The Adaptors Earth Day Special

Earth Day Radio Special

This hour-long radio edition of The Adaptors is being broadcast this spring on hundreds of public radio stations from one coast to another and in between. Flora Lichtman and Alex Chadwick introduce us to people with outside-the-box solutions for addressing climate change. Like an inventor in Canada who believes we can power the world with tornado machines, and a chemist who is building a better battery. Plus, a philosopher’s radical idea of engineering the human body to adapt to a changing climate.

 

 

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Video from The Adaptors

What if you had an idea that you thought could solve the world’s energy problems? What if your idea was a tornado machine?

Engineer Louis Michaud is be part of our Earth Day radio special.

Here’s a video taste of his story.

 

 

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Wind Science, Energy, and Growing Prevalence

Wind is the kinetic energy of molecules in the air. Wind has powered ships and mills for centuries or longer.

Modern windmills convert the wind into rotational energy by allowing the air molecules to bombard the blades, turning them. The blades are connected to turbines, which generate electricity from that rotational energy.

Wind energy is one of the cleanest forms of energy available because it doesn’t require a fuel or produce greenhouse gas or other bi-products, outside of those from production and maintenance of equipment and transmission.

Wind turbines themselves take up only a small area compared to their generating potential, making it possible to install them on agricultural, forest, or grazing lands.

RAPID GROWTH

In just ten years, wind power in the United States grew more than ten-fold, from just over 2,000 megawatts in 1999 to more than 34,000 megawatts in 2009, when wind accounted for 9 percent of renewable energy produced in the country and more than geothermal and solar combined.

Here’s an animated map of wind development from 2000 to 2010.

Texas, Iowa, and Minnesota had the greatest wind capacity in 2010. Additionally, at least 27 other states used wind to generate electricity that year.

DRAWBACKS TO WIND ENERGY

Wind is an intermittent resource, meaning that the windmills can’t continuously and predictably produce energy. They only work when the wind blows, and they can only work as hard as the wind is blowing at that time.

Research is ongoing into predicting what regions of the country have significant wind resources suitable for wind development, a process that requires computer programming and meteorological knowledge.

Furthermore, public and private researchers are working to produce better models of wind on an hourly, daily, and seasonal basis to make it easier for wind energy producers to forecast their output and sell it ahead of time.

Another major hurdle to wind power is that it is expensive compared with fossil fuel-based electricity. Modern windmills cost a lot to design and build, especially as they have to be strong enough to endure extreme weather, even though they will mostly operate in moderate weather. That makes competing with other energy sources difficult without government intervention.

Some people don’t like the way windmills look, and windmills can also kill bats and birds, though newer designs have slower and less deadly blades. A 2010 study published in the Journal of Ornithology estimated that windmills kill around 440,000 birds every year. However, the same study showed that house cats kill more than 1,000 times that number, as many as 500 billion per year.

SOURCES
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Photovoltaic Cells, Solar Power, and LEDs

Most of the world’s energy can go back to our sun. Every day we are heated by its electromagnetic rays, and plants use the sun’s energy to make sugars and ultimately proteins and other good things to eat. Fossil fuels were also once made from these plant and other organisms that relied on the sun’s energy millions of years ago. Today, humans can convert the sun’s energy directly into electricity, through solar thermal and solar photovoltaic systems.

SOLAR THERMAL OR PHOTOVOLTAIC?

Solar panels, also called solar thermal, convert sunlight to heat and then heat to electricity. Photovoltaic cells, or solar cells, convert sunlight directly into electric current by way of carefully-engineered semiconductor materials.

Though solar photovoltaics are more efficient converters of sunlight, they are also more expensive.

As of May 2011, the world’s largest solar power plant is a concentrating solar thermal power plant in the Mohave desert in California. Solar Energy Generating Systems has a capacity of 310 megawatts and uses parabola-shaped reflective troughs to concentrate electromagnetic radiation.

The world’s largest solar photovoltaic plant is probably the Sarnia Solar Project in Ontario, Canada. It has a capacity of roughly 80 megawatts.

