Earth Day has undoubtedly become a mainstream celebration in the 45 years since it was first launched in response to a massive oil spill in waters near Santa Barbara, California in 1969. Unfortunately, we just marked the anniversary of another massive oil spill (the worst one yet). But instead of giving you all the doom and gloom about how far we have yet to go, let's take a moment to celebrate how far we've come. By looking at these impressive statistics from the U.S. Census Bureau, you will see there are many reasons to be hopeful this Earth Day.
There are many reasons to be hopeful this Earth Day.
Photo credit: Shutterstock
Renewable Energy
$9.8 billion
Revenues in 2012 for electric power generation industries that use renewable energy resources, such as hydro, wind, geothermal, biomass, solar and other electric power generation. This figure is up 49 percent from $6.6 billion in 2007.
697
The number of wind, geothermal, biomass, solar and other electric power generation business establishments in 2012, up from 312 in 2007.
5,456
The number of employees in wind electric power generation, the most among the industries using renewable energy in 2012.
$5 billion
Revenues for the wind electric power generation industry in 2012, the highest among the industries using renewable energy resources. Hydroelectric power generation followed with revenues of $2.4 billion. Geothermal electric power generation had revenues of just under $1 billion ($995.4 million), followed by biomass electric power generation, with $934.6 million in revenues, solar electric power generation, with $472.4 million, and other electric power generation, with $59 million.
50,235
Estimated number of occupied housing units across the country totally heated by solar energy in 2013.
Sustainable Transportation
882,198
Estimated number of people who rode a bicycle to work in 2013. This comes out to about 0.6 percent of the American workforce.
4,000,459
Estimated number of people who walked to work in 2013. This comes out to about 2.8 percent of the American workforce.
Energy Use
18,817 trillion Btu
The energy consumption in the U.S. manufacturing sector in 2010, down 17 percent from the 22,576 trillion Btu (British thermal units) consumed in 2002.
-32%
The drop in the consumption of coal in the U.S. manufacturing sector from 2002 to 2010, going from 1,956 trillion Btu in 2002 down to 1,328 trillion Btu consumed in 2010.
Recycling
19.8%
Increase in the number of recyclable material merchant wholesalers establishments across the U.S. in 2012, from 7,377 establishments in 2007 to 8,838 establishments in 2012.
116,229
Number of employees working for recyclable material merchant wholesalers in 2012, up 11.0 percent from 104,671 employees in 2007.
$93.5 billion
Sales for recyclable material merchant wholesalers in 2012, up 16.7 percent from $80.1 billion in 2007. 2012 sales for recyclable paper and paperboard products: $9.8 billion. 2012 sales for recyclable plastics products: $2.3 billion. 2012 sales for recyclable glass products: $0.6 billion.
$8.4 billion
Product shipments value for recycled paperboard in 2013.
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An Edith's Checkerspot butterfly in Los Padres National Forest in Southern California. Patricia Marroquin / Moment / Getty Images
Butterflies across the U.S. West are disappearing, and now researchers say the climate crisis is largely to blame.
