The German firm’s Sunmodule Bisun glass-glass module, which uses bifacial cells based on PERC technology, to be presented at forthcoming exhibition in Frankfurt; modular SunPac LiOn battery also to be unveiled.
By: Ian Clover
First revealed at last year’s Intersolar Europe exhibition in Munich in June, SolarWorld’s new bifacial modules and flexible lithium-ion home storage batteries are set to be unveiled to the market at next month’s Light + Building show in Frankfurt.
The German solar company has hinted at further innovation in both the module field and storage sector for many months, and it appears that the firm’s latest products for both sectors are one step closer to market.
Its Sunmodule Bisun module is a glass-glass module that comprises 60 bifacial cells based on PERC technology. According to SolarWorld, this ensures a 25% increase in energy yield, plus a longer lifespan and added durability is attained because the cells are embedded into the glass and thus protected against external environmental and mechanical influences.
Able to utilize incident light on both the front and rear, this double-sided module thus absords a higher portion of sunlight, and is particularly suitable for flat roofs and ground-mounted systems where more light is reflected from surrounding surfaces. With higher yield and a longer life, SolarWorld believes that the power generation costs per kWh are significantly lower than standard modules in the field.
The expected growth of the German home storage sector this year has shaped SolarWorld’s efforts to remain a key concern for residential solar customers, and its SunPac LiOn storage system has been designed to meet the needs of such consumers.
Starting with a storage capacity of 2 kWh, the battery can be scaled up to 10 kWh in increments of 2 kWh, meaning it can expand or contract to mirror the energy storage needs of an average home. SolarWorld adds that the lithium-ion cells ensure 10,000 complete charge and discharge cycles, which would equate to around 20 year of service life for most households.
The system is connected on the AC side, so is easily retrofittable to existing solar systems and inverters, and has a charge controller that automatically recognizes the number of battery modules connected and the scale of power required.
Both components are set to be unveiled at the Light + Building show in Frankfurt, 13-18 March.
MOSAIC award spurs MIT research into concentrator solar cells that can run in shade and full sun with power control and wavelength separation.
By: Denis Paiste
Lighter, more efficient flat-plate solar cells are the goal of MIT researchers who kicked off a collaborative research effort Dec. 15 with a three-year, $3.5 million award under the Department of Energy’s ARPA-E program. Their aim is to bring the technology to the marketplace.
“We are early on looking for companies to collaborate with us who are interested in finding a way to bring that technology into the marketplace after the three-year project funding,” says principal investigator Jurgen Michel, senior research scientist at the MIT Microphotonics Center and senior lecturer in the Department of Materials Science and Engineering. “The best outcome is a solar cell and companies that will actually make those or take that into further development to make a product.”
ARPA-E’s Micro-Scale Optimized Solar-Cell Arrays with Integrated Concentration (MOSAIC) program has challenging specifications, Michel says. The goal is to reach overall efficiency of greater than 30 percent, which is about 5 percentage points higher than the best efficiency achieved with crystalline silicon solar cells.
The MIT-led project, “Integrated Micro-Optical Concentrator Photovoltaics with Lateral Multijunction Cells,” aims to develop a three-junction concentrator cell in a flat-plate system just under 1 inch thick. It includes a partnership with Arizona State University. Besides Michel, collaborators include:
Juejun (JJ) Hu, the Merton C. Flemings Assistant Professor in Materials Science and Engineering, who will design and prototype a special microlens to split sunlight into wavelengths from visible to near infrared and concentrate sunlight up to 300 times;
Eugene A. Fitzgerald, the Merton C. Flemings-SMA Professor of Materials Science and Engineering, who will work on solar cells made from indium gallium arsenide;
David J. Perreault, professor of electrical engineering and associate department head, who will work on power management of the solar cells; and
Cun-Zheng Ning, professor of electrical engineering at Arizona State University, who will work on nanopillar semiconductor material with a bandgap gradient that is grown in a single step.
Ning developed a single-growth process for varying the bandgap in nanopillars by varying the temperature in the reactor. “That would be very low cost, but the challenge there is efficiency. For our approach, we have to get our substrate to low enough threading dislocation densities in order to get low-cost, high-efficiency solar cells,” Michel says.
The proposed solar system with a mix of cells to maximize collection of light a varying times of day addresses one of the key issues with solar energy, which is its intermittent nature. As more solar systems are deployed, they will have to be integrated with energy storage systems to achieve maximum benefit, according to The MIT Energy Initiative report, “The Future of Solar Energy,” released in May 2015. Without storage, solar systems can provide power only during the day.