HOW SOLAR THERMAL WORKS

Sunlight heats a design element (water, air, chemical fluids), and that thermal energy is transmitted for other applications, such as heating water, heating space, or generating electricity. In solar thermal power plants, sunlight heats a specialized fluid, which in turn heats water into steam, which can run turbines and produce electricity.

Solar thermal power plants use concentrators that bounce the sunlight off elliptical mirrors to a central tube, in which the specialized fluid lies.

HOW PHOTOVOLTAICS WORK

Photovoltaic cells are made of specialized diodes. Electrons (natural components of atoms) in the photovoltaic cells absorb light, which excites them to a state where they can be conducted as electrical current. This difference in energy, between the valence band (the state of a normal electron staying around its home atom) to the conduction band (electron free to move between atoms) is called the band gap.

Solar photovoltaic farm in Indonesia. Photo by Chandra Marsono.

Well-engineered photovoltaics have a band gap that coincides with the energies of as broad a spectrum of light as possible, to convert the maximum amount of the sunlight into electricity.

As sunlight energy pops electrons into the conduction band and away from their home atoms, an electric field is produced. The negatively-charged electrons separate from the positively-charged “holes” they leave behind, so that when electrons are freed into the conduction band, they move as electric current in the electric field, electricity.

PHOTOVOLTAICS ARE MADE OF SPECIALIZED MATERIALS

An ever-expanding variety of semiconductor materials can be used to make solar cells; universities and companies worldwide are researching these options, from special bio-plastics to semiconductor nanocrystals. Nonetheless, the photovoltaic cells available today require precise manufacturing conditions and are therefore far more expensive to produce than solar panels.

Silicon has to be processed under clean room conditions — carefully regulated atmospheres — to remove impurities and prevent introducing contaminants, both of which can change the band gap. Thin film-based photovoltaics require special production methods, like chemical vapor deposition. Semiconductor processing also uses strong acids and often dangerous chemicals for etching.

Today, commercially-sold cells are made from purified silicon or other crystalline semiconductors like cadmium telluride or copper indium gallium selenide.

WHERE DO WE GET THE STARTING MATERIALS?

Silicon is plentiful in the Earth’s crust. Cadmium is a readily available but highly toxic heavy metal, as is arsenic, another chemical used in some cells. As tellurium demand is only recently rising in response to solar demand, it’s unknown what the global supply is for this unusual element but it may be quite abundant. Photovoltaics are a lively area of research, and the future production and environmental costs of starter materials, production, and pollution are difficult to predict.

California, Massachusetts, Ohio, and Michigan produced the most photovoltaics in 2009. However, that year, 58 percent of photovoltaics were imports, primarily from Asian countries like China, Japan, and the Philippines.

LED TECHNOLOGY: MORE THAN HEADLAMPS

Photovoltaic cells work in the opposite direction of light-emitting diodes, or LEDs. LEDs are used interchangeably with other lighting, like light bulbs. However, LED’s work in a completely different manner, far closer to the way photovoltaics work.

Click here see a bar chart comparing how much energy is used by various light sources.

LEDs absorb energy in the form of electricity, exciting electrons into the conduction band. When the electrons in the semiconductor material drop back into the valence band from the conduction band, they emit energy in the form of photons, or electromagnetic radiation.

It’s a highly efficient process because energy isn’t wasted on producing heat, which happens with standard tungsten filament bulbs. LEDs also last a much longer time as they do not have filaments to burn out, and because they are very small and several units are used to replace one large traditional lamp, they do not all burn out at once. That makes LEDs a good choice for stoplights or other safety critical applications.

 

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Major sources of energy/their advantages and disadvantages

There is no easy answer to what is the best source of energy or electricity. Is the priority reliability, affordability, the economy, international human rights, limiting greenhouse gas emissions, preserving environmental resources, or human health?

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It’s undeniable that today — whether we like it or not — humans worldwide are overwhelmingly dependent on fossil fuels: coal, oil, and natural gas. Everything eaten, worn, lived in, and bought is tied to availability of fossil fuels. Even if 100 percent of politicians were determined to stop using them today, society has neither the electricity grid nor the vehicular and industrial technology to sustain the current American lifestyle on non-fossil sources of energy. Yet.