<p>A new study published in <a href="https://science.sciencemag.org/content/371/6533/1042" target="_blank">Science</a> on Thursday looked at three different data sets that cover the last 40 years of butterfly populations across more than 70 locations in the Western U.S. They found that butterfly populations had fallen by 1.6 percent per year, and that this was linked to warmer weather during the fall.</p><p>"That so many of our butterflies are declining is very alarming," Dr. Tara Cornelisse, an entomologist and senior scientist at the Center for Biological Diversity (CBD), said in <a href="https://biologicaldiversity.org/w/news/press-releases/study-climate-change-contributing-to-widespread-butterfly-decline-across-western-united-states-2021-03-04/" target="_blank">response to the findings</a>. "These declines are a wake-up call that we need to dramatically reduce greenhouse gases to save these beautiful and beloved butterflies, as well as our very way of life."</p>
<p>In recent years, scientists have raised the alarm about a worldwide decline in <a href="https://www.ecowatch.com/tag/insects" target="_self">insects</a>. A <a href="https://www.ecowatch.com/insect-land-decrease-study-2645822562.html" target="_self">study published last spring</a> found that the number of land-based insects was falling by about nine percent per decade. However, it has been difficult to tease out the causes of this decline, since factors like land-use change, pesticide use and climate shifts may all contribute, <a href="https://earther.gizmodo.com/climate-change-is-killing-butterflies-in-the-american-w-1846408143" target="_blank">Gizmodo's Earther pointed out</a>.</p><p>To investigate the role of climate change, the researchers chose to focus on the Western U.S. because it has seen general warming and drying trends covering a wide variety of ecosystems and land uses. They looked at 450 species in 11 states, from Washington to California to New Mexico to Montana, and compared population data with temperature trends.</p>
<p>They found that butterfly populations actually increased with summer temperatures, probably because the warmth meant more nectar and larval bugs as food for butterflies and caterpillars. However, the warmer autumns caused their populations to fall again, likely because plants cannot survive the extended warmth and the population of predators increases. Because the declines occurred in a variety of ecosystems, including protected areas that are less impacted by pesticides, the researchers thought climate change was to blame.</p><p>"Out there, removed from those factors, we see a shifting climate as the main driver of declining butterfly numbers," University of Texas in Reno biologist and lead study author Matthew Forister told Earther in an email.</p>
<p>University of Connecticut ecologist David Wagner, who was not involved with the study, said it was notable because it included protected areas.</p><p>"[T]his is one of the first global cases of declines occurring in wildlands, away from densely populated human-dominated landscapes, and the rate of 1.6 percent is calamitous," he told <a href="https://www.washingtonpost.com/climate-environment/2021/03/04/climate-change-butterflies/" target="_blank">The Washington Post</a>.</p><p>Examples of species in decline include the iconic monarch butterfly, the common cabbage white butterfly and the vulnerable Edith's checkerspot. Forister told The Washington Post that both widespread and rare species were impacted.</p><p>The findings have important implications for <a href="https://www.ecowatch.com/tag/conservation" target="_self">conservation</a>, because they show that simply protecting one habitat is not sufficient in the context of climate change.</p><p>"We need a multi-prong approach to conserve insects. This new study adds to the evidence that in addition to habitat protections and pesticide reform, that approach must include swift and bold climate change policy," CBD's Cornelisse said.</p>
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A wildfire burns in the Hollywood hills on July 19, 2016 in Hollywood, California. AaronP / Bauer-Griffin / GC Images
California faces another "critically dry year" according to state officials, and a destructive wildfire season looms on its horizon. But in a state that welcomes innovation, water efficacy approaches and drought management could replenish California, increasingly threatened by the climate's new extremes.
<p>The Sierra Nevada snowpack supplies the state with 30 percent of its water supply. But on Tuesday, California's Department of Water Resources recorded a snow depth of 56 inches and water content of 21 inches at Phillips Station – 61 percent of the average for March 2 and 54 percent of the average for April 1, when it's at its maximum, the <a href="https://www.latimes.com/california/story/2021-03-02/california-snowpack-increases-a-drought-could-be-on-the-horizon" target="_blank">Los Angeles Times reported</a>.</p><p>The state's largest reservoirs – responsible for maintaining the state's water supply throughout the year – also experienced low levels this year, storing only about 38 percent and 68 percent of their capacity, according to <a href="https://www.theguardian.com/us-news/2021/mar/03/california-snowpack-water-supply-shortage-conservation" target="_blank">The Guardian</a>.</p>
