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AI and energy

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MIT recently hosted a symposium on the subject of artificial intelligence being both a problem and a solution for the clean energy transition.

AI-powered computing centers are expanding rapidly, creating an unprecedented surge in electricity demand.  Electricity demand in the US had been relatively flat for decades but now these computing centers consume about 4% of the nation’s electricity.  Some projections say that this demand could rise to 12-15% in the next five years. 

The power required for sustaining some of the AI large-language models is doubling every three months.  The amount of electricity used by a single ChatGPT conversation is as much as it takes to charge a phone and consumes the equivalent of a bottle of water for cooling. 

The MIT symposium focused on the challenges of meeting these growing energy needs but also on the potential for AI to dramatically improve power systems and reduce carbon emissions. 

Research shows regional variations in the cost of powering computing centers with clean electricity.  The central United States offers lower costs due to complementary solar and wind resources but would require massive battery deployments to provide uninterrupted power.

Because of data center demand, there is renewed interest in nuclear power, often in the form of small modular reactors, as well as efforts in long-duration storage technologies, geothermal power, or hybrid approaches.

Artificial intelligence offers both great promise and great peril.  It will take real intelligence to steer it in the right direction.

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Confronting the AI/energy conundrum

Photo, posted August 31, 2024, courtesy of Jefferson Lab via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Soda can hydrogen

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Hydrogen is an ideal climate-friendly fuel because it doesn’t release carbon dioxide when it is used.  But most hydrogen is produced in ways that result in significant carbon emissions. Thus, the search for green hydrogen goes on. 

Last year, engineers at MIT developed a new process for making hydrogen that significantly reduces the carbon footprint of its production.  The recipe uses seawater and recycled soda cans. 

Pure aluminum reacts with water, breaking up the water molecules to produce aluminum oxide and pure hydrogen.  But when aluminum is exposed to oxygen, it forms a shield-like layer that prevents the reaction.

The MIT researchers found that the shield can be removed by treating aluminum with a small amount of gallium-indium alloy.  Mixing the pure aluminum with seawater not only produces hydrogen, but the salt in the seawater precipitates out the gallium-indium, making it available for reuse.

The research team carried out a “cradle-to-grave” life cycle assessment of the process, taking into account every step in using the hydrogen-production process at an industrial scale.  They found that using recycled aluminum – chopped-up soda cans – is environmentally and economically superior to using “primary” aluminum, mined from the earth. The cans would be shredded into pellet and treated with the gallium-indium alloy.  The pellets would be processed near a source of seawater where they would be combined to generate hydrogen on demand.

According to their analysis, the hydrogen produced would be at least competitive economically and environmentally with other potential methods of producing green hydrogen.

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Study shows making hydrogen with soda cans and seawater is scalable and sustainable

Photo, posted July 29, 2020, courtesy of Bruce Dupree via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Grid reliability and grid-edge resources

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A new study by MIT researchers looked at the potential for grid-edge resources to enhance the ability of the electric grid to respond to unforeseen power outages.  Grid-edge resources are devices found close to consumers rather than located near central power plants, substations, or transmission lines.  These include residential solar panels, storage batteries, electric vehicles, heat pumps, smart thermostats and smart water heaters.

These grid-edge devices can independently generate, store, or tune their consumption of power and increasingly, they are online internet-of-things devices.  The MIT study outlined a blueprint for how such devices could reinforce the power grid through a local electricity market.  Owners of grid-edge devices could subscribe to such a market and essentially loan out their device as part of a microgrid or local network as on-call energy resources.

Electric vehicles could provide power rather than consuming it when necessary.  Storage batteries could do the same.  Devices like smart dishwashers and thermostats would reduce their power demands when necessary.

In the event that the main power grid is compromised, an algorithm would determine which grid-edge devices were available and trustworthy and would either use them to pump power into the grid or reduce the power they are drawing from it in order to help mitigate the power failure. 

