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Improved Radar For Cars | Earth Wise

December 31, 2020 By EarthWise Leave a Comment

Self-driving cars require a variety of sensor systems in order for the cars to safely navigate roads and deal with the wide range of objects and conditions that they encounter. Two competing technologies that cars use to identify and locate objects on the scene are radar and LiDAR.

Radar uses transmitted radio waves to locate objects and LiDAR bounces laser beams off of objects. Each has its shortcomings. Radar has the problem that only a small fraction of the transmitted signals gets reflected back to the sensor, so that there is frequently insufficient data to fully characterize a scene. LiDAR has the problem that it is an optical system that does not work well in fog, dust, rain, or snow. It is also much more expensive than radar.

Researchers at the University of California San Diego have developed a new system that they describe as a LiDAR-like radar. The system consists of two radar sensors placed on a car’s hood and spaced about 1.5 meters apart. This configuration enables the system to see more space and detail than a single radar sensor.

Having two radars at different vantage points with an overlapping field of view creates a region of high-resolution with a high probability of detecting the objects that are present. The system also overcomes noise problems of conventional radar systems.

The researchers developed new algorithms that can fuse the information from two different radar sensors and produce a new image free of noise.

Self-driving cars have to combine detection technologies like radar with cameras and ultrasonic sensors. Duplicating the capabilities that people use in order to safely drive a car is a complex problem requiring a combination of multiple sensors and sophisticated software.

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Upgraded radar can enable self-driving cars to see clearly no matter the weather

Photo, posted January 2, 2014, courtesy of Bradley Gordon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Finding Methane Leaks from Space | Earth Wise

December 23, 2020 By EarthWise Leave a Comment

There is growing concern about the climate effects of methane leaking from oil and gas wells. The 20-year global warming potential of methane is 84, meaning that over a 20-year period, it traps 84 times more heat per mass unit than carbon dioxide. Global methane concentrations have increased by nearly a factor of 3 since the industrial revolution.

More than a century of oil and gas drilling has left behind millions of abandoned wells, many of which are leaching pollutants into the air and water. In the U.S. alone, more than 3.2 million abandoned oil and gas wells emitted 280,000 tons of methane just in 2018. And the data is incomplete.

Part of the problem is finding out which wells are leaking. Ground-based sensors or airplanes and drones are effective ways to find leaks but considering how many wells there are to check, the costs are considerable, and the process is time consuming and complicated.

New technology is coming along that uses satellites to detect methane leaks. A Canadian company called GHGSat recently used satellites to detect what it has called the smallest methane leak ever seen from space and has begun selling data to emitters interested in pinpointing leaks.

Another company, New York-based Bluefield Technologies, plans a group of satellites for launch in 2023 that promises even finer resolution. The Environmental Defense Fund, with support from Jeff Bezos’ Earth Fund, plans to launch MethaneSAT in the next couple of years, which is designed to find small sources of methane.

Research at Stanford University determined that just 5% of methane leaks produce around half the total leakage.

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New Technology Claims to Pinpoint Even Small Methane Leaks From Space

Photo, posted June 8, 2011, courtesy of Jeremy Buckingham via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Hydrogen-Powered Transport In Britain | Earth Wise

November 27, 2020 By EarthWise Leave a Comment

The first hydrogen-powered train in the UK had its first mainline runs at the end of September. The train, known as HydroFLEX, was developed under a project headed by the University of Birmingham under the UK government’s Department for Transport.

Hydrogen-powered trains do not emit harmful gases but rather use hydrogen and oxygen to produce electricity, water, and heat. The technology in the HydroFLEX train will be available by 2023 to retrofit existing diesel-powered trains and thereby de-carbonize the rail network and make train travel greener and more efficient.

The UK has ambitious plans for the use of hydrogen technology. The Department of Transport plans to publish a master plan in January that will outline how green hydrogen could power buses, trucks, rail, maritime, and aviation transport across the UK.

