cost effective

Trees Are Growing Bigger | Earth Wise

November 3, 2022 By EarthWise Leave a Comment

The alarming rate of carbon dioxide flowing into the atmosphere is having a real and actually positive effect on plant life. Higher concentrations of carbon dioxide make plants more productive because photosynthesis makes use of the sun’s energy to synthesize sugar out of carbon dioxide and water. Plants make use of the sugar both as a source of energy and as the basic building block for growth. When carbon dioxide levels go up, plants can take it up faster, supercharging the rate of photosynthesis.

In a new study published in the journal Nature Communications, scientists at Ohio State University found that trees are feasting on decades of carbon dioxide emissions and are growing bigger as a result.

The researchers tracked wood volume in 10 different tree groups from 1997 to 2017 and found that all of them except aspens and birches grew larger. Over that time period, carbon dioxide levels climbed from 363 parts per million to 405 parts per million. According to the study, each 1% increase in lifetime CO₂ exposure for trees has led to more than a 1% increase in wood volume.

In the big picture, the news isn’t so positive. The global warming caused by increasing carbon dioxide levels increasingly threatens the forests of the world. It has led to worsening droughts, insect infestations, and wildfires. So overall, increasing levels of carbon dioxide are by no means a good thing for the world’s trees. However, since trees are growing bigger more quickly, it means that planting them is an increasingly cost-effective method for fighting climate change because the same number of trees can sequester more carbon.

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As Carbon Dioxide Grows More Abundant, Trees Are Growing Bigger, Study Finds

Photo, posted September 12, 2015, courtesy of Nicholas A. Tonelli via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Floating Renewable Energy | Earth Wise

July 22, 2021 By EarthWise Leave a Comment

A team of researchers at Texas A&M University believes that the next generation of offshore energy could come in the form of a synergistic combination of multiple renewable energy generators installed on a floating offshore platform.

Their concept for the ocean renewable energy station comprises wind, wave, ocean current, and solar energy elements that could generate electricity for anything from a coastal or island community to a research lab or military unit. The station would be tethered to the sea bottom and could be used in locations where the water depth increases quickly, such as along the U.S. Pacific Coast or Hawaii.

Offshore wind is already commercially competitive, while wave-energy converters so far have been less cost-effective and only useful for specialized, smaller-scale applications. The proposed ocean renewable energy station would make use of multiple different methods of electricity generation and incorporate innovative smart materials in the wave energy converters that respond to changes in wave height and frequency and allow for more consistent power production.

Denmark is already building a huge multi-source, multi-purpose ocean energy island. This world’s first energy island will be 30 acres in area and serve as a hub for 200 giant offshore wind turbines generating 3 GW of electric power. It is the largest construction project in Danish history, and will cost an estimate $34 billion. As well as supplying other European countries with electricity, the goal is to use the new offshore island to produce green hydrogen from seawater, which can also be exported. Large battery banks on the island will store surplus electricity for use in times of high demand.

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Research Underway On Floating Renewable Energy Station

Photo, posted September 27, 2014, courtesy of Eric Gross via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Food Waste Into Wearables | Earth Wise

November 20, 2020 By EarthWise Leave a Comment

A new startup company spun out of the University of Toronto wants to make clothing from food waste. If they are successful, you may someday buy a shirt or a pair of gym shorts made from banana peels, rotten tomatoes, coffee grounds, or moldy bread.

A problem faced by the clothing industry is that most textiles are blended with synthetic and non-renewable fiber polyester, which makes them unrecyclable. An alternative that has come on the scene in recent years is polylactic acid (or PLA), which is a decomposable bioplastic that is currently used for food packaging, medical implants, and 3D printing. It is likely that a sustainable future for the fashion industry will depend on the ability to make use of biodegradable and carbon-neutral materials.

PLA is typically made from cornstalk, but the startup – called ALT TEX – does not want to rely on a crop already used for feedstock, human consumption, and alternative fuel. Furthermore, there is no need to plant more corn when there is an abundant supply of unused post-industrial food waste from growers, producers, and retailers that contains the same biological building blocks for producing PLA.

ALT TEX has been conducting experiments using discarded apples to create a PLA-based fabric that is strong, durable, decomposable, and cost effective. They are working with farmers and food suppliers to access their waste. If their efforts are successful, it would be possible to divert significant amounts of organic waste that currently emits the powerful greenhouse gas methane and instead enable the fashion industry to be more sustainable.

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Earth-friendly fashion: U of T startup turns food waste into wearables

Photo, posted August 30, 2019, courtesy of Ruth Hartnup via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Plants Paying For Biofuels | Earth Wise

May 7, 2020 By EarthWise Leave a Comment

Biofuels are an important element in broader strategies to replace petroleum in transportation fuels like gasoline, diesel, and jet fuel. The idea is that biofuels recycle carbon by getting it from growing plants rather than from fossil sources. The biggest problem with biofuels is that they cost more than conventional petroleum fuels, so there is economic incentive to keep burning the fossil fuels.

One strategy to make biofuels cost competitive is to have the plants provide additional economic benefits beyond being a feedstock for fuel. This in principle can be done by engineering plants to produce valuable chemical compounds, or bioproducts, as they grow. Bioproducts include such things as flavoring agents and fragrances as well as biodegradable plastic. These bioproducts can be extracted from the plants and then the remaining plant material can be converted to fuel.

Researchers at Lawrence Berkeley National Laboratory recently published a study to determine what quantities of bioproducts plants need to produce to result in cost-effective biofuel production.

The study looked at a compound called limonene, which is used for flavoring and fragrance. They calculated that if this compound was accumulated at 0.6% of the biomass dry weight, it would offer net economic benefits to biorefineries. This corresponds to recovering 130 pounds of limonene from 10 tons of sorghum on an acre of land.

Such quantities are completely practical but, on the other hand, none of these substances are needed in huge quantities. Just six refineries could supply the world with limonene. So, fuel crops would need to be engineered to produce a broad range of bioproducts to enable a viable cost-effective biofuel industry.

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Making Biofuels Cheaper by Putting Plants to Work

Photo, posted September 28, 2019, courtesy of Michele Dorsey Walfred via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Bigger Is Better For Wind Energy

February 13, 2019 By EarthWise Leave a Comment

Bigger is almost always better for wind power. Bigger wind farms are better than smaller wind farms and bigger wind turbines are better than smaller ones.

The biggest turbines currently available produce nearly 10 MW of power, which is enough to supply over 2,000 homes with electricity. A wind farm with just a few of these turbines could produce enough electricity for a small town. A big wind farm, like the giant 1,550 MW Alta Wind Energy Center in California can generate enough power for a small city.

Vestas Wind Systems, an industry leader based in Denmark, has announced a 10 MW turbine that will be ready for installation in two years. The rotor diameter of the giant machine is 538 feet and the blades sweep out an area of 227,000 square feet, the size of nearly 4 football fields.

Not to be outdone, General Electric is developing a 12 MW offshore wind turbine that will stand 850 feet tall and sweep out an area of more than 400,000 square feet. GE estimates that its 12 MW turbine will achieve nearly twice the capacity factor of its 6 MW turbine.

Companies are building bigger and bigger wind turbines because they are more cost effective. The capacity factor, which is the actual energy production divided by the potential energy production, goes up as the turbines get bigger and more efficient. In terms of dollars spent to produce a given amount of power, larger windfarms are less expensive to build than smaller ones. A wind farm of 200-500 MW capacity is about 40% cheaper per MW capacity than a 25 MW wind farm.

When it comes to wind energy, there is no doubt that bigger is better.

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