The MIT researchers illustrated this grid resilience strategy through a number of grid attack scenarios including failures from cyber-attacks and natural disasters.   Their analysis showed that various networks of grid-edge devices are capable of defeating various types of grid failures.

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Rooftop panels, EV chargers, and smart thermostats could chip in to boost power grid resilience

Photo, posted October 10, 2019, courtesy of Noya Fields via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Thermal batteries for heavy industry

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Heavy industries like cement, steel, chemicals, and paper require large amounts of heat and, for the most part, that heat comes from burning fossil fuels.  Other sectors of the economy have been making progress in reducing carbon emissions, but heavy industry has not found easy answers for supplying the heat it needs for manufacturing.

Researchers at MIT have developed a way to supply heat that only uses electricity, which in principle can come from carbon-free sources.  The idea is to use thermal batteries.  These are basically an electrically conductive equivalent of ceramic firebricks, which have been used to store heat for centuries in fireplaces and ovens.

A spinout company called Electrified Thermal Solutions has demonstrated that its firebricks can store heat efficiently for hours and release it by heating air or gas up to 3,272 degrees Fahrenheit. 

The firebrick arrays are contained in insulated, off-the-shelf metal boxes.  The standard system can collect and release about 5 megawatts of energy and store about 25 megawatt-hours.  The thermal battery can run hotter and last longer than any other electric heating solution on the market.

Using this technology can be a way to take advantage of the low cost of electricity in off-peak hours.  In the so-called wind belt in the middle of the U.S., electricity prices can even be negative at times.  Using the firebrick technology – called the Joule Hive Thermal Battery – it can be possible to provide industrial heating capability at very competitive prices, and that doesn’t even factor in the positive climate impact.

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Decarbonizing heavy industry with thermal batteries

Photo, posted April 19, 2019, courtesy of Hans M. via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Hydrogen-powered aviation

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The transportation sector is responsible for about a quarter of human-generated greenhouse gas emissions.  Most of the energy used by transport systems comes from fossil fuels.  The transition to electric vehicles – cars, trucks, and buses – is making a real difference.  However, the emissions from the aviation industry have continued to grow faster than those of other forms of transportation.  There have been increased efforts to develop hydrogen-powered aircraft, but the challenges are substantial.

Hydrogen can be used for aviation both as a directly combusted fuel, or to power electric fuel cells.  Its advantages are that its use produces no carbon dioxide, and, in fact, hydrogen produces more energy per pound than jet fuel.

A study by researchers at MIT looked at the prospects for hydrogen use in aircraft and what needs to be done to make it practical.  The biggest issue is that the extra bulk of a hydrogen fuel tank and fuel cells in a plane would have to be offset by weight reductions elsewhere, such as reducing payload (cargo or passengers).  This would mean there would need to be more flights, thereby reducing the gains made.  The researchers argued that improvements in fuel cell power and more weight efficient fuel systems could eliminate the need for additional flights.

The bigger challenge is the infrastructure for generating and distributing hydrogen.  There needs to be green hydrogen – hydrogen produced without carbon emissions – and the infrastructure for getting it to planes where it is needed has to also not produce substantial emissions.

The study suggests that the rollout of hydrogen-based aviation should start at locations that have favorable conditions for hydrogen production.

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Fueling greener aviation with hydrogen

Photo, posted December 20, 2016, courtesy of Dylan Agbagni via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar-powered desalination

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People in remote, low-income regions far from the ocean often need to meet their water needs from groundwater and groundwater is becoming increasingly saline due to climate change.  Desalination of brackish groundwater is a huge and largely untapped source of drinking water, but there are challenges in making the process efficient and reliable.

Engineers at MIT have developed a solar-powered desalination system that requires no batteries or external power sources and is capable of producing large quantities of clean water despite the variations of sunshine throughout the day.

The system is based on the process of electrodialysis and consists of water pumps, an ion-exchange membrane stack, and a solar panel array.  What is unique about it is that it makes use of sensors and a control system that predicts the optimal rate at which to pump water through the system based on the output of the solar panels.  As a result, it uses nearly all of the electricity generated to produce clean water and does not need stored or grid-based energy.

