Can a big roof generate economical solar power?

We have a 200,000 SF Warehouse in Elizabethton, TN. There is a $50MM fund to finance energy projects in TN at below market interest rates for up to 10 years. Is there a way to make our roof a 200,000 SF Solar panel and make the numbers work?

View the original article here

Fractional Distillation Of Crude Oil

Fractional distillation of crude oil is the first step in the production of many of the materials we have come to rely on in modern life.

All our fossil fuels, virtually all our plastics, detergents and commercial alcohols are made from products of this process. Appreciating the process of fractional distillation will further improve our understanding of the sources of fuels and plastics and the limited nature of their availability.

From the Oil Field to the Refinery

The first step is the transport of the crude oil from its natural location to the refinery. Oil drilling occurs both at sea and on land, depending on the size and profitability of the oil deposits located. Fossil fuel formation is the result of environmental conditions in the distant past and the geological processes that have occured since the laying down of the original organic matter from which the oil is formed.

Once obtained from the ground, the oil is transported by ship, truck or pipeline to the refinery.

At the Refinery

Once the oil reaches the refinery the work to separate it into useful products begins. Oil refineries are enormously complex and each part of the distilled oil goes through several stages of processing. However, the very first step is to break up the crude oil.

The crude oil is a mixture of many different chemicals. The majority of these are hydrocarbons, which are molecules made only from the element Carbon and the element Hydrogen. The mixture of hydrocarbons contains both alkane and alkene molecules and the length of the chains vary wildly, from five Carbon atoms long to 60 Carbons or more. Since fuels need to be very specific in terms of the length of the Carbon chain, the different lengths need to be separated. These different length chains are called FRACTIONS.

The boiling point of a Hydrocarbon fraction, which is the temperature at which it evaporates, is dependent on the length of the Carbon chain. Those fractions with shorter chains evaporate more easily than those with longer chains. This explains why petrol, which is mainly made of the 8-Carbon molecule octane, evaporates more easily than engine oil which has carbon chains in the range of 20 or more.

Fractional Distillation Of Crude Oil

In order to separate the different length chains in the crude mix, it is heated to a very high temperature. The temperature is set so that all those fractions with a Carbon chain length of 20 and below are evaporated from the crude mix. The temperature cannot be set higher than this as there is a risk that the lighter fractions will ignite.

The remaining liquid, which is composed of only the heavier fractions, passes to a second location where it is heated to a similar temperature, but at lower pressure. This has the effect of making the heavy Hydrocarbon fractions more likely to evaporate.

How the Distillation Tower Works

The way the Distillation Tower works is by becoming progressively cooler from the base to the top. All the Hydrocarbon fractions start off in gas form, as they have been heated to that point. The gases then rise up the tower.

The gas mixture then encounters a barrier through which there are are only openings into the bubble caps. The gas mixture is then forced to go through a liquid before continuing upwards. The liquid in the first tray is at a cool enough temperature to get the heaviest gas fractions to condense into liquid form, while the lighter fractions stay gaseous.

In this way the heaviest hydrocarbon fractions are separated out from the mixed gas. The remaining gas continues its journey up the tower until it reaches another barrier. Here the bubble cap process is repeated but at a lower temperature than before, which then filters out the next lightest set of fractions.

This process continues until only the very lightest fractions, those of 1 to 4 Carbon atoms, are left. These stay in gas form and are collected at the top of the tower.

The separation of the heavier elements in the second tower follows exactly the same process but at lower pressure.

After the Fractional Distillation Of Crude Oil

The separated fractions still contain a mixture of different hydrocarbons. After their initial separation the fractions require further processing and purification. Treatment of the initial products of the fractional distillation of crude oil also occurs in the refinery. The results of these processes are the products we use in every day life.