<p>"With below-average precipitation across the state, California's reservoirs are starting to see the impacts of a second consecutive dry year," said Sean de Guzman, the department's chief of snow surveys and water supply forecasting, according to <a href="https://www.theguardian.com/us-news/2021/mar/03/california-snowpack-water-supply-shortage-conservation" target="_blank">The Guardian</a>.</p><p>These effects are being felt across the state. During the city's wettest months of December, January and February, L.A. received just 2.44 inches of the expected 3.12 inches of rain, the Los Angeles Times reported. At the same time Northern California remains in one of the worst two-year rain deficient since the Gold Rush of 1849 – its precipitation at only 30 percent to 70 percent of a normal year, <a href="https://www.theguardian.com/us-news/2021/feb/11/california-dry-weather-drought-wildfire-agriculture" target="_blank">The Guardian reported</a>.</p>
<p>Three to five winter storms supply California's snowpack and reservoirs with water. But the state's dependency on these few winter storms makes it especially vulnerable when they occur less frequently, <a href="https://www.theguardian.com/us-news/2021/feb/11/california-dry-weather-drought-wildfire-agriculture" target="_blank">The Guardian reported</a>.</p><p>"In years where you miss out on one or two of those, you're probably going to struggle to get close to normal," John Abatzoglou, a climatology researcher at the University of California, Merced, <a href="https://www.theguardian.com/us-news/2021/feb/11/california-dry-weather-drought-wildfire-agriculture" target="_blank">told The Guardian</a>, who added that the state is increasingly living in extremes – either experiencing abnormally heavy rain or no rain at all. "We're banking on a miracle March or awesome April to dig out of this hole... In all likelihood, we're going to end the water year with another dry year."</p><p>The dry winter not only invites a destructive wildfire season but comes with a heavy price tag for the state's agricultural industry. Between 2012-2016, for example, the state experienced a drought that cost $2.7 billion in losses for the industry, and more than 18,000 lost jobs, <a href="https://www.theguardian.com/us-news/2021/mar/03/california-snowpack-water-supply-shortage-conservation" target="_blank" rel="noopener noreferrer">The Guardian reported</a>. This drought also killed about 102 million forest trees.</p>
<p>"Our state's water future remains uncertain due to the variability in precipitation and changing climate," Guzman said, according to the <a href="https://www.latimes.com/california/story/2021-03-02/california-snowpack-increases-a-drought-could-be-on-the-horizon" target="_blank">Los Angeles Times</a>. Now more than ever, new approaches to water efficacy are necessary. Fortunately, new ideas are plentiful in a state that is often celebrated for its sustainable policy.</p><p>One solution, for example, could include paying Californians to conserve water as a cost-effective way to reduce energy consumption, Sammy Roth, a staff writer for the Los Angeles Times wrote in the newsletter <a href="https://www.latimes.com/environment/newsletter/2021-03-04/want-to-save-energy-and-fight-climate-change-try-using-less-water-boiling-point" target="_blank">Boiling Point</a>.</p><p>Water and electricity go hand-in-hand in California. "Nearly one-fifth of electricity use in California goes to transporting and treating water. And nearly one-third of non-power plant natural gas use is water-related, primarily water heating," <a href="https://www.latimes.com/environment/newsletter/2021-03-04/want-to-save-energy-and-fight-climate-change-try-using-less-water-boiling-point" target="_blank" rel="noopener noreferrer">Roth wrote</a>, mentioning the state's complex <a href="https://water.ca.gov/Programs/State-Water-Project" target="_blank" rel="noopener noreferrer">water projects</a> that include systems "of reservoirs, aqueducts, power plants and pumping plants extending more than 700 miles."</p>
<p>Based on <a href="https://iopscience.iop.org/article/10.1088/1748-9326/abb9de/meta" target="_blank">research</a> that looked at what happened if the Los Angeles Department of Water and Power paid people to use less electricity rather than less water, the researchers concluded "that paying for water conservation can actually be a more cost-effective way to slash energy consumption than paying for energy conservation," Roth added.</p><p>In a drier, hotter and rapidly changing climate, that brings new <a href="http://www.ecowatch.com/tag/extreme-weather">weather extremes</a> to the state each year, water conservation is imperative for California and the nearly 40 million that call it home. "It's more critical than ever that Californians adopt sustainability, embrace new approaches and emerging technologies and work together to save water for a secure future," Guzman added, according to <a href="https://www.theguardian.com/us-news/2021/mar/03/california-snowpack-water-supply-shortage-conservation" target="_blank">The Guardian</a>.</p>
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Wisdom is seen with her chick in Feb. 2021 at the Midway Atoll National Wildlife Refuge. Jon Brack / Friends of Midway Atoll National Wildlife Refuge / Flickr / CC 2.0
Wisdom the mōlī, or Laysan albatross, is the oldest wild bird known to science at the age of at least 70. She is also, as of February 1, a new mother.