The MIT engineers tested a community-scale prototype on groundwater wells in New Mexico over a six-month period.  The system harnessed on average over 94% of the electricity generated by its solar panels and produced as much as 5,000 liters of water per day despite large variations in weather and sunlight.

The new renewable-powered, battery-free system could provide much-needed drinking water at low cost, especially for communities where access to seawater and to grid power are limited.  The team plans to further test and scale up the system so it can supply larger communities and even whole municipalities with low-cost drinking water.

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Solar-powered desalination system requires no extra batteries

Photo courtesy of Shane Pratt.

Earth Wise is a production of WAMC Northeast Public Radio

Increasing plastic recycling

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Recycling plastic is a complicated matter.  There are many different types of plastic and knowing which things are made of which type isn’t easy.  There are increasingly widespread recycling systems across the U.S., but the actual rates of recycling have been described as “abysmal”.

The plastic commonly used in beverage bottles is polyethylene terephthalate, or PET.  The present nationwide rate of recycling PET is about 24% and has been about at that level for a decade.

A new study by MIT has found that with a nationwide bottle deposit program, the rates could increase to 82%.  At that level, nearly two-thirds of all PET bottles could be recycled into new bottles at a net cost of just a penny a bottle.

The study looked at PET bottle collection and recycling rates in different states as well as other nations with and without bottle deposit policies, and with and without curbside recycling programs.  The study is the first to look in detail at the interplay between public policies and the detailed end-to-end aspects of the packaging, production and recycling market.

Recycling of PET is highly successful in terms of quality.  New products made from all-recycled material is virtually indistinguishable from virgin material.  The crucial bottleneck is the collection of sufficient amounts of material to meet the needs of processing plants.  So, the conclusion of the study is that with the right policies in place, significant improvements can be made.  Several European countries manage to collect more than 90% of PET bottles for recycling.  So, it can be done.

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How to increase the rate of plastics recycling

Photo, posted August 10, 2013, courtesy of Lisa Risager via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Around-the-clock clean energy

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Using solar and wind power can go a long way toward replacing fossil fuel-generated electricity, particularly with the addition of battery energy storage.  But because of the intermittent nature of both sun and wind, other sources are still needed.  There is also the need for ways to produce high temperature for industrial processes.  Complete decarbonization will require a host of complementary technologies.

A spinout company from MIT called 247Solar is building high-temperature concentrated solar power systems that make use of overnight thermal energy storage to provide electric power around the clock as well as industrial-grade heat.

The system uses a field of sun-tracking mirrors to reflect sunlight to the top of a central tower.  A proprietary solar receiver heats air to over 1,800 degrees Fahrenheit.  The heated air drives turbines that generate 400 kilowatts of electricity and produces 600 kilowatts of heat.  Some of the hot air is routed through a long-duration thermal energy storage system and the stored heat is then used to drive the turbines when the sun isn’t shining.  The unique part of the technology is not the concentrated solar power; it is the solar receiver.

The modular systems can be used as standalone microgrids for communities, or to provide power in remote places.  They can also be used in conjunction with conventional wind and solar farms to enable around-the-clock renewable power.

The first deployment will be with a large utility in India.  If it is successful, 247Solar hopes to scale up rapidly with other utilities, companies, and communities around the globe.

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Offering clean energy around the clock

Photo credit: 247Solar.

Earth Wise is a production of WAMC Northeast Public Radio

Tracking down PFAS toxins

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PFAS – per- and polyfluoralkyl substances – are a group of organic compounds that have been extensively used to provide water-, oil-, and dirt-resistance to a wide range of products ranging from non-stick pans, clothing, and packaging to paint, car polish, and fire-suppressant foam.  Exposure to specific PFAS compounds is associated with multiple adverse health effects, including altered immune and thyroid function, liver disease, kidney disease, poor reproductive and developmental outcomes, and cancer.  PFAS compounds do not break down in the environment and therefore, over time, become concentrated in plants, animals, and people.