Fractional Distillation of Crude Oil

Return from Fractional Distillation of Crude Oil to Fossil Fuels or return to the Green Planet home page for more Solar Power Facts

View the original article here

Buying cheap Solar Panels

If you know what to look for you can find cheap solar panels in many places. These can be either new or used solar panels. Either way, here are some tips about getting the best out of your hard earned dollars. These are not foolproof and are my suggestions, but will give you the best chance of a successful purchase.

Postage, insurance and supplier service will be much cheaper and easier if you buy from the country you live in. In Australia you can get registered and insured post quite cheaply. However, when posting a parcel overseas from Australia no such option is available. That's fine if the object is unbreakable but very few are.

It will also be quicker and easier to return the item if needed. Also, since items have less traveling to do, there will be less chance of damage to them in transit.

There are a few claims around about being able to produce cheap solar panels and wind generators with very little know how.

This is certainly true, if you have access to the materials outlined in the manuals.

The most reliable and long running of these ebooks is Earth 4 Energy. They have a full refund within 8 weeks so you can't go wrong. This is a very reliable company with a good track record of giving refunds when requested.

While the ebook deals with adapting systems to non-USA power grid systems, it must be noted that this book is written for the USA. If you live outside the USA you may find it difficult and expensive to find some of the parts used in the manual.

New solar panels and other equipment should come with a warranty an an indication of build quality. Check with the seller how that warranty would be employed; is the seller the person who would deal with a damaged item, or is this your responsibility? Posting a damaged solar panel from one side of the country to the other in order to get it repaired would be both time consuming and expensive.

These factors need to be weighed against the possibly lower item cost if it is being sold by a new vendor or on an auction site.

Clearly the best way to get new cheap solar panels is straight from the manufacturer or the manufacturer's main supplier where ever possible. That will cut down on vendors' profit margins and the big suppliers are usually much more reliable when it comes to support with warranty issues.

Have a look at what happened to this solar lawn light set. It did not come with a warranty. By making informed decisions you can avoid similar money wasting mistakes.

It is also necessary to be wary of possible scams. Several sites have claimed to be selling solar paint. These sites are almost certainly scams, as commercially available paint on coatings that could produce electricity are still years away from production.

Used solar panels can be an excellent deal, but there are a few things to ask the seller.

a) How old is it? The age of a panel will affect its productivity, especially if it is a thin film panel. The efficiency of used thin film panels can be as low as 6%. On the other hand, if it is a monocrystaline or polycrystalline panel its age should not have much of an effect on its operation.

b) Is it structurally sound? If the panel is not sealed properly you will find moisture condensing on the inside of the glass or plastic cover. This will have a significant impact on its performance.

c) Does it provide a steady current flow throughout the day? If the panel shows fluctuating voltage or the voltage drops in the brightest part of the day then it probably has some issues with corrosion or other damage to the internal circuitry. This is often the case with old thin film solar cells. Unless you are the engineering type repairing this damage is way too much work to make the purchase worthwhile. Cheap solar panels that don't work are not a good deal!

d) Has it been used on a boat? Used marine solar panels need to be looked at very carefully, otherwise what looks like a great deal will leave you out of pocket and with a worthless panel.

One good place to look for used cheap solar panels is on eBay.

If you are not already an eBay member you will need to sign up before you can bid or buy. eBay requires you to provide them with a valid credit card number in order to prevent scamming. I was unhappy about this when I signed up, but after three years I have had no problems with eBay and my details have been secure. Here are the issues I have become aware of when buying on eBay.

There are a swag of portable solar panels on the market, but most of these are for small devices or camping. One larger scale option is the portable solar panels by Verandah that are designed for household use but can be transported as well.

We need to have open, loud and clear discussion about the government policies and how these affect the implementation of current and new solar power technologies.

At present, solar energy technology is at a sufficiently advanced stage that it can be a serious contributor to a clean energy system. What is missing is the political will to make this happen.

As a result solar power is still far too expensive to be considered a real option for most home owners.

