May 2015 – Solar Magazine

Solar-powered LED lighting for Northern regions

Danish research collaboration results in solar-powered LED lighting that operates in Northern regions. Image via ledsmagazine.com

At first glance, the best approach to make a solar powered outdoor lighting product work at winter in the far North is to go for state-of-the-art components: photovoltaic panels, batteries and super effective LEDs. However, the heart of the systems is actually what binds these components together: the power supply and the battery management system.

With a very limited amount of PV power input during the short winter days, the energy conversion efficiency and the stand-by power consumption of the management system are crucial factors. In this project, a prototype channeled the power generated in the PV panel to the battery with an extreme efficiency of 98-99%.

According to ledsmagazine.com, most commercial LED power supplies consume 8-15% of the load. Nevertheless, the same prototype discharged a 10-25W output from the battery to the LED with an impressive conversion efficiency of 97.5%.

A much smaller 10W version was prototyped as well. In this case, high efficiencies are even harder to obtain, but even this model produced similar impressive conversion efficiencies for the solar-powered LED lighting.

The results have great potential in actual solutions that are ready for the market. Both prototypes were specified in close cooperation with private companies to enable direct use in real products. Hence, the prototypes were tested in five different outdoor products with LED.

And who says it will stop here? The project generated an advanced design and dimensioning tool that can manage all of the limiting conditions. All parts are highly dependent on temperature conditions in the environment and the PV panels obviously depend on latitude and shading conditions. Hence, all local conditions as well as the dynamical and technical performance figures of potential components can be loaded into the design tool, and an optimized solution can be designed.

This design tool is valuable not only in stand-alone solar-powered LED lighting systems in the Nordic region but essentially all over the world. Furthermore, the prototyped power managements system can be applied to many other PV systems, as for instance stand-alone outdoor surveillance and intelligent parking meters.

The project was sponsored by the Danish Energy Agency (EUDP) and was managed by the DTU Fotonik (Technical University of Denmark) in close collaboration with DTU Energy and DTU Elektro. Three different private companies participated (Out-sider, AKJ Inventions and Morten Lyhne).

Efficiency record for black silicon solar cells jumps to 22.1%

Aalto University researchers have developed black silicon solar cells that achieve a record 22.1 percent efficiency when turning the Sun’s rays into usable energy. Photo credits: Aalto University

Aalto University’s researchers have obtained the record-breaking efficiency of 22.1% on nanostructured silicon solar cells as certified by Fraunhofer ISE CalLab. An almost 4% absolute increase to their previous record is achieved by applying a thin passivating film on the nanostructures by Atomic Layer Deposition, and by integrating all metal contacts on the back side of the cell.

According to a press release, the surface recombination has long been the bottleneck of black silicon solar cells and has so far limited the cell efficiencies to only modest values.

The new record cells consists of a thick back-contacted structure that is known to be highly sensitive to the front surface recombination. The certified external quantum efficiency of 96% at 300nm wavelength demonstrates that the increased surface recombination problem no longer exists and for the first time the black silicon is not limiting the final energy conversion efficiency.

The results were published online in Nature Nanotechnology.

For Nordic conditions

“The energy conversion efficiency is not the only parameter that we should look at”, explains Professor Hele Savin from Aalto University, who coordinated the study. Due to the ability of black cells to capture solar radiation from low angles, they generate more electricity already over the duration of one day as compared to the traditional cells.

“We have demonstrated that in winter Helsinki, black cells generate considerably more electricity than traditional cells.”

This is an advantage particularly in the north, where the sun shines from a low angle for a large part of the year. “We have demonstrated that in winter Helsinki, black cells generate considerably more electricity than traditional cells even though both cells have identical efficiency values”, she adds.

In the near future, the goal of the team is to apply the technology to other cell structures – in particular, thin and multi-crystalline cells.

“Our record cells were fabricated using p-type silicon, which is known to suffer from impurity-related degradation. There is no reason why even higher efficiencies could not be reached using n-type silicon or more advanced cell structures”, Hele Savin predicts.

The development of the cells fabricated last year will continue in the upcoming “BLACK” project, supported by the European Union, in which Professor Savin together with her team will develop the technology further in cooperation with industry.