Government agencies such as the EPA in this country and the EU have set strict limits for allowable levels of PFAS in drinking water.  Testing water for the trace amounts of PFAS that constitute the limits is time-consuming and expensive and requires complex equipment and experienced personnel.

Researchers at MIT have now introduced a technique for making a portable, inexpensive test that can easily and selectively detect PFAS in water samples.  The test makes use of a special polymer containing fluorinated dye molecules that cause the polymer to fluoresce red.  If PFAS are present in the sample, they enter the polymer and displace the dye molecules and switches off the red fluorescence. 

The new technique is suitable for on-site detection in highly contaminated regions.  Detecting smaller concentrations can be achieved with sufficient precision after pre-concentrating the samples using the process of solid-phase extraction.

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Tracking down Environmental Toxins

Photo, posted October 16, 2021, courtesy of Nenad Stojkovic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar thermochemical hydrogen

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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. 

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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

Harvesting Water From The Air | Earth Wise

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Engineers at MIT have created a superabsorbent material that can soak up significant amounts of moisture from the air, even in desert-like conditions.

The material is a transparent, rubbery substance made from hydrogel, which is a naturally absorbent material that is already widely used in disposable diapers.  The MIT researchers enhanced the absorbency of hydrogel by infusing it with lithium chloride, which is a type of salt that is a powerful desiccant.

They found that they could infuse hydrogel with more salt than was possible in previous studies.  Earlier studies soaked hydrogels in salty water and waited 24 to 48 hours for the salt to infuse into the gels.  Not much salt ended up in the gels and the material’s ability to absorb water vapor didn’t change much.  In contrast, the MIT researchers let the hydrogels soak up the salt for 30 days and found that far more salt was absorbed into the gel.  The result was that the salt-laden gel could then absorb and retain unprecedented amounts of moisture, even under very dry conditions.

Under very dry conditions of 30% relative humidity, the gels captured 1.79 grams of water per gram of material.  Deserts at night have those levels of relative humidity, so the material is capable of generating water in the desert.

The new material can be made quickly and at large scale.  It could be used as a passive water harvester, particularly in desert and drought-prone regions.  It could continuously absorb water vapor from the air which could then be condensed into drinking water.  The material could also be used in air conditioners as an energy-saving, dehumidifying element.

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This salty gel could harvest water from desert air

Photo, posted July 26, 2021, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Electric Motors For Aviation | Earth Wise

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Aviation contributes about 3% of global greenhouse gas emissions.  Its carbon footprint is one of the more difficult ones to reduce.  Electrifying planes would shrink that footprint considerably, but it represents a significant technical challenge.  To date, only small all-electric planes have gotten off the ground.  The electric motors in those planes generate hundreds of kilowatts of power.  To power large planes, like commercial airliners, megawatt-scale motors are required.

A team of MIT engineers is developing a 1-megawatt motor that could be a key step towards electrifying commercial aircraft.  They have designed and tested major components of the motor and have calculated how the completed design could generate one megawatt of power at a weight and size competitive with existing small aircraft engines.

To be suitable for aircraft use, motors have to be compact and lightweight.  The more power electric motors generate, the bigger they are and the more heat they produce.  Cooling motors requires additional components that take up space and add significant weight.  The MIT motor design and associated power electronics are each about the size of a typical checked suitcase and weigh less than an adult passenger.

Once the MIT team can demonstrate an entire functional motor, the design could be used to power regional aircraft and could be the enabling element of hybrid-electric propulsion systems for jet aircraft.  Possible future configurations could make use of multiple one-megawatt motors powering multiple fans distributed along aircraft wings.

Electrification of aircraft is a slow but steady area of development and technologies such as that being developed at MIT could end up meeting the practical needs of the aircraft of the future.

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Megawatt electrical motor designed by MIT engineers could help electrify aviation

Photo, posted September 14, 2019, courtesy of Dylan Agbagni via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Concrete And Carbon | Earth Wise

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After water, concrete is the world’s second most consumed material.  It is the cornerstone of modern infrastructure.  Its production accounts for 8% of global carbon dioxide emissions.  The carbon dioxide is a result of chemical reactions in its manufacture and from the energy required to fuel the reactions.

