The hot news in cleantech this week ... | RenewEconomy

The hot news in cleantech this week …

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Mining the ocean for renewable terrawatts; has Melbourne developed the world’s most efficient thin-film solar cells?; revolutionising electric motors; and rooftop solar vs solar rooftops?

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It’s a relatively well-known fact these days that the US military is one of renewable energy’s biggest fans, so it shouldn’t come as too big a surprise that Lockheed Martin – the US-based global aerospace, defense and security technology powerhouse – is getting in on the act too. CleanTechnica reports that the company best known for its airborne innovation is busy developing a way to mine renewable energy from the deep blue sea. In fact, says the blog, Lockheed Martin has been working on this potentially “disruptive” technology – a twist on ocean thermal energy conversion (OTEC) – since the 1970s, but proceedings got a much-needed boost in 2009, when the US Naval Facilities Engineering Command awarded the company $12.5 million to develop a pilot plant. So, with the Department of Energy’s Oak Ridge National Laboratory also on board, that is what they are doing.

Jim Pearce, from ORNL, says OTEC systems in tropical waters have the potential to generate up to 5 terawatts of clean, renewable, base power without affecting the ambient temperature of the ocean. And, like geothermal, they operate continuously and so could potentially serve as a reliable back up to intermittent renewable sources like wind and solar. To tap this energy gold, you need to reach 3,000 feet below the surface where, in the tropics, the temperature difference between that depth and the surface is about 20 degrees Celsius. The OTEC system would use this supply of warm and cold water to run a power plant based on Rankine engine technology – external combustion engines in which a piston is moved by cycles of heat and cold.

The main obstacle blocking this technology from being commercially viable is the cost of a heat exchanger, says CleanTechnica, which is needed intensify the energy of the warm surface water. On this front, Lockheed is set to begin a six-month round of testing on a new 20-foot tall heat exchanger. The exchanger, shipped to Hawaii last month, was constructed using a process called friction stir welding to reduce corrosion, says the blog – a process that has been used successfully on ships and spacecraft. The team have also used graphite foam on the heat exchanger to boost its efficiency – a new twist that could amount to savings of about 50 percent.

From little things…

A team of researchers from Melbourne’s Swinburne University of Technology and China-based solar giant Suntech have developed what they  claim are the world’s most efficient broadband nanoplasmonic solar cells. Energy Matters reports that researchers from Victoria-Suntech Advanced Solar Facility (VSASF) – a $12 million program jointly funded by the Victorian government, Swinburne and Suntech – have been working on improving silicon-based thin-film cell efficiency by embedding gold and silver nanoparticles into the cells, to increase the wavelength range of the absorbed light, boosting the conversion of photons into electrons.

The team also incorporated nucleated or ‘bumpy’ nanoparticles, which scatter light even further into a broadband wavelength range, leading to greater absorption and improved cell efficiency, says Energy Matters – and in a paper published in Nano Letters, the researchers claim an absolute efficiency of 8.1 per cent. “One of the main potential applications of the technology will be to cover conventional glass, enabling buildings and skyscrapers to be powered entirely by sunlight,” says Swinburne Professor Min Gu, Director of the VSASF. With further developments, Professor Gu expects 10 per cent efficiency to be achieved by the middle of this year and for the panels to be available commercially by 2017.

Edison would be proud

A press release from a smallish US-based electric drive motor developer caught our eye this week, by claiming that its motor system technology – recently selected as a finalist in America’s prestigious Edison Awards, in the energy and sustainability category – “might be the most significant breakthrough in electric motor systems since Thomas Edison’s heyday.” The Austin, Texas-based company says its innovative system, complete with motor, battery pack and controller, represents a “significant advancement in practical use of electric propulsion for high-volume products,” like motor scooters and motorcycles, elevators, escalators, forklifts and wind-generation equipment.

Christian Okonsky, founder and CEO of KLD says the Awards recognises its system as “an important technological leap,” and says the implications of the technology could be enormous, considering estimates that suggest a 10 per cent improvement in the efficiency of electric motors could reduce global energy costs by $100 billion, not to mention cut carbon emissions. “For decades, people have been advocating for electric technology because of its potential for clean, efficient, high-performance propulsion,” Okonsky said. “That promise has been unfulfilled because the world has been saddled with what’s now 100-year-old electric-motor technology.”