The surface area of the best cells in the study was already 9 cm2. This is a good starting point for upscaling the results to full wafers and all the way to the industrial scale.

This solar-powered floating farm will produce 20 tons of vegetables every day

Solar-powered floating farms to provide food for world. Image via inquisitr.com

Given the fact that a community that supports green technology also supports organic growing, it is evident that its members would design clean ways to produce healthy, organic food with as little impact on the environment possible. One such farm exists in Japan. Not only is it the world’s largest indoor farm, it produces 100 times more food than conventional farming methods.

Now, an architecture company known as Forward Thinking Architecture has designed a solar-powered floating farm. What is unique about it is the fact that through its green technology, it produces 20 tons of vegetables every day.

According to inquisitr.com, there has been a concern that the world’s food supply wouldn’t be able to keep up with the world’s population growing at an exponential rate for many years. Forward Thinking Architecture provided an innovative and viable solution with their farms. The fact that it is built on water addresses the issue of decreasing supply of arable land. However, it must be noted the floating farms are, at this moment, made to supplement traditional farming, not replace it.

A follow-up by Minds provides more details to the floating farm. The farms — which were inspired by Chinese floating fish farms — are modules that measure 200 meters by 350 meters and consist of three floors. The bottom floor focuses on aquaculture and water desalination. The next floor up focuses on hydroponics crop cultivation. Finally, the roof is fitted with numerous solar panels, skylights, and rainwater collectors.

As mentioned earlier, each floating farm module can produce 20 tons of food everyday. Over the course of a year, the anticipated estimate is 8,152 tons of vegetables! Apparently, the solar farms are also fisheries as they can bring in 1,703 tons of fish a year too! Finally, the fact that the floating farm modules can be connected to form a grid (or any design allowable by its architecture as shown in the above picture), entire cities can be fed if they are scaled up to be huge farms, kind of like a floating farm metropolis.

Solartab: the premium solar charger

Clean power for your gadgets with Solartab. Image credit: mysolartab.com

The Solartab is unlike any other power bank or solar charger. A truly unique product featuring great design, a high-capacity internal battery and a built-in cover that ensures maximum sun exposure at all times. And a solar panel large and powerful enough to charge even your tablet.

Acccording to its Kickstarter Campaign, the Solartab was born out of the idea of creating a high quality solar charger with attractive design and a truly efficient solar panel.

“Solar power should never be a mere gimmick – on the contrary, we believe it’s the future of power consumption! A tablet-sized solar charger makes for a powerful and essential asset that truly liberates you from the power outlets of your home. Every day.”

Thanks to the Solartab’s large solar panel you can always charge your device directly from the sun. Even while listening to your favorite summer tune or phoning your friends at the same time!

With two USB ports and a micro USB port, the Solartab is ready to keep any of your mobile devices going at all times. An environmentally friendly, portable and never-ending source of energy, always ready for use.

Solar-powered spacecraft is ready for its first test launch

The LightSail uses sunlight for propulsion. Picture: Josh Spradling / The Planetary Society Source: Supplied

The LightSail, a spaceship with sails that relies on just sunlight for fuel is set for its first test in space when it launches on Wednesday.

According to news.com, the so-called LightSail is a privately-funded project by The Planetary Society, the world’s largest non-profit space advocacy group.

It is sending two small spacecraft into Earth orbit carrying large, reflective sails measuring 32 square metres. CEO Bill Nye says Wednesday’s test flight will pave the way for a second, full-fledged solar sailing demonstration in 2016.

Solar sails use the sun’s energy as a method of propulsion — flight by light. Light is made of packets of energy called photons. While photons have no mass, a photon travelling as a packet of light has energy and momentum.

Solar sail spacecraft capture light momentum with large, lightweight mirrored surfaces — sails. As light reflects off a sail, most of its momentum is transferred, pushing on the sail. The resulting acceleration is small, but continuous. Unlike chemical rockets that provide short bursts of thrust, solar sails thrust continuously and can reach higher speeds over time.

The LightSail is hitching a ride on a Atlas V rocket which will also carry a top-secret mini military space plane on another long orbital test flight.