About half of the emissions associated with concrete come from burning fossil fuels to heat up the mixture of limestone and clay that ultimately becomes ordinary Portland cement.  These emissions could eventually be eliminated by using renewable-generated electricity to provide the necessary heat.  However, the other half of the emissions is inherent in the chemical process.

When the minerals are heated to temperatures above 2500 degrees Fahrenheit, a chemical reaction occurs producing a substance called clinker (which is mostly calcium silicates) and carbon dioxide.  The carbon dioxide escapes into the air.

Portland cement is then mixed with water, sand, and gravel to produce concrete.  The concrete is somewhat alkaline and naturally absorbs carbon dioxide albeit slowly.  Over time, these reactions weaken the concrete and corrode reinforcing rebar.

Researchers at MIT have discovered that the simple addition of sodium bicarbonate (aka baking soda) to the concrete mixture accelerates the early-stage mineralization of carbon dioxide, enough to make a real dent in concrete’s carbon footprint.  In addition, the resulting concrete sets much more quickly.  It forms a new composite phase that doubles the mechanical performance of early-stage concrete.

The goal is to provide much greener, and possibly even carbon-negative construction materials, turning concrete from being a problem to part of a solution.

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New additives could turn concrete into an effective carbon sink

Photo, posted April 4, 2009, courtesy of PSNH via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Minimizing The Impact Of EVs On The Grid | Earth Wise

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Two current trends are the increasing reliance on renewable sources in the electric grid and the increasing use of electric vehicles.  According to some projections, these trends could lead to the need for costly new power plants to meet peak loads in the evening when cars are plugged in to charge.  Overproduction of power from solar farms during the daytime would require expanded energy storage capacity so as not to waste all that generating capacity.

A new study by MIT researchers has found that it is possible to mitigate or eliminate these problems without the need for advanced technological systems and complex infrastructure.  The key elements of the strategy are the strategic placement of charging stations and the practice of delaying the onset of home charging.

Better availability of charging stations at workplaces could help to soak up peak power being produced at midday from solar power installations.  In general, placing of charging stations in strategic ways, rather than letting them spring up just anywhere, could make a big difference.

Delaying home charging to times when there is less electricity demand could be accomplished with the use of a simple app that would estimate the time to begin the charging cycle so that it finishes charging just before the car is needed the next day.  Since different people have different schedules and needs, by delaying the onset of charging appropriately, not everyone will be charging at the same time, and therefore the peak in demand would be smoothed out.

There are substantial government funds earmarked for charging infrastructure and creating that infrastructure in suitably strategic ways could make a big difference in supporting EV adoption and supporting the power grid.

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Minimizing electric vehicles’ impact on the grid

Photo, posted July 2, 2020, courtesy of Ivan Radic via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

A Better Way To Recycle Plastics | Earth Wise

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The global accumulation of plastic waste is an ever-growing problem.  At least five billion tons of the stuff has accumulated on land and sea and is even showing up in the bodies of animals and humans.  Recycling plastic instead of making even more of it seems like an essential thing to do but it has proven to be extremely challenging.

The main problem is that plastics come in many different varieties and the ways of breaking them down into a form that can be reused are very specific to each type of plastic.  Sorting plastic waste by plastic type is extremely impractical at large scale.  Certainly, most consumers can’t do it themselves.  As a result, most plastic gathered in recycling programs ends up in landfills.

New research at MIT has developed a chemical process using a catalyst based on cobalt that is very effective at breaking down a variety of plastics, including polyethylene and polypropylene, which are the two most widely produced plastics.   The MIT process breaks plastics down into propane.  Propane can be used as a fuel or as a feedstock for making many different products, including new plastics.

Plastics are hard to recycle because their long-chain molecules are very stable and difficult to break apart.  Most chemical methods for breaking their chemical bonds produce a random mix of different molecules which would somehow have to be sorted out in order to be useful for anything.