<p>Wisdom hatched her latest chick on Midway Atoll National Wildlife Refuge and Battle of Midway National Memorial, home to the world's largest albatross colony where millions of birds return each year to nest in the same place and, usually, with the same partner.</p><p>"Each year that Wisdom returns, we learn more about how long seabirds can live and raise chicks," Dr. Beth Flint, U.S. Fish and Wildlife Service (USFWS) biologist, said in a <a href="https://medium.com/usfwspacificislands/worlds-oldest-known-banded-wild-bird-hatches-chick-at-midway-atoll-2708a0b3f2c0" target="_blank">USFWS Pacific Islands post announcing the birth</a>. "Her return not only inspires bird lovers everywhere, but helps us better understand how we can protect these graceful seabirds and the habitat they need to survive into the future."</p>
<div id="dadb2" class="rm-shortcode" data-rm-shortcode-id="aa2ad8cb566c9b4b6d2df2693669f6f9"><blockquote class="twitter-tweet twitter-custom-tweet" data-twitter-tweet-id="1357796504740761602" data-partner="rebelmouse"><div style="margin:1em 0">🚨Cute baby alert! Wisdom's chick has hatched!!! 🐣😍 Wisdom, a mōlī (Laysan albatross) and world’s oldest known, ban… https://t.co/Nco050ztBA</div> — USFWS Pacific Region (@USFWS Pacific Region)<a href="https://twitter.com/USFWSPacific/statuses/1357796504740761602">1612558888.0</a></blockquote></div>
<p>Laysan albatrosses typically live 12 to 40 years, <a href="https://www.bbc.com/news/world-us-canada-56281983" rel="noopener noreferrer" target="_blank">BBC News reported</a>. Wisdom, however, was first banded in 1956 by biologist Chandler Robbins, according to <a href="https://www.theguardian.com/environment/2021/mar/05/wisdom-the-albatross-the-worlds-oldest-known-wild-bird-has-another-chick-at-age-70" rel="noopener noreferrer" target="_blank">The Guardian</a>. She has gone on to outlive him and likely her first mate. In that time, she has also hatched 30 to 36 chicks, according to USFWS. Since at least 2012, her mate has been a male albatross named Akeakamai.</p><p>"At least 70 years old, we believe Wisdom has had other mates," Flint said. "Though albatross mate for life, they may find new partners if necessary — for example if they outlive their first mate."</p><p>Wisdom is among the 70 precent of mōlī that nest on Midway Atoll, one of the oldest atoll-type islands in the world, located at the northern end of the Hawaiian island chain. In addition to mōlī, nearly 40 percent of kaʻupu (black-footed albatross) and <a href="https://www.ecowatch.com/tag/endangered-species" target="_self">endangered</a> makalena (short-tailed albatross) breed there, along with more than 20 other bird species.</p><p>Albatrosses arrive on the atoll beginning in October. Their eggs hatch around January or February following a 65-day incubation period, and the baby birds begin to fly in June or July. Wisdom laid this year's egg in late November. The Midway gathering can be a family reunion of sorts. In 2018, she nested a few feet away from a chick she had in 2011.</p>
<p>Albatrosses hatch one egg at a time, but don't lay eggs every year.</p><p>"Because she only nests every two years, the international bird community looks forward to see if she's been able to come back and nest," Sean Dooley, BirdLife Australia's national public affairs manager, told The Guardian. "The odds are stacked against them so much, whenever it happens it's always a cause for celebration."<br></p><p>Albatrosses face several threats, Dooley said, including <a href="https://www.ecowatch.com/tag/fishing" target="_self">fishing</a> practices that accidentally harm birds, such as using long lines. The <a href="https://www.ecowatch.com/climate-change/" target="_self">climate crisis</a> poses another danger.</p><p>"The changes in water temperate and the changes in currents in water and winds means... the extent they have to fly to find food increases as their prey species seek out colder water — it's a big looming threat that sea birds are facing, albatross in particular," Dooley explained.</p>