The US Air Force is tight-lipped about the unmanned mission.

What is known is that this will be the fourth flight of the X-37B space plane, a secretive, experimental program run by the Air Force. The three previous missions also began with rocket launches from Cape Canaveral Air Force Station.

The mystery test vehicle — essentially a technology test bed — is designed to orbit the Earth and then land like one of NASA’s old shuttles. It is operated robotically, without anyone on board, and is reusable. It is 8.8m long — about one-quarter the size of a NASA shuttle.

The longest X-37B flight lasted about 675 days; touchdown was last October. There’s no official word on how long this one will stay up. All three previous missions ended in California.

NASA has a materials experiment aboard, while the Planetary Society is tagging along with a solar-sail demo.

Although largely mum about this X-37B flight, the Air Force has acknowledged a thruster experiment involving electric propulsion. Air Force researchers want to check design modifications to ion thrusters already flying on some advanced military communication satellites.

GE uses holograms and the industrial internet to make wind farms more efficient

GE plans to make generating wind energy 2o percent better. Photo via clevescene.com

Two new products that rely on data and the industrial internet will help GE make wind farms more efficient.

The secret to generating more electricity from wind turbines may not rest in better blade designs but in better communication between those turbines and holograms, according to Steve Bolze, the president & CEO of GE’s Power & Water division. At the American Wind Energy Association Windpower event, GE is expected to announce two products that will make wind farms 20% more efficient through the use of GE’s industrial internet software and sensors.

According to Fortune, the overall idea is to look at wind farms as a whole, instead of focusing on the turbines individually. GE has optimized turbines in the last decade using its PowerUp program that saw a 5% increase in efficiency thanks to better designed blades. That’s all well and good for boosting a renewable energy source that met 4.5% of the U.S. energy demands in 2013, but GE is aware that it needs to do more. So it turned to holograms.

In what it calls its Digital Twin product, GE takes data from a future wind farm site and starts simulating the future farm, modeling what turbines should go where, how high they should sit, and how fast they should turn. The resulting data is turned into a hologram of the future site so engineers can visualize other problems to see what computers might not.

The second product is another mess of data, only this time, it’s generated by the actual turbines in the wind farm. But instead of sharing the data about wind speed solely back to GE so it could optimize the blade design, as happened in the PowerUp project, now the turbines talk to each other. This means the sensors on turbines in the wind farm can communicate with turbines far back in formation to share data about the wind. Instead of each turbine working alone, it now works as part of a team. This Digital Wind Farm technology works with turbines made by GE, and with turbines made by GE’s competitors.

There is a huge benefit to including all of the turbines. Depending on the algorithms that GE writes, it’s possible that techniques such as having turbines at the outer edge operate at 70% capacity and having those further back operate at 80% generates the optimal amount of electricity when accounting for wear and tear on the turbines. Such communication can also help account for turbines that might be out of commission.

It’s through this better forecasting in the planning stages and then, better communication once operating, that GE hopes to keep wringing the efficiency out of the wind generation business. Bolze says that since the products are just being announced, there are no customers yet, but he expects them before the end of the year.

Solar power for the world’s largest tram network

Digital impression of a Melbourne tram as part of a pitch before the state government to power the network with solar energy. Photo: Australian Solar Group

Melbourne’s entire tram network could be powered by solar if the state government gave a bold renewable energy proposal the green light.

While the pitch may conjure up images of trams with rooftop panels on them like the family home, the power would instead be generated at two new solar farms the project proponents plan to build near Swan Hill and Mildura.

According to smh.com.au, the company behind the bid, the Australian Solar Group, have held quiet talks over four years with different arms of the government to try get the project off the ground, but has so far not got final backing.

The two solar farms would generate 80 gigawatt-hours of electricity a year, about the same amount used by Melbourne’s tram network, which is the world’s largest.

Under the proposal the government would back the project by signing Public Transport Victoria (PTV) up to a power purchase agreement with the solar farms, creating a reliable revenue source alongside the renewable energy target.