When comparing sources of energy, it’s easy to forget how universal fossil fuels are. These sources continue to dominate for reasons that are difficult to measure, like political influence, advertising clout, and control over energy infrastructure. Other sources have disadvantages purely because they don’t fit in as well.

Volume brings another difficulty in comparing sources of energy. There is so much more fossil energy, and it’s been used for a long time, so we know a lot more about its hazards and benefits. More modern technologies are harder to quantify. Some are renewable but still pollute (biofuels), some are very clean except in accidents or waste disposal (nuclear). Most electricity sources (renewable or not) use steam turbines, and all the water to make steam has to come from somewhere, but how important should that factor be?



Clicking the graphic above will give an abbreviated chart comparing sources line by line, but that doesn’t provide anywhere close to the whole story.

Each of the following topics compares the major sources of energy  through a different lens. Though environmental and local issues may seem the most important to those of us who don’t own power plants or utility companies, the cost of energy drives which sources are actually in place today and which sources will see investment tomorrow.

 

 

 

 

 

 

 

 

 

 

 


Source: U.S. Energy Information Administration

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The Connection Between Greenhouse Gases, Climate Change & Global Warming


 

WHAT IS THE DIFFERENCE BETWEEN CLIMATE CHANGE AND GLOBAL WARMING?

Climate change is the shift in long-term, global weather patterns due to human action; it’s not exclusive to warming or cooling.

Climate change includes any change resulting from different factors, like deforestation or an increase in greenhouse gases. Global warming is one type of climate change, and it refers to the increasing temperature of the surface of Earth. According to NASA, the term global warming gained popular use after geochemist Wallace Broecker published a 1975 paper titled Climatic Change: Are We on the Brink of a Pronounced Global Warming?

Since 1880, the average surface temperature of the Earth has increased by roughly 0.9 degrees Fahrenheit, but the rate it’s increasing is faster than that, depending on which region you live in. If you’re closer to the equator, temperatures are increasing more slowly. The fastest increase in temperatures in the United States is in Alaska, where average temperatures have been increases by more than 3 degrees Fahrenheit per century. For a graph of average global temperatures by year, see the NASA website here.

 

HOW GREENHOUSE GASES RELATE TO CLIMATE CHANGE

Greenhouse gases are those thought to contribute to the greenhouse effect, an overall warming of the Earth as atmospheric gases trap electromagnetic radiation from the sun that would otherwise have been reflected back out into space.

Noteworthy greenhouse gases are methane, nitrous oxide, carbon dioxide, hydrofluorocarbons (HFCs), perfluorocarbons (PFCs), and sulfur hexafluoride (SF6). These gases are thought to affect the climate directly and indirectly, even though they constitute only a small fraction of the blanket of gases that make up the atmosphere.

Currently, the composition of the atmosphere is mostly nitrogen and oxygen, with just 0.033 percent carbon dioxide and all other gases accounting for even less.

 

WHICH GASES CONTRIBUTE THE MOST?


According to 2010 models cited by NASA, 20 percent of the greenhouse effect is attributed directly to carbon dioxide and 5 percent to all other greenhouse gases. The remaining 75 percent of the greenhouse effect is thought to be due to water vapor and clouds, which are naturally-occurring. However, even though carbon dioxide and the other greenhouse gases are such a small percentage of the total gas in the atmosphere, they affect when, where and how clouds form, so greenhouse gases have some relevance when it comes to 100 percent of the greenhouse effect. Carbon dioxide is thought to modulate the overall climate, like a atmospheric thermostat.

Some greenhouse gases are produced in natural processes, like forest fires, animal manure and respiration, or volcanic eruptions. However, the majority of new greenhouse gases are produced from industrial processes and energy production.