Solar has enormous potential over the long-term. According the MITEI report, installing solar on less than one-half of 1 percent of the continental United States could produce all the electricity the country needs today. Solar also can reduce the nation’s carbon dioxide emissions, the report noted.
Michel previously received a one-year ARPA-E FOCUS grant for research on Spectrum Splitting for High-Efficiency Photovoltaic and Solar Thermal Energy Generation. Two papers are pending publication on that work, including significant reductions in threading dislocations in solar cells and enhanced performance of indium gallium phosphide (InGaP) solar cells. These indium gallium phosphide materials are called III-V materials because their elements come from columns III and V of the periodic table.
“One of our main goals was to lower the cost of III-V semiconductor solar cells, so we’ve been using a silicon wafer with a germanium-on-silicon virtual substrate to grow our III-V cells on top of that,” Michel explains. “We’ve reduced the threading dislocation density to below mid-106 per square centimeter. Once you get down to about 106 per cm2 in threading dislocation density, you get actually high quality III-V semiconductor materials for high performance solar cells on a silicon substrate and that reduces the cost dramatically.” This technology is available for licensing through the MIT Technology Licensing Office.
In the new MOSAIC work, researchers will include the indium gallium phosphide (InGaP) solar cells based on the germanium-on-silicon approach in the FOCUS program and add solar cells made from gallium arsenide (GaAs) and indium gallium arsenide (InGaAs) to cover the whole spectrum of sunlight. These cells will be connected to each other in a parallel layout. The lens will direct specific wavelengths of light to matching solar cells.
The work builds on an earlier theoretical paper that showed that under realistic operating conditions over the course of a year, parallel cells coupled with wavelength separation, or spectrum splitting, outperformed a stacked array, or tandem, solar cell. “We found that if you split your spectrum in the way you spread it out onto separate solar cells, you have an overall gain in power output compared to the other solar cell,” Michel explains.
In the new project design, Michel says, “We can optimize the power point for each of the cells individually, because we have now CMOS control. That means we can respond very quickly to shading, for instance, [as] a cloud moves across a panel.” Under cloudy skies, light absorbed by silicon cells in the structure will maintain power output at about 20 percent power efficiency.
Despite the three-year prototype goal, it probably will take three to five years beyond that to bring to market a solar cell system that will last for 30 years. “If that can be done, then you’d actually have solar cells that would have a much higher output than current solar cells for thin plates, which makes it much easier to handle,” Michel explains. “Also if you have to, for instance, track your cells with the sun, weight is much lower, efficiency is high, and so that could be the next step in solar cell efficiency. We are not the only ones that are working on that. There are quite a few competitors. We just hope that one will be successful at least,” he says. “The best outcome is a solar cell and companies that will actually make those or take that into further development to make a product.”
The Clean Energy Council has congratulated its members AGL and First Solar on the launch of the large-scale solar power plants in Broken Hill and Nyngan today, which have doubled the amount of large-scale solar built in Australia.
Clean Energy Council Chief Executive Kane Thornton said the landmark projects will make it easier for others to follow.
“Australia has some of the most intense sunshine in the world, and there is obviously an incredibly bright future for large-scale solar in this country,” Mr Thornton said.
“The first time you build a new technology on a large scale such as this, a whole host of challenges and opportunities become apparent. Trail-blazing projects like AGL’s at Broken Hill and Nyngan make building the next generation of solar power plants cheaper and more efficient, and that’s great for the entire industry.
“The construction of these projects using First Solar technology created approximately 400 jobs and pumped almost $29 million straight into the local economies.”
The 102 MW Nyngan and the 53 MW Broken Hill solar plants are the two largest in the country, providing enough electricity for approximately 50,000 average Australian homes. Support from both the Federal Government and the NSW Government helped to make them viable.
Mr Thornton said large-scale solar is still evolving in Australia, which is why the support of organisations such as the Australian Renewable Energy Agency (ARENA) remain crucial.
“ARENA’s support for emerging technologies plays a crucial role in driving innovation in Australia’s energy sector,” he said.
“Solar power is incredibly popular in Australia, and the landmark climate agreement reached in Paris late last year underlines the importance of renewable energy to help us reduce the emissions from our electricity sector.”
Shell’s Bennett Cohen believes it represents a profound shift in the way we power society.
By: Bennett Cohen
In May 2015, Elon Musk revealed the Tesla Powerwall — a stationary battery for homeowners that features essentially the same battery technology as Tesla’s cars. Energy analysts pored over the specifications of the lithium-ion technology because of the promise it has to impact both transportation and electricity markets.
