There's a lot more to green technology than renewable energy. From more efficient aircraft to thread made from chicken feathers, the world is awash with ingenious ideas. So we have scoured research labs and start-ups, and made some hard choices. Here you will find our pick of the best ideas to make our planet a more energy-efficient place
Pee-n-grow
Manufacturing artificial fertiliser is a highly energy intensive process that consumes roughly 1 per cent of the world's energy supply. As odd as it sounds, using sterile, nitrogen-rich human urine instead could prevent the emission of more than 180 million tonnes of C02 each year. Urine collection systems with basement storage tanks have been built by the Stockholm Environmental Institute in more than 800 apartments in rural China, saving an estimated 20 tonnes of C02 emissions annually.
China: available now
Magnetic fridge
The two biggest consumers of electricity in the home - air conditioners and refrigerators - may soon become much more energy efficient thanks to a new method of cooling. Magnetic refrigeration subjects metal alloys to a magnetic field, causing them to cool down. Camfridge, based in Cambridge, UK, says its fridges and air conditioners will cut energy usage by around 40 per cent in comparison with conventional models.
Cambridge, UK: under development
Green machine
The world's first "virtually waterless" washing machine could soon slash the water and energy demands of dirty laundry. Prototypes developed by UK start-up Xeros rely on thousands of polarised nylon beads. These stick to dirt and gobble up stains, leaving clothes dry, and using 90 per cent less water and 40 per cent less energy than conventional washers and driers combined. If the estimated 300 million households worldwide with existing washers switched to these machines, annual C02 emissions would drop by 28 million tonnes.
Leeds, UK: available 2010
Better windows
Increase the number of layers of glass or plastic in a window and you'll save big on heating and cooling. Visionwall of Edmonton in Alberta, Canada, makes a quadruple-glazed window consisting of two layers of rigid polyethylene sandwiched between two glass layers which cuts heat loss by a factor of 4 compared with conventional double-glazed windows.
Edmonton, Canada: available now
The power of pond scum
Green algae grow like mad when fed CO2, and if turned into biofuel can yield up to 100 times the biofuel per hectare as corn, soy or sugar cane crops. Petroalgae of Melbourne, Florida, plans to license their first 2000-hectare commercial alga biodiesel plant in China next year and says the green stuff can ingest C02 straight from the smokestacks of power plants. If emissions from all the world's power plants were harnessed for alga growing and recycled as biodiesel, C02 emissions would drop by roughly 9 billion tonnes per year.
Melbourne, Florida, US: available 2010
Methane harvesting
Methane extracted from animal waste can be used as a fuel. The world's largest biogas plant in Penkun, Germany, was completed in 2008 and converts 84,000 tonnes of manure a year into usable fuel. The liquid manure, along with maize and grain, is fed into fermenters where the biomethane generates 20 megawatts of electricity and 22 megawatts of heat for the town's 50,000 inhabitants.
Penkun, Germany: available now
Superconducting grid
Up to 10 per cent of all electricity produced is lost before it even reaches the intended user due to inefficiencies in the grid. American Superconductor based in Devens, Massachusetts, has developed a superconducting wire that cuts transmission line losses threefold when chilled to -196 ° C. In 2008, the company supplied the wire for the world's first superconducting transmission line, a 600-metre, 574-megawatt cable in New York state.
US: available now
Giant microwave ovens
Known for their ability to warm food using little energy, microwaves could soon save the chemicals industry massive amounts of electricity by heating chemical reagents in much the same way. Each year, chemical manufacturers in the UK alone consume the equivalent of the electricity produced by 20 coal-fired power plants. Recent tests suggest that microwaves can cut energy requirements for heating in chemical production by as much as 90 per cent.
UK: under development
Pleasant light
Light-emitting diodes can produce the same light as incandescent or even compact fluorescent lighting for only a tiny fraction of the energy. However, the light they produce is pale and cool, which means people are reluctant to use them. UK-based company Oxford Advanced Surfaces has the answer. It is developing phosphorescent screens that convert blue-tinged LED light into the warm white light we are used to from conventional bulbs. Worldwide adoption of LEDs could cut global energy consumption for lighting in half, the company says.
UK: under development
Waggling wings
Modern passenger planes are masterfully streamlined but the aircraft are still burdened by turbulence that forms as a result of friction between the plane's skin and the air that passes over it. Wind tunnel tests now show that if only a small part of an aircraft's wings were made to oscillate from side to side, the resulting decrease in drag would reduce fuel consumption by 20 per cent.
