ship

Solar thermochemical hydrogen

November 23, 2023 By EarthWise Leave a Comment

For decades, there has been talk of the hydrogen economy in which hydrogen would take the place of fossil fuels in a wide range of domestic and industrial applications. Over time, hydrogen’s potential advantages in some applications have diminished but it is still seen as perhaps the most promising way to decarbonize long-distance truck, ship, and plane transportation as well as many heavy-duty industrial processes.

Hydrogen is the most common element in the universe, but here on Earth, it is tightly bound up in chemical compounds, notably water and hydrocarbons. Extracting hydrogen from these compounds takes lots of energy. To date, most hydrogen is produced from fossil fuel sources, resulting in carbon dioxide emissions. So-called green hydrogen is made by splitting up water into its component elements.

Getting hydrogen from water generally uses electrolysis, which requires lots of electrical power. That is why it isn’t the standard way to produce hydrogen; it costs too much to pay for all that power.

MIT scientists have been developing a process to make solar thermochemical hydrogen, or STCH. STCH uses the sun’s heat to split apart water and no other energy source. An existing source of solar heat drives a thermochemical reaction in which a heated metal surface grabs oxygen from steam and leaves hydrogen behind. MIT did not invent the concept; their efforts are to make it practical.

Previous STCH designs were only capable of using 7% of incoming solar heat to make hydrogen. The MIT process may be able to harness up to 40% of the sun’s heat and therefore generate far more hydrogen.

**********

Web Links

MIT design would harness 40 percent of the sun’s heat to produce clean hydrogen fuel

Photo, posted August 23, 2017, courtesy of Evan Lovely via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

An Electric Cruise Ship | Earth Wise

July 31, 2023 By EarthWise Leave a Comment

The shipping industry accounts for about 3% of global manmade greenhouse gas emissions. In 2018, the International Maritime Organization, the UN body that regulates global shipping, set a target to cut the industry’s greenhouse gas emissions by at least half by 2050.

This goal has led to a variety of designs for eco-friendly ships, including car carriers, superyachts, and cargo ships with retractable sails. But most of the designs still rely to at least some extent on engines that run on fossil fuels.

The Norwegian cruise ship company Hurtigruten has announced that it will build a zero-emissions electric cruise ship with retractable sails covered in solar panels. The ship is expected to set sail in 2030. Hurtigruten is a relatively small company, with a fleet of eight ships, each with a capacity of 500 passengers. But the company hopes that its innovative plan will inspire the entire maritime industry.

The ship will predominantly run off of electric motors powered by 60 megawatt batteries that can be charged in port with renewable energy. To reduce reliance on the battery, when it is windy, three retractable sails will rise out of the deck, reaching a maximum height of 164 feet. The sails will be covered in solar panels that will generate energy to top off the batteries while sailing.

The ship will have 270 cabins to hold 500 passengers and 99 crew members. The streamlined shape of the ship will result in less air resistance to further reduce energy use.

Hurtigruten already has a hybrid, battery-supported cruise ship and is currently in the process of converting its entire fleet to hybrid battery power.

**********

Web Links

An electric cruise ship with gigantic solar sails is set to launch in 2030

Photo, posted January 15, 2023, courtesy of Bernard Spragg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Life In The Garbage Patch | Earth Wise

May 23, 2023 By EarthWise Leave a Comment

A team of scientists has found thriving communities of coastal creatures living thousands of miles from their original homes and now ensconced on plastic debris in the Great Pacific Garbage Patch.

A new study published in the journal Nature Ecology & Evolution reports that dozens of species of coastal invertebrate organisms – including tiny crabs and anemones – have been able to survive and reproduce on plastic garbage that has been floating in the ocean for years.

The Great Pacific Garbage Patch is an area in the ocean between California and Hawaii, larger than Texas, where plastic debris has been collected by the North Pacific Subtropical Gyre, one of five huge, spinning circular currents in the world’s oceans. The patch is estimated to contain about 1.8 trillion pieces of plastic weighing an estimated 90,000 tons. The Ocean Cleanup Initiative is dedicated to removing this immense accumulation of plastic, but it is an immense job.