The four largest human sources of U.S. greenhouse gases in 2009 were energy, non-fuel use of fossil fuels, natural gas production, and cement manufacture, in descending order. Non-fuel, greenhouse gas-producing applications of fuels include industrial production like asphalt, lubricants, waxes and other . Emissions related to cement manufacture happen when limestone (calcium carbonate) is reacted with silica to make clinker, the lumps ground to make cement. ( Emissions of Greenhouse Gases in the United States 2009: Independent Statistics & Analysis.)

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Ocean Energy

You don’t have to talk about hurricanes and tsunamis to know that the oceans are powerful. People have dreamed about harnessing their energies for centuries, and today there are many projects worldwide experimenting with just how to plug into the oceans.

However, ocean energy projects are expensive because of the nature of their energy source. The salty seas can be corrosive, unpredictable, and destructive.

Several aspects of the ocean’s energy can be exploited to generate power;  we’re not limited to the crashing waves. The three most well-developed ideas are tidal power, wave power, and ocean thermal energy conversion.

There are many different projects in various stages of development in coastal states today. However, as yet, ocean energy isn’t a significant source of energy nationally.

Ocean energy is renewable, and it’s clean because of its lack of emissions. However, using ocean energy along coastlines can cause conflict with other coastal uses – transportation and scenic oceanfront – and ocean energy can as affect marine life and environmental conditions.

 

WAVE ENERGY

Wave energy capitalizes on the power of waves as they roll through the ocean. There are small wave systems generating small amounts of electricity today, though the development costs are high and it is difficult to design equipment that can withstand the salt water, weather and water pressures.

Systems have to be designed for average waves but must also withstand the much stronger waves that occur in seasonal storms and the extreme waves that appear only rarely. Waves shift direction, so systems are designed to move to optimize direction.

Prototype plants currently operating have capacities of fractions of a megawatt, which is the tiniest drop in the bucket compared to average-sized power plants in the hundreds of megawatts.

There are over 100 wave energy technologies in various states of planning and testing or in operation as prototypes. However only one type is operating commercially, the Pelamis Wave Power, according to the World Energy Council.

In the United States there are other projects in planning or testing in Hawaii, New Jersey, Oregon, Texas, and California.

 

TIDAL ENERGY

Using the potential energy of rising and falling ocean tides is called tidal energy.

One way of harnessing the tides is to trap the high tide behind dams.When the ocean rises to its highest tide, the dam is closed and high water is held in a reservoir by the dam. After the water recedes in low tide, the trapped water can be released through turbines like in hydroelectric plants.

Tidal energy plants of this type demand a large height difference between high and low tides, a condition that applies to only select global locations. However, research is ongoing to bypass this limitation.

The one major tidal power plant in operation is the 240 megawatt plant in La Rance, France, which has been operating since 1966, according to World Energy Council. There is also an 18 MW experimental plant in Annapolis Royal, Nova Scotia and a 0.4 megawatt plant near Murmansk, Russia.

Tidal energy can have the same drawbacks as hydroelectric power, such that dams may interfere with aquatic life.

 

THERMAL ENERGY CONVERSION

Thermal energy conversion harnesses the difference in temperature between the warm, surface waters of the ocean and the colder, deep water. The two temperatures of water are matched to a fluid that has a low boiling point, like ammonia. Using the heat of the warmer water in a heat exchanger, the ammonia is evaporated and, once in gas phase, it rotates a turbine. Then, the colder seawater cools the ammonia back to liquid in a second heat exchanger. The rotating turbine generates electricity.

Open-cycle thermal energy conversion is similar but uses low pressure vessels to boil the warm surface water, instead of employing a fluid like ammonia. Water will boil at lower than its boiling point if the pressure is less than atmosphere. The steam runs a turbine, and then the cold seawater cools the steam back into fluid water.

These projects are expensive and difficult to site, since they must have deep enough water to get a substantial enough difference in temperature, yet the site must also be close enough to shore to transmit electricity.

Thermal plants can change the temperature gradient of the ocean around them, having a potential affect on marine life.

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Petroleum, Natural Gas, and Coal

The world depends on fossil fuels for its energy, and the United States is no exception. The vast majority of U.S. energy — more than 80 percent in 2009 — comes from burning fossil fuels. (more…)

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