<p>Feeding their chicks can also be dangerous. Male and female albatrosses share incubation and feeding duties, USFWS noted. To feed their young, the birds catch squid and fish eggs that are rich in fatty acids and regurgitate them into their chicks' mouths. However, sometimes the parents bring home <a href="https://www.ecowatch.com/tag/plastics" target="_self">plastic</a> instead, the <a href="https://ocean.si.edu/ocean-life/seabirds/laysan-albatrosses-plastic-problem" target="_blank">Smithsonian reported</a>:</p><blockquote>Many birds accidentally eat plastic and other <a href="https://ocean.si.edu/ocean-news/ocean-trash-plaguing-our-sea" target="_blank">marine debris</a> floating in the ocean, mistaking it for food. But the problem is intensified in Laysan albatrosses because of the way they catch fish, squid and other seafood: by skimming the surface of the water with their beak. Along the way, they accidentally pick up a lot of floating plastic, which they then feed to their chicks. Adults can regurgitate plastic they've swallowed, but chicks are unable to, so it fills up their stomachs.</blockquote><p>Photographer Chris Jordan took <a href="http://www.chrisjordan.com/gallery/midway/#CF000313%2018x24" rel="noopener noreferrer" target="_blank">shocking photographs</a> of albatross chicks whose stomachs were full of plastic, and went on to make a <a href="https://www.albatrossthefilm.com/" rel="noopener noreferrer" target="_blank">film about the birds</a>.</p><p>"There's something so archetypal about these legendary birds and seeing bright colors of ocean plastic against dead sterility is a powerful symbol for our human culture right now. We're in a state of emotional bankruptcy," Jordan told <a href="https://www.theguardian.com/environment/2018/mar/12/albatross-film-dead-chicks-plastic-saving-birds" rel="noopener noreferrer" target="_blank">The Guardian in 2018</a>.</p><p>It is hard to know exactly how much plastic impacts the birds. Lead poisoning poses another threat to Laysan albatross chicks on Midway, the Smithsonian reported, so it can be difficult to determine their cause of death. However, more than 97 percent of dead albatross chicks found on Midway in recent years had plastic in their stomachs, according to <a href="https://www.theguardian.com/environment/2018/mar/12/albatross-film-dead-chicks-plastic-saving-birds" rel="noopener noreferrer" target="_blank">The Guardian</a>.</p>
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The Science Behind Frozen Wind Turbines – and How to Keep Them Spinning Through the Winter
05 March
Renewable Energy
Wind turbines in Norway. piola66 / E+ / Getty Images
By Hui Hu
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.
<p>
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</p>
<p>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.</p><p>Frequent severe icing can cut a wind farm's annual energy production by <a href="https://community.ieawind.org/HigherLogic/System/DownloadDocumentFile.ashx?DocumentFileKey=04b5c3d8-9a6f-7d9a-c1d6-aa848027ca1d" target="_blank">over 20%</a>, 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 <a href="https://doi.org/10.1002/wene.170" target="_blank" rel="noopener noreferrer">wear out more quickly</a>. It can also induce vibrations that cause the turbines to shut down. In the case of extreme icing, restarting turbines <a href="https://doi.org/10.1016/j.rser.2007.11.009" target="_blank" rel="noopener noreferrer">may not be possible for hours and potentially days</a>.</p>
<p>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 <a href="https://www.windpowerengineering.com/the-cold-hard-truth-about-ice-on-turbine-blades/" target="_blank">strategies</a> <a href="https://www.skekraft.se/english_pages/wind-power/#box-no-8" target="_blank">for keeping ice off</a> wind turbines blades come from aviation. And airplane wings and wind turbines are built differently and operate under very different conditions.</p><p>I am an <a href="https://www.aere.iastate.edu/~huhui/resume.html" target="_blank">aerospace and mechanical engineer</a>, and my colleagues and I have been studying <a href="https://www.aere.iastate.edu/~huhui/WT-icing.html" target="_blank" rel="noopener noreferrer">wind turbine icing physics</a> over the past 10 years and exploring <a href="https://doi.org/10.1016/j.renene.2019.03.112" target="_blank" rel="noopener noreferrer">better solutions for turbine icing protection</a>.</p>
<h3>Not All Ice Is the Same</h3><p>Ice isn't the same everywhere. It may come from precipitation, clouds or frost. It also freezes in different ways in different climates.</p><p>For example, <a href="https://www.mprnews.org/story/2018/12/10/winter-magic-the-beauty-of-freezing-fog-rime-ice-and-hoar-frost" target="_blank" rel="noopener noreferrer">rime icing</a>, 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.</p>
