ASU, Dash publish new research on blockchain scalability


July 30, 2018

The Arizona State University Blockchain Research Lab and Dash, a top digital currency for payments and e-commerce, have released new research that highlights some of the scaling challenges and potential opportunities for the Dash blockchain. The paper, “Block Propagation Applied to Nakamoto Networks,” discusses the results of different scaling solution scenario simulations for the Dash network while also providing potential insights on the scalability challenges facing proof-of-work blockchains.

“The scalability question has been a major limiting factor for most cryptocurrencies, as there has been doubt surrounding whether or not these networks can scale to handle mass adoption," said Dragan Boscovic, director of the ASU Blockchain Research Lab and professor in the Ira A. Fulton Schools of Engineering. "Through this research, which was made possible by our partnership with Dash, we were able to investigate the scaling limitations of the Dash network while also exploring various block propagation techniques. We’re excited to broaden our research in the future to potentially explore other pertinent topics including the operation of mining pools, and the role of multi-tier networks.” Dragan Boscovic, ASU Dragan Boscovic, ASU Ira A. Fulton Schools of Engineering research professor. Download Full Image

The team — led by Boscovic and researchers Nakul Chawla and Darren Tapp — focused on simulating different block size scaling scenarios for the Dash network with three different types of block propagation protocols: traditional full block propagation, compact block propagation and extreme thin (xthin) block propagation. Each simulation was applied to networks with at least 6,000 nodes and, to account for variance, the simulations were run long enough to simulate at least 700 blocks.

Some highlights from the research include:

• Scaling to 10MB block sizes is feasible for the Dash network when utilizing xthin block propagation. Utilizing compact block propagation, the Dash network can reliably scale to between 6-8MB block sizes with a negligible orphan block rate.

 • Based on the simulation data, scaling well beyond 10MB block sizes using compact or xthin block propagation, while maintaining a minimal orphan block rate, is realistic.

 • If miners are acting “rationally” and “in search of a profit,” there is an “economic limit” that disincentivizes mining blocks that eclipse .9MB in transactions using traditional block propagation techniques (unless higher transaction fees are included in the block); however, when using xthin propagation the economic limit disappears in block sizes up to 10MB.

“Scalability has been a key challenge for the blockchain industry, but the lack of academic research into the issue has been notable," said Ryan Taylor, CEO of Dash Core. "The implication of this research is prodigious not only for Dash, but for crypto as a whole. First, it means we can continue increasing block size and network capacity to at least five times our current capacity in the near term. This means we will soon have 40 times the capacity of the Bitcoin network and a credible path to scaling further in the future. This is the type of scalability we need to achieve mass adoption as a daily payments solution.”

The simulations were carried out at ASU’s Center for Assured and Scalable Data Engineering. The research is part of a $350,000 partnership that was announced in January 2018 between Dash and ASU, which was funded by Dash’s unique treasury system and includes funds earmarked for the Blockchain Research Lab as well as a Dash Scholars program.

Read the full paper

ASU research demonstrates silicon-based tandem photovoltaic modules can compete in solar market

Nature-Energy features ASU study that depicts acceptable intersection of improved solar technology costs vs. efficiency


July 30, 2018

New solar energy research from Arizona State University demonstrates that silicon-based tandem photovoltaic modules, which convert sunlight to electricity with higher efficiency than present modules, will become increasingly attractive in the U.S.

A paper that explores the costs vs. enhanced efficiency of this new solar technology appears in Nature Energy this week. The paper is authored by ASU Ira A. Fulton Schools of Engineering Assistant Research Professor Zhengshan J. Yu, graduate student Joe V. Carpenter and Assistant Professor Zachary Holman. ASU Professor Zhengshan Yu addresses how current solar tell technologies are reaching the limits of efficiency. ASU Assistant Research Professor Zhengshan Yu addresses how current solar cell technologies are reaching the limits of efficiency. Photo courtesy of ASU Holman Lab Download Full Image

The Department of Energy’s SunShot Initiative was launched in 2011 with a goal of making solar cost-competitive with conventional energy sources by 2020. The program attained its goal of $0.06 per kilowatt-hour three years early, and a new target of $0.03 per kilowatt-hour by 2030 has been set. Increasing the efficiency of photovoltaic modules is one route to reducing the cost of the solar electricity to this new target. If reached, the goal is expected to triple the amount of solar installed in the U.S. in 2030 compared to the business-as-usual scenario. 

But according to Holman, “the dominant existing technology — silicon — is more than 90 percent of the way to its theoretical efficiency limit,” precipitating a need to explore new technologies. More efficient technologies will undoubtedly be more expensive, however, which prompted the paper co-authors to ask, “Does a doubling of module efficiency warrant a doubling of cost?”

Tandem modules stack two, complementary photovoltaic materials — for instance, a perovskite solar cell atop a silicon solar cell — to best use the full spectrum of colors emitted by the sun and exceed the efficiency of either constituent solar cell on its own. The study was designed to determine how much more expensive high-efficiency tandem photovoltaic modules can be and still compete in the evolving solar marketplace. 

ASU Assistant Research Professor Zachary Holman reflects on the efficiency of new solar technologies vs. the costs.

ASU Assistant Professor Zachary Holman reflects on the efficiency of new solar technologies vs. the costs. Photo by Deanna Dent/ASU Now

Results indicate that in the expected 2020 U.S. residential solar market, 32-percent-efficient anticipated tandem modules can cost more than three times that of projected 22-percent-efficient silicon modules and still produce electricity at the same cost. This premium, however, is a best-case scenario that assumes the energy yield, degradation rate, service life and financing terms of tandem modules are similar to those of silicon modules alone. The study also acknowledges that cost premium values will vary according to region. 

“Our previous study defines the technological landscape of tandems; this study paints the economic landscape for these future solar technologies that are only now being created in labs,” Yu said. “It tells researchers how much money they’re allowed to spend in realizing the efficiency enhancements expected from tandems.”

Holman’s research group is a leader in silicon-based tandem photovoltaic technologies, having held the efficiency world record in collaboration with Stanford University for a perovskite/silicon tandem solar cell until last month. As the team strives to reclaim the record while sticking to inexpensive materials and simple processes, it now knows that its innovations will likely find their way to a U.S. rooftop.

Terry Grant

Media Relations Officer, Media Relations and Strategic Communications

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