For most observers, the salient detail was the Powerwall’s price. Weighing in at $350 per kilowatt-hour, all-in — well below the industry’s expectations for battery cost evolution — the device raised a lot of eyebrows.
What intrigued us most was that the Powerwall is clearly conceived as a consumer product. While its sleek design and hyped launch felt totally natural to those accustomed to following Apple, it served as a wakeup call to the energy industry: energy is being consumerized.
It’s remarkable that fans went nuts over the launch of a battery — a technology that usually just enables something interesting (like an iPhone) rather than being interesting in and of itself. Energy, the basic foundation of our prosperous lifestyles, is moving away from centralized power plants and closer to the customer. And customers choose winners and losers in radically different ways than do utilities or the other incumbents of the energy industry.
This disruption and consumerization of energy is being driven by a number of accelerating trends:
1. The shift from a centralized to a more distributed energy system architecture
2. The global drive toward lower-carbon energy
3. The rollout of the internet of things
4. Developing countries leap-frogging conventional power grids to consumer energy
From Centralized to Distributed Energy
As Amory Lovins and I wrote about in 2010, the power markets are clearly shifting away from cathedral-like coal and nuclear power stations toward modular, mass-producible, and highly scalable micropower technologies — renewables, like solar and wind, and efficient combined-heat-and-power systems (mostly fueled with natural gas). The ascendancy of micropower is democratizing the future of the energy system, enabling everyone from individual homeowners to commercial and industrial customers to quickly select and obtain a portfolio of distributed solutions, avoiding the decade-long approval processes required to build multibillion-dollar coal or nuclear power plants.
The Decarbonization of Energy
The Paris climate agreement made at least one thing clear — the world intends to shift toward a lower-carbon energy system. Technologies like rooftop solar and home batteries can significantly contribute to decarbonizing the power sector. Having just committed to emission-reduction targets on the global stage, governments around the world will find it hard to side with incumbents to slow the adoption of these consumer energy technologies. In fact, governments will likely promote them, further accelerating the consumerization of energy.
The Internet of Energy
The internet of things is moving out of a phase characterized by hype and uncertainty into one of scale and impact. Many sectors will be impacted, including energy. A proliferation of sensors and controls will enable an intelligent and resilient energy system made up of myriad distributed energy resources. The internet of things will also create a platform for new business models that derive additional value from distributed energy resources for both customers and energy markets.
In countries like the U.S., we are slowly seeing a transition from the old energy system to the new. In contrast, developing countries in Asia and Africa are more often leap-frogging the centralized power system and going straight to consumer energy. Tired of waiting for a centralized solution to reach them, customers in countries as varied as Kenya and Nepal are choosing to purchase consumer solar-plus-battery power products from M-Kopa or Empower Generation. For many families and communities in these regions, their first experience of reliable electricity will come from a solar panel on their roof and a small battery on their wall. Though on a smaller scale, these are the same essential technologies and concepts behind Tesla’s Powerwall.
The consumerization of energy is just beginning, and it represents a profound shift in the way we power society. Opportunities abound for entrepreneurs and investors, but most of all for consumers of energy.
Bennett Cohen is a senior investment associate with Shell Technology Ventures and chairman of Empower Generation.
By: Lori Zimmer
You may soon be able to wash your smart phone with good old fashioned soap and water. Japanese telecom firm KDDI and Kyocera have been busy working on the “Digno Rafre phone,” which users can scrub-a-dub with suds. With waterproof phones already on the market, KDDI is developing the washable phone geared toward parents needing to effectively keep their phones clean from their kids’ grubby hands- or phone addicts who can’t part with their gadgets at bath time.
The folks behind the Digno Rafre envision a world where your trusty side kick- your phone– can be close by in a myriad of scenarios- like cooking, cleaning, and even in the bath. Incorporating phone-time with bath-time is even emphasized by a special phone holder- appropriately shaped like a rubber duck. But Rafre can also hop in the bath with you, to wash off bacteria and other grime that happen when you bring your phone everywhere with you.
Aside from being totally scrubable, the Rafre also claims to have a touch panel that works when wet, or when touched by soapy hands. The phone also features a Smart Sonic Receiver by Kyocera, which provides incredible audio without a speaker- which would otherwise get waterlogged.
Like other smart phones, the Rafre includes a 13 megapixel camera, 5 inch 720 p display and a 3,000mAh batter. For now, the washable phone will just be available in Japan, at a competitive price of around $465.