<img lazy-loadable="true" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTc0Njc4My9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTYzNzc5NzcyMn0.XRlFjF9QP6cUIN4g2OKUAlAr4k-cA65QNeFs-_3jrks/img.png?width=980" id="e137d" class="rm-shortcode" data-rm-shortcode-id="ad12febe93cfaa27a59f784b50ac0b1d" data-rm-shortcode-name="rebelmouse-image" data-width="1200" data-height="566" />
Comparing rime ice and glaze ice shows how each changes the texture of the blade. Gao, Liu and Hu, 2021, CC BY-ND
<p><a href="https://glossary.ametsoc.org/wiki/Glaze" target="_blank" rel="noopener noreferrer">Glaze icing</a> 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 <a href="https://www.reuters.com/article/uk-factcheck-texas-wind-turbines-explain/fact-check-the-causes-for-texas-blackout-go-well-beyond-wind-turbines-idUSKBN2AJ2EI" target="_blank" rel="noopener noreferrer">natural gas, coal or nuclear</a>, wind turbines also struggled.</p>
<h3>Tempests in a Wind Tunnel</h3><p>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.</p><p>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.</p><p>Using the <a href="https://www.aere.iastate.edu/facilities/icing-wind-tunnel/" target="_blank">Icing Research Tunnel</a> 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 <a href="https://doi.org/10.1016/j.renene.2018.10.032" target="_blank">airflow separation</a>. In airplanes, that's a dangerous situation that can cause them to stall. In wind turbines, it reduces their <a href="https://doi.org/10.1016/j.renene.2020.12.014" target="_blank">rotation speed and the amount of power</a> they can produce.</p>
<img lazy-loadable="true" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTc0Njc4NS9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY3MDk2NjcxNH0.vUPGiFyUz1ranua9stJmt4l_Ydw9RVhr39btf_1Yu1s/img.png?width=980" id="98372" class="rm-shortcode" data-rm-shortcode-id="edd9337fc7178dac5b64da1b6419d630" data-rm-shortcode-name="rebelmouse-image" data-width="1200" data-height="2052" />
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
<p>We also <a href="https://doi.org/10.1016/j.renene.2020.12.014" target="_blank" rel="noopener noreferrer">study wind turbines in operation around the country</a> as they face some of their toughest conditions.</p><p>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.</p><p>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 <a href="https://doi.org/10.1016/j.renene.2020.12.014" target="_blank">only 20% of their normal power</a> over that period.</p>
<img lazy-loadable="true" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTc0Njc5MC9vcmlnaW4ucG5nIiwiZXhwaXJlc19hdCI6MTY0ODE3MzEwM30.FpLWjSNfXfSUDmrZcraJima_XOsvR6-Pz4hkGo5GsKk/img.png?width=980" id="68ced" class="rm-shortcode" data-rm-shortcode-id="82fb5f19acbf7477eb44e146e50cc2e0" data-rm-shortcode-name="rebelmouse-image" data-width="1200" data-height="1052" />
How ice builds up on the tips of turbine blades. Gao, Liu and Hu, 2021, CC BY-ND
<h3>Keeping Ice Off Blades</h3><p>There are a few reasons the strategies that effectively keep ice off aircraft wings aren't as effective for wind turbine blades.</p><p>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 <a href="https://doi.org/10.1038/35083698" target="_blank" rel="noopener noreferrer">dust and insect collisions</a>, which can change the smoothness of the blade surface and <a href="https://doi.org/10.1016/j.ijmultiphaseflow.2020.103254" target="_blank" rel="noopener noreferrer">slow water running off the blade, promoting ice formation</a>.</p><p>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.</p><p>Most current wind turbine anti-icing and de-icing methods remove ice buildup through <a href="https://www.youtube.com/watch?v=8heUjOsUoBI" target="_blank" rel="noopener noreferrer">electric heating</a> 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.</p><p>Another strategy in cold-weather regions is to use <a href="https://doi.org/10.1016/j.renene.2020.10.013" target="_blank" rel="noopener noreferrer">surface coatings</a> 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.</p>