UK: under development
Floating wind turbines
Conventional offshore wind turbines are fastened to the seabed with giant thick monopiles. This limits their use to shallow waters, but the strongest winds are often far offshore, where the water is deep. So why not let the turbine float like a boat, anchored to the seabed with huge chains? In June, Hywind, the world's first full-scale floating wind turbine, was anchored 10 kilometres off the Norwegian coast. The 2.3-megawatt turbine floats in 200 metres of water. It will begin feeding power into the grid this month.
Karmøy, Norway: available now
Smarter smelting
A new method of smelting aluminium could help trim the appetite of a process that consumes 2 per cent of all electricity generated worldwide. Conventionally you smelt aluminium by passing an electric current through molten aluminium oxide and surrounding all of the molten material with a magnetic field generated by a direct current electromagnet, which contains the current within the molten aluminium. Sergei Molokov at Coventry University, UK, suggests substituting direct current with alternating current. He says this would lead to a 20 per cent reduction in energy used for the process.
Coventry, UK: under development
Hybrid elevators
The process that allows energy to be recovered when you hit the brakes in hybrid vehicles, called regenerative braking, could also slash the energy elevators use. A new generation of elevators developed by elevator manufacturer Otis based in Farmington, Connecticut, use electric motors instead of brake pads to come to a stop and recoup 25 per cent of the system's energy requirements in low to tall buildings. You can cut energy requirements by an additional 50 per cent, the company says, if elevators use highly efficient variable speed motors and steel belts instead of cables and gears.
Farmington, Connecticut: available now
See-through solar cells
How do you generate renewable electricity in crowded city centres which lack the roof space for photovoltaic cells? Easy: stick transparent solar cells onto every window. Conventional silicon cells block out too much visible light, but solar cells developed by Konarka, based in Lowell, Massachusetts, are made from thin layers of organic polymers and have transparent electrodes. They can also be printed out like plastic sheets, so they could eventually be far cheaper than silicon cells. A 50-floor office block could generate around half of its power from the sun, saving up to 2000 tonnes of CO2 annually.
US: available now
Cars with a spin
Some vehicles use flywheels to store energy from braking and reuse it during acceleration, cutting the fuel required to accelerate. However, these devices tend to be large and heavy. Flybrid Systems, based in Silverstone, UK, has designed a smaller, lighter flywheel that uses carbon fibre and spins at over three times the speed of conventional flywheels. This should make the Flybrid system cheaper and easier to fit into vehicles. Flybrid is now developing a system for a Jaguar saloon car which it predicts should cut fuel consumption by around 20 per cent.
UK: under development
Platinum-free fuel cells
Compared to a car with an internal combustion engine, one powered by a hydrogen fuel cell could save 2.4 tonnes of CO2 emissions per year. The snag is that conventional fuel cell designs require around $2000 worth of platinum catalyst per car. Chris Pickett at the University of East Anglia in Norwich, UK, suggests making synthetic versions of the enzyme hydrogenase out of iron and sulphur atoms to take platinum's place as a catalyst. Iron is one-thousandth the price of platinum weight for weight, meaning a much cheaper fuel cell.
UK: under development
Your car is a battery
Electric cars run off the juice in their rechargeable batteries but some batteries can store up to four times the electricity that the typical owner actually uses. The typical urban range of a car is around 30 to 50 kilometres per day, yet the new generation of electric cars have batteries with the capacity to store 160 km per charge. Instead of sitting idle in garages across the world, stationary electric cars could store energy from renewable sources when supply exceeds demand. This stored energy could then be released to the grid when the demand outstrips supply. The idea is being pushed by several research groups, including Curtin University of Technology in Perth, Western Australia and the University of Delaware, Newark.
US, Australia: under development
Idle engines
Big engines burn a lot of fuel when they are left to idle. In the US, long-haul trucks run their engines for 8-hour stretches while their drivers sleep. Train yard locomotives spend as much as 72 per cent of their time idling. In the US alone, that adds up to 4 billion litres of wasted diesel fuel and 11 million tonnes of CO2 emissions per year. New, readily available technologies, including electrified parking spaces at truck stops and automated systems that turn engines off and on based on temperature and other conditions, can reduce these impacts by 90 per cent.
Various, US: available now
Offshore and vertical
The stronger, steadier wind offshore means that each turbine generates 30 to 50 per cent more energy than an equivalent onshore turbine. The Aerogenerator turbine, being developed by Wind Power in Cranfield, UK, rotates around the vertical axis, and is particularly suited to offshore operation with its low centre of gravity and insensitivity to wind direction. This means that it can be made larger than horizontal-axis turbines, which become inefficient and unstable above a certain height. It is also cheaper and easier to maintain than conventional turbines because the necessary machinery can be located at sea level.
