buildings made from baked bricks that we travel to in kiln-cured cars. But only around 25 per cent of the energy used in a kiln actually treats the product in it: the other 75 per cent is used to heat both the kiln and the ‘kiln car’ that ferries the product through the kiln itself.

The solution:
Professor Ron Jones from Horizon Composites in Cumbria is testing a new type of kiln. It is a hollow shell, which has strength and rigidity, so it doesn’t need lots of support engineering around it. It has precise geometry, so kilns can be fitted together easily and reliably. And the kilns are then lined with a freeze-cast ceramic foam. This provides good insulation and low thermal mass, which means the kiln heats up quickly and therefore cheaply.

The outlook:
“I am about to build the first demonstration furnace in my facility in Cumbria and get the energy statistics from it,” says Professor Jones. “If it is beneficial and cost-effective, we will put together a licensing package, on a non-exclusive licence basis, so that this kiln technology can be produced worldwide, hopefully before the year is out. In the UK alone, we think it will save 384,000 tonnes of carbon dioxide per annum.”

Low-cost lighting

The problem:
Europe is phasing out incandescent light bulbs. They use a large amount of electricity, most of which is wasted as heat which can also burn fingers. And as a result, changing a light bulb can cost £100 a time in maintenance costs. That’s a big expense, given that many incandescent bulbs only last between 750 and 1,000 hours. Alternative compact fluorescent bulbs that use less energy are available and last up to 15,000 hours. But these contain mercury which is, in itself, a pollution hazard. Another light – the Light Emitting Diode or LED – projects a thin beam of light rather than the all-round glow of a conventional bulb, until now.

The solution:
Thomas Bayat, managing director of Glowled Ltd, has developed a way of creating an ‘envelope’ of light from an LED, making this light source suitable for all kinds of commercial and domestic applications. A patent is in place and the first products have been made. “They use one hundredth of the energy of an incandescent bulb, they are not hot to the touch and their lifespan is between 50,000 and 100,000 hours so they rarely need changing,” says Mr Bayat. “This technology offers big potential savings for hotels, restaurants, offices and other environments where bulbs are used for long periods.”

The outlook:
Mr Bayat has been refining his product range and undertaking detailed testing with support from the Carbon Trust. Now, GlowLED is initiating a funding round to secure up to £2.5 million in capital to start manufacturing the products and developing the marketplace. “It is the way investment works: we need to start selling the products to attract serious investment,” says Mr Bayat.

Solar power

The problem:
It is estimated that 40 minutes' worth of the sunlight that falls on the Earth is enough to power the planet’s entire energy needs for a year – but only if you can harness it. That’s a huge technical challenge. One way is to focus the sunlight on a very black semi-conductor: the blacker it is, the more solar energy that it absorbs, and this in turn releases electrons, which drive an electrical current. The trouble is, most of the solar energy gets bogged down in the structure of the compounds that are used. Mass-produced solar panels, literally rolled out on a thin film, use compounds like copper indium di-selenide, which is only ten per cent efficient. That means that to generate one gigawatt of power – enough to drive around half a million kettles, say – you would need 50 tonnes of indium, which costs a whopping US$660 per kilogram.

The solution:
“These technologies work in the lab, but for mass power in the future the cost is prohibitive,” says Professor Ken Durose at Durham University. He is principal investigator on the PV21 programme – a multi-establishment team effort to develop new solar technologies for the 21st Century. From 1 April, researchers at the Universities of Bath, Southampton, Cranfield, Northumbria and the Technium OpTIC facility in St Asaph in North Wales will be working to find new semi-conductor compounds that can compete with those based on indium but which use cheaper metals like zinc and tin. They will also be looking to maximise the efficiency in other ways. “Our colleagues at Southampton have found that by texturing the cells they can get an extra ten per cent from the sun,” says Professor Durose.

The outlook:
“In five years, we will have a whole bunch of patents on new ideas in solar energy,” says Professor Durose. “It really is very exciting. We’ve got a huge opportunity and a great team in the UK – and we get about 45 per cent of the sunlight found in places like the Australian desert.”

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