<h3>A Better Solution</h3><p>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 <a href="https://doi.org/10.1016/j.renene.2019.03.112" target="_blank" rel="noopener noreferrer">the entire surfaces</a> of turbine blades.</p><p>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.</p><p>Worldwide, <a href="https://www.climateaction.org/news/global-wind-power-capacity-to-surpass-800-gw-by-2021" target="_blank" rel="noopener noreferrer">nearly 800 gigawatts</a> of wind power have been installed so far, including <a href="https://cleantechnica.com/2021/03/03/the-united-states-installed-more-wind-turbine-capacity-in-2020-than-in-any-other-year/amp/" target="_blank" rel="noopener noreferrer">over 110 gigawatts in the U.S. alone</a>. As the market quickly grows and wind power supplants higher-polluting energy sources, de-icing and ice-proofing strategies are becoming essential.</p>
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<em>Hui Hu is a professor of aerospace engineering at Iowa State University.<br/>
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<em>Disclosure statement: </em><em>Hui Hu receives funding from National Science Foundation (NSF) and Iowa Energy Center (IEC) to study wind turbine icing physics and anti-/de-icing.</em>
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<em>Reposted with permission from <a href="https://theconversation.com/the-science-behind-frozen-wind-turbines-and-how-to-keep-them-spinning-through-the-winter-156520" target="_blank">The Conversation</a>.</em>
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Jaffa Port in Israel. theDOCK innovated the Israeli maritime space and kickstarted a boom in new technologies. Pixabay
While traditional investment in the ocean technology sector has been tentative, growth in Israeli maritime innovations has been exponential in the last few years, and environmental concern has come to the forefront.
<p>As the planet's largest ecosystem, the <a href="https://www.ecowatch.com/stable-oceans-climate-crisis-2647855196.html" target="_self">ocean stabilizes climate</a>, <a href="https://www.ecowatch.com/oceans-absorb-co2-2631712140.html" target="_self">stores carbon</a>, <a href="https://www.ecowatch.com/ocean-biodiversity-2646073009.html" target="_self">nurtures biodiversity</a> and directly supports human well-being through food, energy, medicinal, cultural and recreational services, the <a href="https://www.oceandecade.org/assets/The_Science_We_Need_For_The_Ocean_We_Want.pdf" rel="noopener noreferrer" target="_blank">United Nations</a> recently reported. However, poor management and conservation have led to serious degradation of ocean resources, which is only set to increase as the world's population does, the report noted.</p>
<img lazy-loadable="true" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTcxOTcxNS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNjI4MzgwOH0.LC8AXok7iHO_CBrhKkN9W5QLUZrUALh00X2Mq8Dk8zw/img.jpg?width=980" id="a5919" class="rm-shortcode" data-rm-shortcode-id="9a0dabcc86590e657483d2087e4b8720" data-rm-shortcode-name="rebelmouse-image" data-width="1920" data-height="1280" />
theDOCK aims to innovate the Israeli maritime sector. Pexels
<p>The UN hopes that new investments in ocean science and technology will help turn the tide for the oceans. As such, this year kicked off the <a href="https://www.oceandecade.org/" target="_blank" rel="noopener noreferrer">United Nations Decade of Ocean Science for Sustainable Development (2021-2030)</a> to galvanize massive support for the blue economy.</p><p>According to the World Bank, the blue economy is the "sustainable use of ocean resources for economic growth, improved livelihoods, and jobs while preserving the health of ocean ecosystem," <a href="https://www.sciencedirect.com/science/article/pii/S0160412019338255#b0245" target="_blank" rel="noopener noreferrer">Science Direct</a> reported. It represents this new sector for investments and innovations that work in tandem with the oceans rather than in exploitation of them.</p><p>As recently as Aug. 2020, <a href="https://www.reutersevents.com/sustainability/esg-investors-slow-make-waves-25tn-ocean-economy" target="_blank" rel="noopener noreferrer">Reuters</a> noted that ESG Investors, those looking to invest in opportunities that have a positive impact in environmental, social and governance (ESG) issues, have been interested in "blue finance" but slow to invest.</p><p>"It is a hugely under-invested economic opportunity that is crucial to the way we have to address living on one planet," Simon Dent, director of blue investments at Mirova Natural Capital, told Reuters.