The hot news in cleantech this week…

This week saw a major breakthrough in the development of the SolarWindow – a US-made transparent organic photovoltaic (OPV) solar panel capable of generating electricity on glass – with the successful production of the largest-area OPV module ever produced at the Department of Energy’s National Renewable Energy Laboratory. Coming in at 170x170cm, it is 14 times the size of any OPV solar panel ever produced at the NREL. And Maryland-based New Energy Technologies, the other half of the team behind the collaborative project, says the milestone achievement means they have finally overcome the biggest obstacle confronting the technology’s commercialisation – scale-up.

“The fabrication of a large-area see-through solar module of these dimensions is an important step in New Energy’s SolarWindow ongoing development,” said Dr David Ginley, an award-winning NREL Research Fellow and OPV expert, on Tuesday. “We believe that building integrated applications provide a promising avenue for OPV deployment and we are continuing to work with New Energy Technologies to further address scale-up, a key milestone toward developing a deployable technology.”

OPV panels are made by applying see-through electricity-generating coatings – largely consisting of ‘polymers’ produced through organic synthesis – onto glass surfaces. These solar coatings are less than 1/10th the thickness of thin films and use the world’s smallest functional solar cells. But, as Energy Matters points out, “size matters when it comes to OPV solar panels as they have far lower sunlight-to-energy efficiency conversion rates than silicon-based PV modules.” The new SolarWindow is considerably larger than the February 2011’s 30x30cm model, says the website, “and positively dwarfs 2010’s four-inch prototype.”

The breakthrough that led to SolarWindow’s significant “scaling-up” came last month, when New Energy announced that researchers had investigated and made use of a high-speed/large-area solution-coating process, which allows for production of larger glass surface areas. New energy says the improved process also makes for more uniform and faster application of electricity-generating coatings than conventional methods. The company also mentions that SolarWindow is currently the subject of 10 new patent filings. And considering the vast market potential of the technology in the estimated 85 million commercial buildings and homes throughout the USA, it’s no wonder they’re fighting for control.

Bacteria battery gets a space boost

Microbial power technology has taken one small step towards to its goal of providing a portable, independent and renewable energy source, with scientists revealing this week that they have doubled the power output of a “bacteria battery” by using microbes from a UK river estuary, including one normally found in space. The Guardian reports that a team from Newcastle university collected different bacteria from the River Wear, in north-east England, and tested them for their energy-generation potential. The survey, the results of which were reported in the latest issue of the Journal of Environmental Science and Technology, came up with an impressive array of relatively powerful microbes; one of the most powerful being Bacillus stratosphericus, a bacteria that’s found in large quantities 30km above the Earth and ended up in the river bed via atmospheric cycling.

Seventy-five species were tested before the best were combined in a microbial fuel cell whose output then rose from 105 watts per cubic meter to 200 – enough to run an electric light. “The research and findings show the potential power of the technique,” said Grant Burgess, professor of marine biotechnology at Newcastle. “What we have done is deliberately manipulate the microbial mix to engineer a biofilm that is more efficient at generating electricity,” he said. “This is the first time individual microbes have been studied and selected in this way. Finding B. stratosphericus was quite a surprise but what it demonstrates is the potential of this technique for the future – there are billions of microbes out there with the potential to generate power. …We have got used to seeing road signs powered by small solar cells. In the same way, an MFC could potentially be portable and just need immersing in water or sticking in soil for the bacterial process to start.”

Beating the heat with solar

One year after world-leading solar diesel power systems were installed in two of Australia’s hottest locales,  ABC News has checked in on the East Pilbara townships of Nullagine and Marble Bar to see how they’re travelling. According to David Edwards, chief engineer with Horizon Power, who installed the “state-of-the-art power stations,” they combine diesel and solar power technology. “The technology used in those stations prefers renewable energy,” Edwards said. “So, what that does is when the sun is shining it will make sure that the maximum amount of solar energy will go into the town’s network by lowering the amount of diesel generation. …Then, at the end of the day or perhaps when a cloud comes along and obscures the sun, it ramps the diesel generation back up again so that the town sees a continuous supply, but it prefers to deliver renewable energy first.”

Edwards told the ABC that before the systems were installed, the two towns experienced a lot of power outages – “an average of about 38 minutes worth of outages a year in Marble Bar and about 110 minutes [a year] of outages in Nullagine.” But, he added, since the new installation of the new stations, the outages in Marble Bar have been reduced to 8 minutes a year and Nullagine’s power supply has been uninterrupted so far. The systems also constitute the largest single axis tracking arrays in Australia, says the ABC’s Ebonnie Spriggs, and generate more than 1000MWh of renewable energy per year, which is 30 per cent of the towns’ annual energy demand.

Edwards says that back when they were installed, the stations earned the title of ‘world first’ – a title that is yet to be challenged. “There haven’t been any since,” Edwards told the reporter. “I know a couple of companies are looking at what we have done and they are developing their own technologies but at the moment they are still the world’s first solar diesel hybrid stations.”