This may seem a pretty simple scenario; but behind the scenes, a vast framework of wasteful and polluting processes is at work. In big cities, the water in your kettle and the electricity to boil it may have travelled over 100km to reach you.

What toll is that cup of tea taking on the planet – and your wallet?

Trigeneration – the simultaneous production of electricity, hot water and cold water from a single fuel source – is set to revolutionise the way we manage our resources. The technology isn’t new: Thomas Edison built the prototype system in 1882. But the green revolutionary potential of trigeneration is only now being realised.

Getting back to nature

At the moment, our cities’ resources are managed in linear, isolated systems – power and water coming in, waste going out. This is in stark contrast to the interconnected loops of natural ecosystems, where the output of one process forms the input of the next.

“We do everything to excess in Australia,” says Vanessa Rauland, who is researching city decarbonisation at the Curtin Sustainability Policy Institute in Perth. “We consume more resources and produce more emissions than almost anyone else in the world.”

To get our urban metabolism under control, Rauland says we need to get back to nature: “We need to move towards an integrated, circular system where resources are continuously recycled – just like an ecosystem. This is far more achievable at the local level.”

In other words, cities need to ‘decentralise’ energy: instead of relying on a couple of large out of‐ town power plants, we need to embed many small‐scale ones in and around the city.

Cleaner, cheaper and more efficient than conventional technology, trigeneration is a perfect candidate.

Three‐fold benefits

Trigeneration works on the same basic principle as the coal-fire process that currently meets the staggering energy demands of most cities: water is boiled to create steam, which turns turbines to generate electricity.

But it is where the two technologies differ that trigeneration’s appeal lies. Instead of burning carbon-intensive coal (“the primary cause of climate change,” says Rauland), trigeneration relies on low‐carbon natural gas.

And where coal‐fired plants waste two‐thirds of the thermal energy they produce – as gas released into the atmosphere – trigeneration captures and recycles this excess heat.

Trigeneration’s hot water by-product can be used directly, to heat buildings or to drive absorption chillers to generate cold water, which can be used for air‐conditioning.

It’s this on‐the‐spot recycling that gives trigeneration its 2.5 fold efficiency edge over coal-fire. “The capture and use of waste heat means trigeneration achieves around 85% efficiency,” says Rauland. “For coal‐fire, that figure is closer to 30%.”

But herein also lies a major potential stumbling block for decentralised trigeneration. Without demand for hot and cold water nearby, trigeneration’s efficiency advantage is squandered.

“Although trigeneration theoretically can work at any level, I can’t see this being feasible in our low‐density suburban sprawl,” says Rauland. “It will only be economically viable in denser city centres.”

Housing a mini power plant in your basement would also eliminate much of the transmission losses and substantial costs associated with bringing out‐of‐town power into the city.

Fuelling the future

But just how green is trigeneration; isn’t gas a fossil fuel? Although cleaner than coal, gas is still a non‐renewable energy. In fact, its primary component, methane, is itself a more potent greenhouse gas than carbon dioxide.

This drawback could be overcome by perhaps the most exciting and cutting-edge aspect of trigeneration technology: its potential use of new‐wave renewable and low‐carbon fuel sources.

We’re talking about the untapped energy of waste; food scraps, agricultural biowaste, even sewage, can be recycled into synthetic gas, which could be fed into trigeneration plants.

One particularly impressive emerging technology, plasma arc gasification, blasts organic waste into its component gases at super‐hot temperatures. This process, however, requires electricity – which seems somewhat counter‐productive – and isn’t yet an economically viable option.

Powering ahead

Meanwhile, gas‐fuelled trigeneration is already making an impact. A retrofitted network of trigeneration plants has transformed the Borough of Woking in the UK, reducing emissions by around 80% from 1990 levels.

Woking has also highlighted another major advantage of decentralised energy: the debilitating blackouts that plague our current systems could become a thing of the past.

Trigeneration pioneer Allan Jones, credited with the success of Woking and similar results in London, told a 2008 symposium audience: “We’ve had four national grid power cuts in the last couple of years. [In Woking] people were totally unaware there was a blackout.”

When the City of Sydney was looking to reduce its emissions, it commissioned Jones to weigh up the available technologies. His consultancy group identified trigeneration as cheaper than large‐scale renewable energies such as wind and solar.

Sydney is now aiming to meet 70% of its energy needs with trigenerated electricity by 2030. David Holden of sustainability analysis company Kinesis, who collaborated on the master plan, says he expects to see the first plants implemented next year.

And Sydney is not restricting the overhaul to electricity. It is also looking to simultaneously install decentralised water infrastructure. And remember that used teabag? An underground network of tubes to remove garbage at 70km/h is also on the table.

Several other Australian cities are moving to follow Sydney’s lead. It appears trigeneration is proving the catalyst for a radical transformation of the way we manage our resources.

But a few hurdles to decentralisation still remain.

“We are essentially completely redesigning the way we deliver energy to a city,” says Holden. “So it’s not without challenges.”

