Day: March 23, 2021

‘The Cadillac of fibers…’ Upcycled ingredients startup Comet Bio gears up for commercial launch of arabinoxylan prebiotic fiber

Read the full story at Food Navigator USA.

Clinical data suggests that arabinoxylan – a fiber found in the cell walls of several plants – has a range of benefits from prebiotic effects to blood glucose control and immune health support. But no one has found a cost-effective way to isolate and produce it on an industrial scale… until now, claims Comet Bio, which is gearing up for the commercial launch of the ‘Cadillac of fibers’ in 2022.

The science behind frozen wind turbines – and how to keep them spinning through the winter

Ice can be a wind turbine’s worst enemy. AP Photo/Robert F. Bukaty

by Hui Hu (Iowa State University)

Winter is supposed to be the best season for wind power – the winds are stronger, and since air density increases as the temperature drops, more force is pushing on the blades. But winter also comes with a problem: freezing weather.

Even light icing can produce enough surface roughness on wind turbine blades to reduce their aerodynamic efficiency, which reduces the amount of power they can produce, as Texas experienced in February.

Frequent severe icing can cut a wind farm’s annual energy production by over 20%, costing the industry hundreds of millions of dollars. Power loss isn’t the only problem from icing, either. The uneven way ice forms on blades can create imbalances, causing a turbine’s parts to wear out more quickly. It can also induce vibrations that cause the turbines to shut down. In the case of extreme icing, restarting turbines may not be possible for hours and potentially days.

The solution is obvious: de-ice the blades, or find a way to keep ice from forming in the first place. So far, however, most of the strategies for keeping ice off wind turbines blades come from aviation. And airplane wings and wind turbines are built differently and operate under very different conditions.

I am an aerospace and mechanical engineer, and my colleagues and I have been studying wind turbine icing physics over the past 10 years and exploring better solutions for turbine icing protection.

Not all ice is the same

Ice isn’t the same everywhere. It may come from precipitation, clouds or frost. It also freezes in different ways in different climates.

For example, rime icing, formed when tiny, supercooled water droplets hit the surface, usually occurs in regions with relative dry air and colder temperatures, under 20 F. That’s what we typically see in Iowa and other Midwest states in the winter.

Images of ice forming on wind turbine blades
Comparing rime ice and glaze ice shows how each changes the texture of the blade. Gao, Liu and Hu, 2021, CC BY-ND

Glaze icing is associated with much wetter air and warmer temperatures and is commonly seen on the Northeast coast. This is the worst type of ice for wind turbine blades. It forms complicated ice shapes because of its wet nature, which results in more power loss. It’s also likely what formed in Texas in February 2021 when the cold air from the north collided with the moist air from the Gulf Coast. While the majority of the power shut down by the storm was from natural gas, coal or nuclear, wind turbines also struggled.

Tempests in a wind tunnel

Building a wind power operation that can thrive in icy conditions requires a keen understanding of the underlying physics, both of how ice forms and the performance degradation that results from ice building up on turbine blades.

To explore those forces, we use a special wind tunnel that can demonstrate how ice forms on samples of turbine blades, and fly camera-equipped drones.

Using the Icing Research Tunnel at Iowa State University, my team has been replicating the complex 3D shapes of ice forming on turbine blade models in different environments to study how they affect the wind and the blades. Ice can create massive airflow separation. In airplanes, that’s a dangerous situation that can cause them to stall. In wind turbines, it reduces their rotation speed and the amount of power they can produce.

illustration of air flow separation
Ice buildup changes air flow around the turbine blade, which can slow it down. The top photos show ice forming after 10 minutes at different temperatures in the Wind Research Tunnel. The lower measurements show airflow separation as ice accumulates. Icing Research Tunnel of Iowa State University, CC BY-ND

We also study wind turbines in operation around the country as they face some of their toughest conditions.

Using drones equipped with high-resolution digital cameras, we can hover in front of 80-meter-high wind turbines and take photos of the ice right after it forms on the blades. Pairing that with the turbine’s production data shows us how the ice influences power production.

While ice can form over the entire span of the blade, much more ice is found near the tips. After one 30-hour icing event, we found ice as much as a foot thick. Despite the high wind, the ice-heavy turbines rotated much slower and even shut down. The turbines produced only 20% of their normal power over that period.

Chart of ice formation on blade tips
How ice builds up on the tips of turbine blades. Gao, Liu and Hu, 2021, CC BY-ND

Keeping ice off blades

There are a few reasons the strategies that effectively keep ice off aircraft wings aren’t as effective for wind turbine blades.

One is the materials they are made of. While aircraft wings are typically made of metals like aluminum alloy, utility-scale wind turbines are made of polymer-based composites. Metal conducts heat more effectively, so thermal-based systems that circulate heat are more effective in airplane wings. Polymer-based turbine blades are also more likely to get covered by dust and insect collisions, which can change the smoothness of the blade surface and slow water running off the blade, promoting ice formation.

Wind turbines are also more prone to encounters with freezing rain and other low-altitude, high-water-content environments, such as ocean spray for offshore wind turbines.

Most current wind turbine anti-icing and de-icing methods remove ice buildup through electric heating or blowing hot air inside. Heating these massive areas, which are many times larger than airplane wings, adds to the cost of the turbine and is inefficient and energy-consuming. Composite-based turbine blades can also be easily damaged by overheating. And there’s another problem: Water from melting ice may simply run back and refreeze elsewhere.

