The printer system uses existing technology to embed polymer solar cells (also known as organic solar cells) in thin sheets of plastic. The A3-sized panels are created by laying a liquid photovoltaic ink onto the thin, flexible plastic.

According to the researchers, the technology is so simple that it could soon mean everyone has the ability to print their own solar panels at home.

Project co-ordinator and University of Melbourne researcher, Dr David Jones, said that “We’re using the same techniques that you would use if you were screen printing an image on to a T-Shirt”.

Near-term uses include putting the panels onto laptop computers or mobile phones. Eventually, they could be printed on to multi-storey building windows or roofs.

(Cross-posted from Aussie Renewables.)

Now, sceintists at the University of Exeter have taken genes from the camphor tree, soil bacteria and blue-green algae and spliced them into DNA from E. coli bacteria. When the modified E. coli were fed glucose, the enzymes they produced converted it into fatty acids and then turned these into hydrocarbons that were chemically and structurally identical to those found in commercial petrol.

In the experiment, the E. coli were fed on glucose made from plants, but the researchers say that, if they were to scale-up, they could tweak the genes to produce enzymes that would allow the bacteria to feed on straw or animal manure.

University of Exeter researcher, John Love, says that "We are biologically producing the fuel that the oil industry makes and sells".

Deakin University's Dr Wei Wei Lei said that "The effective removal of oils, organic solvents and dyes from water is of significant, global importance for environmental and water source protection.”

The absorbant material consists of sheets of boron nitride, also called "white graphene".

The sheets are highly porous, have a high surface area and float on water. When the white sheets are dropped on an oil-polluted water surface they immediately absorb the oil and become dark brown. It only takes about two minutes until all of the oil is taken up by the nanosheets.

Once saturated, the sheets can be easily picked up from the water surface and cleaned by heating or washing to be reused several times.

The ability to recycle so simply and easily makes the porous boron nitride nanosheets ideal for water purification and treatment.

“What we have developed is unique and has enormous potential on the global market," said Dr Lei.

(Cross-posted from Aussie Renewables.)

Current flow batteries pump two different liquids through an interaction chamber where dissolved molecules undergo chemical reactions that store or release energy. The chamber contains a membrane that only allows ions which are not involved in reactions to pass between the liquids.

Flow batteries are among the most promising technologies for grid storage because they include tanks, pumps and pipes which are easily scaled up to whatever size is required.

However, current flow batteries are expensive because the liquid reactants, which are needed in large quantities for grid storage, include costly, rare materials. The membranes are also expensive and require frequent maintenance.

In the new battery design, the reactants are mostly lithium and sulfur, which are relatively inexpensive. These interact with lithium metal coated with a barrier that permits electrons to pass without degrading the metal. The entire molecular stream is dissolved in a non-corrosive organic solvent. The design does not need a membrane at all.

In the video, Stanford graduate student Wesley Zheng demonstrates the principle of the new batteries.

The device uses a two-stage process to purify the water. In the first stage, it removes biological contaminants, such as bacteria and viruses. In the next stage, silver nanoparticles are used to remove chemical and heavy metal pollutants.

The biggest challenge for the research team was to develop a system that could release silver ions continuously as part of the purification process, without using any electricity. They achieved this by creating a composite structure that traps the nanoparticles in "composite cages" made from a clay-like material This allows the device to produce water of drinking standards at a rate of up to 10 litres per hour.

Their concept is to place spherical concrete tanks, about 25 metres in diameter, on the seafloor under floating wind turbines. The concrete tanks would serve both as anchors to moor the floating turbines and as a means of storing the energy they produce.

When the wind turbines produce more power than is needed, that power would be used to pump seawater out of the tank. When power is needed, water would be allowed to flow back in to the tank through a turbine attached to a generator.

The MIT researchers have calculated that one such 25-meter spherical tank in water 400 metres deep could store up to 6 megawatt-hours of power. Preliminary estimates indicate that such a tank could be built and deployed at a cost of about $12 million and that it would yield stored electricity at an estimated cost of about 6 cents per kilowatt-hour, which is comparable to current utility costs. The cost of the undersea storage technology could be expected to be reduced over time.

In this short animation, Guardian columnist George Monbiot teams up with Leo Murray and green charity PIRC to explain the UK's 'carbon omissions':

The system uses a large parabolic dish made from a multitude of mirror facets. The dish is attached to a tracking system that determines the best angle based on the position of the sun. Once aligned, the sun’s rays reflect off the mirror onto triple-junction PV chips. On average, each chip can produce 200 to 250 watts over a typical eight-hour day in a sunny region.

Each solar PV cell is cooled using technology developed by IBM for cooling supercomputers. Microchannels, only a few tens of micrometers in width, pipe coolant in and extract heat for heating buidings or other uses.

In the prototype system, water, heated to 90°C, will pass through a porous membrane distillation system where it will be vaporized and desalinated. The system could provide 30-40 litres of drinkable water per square metre. A large system could provide enough water for a small town.

The PV cells are about 30% efficient, while another 50% of the Sun's energy is captured as heat – making the entire system capable of using arond 80% of the solar energy falling on it.

The developers are targetting a cost of $250 per  square metre – which is a third of the cost of comparable systems.

To date, organic solar cells have usually been fabricated on glass or plastic. Neither of these is easy to recycle if, for example, they are broken during manufacture or installation. Cells on plastic have the further disadvantage of being petroleum-based. Paper substrates have been tried but have limited performance because of paper's rough surface and porosity.

However, cellulose nanomaterials, being made from plants, are renewable and sustainable and, unlike paper, the substrates have a low surface roughness.

The researchers report that they have achieved a power conversion efficiency of 2.7% with the organic solar cells and believe that this can be improved to around 10%, a level similar to solar cells fabricated on glass or plastic.

The great strength and light weight of nanocellulose have fostered interest in using it in everything from lightweight armour and ballistic glass to wound dressings and scaffolds for growing replacement organs for transplantation.

Cellulose is the most abundant organic polymer on earth but most of it is in the form of wood fibre and plant cell walls. Very few organisms produce cellulose in its nanostructure form.

Nanocellulose research has a long history. As early as 1868, Louis Pasteur noted that vinegar-making bacteria produce the "sort of moist skin" now known to be nanocellulose.

Nanocellulose exists in two forms, long-chain polymers and crystals. In the 1980s and 1990s, Dr Brown's team sequenced the nanocellulose genes from A. xylinum bacteria and identified the genes involved in both polymerizing and in crystallizing it. However, they recognised that bacteria would not be suitable for making commercial amounts of nanocellulose because they would need a high-purity broth of food and other nutrients to grow.

Dr Brown has now reported that his team has genetically engineered cyanobacteria (blue-green algae) to produce the long-chain form of nanocellulose and are progressing towards producing the crystalline form, as well as scaling up from laboratory-sized tests to larger outdoor facilities.

The advantage of using cyanobacteria is that they make their own nutrients from sunlight and water – and remove carbon dioxide from the atmosphere while doing so. Cyanobacteria also release nanocellulose into their surroundings, making it easy to harvest.

Dr Brown describes the process as "one of the most important potential agricultural transformations ever",