The proponents say the project has been designed to ensure the cost of tram tickets would not rise, nor would it add to PTV’s power bill. It would cut 100,000 tonnes of greenhouse gas emissions a year from running trams and give the city an obvious global selling point, according to the pitch.

The Australia Solar Group was founded by businessmen Adrian Critchlow and Dave Holland. Mr Crtichlow previously helped start companies Booking.com and AlertMe, before successful sales of both. Mr Holland was formerly the head of Solar Systems, a company that was building a large solar project in Mildura before financial collapse in 2009.

Mr Holland said Australia Solar had tried to get almost all elements of the tram project ready to go before it sought final financial backing.

“This project is virtually ready to go. We can’t see any barriers that would stop it from here,” he said.

The tram project has been supported behind the scenes by members of the Melbourne City Council, including Lord Mayor Robert Doyle. Councillor Arron Wood said it ticked many boxes, from contributing significantly towards the city’s renewable energy target to creating employment and training opportunities in rural Victoria.

“Ultimately, whether this project proceeds rests firmly with the Victorian Government. I just hope they take the action necessary to get it done,” Cr Wood said.

A spokeswoman for the Andrews government said: “We are interested in how the project progresses and will continue discussions with the group.”

Australian Solar says the solar farms would span across 80 hectares and use 130,000 panels to track the sun throughout the day. It has planning and grid connection approvals for its Swan Hill site, with permit processes underway for the second site at Red Cliffs.

Greenpeace: Renewable energy is vital for internet lifestyles

A Greenpeace report charges utilities with hampering efforts to use renewable energy to power data centers needed for services hosted in the cloud. Photo: AFP

A Greenpeace report released on Tuesday accused utilities of hampering efforts to use renewable energy to power data centres needed for services hosted in the cloud.

According to euractiv.com, Greenpeace praised moves made by Apple, Google and other internet titans to fill a skyrocketing demand for electricity with solar, wind or other environmentally-friendly sources but lamented expansion of data centre capacity in places where utilities reliant on carbon-spewing coal fuel dominate markets.

“A growing number of companies have begun to create a corner of the internet that is renewably powered and coal free,” Greenpeace said in its 2015 click clean report.

Internet companies that have committed to being completely powered by renewable energy sources include Apple, Facebook, and Google, according to Greenpeace.

Those commitments have driven growth of renewable power in several key markets, and caused some utilities to invest more heavily in that kind of electricity generation to meet demand, the report stated.

However, some locations that have attracted data centre investments are in markets ruled by utilities with generation powered mostly by coal, gases from which are a culprit in climate change.

Examples listed included Duke Energy in North Carolina, Dominion Resources in Virginia, and Taiwan Power Company in Taiwan.

“These utilities represent the biggest obstacles to building a green internet, and will require collaborative pressure from data centre operators and other electricity customers to secure the policy changes needed to open the market up to competitors that offer meaningful options for renewable energy,” Greenpeace said.

Apple leads the charge

Apple continued to “lead the charge” in using clean energy to power internet operations even as the California-based company rapidly expanded, according to the report.

Apple on Sunday announced broadened renewable energy and environmental protection initiatives in China, including a project with the World Wildlife Fund to promote responsible forest management.

The forestland project aims to protect up to a million acres of working forests used for fiber for paper and wood products, according to Apple.

The project is expected to generate as much as 80 million kilowatt hours annually of clean electricity, enough to power about 61,000 Chinese homes.

About 87% of Apple’s global operations run on renewable energy, and the Sichuan Province solar farms will move the company closer to 100%, according to the maker of iPhones, iPads, iPods, Macintosh Computers, and Apple Watch.

Google is also pushing to rely on renewable energy, but its progress is under threat by monopolies held by coal-using utilities in some data centre locations such as Georgia, Singapore, Taiwan, and the Carolinas, according to Greenpeace.

Amazon, Microsoft, eBay, and Oracle were among technology giants who scored low grades from Greenpeace when it came to green energy deployment and advocacy.

“The magic of the internet seems almost limitless,” Greenpeace said. “But each new internet enabled magic trick means more and more data.”

Increasing demand for data, particularly streaming video, and processing power in the cloud means ramped up demand for power by data centres doing the online work.