The new process uses a catalyst called a zeolite that contains cobalt nanoparticles.  The catalyst selectively breaks down various plastic polymer molecules and turns more than 80% of them into propane.

The researchers are still studying the economics and logistics of the method, but it looks quite promising.

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New process could enable more efficient plastics recycling

Photo, posted April 25, 2016, courtesy of NOAA Coral Reef Ecosystem Program via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar-Powered Desalination | Earth Wise

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About two-thirds of humanity is affected by water shortages.  In the developing world, many areas with water shortages also lack dependable sources of electricity.  Given this situation, there is widespread research on using solar heat to desalinate seawater.  To date, many approaches to this face problems with fouling of equipment with salt buildup.  Tackling this issue has proven to add complexity and expense to solar desalination techniques.

A team of researchers from MIT and China has recently developed a solution to the problem of salt accumulation that is more efficient than previous methods and is less expensive as well.

Previous attempts at solar desalination have relied on some sort of wick to draw saline water through the device.  These wicks are vulnerable to salt accumulation and are difficult to clean.  The MIT-Chinese team has developed a wick-free system instead.  It is a layered system with dark material at the top to absorb the sun’s heat, and then a thin layer of water that sits above a perforated layer of plastic material.  That layer sits atop a deep reservoir of salty water such as a tank or pond.  The researchers determined the optimal size for the holes in the perforated plastic.

The 2.5 millimeter holes are large enough to allow for convective circulation between the warmer upper layer of water above the perforated layer and the colder reservoir below.  That circulation naturally draws the salt from the thin layer above down into the much larger body of water below.

The system utilizes low-cost, easy to use materials.  The next step is to scale up the devices into a size that has practical applications.  According to the team, just a one-square-meter system could provide a family’s daily needs for drinking water.

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Solar-powered system offers a route to inexpensive desalination

Photo, posted February 13, 2017, courtesy of Jacob Vanderheyden via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Removing Lead From Water With Beer Yeast | Earth Wise

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Lead and other heavy metals in water are a serious global problem that is worsening because of electronic waste and discharges from mining operations.  In the U.S., over 12,000 miles of waterways are impacted by mine-drainage water that is rich in heavy metals.

Lead in particular is highly toxic, especially to children.  The European Union established a standard for allowable lead in drinking water of only 5 parts per billion.  In the US, the EPA has declared that no level of lead at all is safe.

Researchers at MIT have recently discovered that inactive yeast can be effective as an inexpensive, abundant, and simple material for removing lead contamination from drinking water supplies.  The MIT study shows that the method works even at parts-per-billion levels of contamination.

The method is called biosorption, in which inactive biological material is used to remove heavy metals from water.  Previously, it has been studied at parts-per-million contaminant levels, but the MIT study shows that it works at much lower levels as well.

The team studied a type of yeast widely used in brewing.   The yeast cells used are inactive and desiccated and require no special care.  Such yeast is abundantly available as a waste product from beer brewing and various other fermentation-based industrial processes. 

The researchers estimate that to clean a water supply for a city the size of Boston would require about 20 tons of yeast a day, or 7,000 tons a year.  That seems like a lot, but one single brewery, the Boston Beer Company, generates 20,000 tons a year of surplus yeast that is no longer useful for fermentation.

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Could used beer yeast be the solution to heavy metal contamination in water?

Photo, posted September 5, 2017, courtesy of Allagash Brewing via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Saving Water At Power Plants | Earth Wise

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Nearly 40% of all the water taken from lakes, rivers, and wells in the U.S. isn’t used for agriculture, drinking, or sanitation.  It is used to cool power plants that produce electricity by burning fossil fuels or with nuclear reactors.   Two-thirds of these power plants use evaporative cooling, which produces huge white plumes billowing from cooling towers.

A new company using technology developed at MIT has the goal of reducing the water needs of power plants and helping to alleviate water shortages in areas where power plants strain the capacity of local water systems.