Join the discussion about relevant issues affecting the production and delivery of cheap solar panels on a global scale.

What Other Visitors Have Said

Click below to see contributions from other visitors to this page...

Return from Cheap Solar Panels to the Green Planet home page for more Solar Power Facts.

View the original article here

Fossil Fuel Formation: Oil and Natural Gas.

Fossil Fuel Formation: Oil and Natural Gas

Oil and natural gas undergo a different process of fossil fuel formation compared to coal. These two substances tend to occur together and the process for forming them is the same. As with coal the formation conditions need to be very specific.

Oil and natural gas are formed from the remains of tiny aquatic animals and plants. As with coal, vast quantities of these organisms are required to make a viable deposit of oil or gas. These organisms, once dead, would have sunk to the bottom of the body of water they were living in, been covered in silt and mud, and then started to decay anaerobically See the description on the formation of coal for the difference between aerobic and anaerobic environments and their effect on decay.

As such, it is reasonable to assume that the bodies of water that these micro-organisms were living in were fairly stagnant, as strong currents in water both improve aeration and prevent the laying down of very thick layers of organic material in the one location. The image shows an algal bloom in a stagnant waterway. See the vast quantity of organic material that can be produced in a short time. With no current to sweep away the dead organisms, a thick layer of debris would quickly build up at the bottom of the water body.

The anaerobic decay of these micro-organisms means that while their cellular structures break down, the carbon chains that are the foundation of their bodies do not. As with coal formation time, pressure and heat drive out other substances such as water leaving mostly the carbon chains behind.

The carbon chains that are in crude oil are different in character to those in coal. Coal contains large strings of carbon rings with 6 carbon atoms in each ring. These are heavy and stuck together well, making coal a solid. The carbon chains in oil, on the other hand, are shorter than those in coal and are usually straight, maybe with a few branches. This is an approximate representation of the difference between coal and oil:

Fossil Fuel Formation: Comparing Coal and Oil Structures.

Coal contains massive molecules of carbon rings. These are from the plant fibres which can be very long, sometimes metres long or more. They also are often twisted around each other giving added solidity. The carbon chains in oil are tiny by comparison. They are the structural remains of microscopic organisms and so they are ALL very small, though there is a great variety within any crude oil sample. It is this the relatively small molecule size and the chemical structure of the carbon chains in oil that make it a liquid.

Natural gas such as methane is merely the tiniest pieces (fractions) of the oil molecules. These are so small that they do not stick together well enough to be a liquid, and so they are gaseous. For this reason Natural Gas is almost always found with crude oil. Natural Gas can sometimes be found on its own (meaning only the tiniest molecules of oil were formed). Oil is always accompanied by some natural gas. Rather than go into a long discussion I will use a series of pictures of the fossil fuel formation process for oil. Here is a scene of the lake or shallow sea with an algal bloom on top:

Since algal blooms are often toxic to animal life in the water body, it is reasonable to assume that at least some of the oil comes from animal remains.

Next the dead matter is covered with silt and mud. This silt and mud eventually compresses into rock, leaving the organic material trapped between two layers of rock:

As more silt and mud is laid down, more layers of rock are added on top of the organic matter layer. Volcanic activity may also be adding extra layers of rock on top of the organic layer. This is taking millions and millions of years. The extra weight of the rock as well as some heating from beneath the crust of the earth are helping to drive water out of the oil-to-be. NOTE: the reason the rock layers are not flat is because they are being pushed sideways as well as down. This is coming from the movement of the tectonic plates that make up the earth?s crust.

So after a while the organic material is looking quite oily, and may find itself in a situation like this:

Let?s assume now that the organic matter has been squeezed and heated enough to break it down into something resembling crude oil. Since it is now in a liquid state, the crude can move.

How does oil collect in vast amounts but in small areas?

It might seem reasonable to conclude that there should be a thin layer of oil spread thinly in the majority of places. However, crude oil and natural gas are concentrated in large deposits in some areas but are absent in others. Why?