The HydroFLEX trial is taking place in Tees Valley in northeastern England and the plan is for that area to become a Hydrogen Transport Hub that will include the world’s largest versatile hydrogen refueling facility. The plans for Tees Valley involve academia, industry, and government participants. The next stages of the HydroFLEX project are well underway with the University of Birmingham developing a hydrogen and battery-powered module that can be fitted underneath a train to allow for more space for passengers in train cars.

The UK government’s Hydrogen for Transport Program is also funding a green hydrogen refueling station and 19 hydrogen-powered garbage trucks in Glasgow, Scotland.

The UK plans to switch to a net zero economy and their current program increasingly embraces hydrogen technology to provide more sustainable, greener forms of transportation.

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UK embraces hydrogen-fueled future as transport hub and train announced

Photo, posted May 15, 2019, courtesy of Jeremy Segrott via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Better Paint For Cooler Buildings | Earth Wise

August 20, 2020 By EarthWise 2 Comments

A research team led by scientists at UCLA have developed a super-white paint that reflects as much as 98% of incoming heat from the sun. Such paint, if used on rooftops and other parts of buildings, could have a major impact on reducing the costs of keeping buildings cool.

Passive daytime radiative cooling is a well-known method to keep buildings cooler. By having building surfaces reflect sunlight and radiate heat into space, building temperatures can be significantly lowered. This in turn cuts down on air conditioner use and associated carbon emissions.

A roof painted white will result in lower indoor temperatures than a darker roof. But a white roof will do even more: it can reject heat at infrared wavelengths that are invisible to our eyes. This results in even more radiative cooling.

The best performing white paints currently available reflect about 85% of incoming solar radiation. The rest is absorbed by materials in the paint. The new research has identified simple modifications in paint ingredients that lead to a major increase in reflectivity.

Current reflective white paints use titanium dioxide, which absorbs UV radiation and therefore heats up under sunlight. The researchers studied replacing it with other substances such as barite – an artist’s pigment – or with powdered Teflon, both of which allow the paint to reflect more of the sun’s radiation.

Many cities are encouraging the use of cool-roof technologies on new buildings. Using the most reflective coatings possible on rooftops, if applied on a sufficiently large scale, could have a real impact on climate change as well as saving significant amounts of energy used for running air conditioners in buildings.

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UCLA-led Team Develops Ways to Keep Buildings Cool with Improved Super White Paints

Photo, posted August 15, 2012, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Dust From The Sahara | Earth Wise

July 9, 2020 By EarthWise Leave a Comment

A vast cloud of dust from the Sahara Desert blanketed the Caribbean in late June before drifting across the southeastern U.S. The phenomenon is nothing new; only the magnitude of the occurrence this time around was unusual. According to experts, this is the most significant Sahara dust event in 50 years.

The Sahara Desert is the major source on Earth of mineral dust, with some 60-200 million tons of it per year being lifted into the atmosphere. Convection currents over hot desert areas lift the dust to very high altitudes. From there, it can be transported worldwide by winds. The dust, combined with the extremely hot, dry air of the Sahara Desert often forms an atmospheric layer called the Saharan Air Layer, which can have significant effects on tropical weather by interfering with the development of hurricanes. The Saharan Air Layer typically moves across the North Atlantic every three to five days from late spring to early fall, peaking in the middle of the summer. It can occupy a layer as much as two miles thick in the atmosphere.

The dust plume this summer was highly visible from space, covering thousands of miles of the Atlantic Ocean and the Caribbean Sea.

A common effect of Sahara dust is that normally blue skies can acquire a milky haze, but beyond that can lead to spectacular sunsets. But apart from the visual spectacle, the dust can aggravate the conditions of people with asthma, respiratory illnesses, and allergies. On the positive side, as long as the dust is around, it is much less likely that tropical storms and hurricanes will form.

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Sahara dust blankets Caribbean, air quality hazardous

Photo, posted June 22, 2020, courtesy of Sagar Rana via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Powering Cars With Cactus Juice

June 24, 2019 By EarthWise Leave a Comment

Back in 2016, a company called Nopalimex, located in Micoacan, central Mexico, built the world’s first cactus-powered energy plant. The facility utilizes a biodigester to make biogas from nopal, also known as prickly pear cactus. The nopal plant has been called the ‘Green Gold of Mexico’ and is a staple in Mexican diets, medicine and cosmetics.