Cranfield, UK: under development
Every drop is precious
Inspired by a beetle that lives in the Namib desert, which has just 10 millimetres of precipitation each year, Andrew Parker at London's Natural History Museum has developed a way to trap every last bit of moisture in the air. With the help of engineers at Qinetiq, a UK-based engineering company, he has designed a material based on the hydrophilic and hydrophobic bumps on the beetle's back that channel water into its mouth. They hope to turn the material into fog catchers to capture water for irrigation and drinking in desert regions. The design is 10 times as efficient as the nets traditionally used.
UK: under development
Power monitor
Now there's no excuse to leave any electrical appliance running when you leave home. A new smart controller developed by Semitech Innovations in Melbourne, Australia, lets you monitor and switch off all your household appliances via software downloaded onto your mobile phone or laptop. One pilot study by the company showed that an office building was able to cut its energy consumption by 25 per cent.
Australia: available now
Fibres from feathers
Every year 38 million tonnes of synthetic fibre such as nylon and polyester are produced from petrochemicals. These, in part, could be replaced by fibres made from the 5 million tonnes of chicken feathers left over by the meat industry every year, says Andrew Poole at the Commonwealth Scientific and Research Organisation in Geelong, Australia. His team has made fibres out of the tough chemical-resistant protein keratin found in waste feathers.
Australia: early R&D stage
Seawater greenhouses
Arid coastal regions, including most of north Africa and other coastal subtropical regions, have severe water shortages and yet are surrounded by the sea. Seawater Greenhouse, a London-based company, is now piloting three projects to economically extract fresh water from the sea using solar power. The company builds greenhouses with integrated solar plants that concentrate the sun's heat to evaporate seawater at one end of the greenhouse. The vapour condenses at the opposite, cooler end and this pure water can then be used for irrigation.
UK: available now
Eyes on the prize
Webcams can make energy-management software work better. Most programs designed to help PCs draw less power are based on putting the computer into sleep mode when the keyboard and mouse aren't in use. But that means the screen also goes dark while you are trying to read or watch a video. The fix: face-recognition software, linked to a webcam. This new approach to energy management puts the computer to sleep only when no one is looking at the screen, rather than after a fixed amount of time. Its makers say the program could save 80 per cent of the energy used by the average desktop each year.
Sheffield, UK: available now
Low heat, high power
Adding metal nanoparticles to the water used in geothermal energy could help tap the renewable resource almost anywhere on the planet. Traditionally, geothermal power plants need heat sources upwards of 160 °C. Unfortunately, only a few regions of the world reach that temperature at depths shallower than 5 kilometres. Some enhanced geothermal systems can run at only 65 °C but are inefficient, so the energy produced is expensive. Adding nanoparticles to water could improve the process, capturing as much as 30 per cent more heat with the same amount of liquid. Researchers at the Pacific Northwest National Laboratory in Richland, Washington, plan a pilot study at the end of the year.
US: under development
Fridge talk
A new generation of intelligent fridges could help smooth out fluctuations in the grid that arise from the irregularity of renewable power - by talking to each other. RLtec based in London has developed technology that lets fridges use supply and demand data from the grid to anticipate power surpluses or deficits and schedule when to turn on or off, thus avoiding sudden spikes in demand when supply is low. The company estimates the technology could reduce the UK's CO2 emissions by 2 million tonnes per year.
UK: under development
Power walking
Every step you take uses energy. So why not recover some? US company PowerLeap has developed floor tiles made out of a piezoelectric material which generate electricity when deformed. It claims that 100 square metres of tiles installed in a busy area such as a train station could generate 18,250 kilowatt-hours per year.
US: under development
Send IT out to sea
One large data centre can use as much energy as 30,000 homes, making it an area ripe for innovation. Sending all those servers to sea either on retrofitted cargo ships or specially designed vessels could cut the need for fossil-fuel energy by half, says Amin Vahdat, director of the Center for Networked Systems at the University of California, San Diego. Ocean-going data centres would use seawater for cooling, instead of mechanical air conditioning, and might be able to turn wave motion into a source of clean energy. Several companies are toying with the idea, but Vahdat estimates that it will be at least three if not five years before such a system would be seaworthy.
Various, US: not yet available
Solar thermal storage
Solar power is great so long as the sun is shining, but the grid still needs back-up power to make it through the night. Soon, however, a 17-megawatt solar thermal power plant will provide stable power round the clock. The Gemasolar project, being built near Seville, Spain, will be the first commercial power plant to trap thermal energy from sunlight in molten salt, and will be capable of storing heat for up to 15 hours. This will be used to generate steam that drives a turbine to produce electricity.
Spain: available nowSource : New Scientist, 2/10/09
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