This last step of fossil fuel formation involves porous and non-porous rock layers. A porous layer is one that contains lots of little holes in it, like a sponge. Basalt, a volcanic rock formed from rapidly cooling lava, is one such rock. Non-porous rocks do not have these holes in them, but are solid.

The oil seeps upwards through porous rocks as a result of the great pressure of the overlying layers. It does this until it hits a non-porous layer, and there it collects, like so:

Fossil Fuel Formation: Predicting Locations

Geologists are able to predict probable locations for oil from examining the structure of rock layers and then test-drill in likely areas. Not all probable locations contain commercially viable oil reserves. Some locations will have no oil or gas, some will have tiny amounts, and yet others will have the oil present but still trapped inside porous rock layers such as oil shale. Only the areas where large reserves of liquid oil are present are generally commercially viable to drill. These locations may be on land or under the sea. The earth?s crust plates are constantly on the move, and the oil reserves move with them.

The reason a lot of the oil drilling occurs at sea is simply because the majority of the crust of the planet, under which the oil is located, is covered by water. It is a testament to our dependence on this source of fossil fuel that it is economically viable to go to the extreme trouble and expense of building and maintaining these structures.

Return from Fossil Fuel Formation - Oil to Fossil Future or return to the Green Planet home page for more Solar Power Facts.

View the original article here

Fossil Fuel Power Plants: how Electricity is Generated.

Fossil fuel power plants produce the electricity which is the lifeblood of the developed nation, and we all rely heavily on it in our daily lives. The majority of current power stations run on fossil fuels. While solar energy power stations are being developed around the world on commercial scales, it is true to say that over 70% of every developed nation?s energy comes from fossil fuel electricity generation. In Australia, over 90% of our electricity is sourced in this way.

Power stations supply the main energy grid with electricity on-demand; that is, the greater the demand the more the power stations churn out.

That means that the greater the demand for electricity, the larger the amount of coal, oil or gas the fossil fuel power station will be consuming. A clear explanation of how the power stations turn fossils into electricity is in order.

An iron bar is made of lots of tiny iron crystals. When all these crystals are aligned, the iron bar will produce a magnetic field. Compasses are tiny magnets that align with the earth?s magnetic field. Have a look at this simple experiment in which you can make your own compass. Early compasses were simply lumps of magnetic iron-rich rock called lodestone.

Why iron does this and many other metals cannot is due to the arrangement of electrons in the d-subshell of each atom. Discussion of that topic is beyond the scope of this website.

It turns out that the magnetic field of a bar magnet looks something like this:

Those lines around the magnet are the FORCE LINES; they make up the magnetic field. Those field lines are able to push free electrons around so that they align with the field lines.

If we make a coil of copper wire and push a magnet through it quickly the electrons will move in one direction and you will have a current. Copper is used because it conducts really well, but any metal can be used for the wire. The reverse is also true; if we push electricity through a copper coil, it will generate a magnetic field. That is called an electromagnet. Electromagnets usually have an iron core to improve the magnetic field.

Now if we take one electromagnet and spin it inside another coil, the field from the electromagnet will create a current flow in the second coil. This is because the magnetic field pushes the electrons in the second wire coil.

Just like any other electrical device, the turbine needs to be connected to a circuit to allow electrons to flow in a loop. The electricity grid that the turbine is connected to is one enormous loop.

Now we have a spinning turbine causing electrons to be pushed out into the loop with some force, the force given to them by the magnetic field. The faster they are going the more energy they have and so the more work they can do for us in our homes.

This is where the fossil fuels come into the equation. Energy is needed to turn the turbine, and that energy needs to be harvested from somewhere. Possibilities include wind, falling water, waves, or steam. Traditional power stations use steam.