KLD’s system breaks from tradition by replacing the motor’s iron core with a composite material that allows operation at significantly increased frequencies, producing higher power and torque. The company’s innovative battery system, under licence from Electron Vault, accommodates different cell chemistries, and is configured to prevent cascading failure of individual cells, extend battery life and lowering the cost of service. The controller then optimises performance of the motor system for different applications and specifications, in part by capturing and regenerating kinetic energy.

KLD says Australia’s Vmoto is one of various companies worldwide preparing to introduce electric scooters and motorcycles based on the Texas company’s technology. KLD also has an agreement with China’s Zhejiang Qianjiang Motorcycle, one of the world’s largest motorcycle and engine companies, to produce the KLD motor system for use in its own products. As for the Edison Awards, results will be announced April 26. A win would certainly be good news for KLD, which – despite receiving $26 million in funding during the past five years, including $10 million just three months ago — last week put an undisclosed number of its workers on “short-term leave,” to concentrate on production.

Rooftop solar out, solar rooftops in

Back in Australia, and Fairfax newspapers reported this week that a new form of rooftop solar panel that heats air and water as well as generating electricity, is being developed by Sydney researchers. Did we say rooftop? What we meant to say was, solar cells are integrated into the actual structural fabric of the roofing material. So, as the reporter puts it, “rather than being attached to a roof, they are the roof.” By adding as insulated space behind the solar cells, the technology can capture the waste heat that is a by-product of the conversion of photons from sunlight into electricity, and use it to heat air or water. And by making the panels extra tough, they also function as the roof itself.

The project is part of a wider in investigation into future energy efficiency projects, while also testing how effective current cleantech methods really are. ”We want to take the building performance to the next level,” said Professor Deo Prasad, head of the research group.”In the past we have had separate experts working on solar panels, on energy efficiency, water efficiency, but what we are looking at now is total integration from the start.”

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  1. Chris Fraser 9 years ago

    “…the panels to be available commercially by 2017”. 2017 ! But i want them Nowww! Shouldn’t the CEFC be providing a leg up for these techy things ?

  2. Jim Baird 9 years ago

    At a conference on Enhanced Ocean Upwelling last month, Gerard Nihous of the Hawaii Natural Energy Institute, University of Hawaii, ventured the maximum possible number of 100 MW OTEC power plants capable of being supported by our oceans is half a million. (this is 50 terawatts or the equivalent of 750 million barrels of oil per day)

    Conventional OTEC has been impeded by the size and cost of the pipes required and environmentally by the volume of water these pipes move.

    Amongst these environmental problems are:
    • entrainment and impingement of marine life,
    • release of CO2 associated with bringing pressurized cold water to the surface,
    • eutrophication of the water column due to over fertilization of phytoplankton with massive upwelling of cold water and,
    • the potential to overturn the Thermohaline by massive dumping of surface heat to the depths.

    Nature provided the analogy for the workaround embodied in the local solution to these problems which use a closed heat pipe and counter-current heat transfer system.

    Evaporation due to overheating oceans moves massive amounts of heat in a hurricane to the edge of the stratosphere, where some is radiated back into space and the balance is absorbed by the latent heat of condensation in raindrops that fall back to earth.

    GWMM OTEC, using the counter-current heat transfer system, inverts the hurricane to overcome the shortfalls of conventional OTEC in several ways.

    • It reduces the size of the conventional infrastructure by as much as 900 per cent, using one-metre pipes rather than 10-metre pipes.
    • It increases the thermodynamic efficiency of the process by transferring heat through phase changes rather than in fluids.
    • And it maximizes energy potential while limiting environmental impact by recirculating heat back to the surface rather than dumping it to the depths.

  3. Mike Straub 9 years ago

    The OTEC happenings out there are really exciting, but I think the much bigger news is happening the Caribbean. The Bahamas committed to building 2 commercial OTEC plants. As the write-up above says, OTEC has been tested and proven for more than 30 years. Other countries from around the world are working on their own OTEC deals right now, because they want to cut their fossil fuel use, and also want to the endless clean water created by an OTEC system. So it’s truly clean power, and millions of gallons of live giving water, truly technology we can be proud to hand off to our grandchildren.

    Here’s the info on the Bahamas deal…

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