“While there may be significant energy efficiency gains from moving our lives online, the explosive growth of our digital lives is outstripping those gains,” Greenpeace said.

MIT scientists show us the future of solar energy

MIT releases report on the future of solar energy

Solar energy holds the best potential for meeting humanity’s future long-term energy needs while cutting greenhouse gas emissions — but to realize this potential will require increased emphasis on developing lower-cost technologies and more effective deployment policy, says a comprehensive new study, titled “The Future of Solar Energy,” released by the MIT Energy Initiative (MITEI).

“Our objective has been to assess solar energy’s current and potential competitive position and to identify changes in U.S. government policies that could more efficiently and effectively support its massive deployment over the long term, which we view as necessary,” says MITEI Director Robert Armstrong, the Chevron Professor in Chemical Engineering at MIT.

According to MIT’s website, the study’s chair, Richard Schmalensee, the Howard W. Johnson Professor Emeritus of Economics and Management at the MIT Sloan School of Management, adds, “What the study shows is that our focus needs to shift toward new technologies and policies that have the potential to make solar a compelling economic option.”

The study group is presenting its findings to lawmakers and senior administration officials this week in Washington.

“The Future of Solar Energy” reflects on the technical, commercial, and policy dimensions of solar energy today and makes recommendations to policymakers regarding more effective federal and state support for research and development, technology demonstration, and solar deployment.

Among its major themes is the need to prepare our electricity systems, both technically and from a regulatory standpoint, for very large-scale deployment of solar generation — which tends to vary unpredictably throughout the day. To this end, the study emphasizes the need for federal research and development support to advance low-cost, large-scale electricity storage technologies.

The analysis finds that today’s federal and state subsidy programs designed to encourage investment in solar systems should be reconsidered, to increase their cost-effectiveness, with greater emphasis on rewarding production of solar energy.

The group also recommends that state renewable portfolio standards, which are designed to increase generation of electricity from renewable resources, be brought under a unified national program that would reduce the cost of meeting set mandates by allowing unrestricted interstate trading of credits.

The study concludes by pointing to the urgent need for an ambitious and innovative approach to technology development, with federal research and development investment focused on new technologies and systems with the potential to deliver transformative system cost reductions.

The MIT “Future of …” studies are a series of multidisciplinary reports that examine the role various energy sources could play in meeting future energy demand under carbon dioxide emissions constraints. These comprehensive reports are written by multidisciplinary teams of MIT researchers. The research is informed by an external advisory committee.

Sunny Scotland to embrace solar energy

More solar panels for Scottish homes

Figures showing last month’s sunshine could have powered all the homes in Scotland have sparked calls for more properties to install rooftop panels.

According to Business Green, Scottish homes with solar panels saw more than 100 per cent of their energy needs met by the sun during April, according to data collated by WeatherEnergy, the UK arm of a Europe-wide network of analysts.

The country received enough sunlight to generate 113 per cent of the electricity needs of an average home in Edinburgh, 111 per cent in Aberdeen, 106 per cent in Glasgow, and 104 per cent in Inverness.

Meanwhile, for those homes fitted with solar hot water panels, there was enough sunshine in Edinburgh, Glasgow and Inverness to generate an estimated 100 per cent of an average household’s hot water needs – and 99 per cent for homes in Aberdeen.

“Scotland has long been leading the charge when it comes to wind power,” said Karen Robinson of WeatherEnergy. “However, despite misconceptions, Scotland also has potential for sun-loving renewables too.”

While over 35,000 Scottish homes and 600 business premises currently have solar PV arrays fitted, wind power remains the country’s major renewable electricity source. During April, wind turbines in Scotland generated enough electricity on average to supply the electrical needs of 69 per cent of Scottish households, equivalent to 1.66 million homes.

Prices of solar panels have plunged in the last two years, while efficiency has increased. Tesla’s announcement last week of $3,000 battery to store solar energy could also ensure green electricity on demand for the first time.

“With these sorts of figures, every home or business with a south-facing roof should seriously consider switching on to the full potential of solar power,” said Lang Banks, director of WWF Scotland. “Similarly, there is no reason why Scotland should not be home to commercial-scale solar farms.”