NREL argues for value of ‘watts per kilogram’ in emerging thin-film, flexible solar technology

NREL lightweight CIGS

This lightweight CIGS photovoltaic cell, on flexible stainless steel, was made by Matthew Reese and his team at NREL. Photo by Dennis Schroeder / NREL

Rigid silicon solar panels dominate the utility and residential markets, but opportunity exists for thin-film photovoltaic and emerging technologies notable for being lightweight and flexible, according to scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL).

Thin films such as cadmium telluride (CdTe) and copper indium gallium selenide (CIGS), along with perovskites and other new technologies, could be ideal for generating the electricity needed for unmanned drones, portable chargers, and building facades. The opportunities and challenges inherent in widespread adoption of these ideas appear in the new Nature Energy paper, “Increasing Markets and Decreasing Package Weight for High Specific Power Photovoltaics.

“We explore the limits behind power-to-weight ratios and how this can generate value for emerging players in photovoltaics to enable them to reach gigawatt scale without having to directly compete with silicon solar panels,” said Matthew Reese, an NREL researcher and lead author of the paper. The paper was co-authored by Stephen Glynn, Michael Kempe, Deborah McGott, Matthew Dabney, Teresa Barnes, Samuel Booth, David Feldman, and Nancy Haegel, all from NREL.

The market opportunity

Silicon panels constitute 95 percent of the global solar market, generating electricity for utilities, residences, and businesses, but the researchers identified applications that must consider value propositions beyond the standard value triad of cost, efficiency, and reliability used for conventional photovoltaic (PV) panels. Flexibility and portability will be important factors, with the performance of the technology quantified in terms of watts per kilogram.

The researchers identified three high-value markets, each with a potential to cumulatively generate a gigawatt (GW) of electricity—at a price above $1 a watt—over the next 10 years:

Aerospace and unmanned aerial vehicles – Powering satellites is driven by extremely high launch costs; whereas, there is an increasing desire to keep drones aloft for very long periods. For both of these applications, limited space makes efficiency and weight critical and cost secondary. A key player in this market is III-V PV, but while highly efficient it’s also too expensive for many applications.

Portable charging – Making it easy for one person to install or move a portable charger is driving the need for PV technology that’s efficient and flexible. Finding the correct balance between those requirements and cost could put millions of units into service by the military, disaster relief workers, and recreational users.

Ground transportation – The integration of PV in electric vehicles will compete with electricity coming from the grid, but the addition could extend the driving range. The PV would have to use smaller panels and be flexible enough to conform the contours of the roof.

The researchers identified these markets as smaller but significant and ones that will pay a premium for the added value of the technology being lightweight to support initial, low-scale production. As production increases, lower costs will follow.

The NREL team determined the lower limit for a lightweight PV device is between 300 and 500 grams per square meter. Below that would reduce reliability, durability, and safety. A lightweight module on the lower side of that range could generate more than a kilowatt of electricity from something that weighs as little as a six pack of soda. Conventional modules, even without the additional weight from the mounting equipment, might require 150–200 pounds to generate this much power.

— Solar Builder magazine

Ascent Solar Technologies nets DOE funding for thin-film, CIGS solar cell development

Ascent Solar Technologies

Thin-film photovoltaic (PV) manufacturer Ascent Solar Technologies has been selected by the U.S. Department of Energy (DOE) for two exclusive development projects. As part of the awards, worth up to $100,000 each, Ascent Solar is to work toward commercialization of sputtered Zn(O,S) buffers in flexible CIGS solar cells and also development of next-generation, high-efficiency Perovskite/CIGS Tandems cell. These projects are part of Ascent Solar’s plans for next-generation lightweight and flexible solar cells.

The first project will utilize sputtered Zn(O,S) buffers, which will help reduce costs and would further improve the environmental friendliness of our CIGS manufacturing process. The Perovskite/CIGS tandem junction project is designed to significantly improve efficiencies and drive further cost reduction by enabling a more complete conversion of the solar spectral energy into electricity.

RELATED: Lux Research: Thin-film solar modules could challenge silicon in the coming years

“These are challenging yet exciting projects,” says Dr. Lawrence Woods, Director and Head of Research & Development for Ascent Solar. “While there are challenges to be overcome with the use of perovskite based devices, with already proven high-efficiencies, we believe that Ascent Solar is well positioned to incorporate these materials into our large-scale roll-to-roll processing.”

“We are honored to be the only PV developer and manufacturer to have been selected for the TCF projects, let alone two projects selected at the same time. This is a strong testament to the DOE’s faith in our ability to once again demonstrate our ‘lab-to-fab’ expertise,” says Dr. Joseph Armstrong, Chief Technology Officer and founding member of Ascent Solar Ascent Solar. “In both cases, we are leveraging our significant intellectual property with flexible monolithically integrated CIGS and teaming with the National Renewable Energy Laboratory (NREL) to inject their substantial knowledge in novel advanced materials to create a potentially substantial leap in the advancement of our product.”

The Office of Technology Transitions (OTT) and Technology Commercialization Fund (TCF) was created by the Energy Policy Act of 2005 to promote promising energy technologies. The TCF selections announced on August 23, 2018, will expand the DOE’s efforts to catalyze the commercial impact of the Department’s portfolio of research, development, demonstration, and deployment activities. TCF funds require a 50 percent match of non-federal funds from private partners.

— Solar Builder magazine

Hanergy working to develop more thin-film PV applications at ‘Green China’ conference

Hanergy-Logo

Hanergy Thin Film Power Group signed a strategic cooperation agreement with Beijing Electric Vehicle at the “Green China – Hanergy Ecological City Comprehensive Solution Plan Conference” held at the Hanergy general headquarters. Working together within the framework of “Smart Transportation, Green Journey,” the two companies pledged to drive forward thin film applications for the car & household, including roofs and charging stations as well as projects to construct distributed energy industrial parks, and to use solar technology to alleviate poverty in agricultural areas.