The coal (or oil or gas) is burned in a furnace. The furnace heats water in a boiler. This generates super heated steam that turns turbines. The steam is then cooled in cooling towers and condensed back into water to be returned to the boiler, reducing heat loss as much as possible. Some steam has to be released in the cooling process; that?s the source of those big white clouds coming out of the power station cooling towers. Here?s a picture of the process:

The exhaust gases are also used to heat the boiler chamber before being released via the chimney stack. This is where the environmental nasties such as CO2, NO, SO2 and ash, called fly ash, are released into the air.

The amount of coal going into the boiler, and therefore the amount of Carbon Dioxide and other gases being emitted from this fossil fuel power, is determined by our actions. We can reduce the amount of pollution from the power stations by using less electricity.

While we are still operating the majority of our power stations as fossil fuel power plants this is crucial; lower energy demands mean less pollution.

Return from Fossil Fuel Power Plants to Fossil Future or return to the Green Planet home page for more Solar Power Facts.

View the original article here

Fossil Fuels or Solar Future? We must choose carefully.

Recent reports on the current status of the reserves of fossil fuels point to a the need to switch to alternative energies such as Solar Power. The thinking behind our current economic policies has driven an exponential increase in our energy usage over the last 100 years. Unfortunately, the worldwide reserves of oil, gas and coal are limited.

Even without considering environmental impacts, it is clear that at some stage we will not be able to meet our ever increasing energy needs from a finite supply of these non-renewable resources.

To gain the best understanding of how to address our dependence on fossil fuels we need to be fully informed. Follow the links for more background information - with knowledge we can make informed, intelligent decisions that give all of us and the planet the best results.

The processes that have lead to the formation of coal are different to those that produced oil and gas. There is also a body of evidence that suggests abiotic oil formation, which has significant implications on the current state of our estimated energy reserves. Find out about the conditions required for the formation of these essential energy sources, and how the fractional distillation of crude oil turns the raw material into useful products. We all take for granted filling up the car or turning on the television, but where does the fuel for these come from? Different sources of fossil fuels need to be extracted according to type and location. We all use electricity every day, and now we can have the facts on how it is generated. Understanding how fossil fuel power stations generate electricity is important if we are to have productive discussion about this at both the personal and governmental levels. Take a look at what happens on a chemical scale when burning fossil fuels. Follow the journey of a simple methane molecule all the way to its transformation into the undesirable Carbon Dioxide.

There are other issues associated with combustion of fossil energy sources. Smog air pollution is a significant health risk to those living in built up areas and despite some measures to improve the situation, photochemical smog continues to pose noticable health risks to city dwellers. Carbon Monoxide Pollution is produced from incomplete fuel combustion and can be detrimental to health even in low doses.

Different types of engines also contribute to either clean or dirty emissions. Four stroke engines are by far the most environmentally friendly version of the internal combustion engine and are used in almost all cars in service today. The two stroke engine is a popular choice for smaller applications, but the 2 stroke exhaust gases are a serious cause for concern.

LPG has been touted as a good replacement for gasoline, with many governments now keen to reduce their dependence on oil supplies, particularly those from outside the country. What about its environmental credentials though? Is it really an alternative fossil fuel? Find out here. There is a fair amount of hype on the internet about using water for gas in automobiles. Find out the facts behind the hype. Learn about the structure of the H2O molecule and how hydrogen electrolysis of water can give perfectly clean fuel.

At the same time we need to be aware of the numerous scams that pop up surrounding potential fuels. One term used to refer to water is dihydrogen monoxide, a fancy title for a common substance.

There are significant advantages of fossil energies for developed countries to continue using these energy sources. The existing infrastructures and economies of most developed nations can at present only survive with continued consumption of fossil energy. Will the supplies of fuels we use today come to an end? Fossil energy sources by their very nature are a limited resource, though some are far more abundant than others.