The technology is relatively simple in principle but developing it to the point where it can be applied at full scale at industrial power plants was a greater challenge. 

The basic idea is to capture water droplets from both natural fog and from the plumes from power plant cooling towers.  The MIT researchers had to improve the efficiency of fog-harvesting systems, which previously captured only 1-3% of the water droplets that pass through them.  They found that water vapor collection could be made much more efficient by zapping the tiny droplets of water with an ion beam, giving them a slight electric charge, thereby making it easy to capture them with the metal mesh of the harvesting system.

The system can essentially eliminate cooling tower plumes and produce large quantities of high-purity water in the process, which has uses at many power plants.  The new company, called Infinite Cooling, has arranged to install their equipment on two operating commercial power plants later this year.  They expect the system to reduce the overall need for water by 20%.

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Vapor-collection technology saves water while clearing the air

Photo, posted March 5, 2019, courtesy of Sam LaRussa via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Seeds And Climate Change | Earth Wise

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Farmers and agricultural communities around the world are on the frontlines of climate change.  They are among the first to feel the impacts of hotter temperatures as well as more frequent and intense droughts and precipitation. These challenges pose a massive threat to both farmer livelihoods and global food security.

As the planet continues to heat up, many arid regions that already have marginal conditions for agriculture will be increasingly under stress. As a result, researchers from the Massachusetts Institute of Technology and the King Mohammed VI Polytechnic University in Morocco are working on a promising new way to protect seeds from this stress during their crucial germination phase. Their simple and inexpensive process, which was recently described in a paper published in the journal Nature Food, also provides plants with extra nutrition at the same.

The research team has developed a two layer coating for seeds designed for tackling issues related to drought. Drawing inspiration from natural coatings that occur on some seeds like chia seeds, the first layer is designed to protect the seeds from drying out. It provides a gel-like coating that grips any moisture that comes along and surrounds the seed with it.  The second (inner) layer of the coating contains preserved microorganisms called rhizobacteria, as well as some nutrients to help the seeds grow. 

The materials for the coatings are biodegradable, readily-available, and often used in the food industry already.  According to researchers, early tests using common beans have demonstrated encouraging results in Morocco, and more field tests of the seeds are currently underway.

As the climate continues to change, more innovations like this will be necessary for global food security.

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Engineering seeds to resist drought

Photo, posted September 17, 2010, courtesy of Stacy via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Disposable Masks And The Environment | Earth Wise

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The Covid-19 pandemic has made face masks and other personal protective equipment essential for healthcare workers.  Disposable N95 masks became the key requirement to help prevent the spread of the coronavirus.  But the wide use of these masks has both financial and environmental costs.

The pandemic is estimated to generate over 7,000 tons of medical waste each day and much of that is in the form of disposable masks.  Even though the pandemic has slowed down in many places, health care workers are continuing to wear masks most of the time.

A new study at MIT has looked at the financial and environmental cost of several different mask usage scenarios with an eye on trying to reduce the toll created by the continued need for using them.

If every health care worker in the US used a new N95 mask for each patient they encountered during the first six months of the pandemic, the total number of masks required would be over 7 billion, at a cost of over $6 billion and would generate 92,000 tons of waste (the equivalent of 252 Boeing 747 jets.)

Decontaminating regular N95 masks so that health care workers can wear them for more than one day could drop costs and environmental waste by at least 75% compared with using a new mask for every patient encounter. 

Fully reusable N95 masks could offer an even greater reduction in waste, but such masks are not yet commercially available.  MIT researchers are developing a reusable N95 mask made of silicone rubber that contains an N95 filter than can either be discarded or sterilized after use.  They have started a new company with the goal of commercializing the masks.

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The environmental toll of disposable masks

Photo, posted August 4, 2020, courtesy of the U.S. Navy / Mass Communication Specialist 3rd Class Jake Greenberg via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

WAMC Northeast Public Radio

WAMC/Northeast Public Radio is a regional public radio network serving parts of seven northeastern states (more...)