Another strategy in cold-weather regions is to use surface coatings that repel water or prevent ice from sticking. However, none of the coatings has been able to eliminate ice completely, especially in critical regions near the blades’ leading edges.

A better solution

My team has been developing a novel method that uses elements of both technologies. By heating just the critical regions – particularly the blades’ leading edges — and using water- and ice-repelling coatings, we were able to reduce the amount of heat needed and the risk of running back water to refreeze over the blade surfaces. The result effectively prevents ice from forming on the entire surfaces of turbine blades.

In comparison to the conventional brute-force surface-heating methods, our hybrid strategy also used much less power, resulting in up to 80% energy savings. Without ice to slow it down, the turbines can produce more power through the winter.

Worldwide, nearly 800 gigawatts of wind power have been installed so far, including over 110 gigawatts in the U.S. alone. As the market quickly grows and wind power supplants higher-polluting energy sources, de-icing and ice-proofing strategies are becoming essential.

Hui Hu, Professor of Aerospace Engineering, Iowa State University

This article is republished from The Conversation under a Creative Commons license. Read the original article.

Equivalent of Covid emissions drop needed every two years – study

Read the full story in The Guardian.

Carbon dioxide emissions must fall by the equivalent of a global lockdown roughly every two years for the next decade for the world to keep within safe limits of global heating, research has shown.

Ralph Lauren announces comprehensive circularity strategy to advance sustainability goal

Read the press release.

Ralph Lauren Corporation today announced a comprehensive circularity strategy to further advance its sustainability goals. Grounded in Ralph Lauren’s iconic vision to create timeless products, the strategy orients around three pillars: design for circularity, establish circular experiences for consumers and advance a circular product economy…

As part of the strategy, the Company is also announcing a partnership with McDonough Innovation to achieve Cradle to Cradle certification™, a globally recognized measure of safer, more sustainable products, with some of its most iconic products.   

Harley-Davidson Announces First Chief Electric Vehicle Officer

Read the press release.

Harley-Davidson, Inc. (“Harley-Davidson”) (NYSE:HOG) today announces the appointment of Ryan Morrissey as Chief Electric Vehicle Officer (CEVO).

Effective April 1, Morrissey will join Harley-Davidson with over two decades of experience in disruptive technologies and the development of new business ventures. As a consultant at Bain & Company, he served most recently as a Senior Partner and head of the Automotive & Mobility practice in the Americas. In this role, he led the development of growth, adjacency and M&A strategies for OEMs, tech providers, and retailers specific to the long-range transition to electric vehicles and autonomous fleets. He has worked extensively with leading global OEMs in powersports, heavy equipment and automotive on developing digital channels, EV product strategy and software-based services. As part of Bain’s work with financial investors, he has advised many leading investment firms on acquisitions in mobility. 

Chipotle will tie 10% of executive incentives to environmental, diversity goals

Read the full story at Restaurant Dive.

Chipotle will tie 10% of its executives’ annual incentives to reaching the company’s environmental and diversity goals starting this year, according to CNBC.

The environmental targets include reaching 37 million pounds of organic, locally or regenerative grown or raised food in 2021. This is up from 31 million pounds reached last year. In terms of diversity, the company wants to maintain both racial and gender pay equity and aims to promote more women and people of color above the restaurant level, according to CNBC. 

Chipotle is among the latest public restaurant companies to hold its executives accountable for environmental, social and corporate governance goals. McDonald’s and Starbucks also recently tied executive compensation to reaching corporate diversity goals. 

Zero Waste Systems A Good Economic Recovery Bet

Read the full story at Biocycle.

A new study from GAIA, Zero Waste And Economic Recovery, finds cities that invest in zero waste programs and policies create good green jobs, in addition to known benefits of reducing pollution and improving community health. “Reuse creates over 200 times as many jobs as landfills and incinerators, recycling creates around 70 times as many jobs, and remanufacturing creates almost 30 times as many jobs,” notes the report, which collected data from a wide range of sources spanning 16 countries.

Puerto Rico’s 1GW RFP for renewables also calls for 500MW of energy storage

Read the full story at Energy Storage.

Puerto Rico has issued a request for proposals (RFP) to construct 1GW of renewable energy capacity and 500MW of battery energy storage on the island.

The Puerto Rico Electric Power Authority (PREPA) is seeking to procure renewable energy resources with a minimum generating capacity of 20MW, and 500MW of collective energy storage, at least 150MW of which will be distributed virtual power plants (VPPs). A resource that will interconnect to the distribution system cannot exceed 25MW capacity.

The agency said in a public document that it will give preference to energy storage systems with a four-hour discharge duration, but would also consider two and six-hour durations.

How the National Green Bank can help small businesses build back greener

Read the full story at Utility Dive.

As the economy recovers from the COVID-19 pandemic, small businesses will be at the forefront of any economic recovery. And while the Biden Administration contemplates ways to support small businesses in their recovery, they should consider the opportunity to align these recovery efforts with the broader imperative of reducing the nation’s impact on climate change. With 30.7 million small businesses located in the U.S., any efforts toward reducing emissions are going to need to include this market.

A scrappy solar developer took utility regulators to court. And won.

Read the full story from the Pittsburgh Post-Gazette.

David Hommrich started his battle against multiple Goliaths — two Pennsylvania utilities and the state itself — seven years ago.

It has been at least that long since he has gotten paid anything for the electricity that a bunch of his solar panels in Washington County have been pumping onto the local grid.

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