There is a lot of discussion about Peak Oil facts and global oil production. Are the reserves about to run out, and how do recent discoveries like the Bakken Oil Field change this outlook? Also, what are the prospects for the development of other fossil sources such as oil shale and oil sands?

The trend in Australian petrol prices is a reflection of the global rise in oil prices. What, if anything, can be done about this situation? We also need to consider the impact of these prices on us both personally and also as a nation. It is also important to keep in mind the principles behind economic growth and the effect our individual attitudes can have.

There has been a lot of talk about it, but can Clean Coal live up to the hype? Find out how this experimental technology works and its possible impacts on global greenhouse emissions.

There are also many varieties of petrol, or gasoline, available for use in vehicles with different Octane ratings. Some of these are supposedly better than others, but what is Octane and what does the rating on the pump really mean?

Find out how the much discussed Carbon Dioxide contributes to global warming, also known as the Greenhouse Effect. Understanding the science behind the discussion is an essential motivator for sustained reduction in personal emissions. It's a burning issue in the minds of all of us. What will the impacts of global warming be on us and our children? Nuclear powered reactors are capable of producing vast amounts of electricity with no greenhouse gas emissions, which is clearly a great benefit given current concerns about climate change. Find out how a nuclear fission reaction allows us to produce this power, and how a nuclear power plant works.

What are the dangers of this energy source, and how likely are large scale catastrophes from malfunctioning nuclear power stations? Also find out what fuels are involved in nuclear power stations and what the term enrichment means in Nuclear Power Information: Fuel Preparation.

Plastics and Oil

Our need for energy competes directly with our requirement for modern materials. We have become heavily dependent on plastics in everyday items that are both re-usable and disposable, meaning that our dependence on oil goes well beyond fueling our cars. Find out about plastics raw materials, how plastics are produced, which ones can be recycled and more.

The information leads us to the unavoidable conclusion that we must find alternatives to both our uses of fossilized fuels and our approach to energy use. That last one is uncomfortable, but I have been working some Government energy use statistics in a spreadsheet program and this is what I've got so far:

This graph depicts past, current and projected energy use based on a consistent 3.3% increase in annual electricity usage. We can see that the amount of electricity we will be using will continue to rise. This is not unreasonable; more and more of the objects we use in our daily lives require electricity and this trend will continue.

A constant rise of 3.3% in energy use may not seem like a lot. It is important to realize though that this is the same as accelerating in a car. Even if we only accelerate a little bit, over time we will end up going ridiculously quickly. Here is that same graph again, but this time projected into the future, up to the year 2200:

It keeps going up exponentially; have a look at the units on the vertical axis; they are quite a bit higher than in the current graph shown first. Clearly this is impossible to sustain. Yet the trend continues and has done so steadily for some time.

It is quite clearly impossible, since by 2200 we would need to cover almost the entire land surface of the planet with solar panels just to provide Australia with its energy needs, which represents a meagre 0.33% of the global population. Were all countries as high in their energy needs as Australia, we would need 300 earths completely covered in solar panels to provide us with the energy we would need.

Do you have a comment or question about the issues raised in this section of the website? Post a new comment / question or reply to an existing one.

What Other Visitors Have Said

Click below to see contributions from other visitors to this page...

I find that having a laugh at things like our energy use helps lighten the load. We are all intelligent people, and surely together we can come up with a solution. We can't afford a doom-and-gloom approach. I like Fred's poetic humor site; good for a laugh if it gets too serious.

Top Of Page

Return from Fossil Future to the Green Planet home page for more Solar Power Facts.

View the original article here

Wind turbines may benefit crops

December 16, 2010 Wind turbines in Midwestern farm fields may be doing more than churning out electricity. The giant turbine blades that generate renewable energy might also help corn and soybean crops stay cooler and dryer, help them fend off fungal infestations and improve their ability to extract growth-enhancing carbon dioxide [CO2] from the air and soil.