Researchers discovered this new ecosystem after analyzing plastic samples collected by The Ocean Cleanup organization during its expeditions in the Pacific. They were surprised to find 37 different invertebrate species that normally live in coastal water and only a dozen species that live in open waters. These species have made their way from North America and have thrived. So, the garbage patch has created a novel community that didn’t previously exist.

Debris from the Great Pacific Garbage patch constitutes the majority of debris arriving on Hawaiian beaches and reefs. Hawaii’s fragile marine ecosystems have long been protected from invasive species because of the very long distances from North America or Asia. With the coastal species now inhabiting the garbage patch, there is increased danger of colonization by them in Hawaii’s ecosystems.

**********

Web Links

Coastal species persist on high seas on floating plastic debris

Photo, posted September 30, 2020, courtesy of Kees Torn via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Arctic Methane Starting To Release | Earth Wise

November 24, 2020 By EarthWise Leave a Comment

An international team of researchers has found evidence that frozen methane deposits in the Arctic Ocean have started to be released over a large area of the continental slope off the East Siberian coast. High levels of methane have been detected down to a depth of 1,100 feet in the Laptev Sea near Russia.

The slope sediments in the Arctic contain huge quantities of methane and other gases, known as hydrates. Methane has a warming effect 80 times stronger than carbon dioxide over a 20-year period. The US Geological Survey has identified Arctic hydrate destabilization as one of the four most serious scenarios for abrupt climate change.

The research team aboard a Russian ship said that most of the bubbles they observed coming up from the sea bottom were dissolving in the water, but that methane levels at the surface were four to eight times what would normally be expected.

Frozen methane deposits have been called the “sleeping giants of the carbon cycle.” If these deposit releases were to reach a high enough level, it would be a tipping point that could greatly increase the speed of global warming. With Arctic temperatures now rising more than twice as fast as the global average, the likelihood of a significant release of the frozen methane grows greater all the time.

Temperatures in Siberia were 9 degrees Fahrenheit higher than average from January to June this year. Last winter’s sea ice melted unusually early. This winter’s freeze has yet to begin, which is already a later start than any time on record.

These new discharges of methane are larger than anything found before and are a very worrisome occurrence.

**********

Web Links

Arctic methane deposits ‘starting to release’, scientists say

Photo, posted September 26, 2014, courtesy of the Office of Naval Research via Flickr. Photo credit: U.S. Navy photo by John F. Williams/Released.

Earth Wise is a production of WAMC Northeast Public Radio.

Getting Rid Of Plastic Here And Abroad

May 23, 2019 By EarthWise Leave a Comment

Efforts in the fight against plastic pollution are really stepping up these days.

New York State lawmakers have agreed to impose a statewide ban on most types of single-use plastic bags from retail sales. The ban would be the second statewide ban after California, which banned the bags in 2016. Hawaii effectively also has such a ban since all of the state’s counties have their own bans.

The New York ban would begin next March and would forbid stores from providing customers with single-use plastic bags. There are a number of exceptions, including food takeout bags in restaurants, bags used to wrap deli or meat counter products, and newspaper bags. New York counties could opt into a plan to charge a 5-cent fee on paper bags, with proceeds going to the state’s Environmental Protection Fund. Some environmentalists point out, however, that paper bags have their own issues. While they do decompose in landfills, they have a substantial carbon footprint since they are made from wood and being heavier, they are more costly to ship. Business groups are concerned about the forthcoming ban based on increased costs.

Meanwhile, European Union member states have reached a provisional agreement to introduce restrictions on single-use plastic products. In 2021. European citizens will say goodbye to plastic cutlery, plastic plates and plastic straws among other products.

According to the European Commission, plastics make up 85% of beach litter in the Mediterranean. Large plastic pieces injure, suffocate, and often kill marine animals but microplastics have reached record levels of concentration – over a million fragments per square kilometer – in the Mediterranean.

Both here and abroad, the war on plastics is heating up.

**********