</p><p>Even with slow investment, the blue economy is still expected to expand at twice the rate of the mainstream economy by 2030, Reuters reported. It already contributes $2.5tn a year in economic output, the report noted.</p><p>Current, upward <a href="https://www.ecowatch.com/-innovation-blue-economy-2646147405.html" target="_self">shifts in blue economy investments are being driven by innovation</a>, a trend the UN hopes will continue globally for the benefit of all oceans and people.</p><p>In Israel, this push has successfully translated into investment in and innovation of global ports, shipping, logistics and offshore sectors. The "Startup Nation," as Israel is often called, has seen its maritime tech ecosystem grow "significantly" in recent years and expects that growth to "accelerate dramatically," <a href="https://itrade.gov.il/belgium-english/how-israel-is-becoming-a-port-of-call-for-maritime-innovation/" target="_blank" rel="noopener noreferrer">iTrade</a> reported.</p><p>Driving this wave of momentum has been rising Israeli venture capital hub <a href="https://www.thedockinnovation.com/" target="_blank" rel="noopener noreferrer">theDOCK</a>. Founded by Israeli Navy veterans in 2017, theDOCK works with early-stage companies in the maritime space to bring their solutions to market. The hub's pioneering efforts ignited Israel's maritime technology sector, and now, with their new fund, theDOCK is motivating these high-tech solutions to also address ESG criteria.</p><p>"While ESG has always been on theDOCK's agenda, this theme has become even more of a priority," Nir Gartzman, theDOCK's managing partner, told EcoWatch. "80 percent of the startups in our portfolio (for theDOCK's Navigator II fund) will have a primary or secondary contribution to environmental, social and governance (ESG) criteria."</p><p>In a company presentation, theDOCK called contribution to the ESG agenda a "hot discussion topic" for traditional players in the space and their boards, many of whom are looking to adopt new technologies with a positive impact on the planet. The focus is on reducing carbon emissions and protecting the environment, the presentation outlines. As such, theDOCK also explicitly screens candidate investments by ESG criteria as well.</p><p>Within the maritime space, environmental innovations could include measures like increased fuel and energy efficiency, better monitoring of potential pollution sources, improved waste and air emissions management and processing of marine debris/trash into reusable materials, theDOCK's presentation noted.</p><img lazy-loadable="true" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNTcxOTcxNi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY2MDc1MDY3Mn0.g_P2Tn6678glHT-XVsn6sFk4GG8uTPfSizJCj2vfvTk/img.jpg?width=980" id="8c24f" class="rm-shortcode" data-rm-shortcode-id="ae2fc8dcb8c8a4709149e98611475748" data-rm-shortcode-name="rebelmouse-image" data-width="3744" data-height="4480" />
theDOCK team includes (left to right) Michal Hendel-Sufa, Head of Alliances, Noa Schuman, CMO, Nir Gartzman, Co-Founder & Managing Partner, and Hannan Carmeli, Co-Founder & Managing Partner. Dudu Koren
<p>theDOCK's own portfolio includes companies like Orca AI, which uses an intelligent collision avoidance system to reduce the probability of oil or fuel spills, AiDock, which eliminates the use of paper by automating the customs clearance process, and DockTech, which uses depth "crowdsourcing" data to map riverbeds in real-time and optimize cargo loading, thereby reducing trips and fuel usage while also avoiding groundings.</p><p>"Oceans are a big opportunity primarily because they are just that – big!" theDOCK's Chief Marketing Officer Noa Schuman summarized. "As such, the magnitude of their criticality to the global ecosystem, the magnitude of pollution risk and the steps needed to overcome those challenges – are all huge."</p><p>There is hope that this wave of interest and investment in environmentally-positive maritime technologies will accelerate the blue economy and ESG investing even further, in Israel and beyond.</p>From Your Site Articles
- 14 Countries Commit to Ocean Sustainability Initiative - EcoWatch ›
- These 11 Innovations Are Protecting Ocean Life - EcoWatch ›
- How Innovation Is Driving the Blue Economy - EcoWatch ›
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