Viva la verde revolución.               

Imagine lying naked on frozen Arctic ground. Every limb shudders with the intense cold. Suddenly, you’re catapulted to the baking dunes of the Sahara desert, engulfed in a cocoon of scorching air. This torment lasts 36 hours. Then your journey begins again.

Every year, 5 million people, mostly children and pregnant women in sub‐Saharan Africa, experience this ordeal – the symptoms of malaria. Of these, one-fifth do not survive. For the majority of malaria sufferers, the only effective antimalarial drug still standing, artemisinin, is too expensive.

And the situation is set to worsen. The parasite responsible for 95 per cent of fatal malaria cases has begun to develop resistance to artemisinin. If this resistance spreads through the parasite population, we will be left without an effective front-line malaria drug.

In an effort to keep artemisinin resistance at bay, the World Health Organization (WHO) has recommended artemisinin combination therapies (ACTs) – uniting artemisinin derivatives with bygone antimalarial drugs – as the preferred front-line treatment. The premise behind this tactic is simple: administering two drugs simultaneously presents a much more complex puzzle to the parasite, dramatically reducing the chance of resilient individuals emerging.

Money no object?

Currently, artemisinin can only be obtained by costly extraction from the plant Artemisia annua. Herein lies a major problem with ACT: artemisinin is expensive on its own, but combined with the cost of a partner drug, the price of ACTs goes through the roof.

This problem is beginning to look surmountable. In an unprecedented venture, the world’s fourth largest pharmaceutical company, Sanofi‐Aventis, has joined forces with a not‐for‐profit organisation, the (DNDI). This collaboration has already provided over 50 million lifesaving ACTs to developing countries at cost price: $1 per adult dose, 50¢ for a child – a reduction of several dollars.

DNDI’s director of research and development, , believes philanthropic public‐private sector cooperation is vital for control of the oft‐neglected developing‐world diseases. “In building partnerships, these products can be developed at a cost so that the largest global health benefit can be attained,” he says.

The new treatments have been specifically developed to reduce the chance of drug resistance evolving in the parasite population. By combining the two partner drugs in a single tablet, the dangerous practice of taking one drug alone is avoided.

Another risky, and common, behaviour is patients not taking the full dosage required to totally eliminate the parasites from their bloodstream. To increase the likelihood of sufferers following the treatment course to completion, these ACTs require just one or two tablets daily for three days. By comparison, treatment with the original antimalarial, quinine, involves three tablets daily for a week.

This initiative is already saving thousands of lives. But when the average sub‐Saharan African lives on less than $2 a day, $1 is still too much.

Cutting costs

Compounding the expense of artemisinin production is an unreliable supply of Artemisia, which produces the drug in scant concentrations. When the WHO elevated ACTs to front-line status, farmers quickly filled the lucrative new market niche and the lifesaving artemisinin became abundant. But this venture was not as profitable as they had anticipated: very few distributors could afford to buy the drug. Supply soon grossly outweighed demand and dozens of farmers went bust as the price of artemisinin plummeted by more than $1000 per kilogram. Now that initiatives to widely distribute ACTs have caught up, there is a shortage of artemisinin and the price is predicted to soar. The big question is: how can we ensure a stable supply of affordable artemisinin in the future?

The team at the (CNAP) at the University of York, UK, is making headway. Their aim is to create high‐yielding Artemisia varieties by using molecular technology to accelerate traditional breeding strategies. By identifying genes that boost artemisinin yield, plants with a winning genotype can be recognised much earlier than with conventional breeding, fast‐tracking the process.

The expense of artemisinin extraction lies largely in the amount of plant matter that needs to be processed. By increasing the artemisinin content of each leaf, the development of high‐yielding Artemisia crops will slash the cost of extraction. CNAP’s approach has already generated new Artemisia hybrids that yield 55 per cent more artemisinin that the current variety of choice ().

CNAP has also created a toolbox for producing plants that are bred to thrive in particular regions by delving into the genotypes of Artemisia from several places around the world. Elspeth Bartlet, communications manager at CNAP, says this is an important aspect of the project because it means farmers in malaria-affected areas can contribute to disease control. “Many African governments want to provide at least part of the solution to their endemic problems,” she says.

However, CNAP believe their approach will provide only part of the solution. “Synthetic artemisinin will act as a valuable second source that will hopefully help to prevent supply‐demand mismatches,” says Bartlet.

and colleagues at the University of Nebraska Medical Center in Omaha have developed a fully synthetic drug with similar properties to artemisinin. The drug, arterolane, is easy and inexpensive to produce and performed well in a recent phase II trial (). According to Neena Valecha of the National Institute of Malaria Research in Delhi, India, who led the trial, arterolane may be available by next year.

The world is on the brink of a turning point in malaria control. If ACTs are to reach those most in need, the price of these lifesaving medicines must be cut dramatically and the catastrophic spread of resistance to our last line of defence avoided at all costs. As with all global problems, it seems that cooperation will prove the key to defeating this destructive disease.