As part of the agreement, BAIC BJEV will work with Hanergy to integrate Hanergy’s thin film solar solutions into the roofs of vehicles, providing auxiliary power and even functioning as the main power source. BAIC BJEV and Hanergy will also work together to use thin film solar technology to provide smart battery charging at electric vehicle charging stations. In terms of shared electric vehicles, the two companies will collaborate on using thin film solar to power automotive GPS and electronic locks.

Furthermore, BAIC BJEV and Hanergy plan to deploy thin film solar technology in BAIC BJEV’s automobile manufacturing plants, constructing a distributed green energy system to support factory operations. Finally, the two companies will begin to build small model villages incorporating the aforementioned technology, including thin film solar roofs, car charging stations and new energy vehicles. As part of this initiative the companies will also explore application of thin film solar for agriculture and poverty alleviation.

Lux Research: Thin-film solar modules could challenge silicon in the coming years

At the signing ceremony, Hanergy CEO Si Haijian said, “Hanergy’s partnership with BAIC BJEV stands as a model for cooperation between the thin film solar and the new energy vehicle industries, reflecting the push within Chinese industry to transform energy production and consumption.”

Aside from BAIC BJEV, the Green China Conference was attended by Haier, Zhong Yuan and other Chinese giants of industry. The conference was devoted to discussion of Hanergy’s Ecological City Comprehensive Solution, an effort under China’s new energy development strategy to lower urban energy consumption. This will be accomplished through reforms in macro level planning, program design, infrastructure construction and transportation services aimed at improving urban energy use. China’s efforts in this area follow similar programs undertaken in France, the Netherlands, Germany and other European countries. Similar to these countries, China has prioritized its plan to phase out gasoline powered cars.

— Solar Builder magazine

Sol Voltaics nets record funding to commercialize its solar panel boosting tech

sol voltaics nanowire

Sol Voltaics has closed a record funding round of $21.3 million, the largest finance raise for a European solar technology company since 2015. The new finance will be used to accelerate commercialization of its highly anticipated solar efficiency boosting technology, SolFilm which the company claims will increase conventional solar panel efficiencies by up to 50%.

SolFilm, a patented, low cost thin-film which is comprised of billions of highly efficient Gallium Arsenide (GaAs) nanowires, enables solar panel manufacturers to reach efficiencies of up to 27 percent when integrated as a tandem-junction module. Having recently confirmed the successful manufacture of nanowires using their low-cost process Aerotaxy, Sol Voltaics is now in the final stages of technology optimization, with anticipated samples of its SolFilm being sent to partners by the end of 2018.

“This latest round of finance gives us the critical capital required to commercialize our efficiency boosting technology for the solar market,” said Erik Smith, Sol Voltaics CEO. “Having achieved our final major technology milestone with Aerotaxy earlier this year, we are now fully focused on reaching mass production of SolFilm. I’d like to thank our investors, both existing and new, for backing our vision and helping bring this revolutionary technology to the mass market.”

The latest funding features new investment from Norwegian company Watrium AS, alongside previous investors Kagra Gruppen AS, Nordic VC firm Industrifonden, FAM AB, Nano Future Invest, Blue Marlin AB and Teknoinvest AS. The investment brings total funding raised to $38m in the past 12 months, following the company’s $17m funding round in 2016.

— Solar Builder magazine

Lux Research: Thin-film solar modules could challenge silicon in the coming years

The two leading thin-film solar manufacturers, First Solar and Solar Frontier, represent a combined manufacturing capacity of 4 GW. While they do not pose a short-term challenge to crystalline silicon players’ market dominance, ongoing innovations will ensure thin-film remains a significant player, according to Lux Research.

Of the two, First Solar is far bigger, with expertise in utility-scale systems and a new large-format module design that will help maintain its gigawatt-scale presence in utility-scale systems, as deployment grows in emerging markets. Solar Frontier has gradually diversified its business away from its home market of Japan and is making steps towards a rooftop building-integrated photovoltaic (BIPV) product.

“Both Solar Frontier and First Solar are moving forward to remain competitive with crystalline silicon. While First Solar will remain the thin-film leader, Solar Frontier has exhibited a willingness to form joint ventures to extend its scale,” said Tyler Ogden, Lux Research analyst and lead author of the report titled, “Tier-One Technology Tracker: Charting the Momentum of Thin-Film Leaders Solar Frontier and First Solar.”

Lux research thin film

Lux Research analysts compared Solar Frontier and First Solar, evaluating the two companies’ varied approaches, strengths and weaknesses. Among their findings:

• First Solar ahead on momentum. In Lux’s momentum analysis, First Solar had a score of 3.7, out of five, moving faster in technology progress and executing a competitive product strategy. Solar Frontier scored 2.9, moving adeptly into new markets through partnerships, while keeping pace in its financial position and manufacturing.

• Solar Frontier capitalizes on niches. Solar Frontier is taking steps toward a BIPV product, with preconfigured systems, flexibility and novel form factors. These are small differentiations in its current rooftop market, but can provide the groundwork for a larger BIPV industry with Solar Frontier at the helm, potentially a huge payoff.

• Challenges lie ahead for both. First Solar’s further growth hinges on plant-wide adoption of its Series 6 module and achieving systems costs below $1.00/W. Solar Frontier’s future rests on its ability to move its success in the lab to commercial production, and a partnership with a storage provider to integrate a lithium-ion battery option with its residential systems.

Thin-Film in 2016: Don’t look now, but thin-film PV is positioned for growth

 

— Solar Builder magazine