Nopalimex is now using the cactus to make biofuel for vehicles.

The fruit of the cactus is pureed, mixed with manure, and then left to decompose, producing methane. The methane produced – about eight tons a day – fuels the biodigester which powers the company’s corn chip and cactus chip production and is being tested in a fleet of government vehicles.

The biogas will cost just 65 cents per liter, which is about a third cheaper than the cost of regular gasoline. Using prickly pear as a feedstock for biofuel is attractive because it can be grown in places where traditional energy crops cannot. One can imagine vast fields of cacti in remote, arid areas of the country where normal crops cannot grow. It would not suck up the resources or space needed to feed people, which is an ongoing criticism of current bioenergy crops.

As long as the nopals are regularly replanted, the process is almost entirely sustainable, producing only water and nopal waste, which can be used to fertilize other crops.

Finding sustainable ways to produce fuel while doing minimal damage to the environment is an important challenge for countries around the world. In Mexico, harnessing the power of the prickly pear cactus is a unique and clever solution.

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Mexico’s ‘green gold’: The company powering cars with cactus juice

Photo, posted July 8, 2006, courtesy of Christian Frausto Bernal via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Solar Equity for Low-Income Communities

May 30, 2019 By EarthWise Leave a Comment

A couple of years ago, the number of American roofs covered with solar panels passed the one million mark and the numbers keep growing. But nearly half of U.S. households – accounting for more than 154 million people – aren’t able to host their own solar arrays because they lack suitable rooftop space, or they rent their homes. But millions more simply can’t afford to spend tens of thousands of dollars to buy or lease solar panels.

In recent years, community solar has become popular. These are projects where multiple participants own or lease shares in a mid-sized solar facility and receive credits that lower their monthly utility bills. Community solar in the U.S. has more than quadrupled just since 2016.

However, the majority of community solar subscribers to date have been businesses, universities, government agencies, and higher-earning households. These users can generally pay steep project enrollment fees or meet various financial requirements. Meanwhile, those who could benefit most from access to renewable energy and lower utility bills – low-income residents – have largely been left out.

Low-income households on average spend over 8% of their income on utility bills, about three times more than moderate- to high-income households. So, reducing electricity bills with community solar power is a big deal for them.

Given this situation, there are now a growing number of programs that make use of community solar to reduce living expenses for low-income households. In a dozen states, new programs include a variety of mandates, financial incentives, and pilot programs targeting benefits for people with low incomes. These programs will allow them to participate in both the environmental and economic benefits of renewable energy.

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Energy Equity: Bringing Solar Power to Low-Income Communities

Photo, posted November 27, 2012, courtesy of Oregon State University via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Problem With Flaring

October 12, 2018 By EarthWise Leave a Comment

Oil and gas are typically produced together. If oil wells are located near gas pipelines, then the gas gets used. But if the wells are far offshore, or it is not economical to get the gas to market, then oil companies get rid of the gas by burning it – a process known as flaring.

Trends Influencing Our Cities

February 23, 2018 By EarthWise Leave a Comment

The Environmental Protection Agency removed its information hub about climate change last year. In response, 17 cities reposted the information on their own city government sites. This is indicative of the fact that cities are increasingly taking on a leadership role in environmental, social and economic change.

A Solar-Powered Vertical Farm

November 21, 2017 By EarthWise 1 Comment

Vertical farming is a method for producing crops in vertically stacked layers or surfaces typically in a skyscraper, used warehouse, or shipping container. Modern vertical farming uses indoor farming techniques and controlled-environment agriculture technology.

Satellites And Conservation Science

August 3, 2017 By EarthWise

Satellites orbiting the earth are becoming an increasingly powerful tool for counting and monitoring wildlife populations and to answer a host of other questions about the natural world.

Arguing Against Climate Change

April 3, 2017 By EarthWise

Most of the world has accepted the analysis of the overwhelming majority of climate scientists that shows that our planet is warming and that our actions are the primary cause. However, some people – notably a number holding high office – reject this analysis. What exactly does it imply to say that climate change is not happening or is not caused by us?