Speaking at the annual meeting of the American Geophysical Union, a scientific society, in San Francisco today, a researcher at the U.S. Department of Energy's Ames Laboratory and his co-researcher from the University of Colorado announced the preliminary findings of a months-long research program aimed at studying how wind turbines on farmlands interact with surrounding crops.

"We've finished the first phase of our research, and we're confident that wind turbines do produce measureable effects on the microclimate near crops," said Ames Laboratory associate and agricultural meteorology expert Gene Takle. According to Takle, who is also a professor of agricultural meteorology and director of the Climate Science Program at Iowa State University, the slow-moving turbine blades that have become a familiar sight along Midwestern highways, channel air downwards, in effect bathing the crops below via the increased airflow they create.

His colleague in the research is Julie Lundquist, assistant professor, Department of Atmospheric and Oceanic Sciences, at the University of Colorado at Boulder, joint appointee at the U.S. Department of Energy's National Renewable Energy Laboratory, and Fellow of the Renewable and Sustainable Energy Institute. Lundquist's team uses a specialized laser known as a lidar to measure winds and turbulence from near the Earth's surface to well above the top tip of a turbine blade.

"Our laser instrument could detect a beautiful plume of increased turbulence that persisted even a quarter-mile downwind of a turbine," Lundquist said.

Both Takle and Lundquist stressed that their early findings have yet to definitively establish whether or not wind turbines are in fact beneficial to the health and yield potential of soybeans and corn planted nearby. However, their finding that the turbines increase airflow over surrounding crops, suggests this is a realistic possibility.

"The turbulence resulting from wind turbines may speed up natural exchange processes between crop plants and the lower atmosphere," Takle said.

For instance, crops warm up when the sun shines on them, and some of that heat is given off to the atmosphere. Extra air turbulence likely speeds up this heat exchange, so crops stay slightly cooler during hot days. On cold nights, turbulence stirs the lower atmosphere and keeps nighttime temperatures around the crops warmer.

"In this case, we anticipate turbines' effects are good in the spring and fall because they would keep the crop a little warmer and help prevent a frost," said Takle. "Wind turbines could possibly ward off early fall frosts and extend the growing season."

Other benefits of wind turbines could result from their effects on crop moisture levels. Extra turbulence may help dry the dew that settles on plants beginning in late afternoon, minimizing the amount of time fungi and toxins can grow on plant leaves. Additionally, drier crops at harvest help farmers reduce the cost of artificially drying corn or soybeans.

Another potential benefit to crops is that increased airflows could enable corn and soybean plants to more readily extract atmospheric CO2, a needed "fuel" for crops. The extra turbulence might also pump extra CO2 from the soil. Both results could facilitate the crops ability to perform photosynthesis.

Takle's wind turbine predictions are based on years of research on so-called agricultural shelter belts, which are the rows of trees in a field, designed to slow high-speed natural winds.

"In a simplistic sense, a wind turbine is nothing more than a tall tree with a well-pruned stem. For a starting point for this research, we adapted a computational fluid model that we use to understand trees," said Takle. "But we plan to develop a new model specific to wind turbines as we gather more data."

The team's initial measurements consisted of visual observations of wind turbulence upwind and downwind of the turbines. The team also used wind-measuring instruments called anemometers to determine the intensity of the turbulence. The bulk of the wind-turbulence measurements and the crop-moisture, temperature and CO2 measurements took place in the spring of 2010.

"We anticipate the impact of wind turbines to be subtle. But in certain years and under certain circumstances the effects could be significant," said Takle. "When you think about a summer with a string of 105-degree days, extra wind turbulence from wind turbines might be helpful. If turbines can bring the temperature down below 100 degrees that could be a big help for crops."

Provided by Ames Laboratory (news : web)

Rate this story - not rated yet

View the original article here

The final frontier: Studying Earth-like planet's atmosphere in detail

December 16, 2010 by Morgan Bettex

Enlarge

The bacteria GFAJ-1, shown here, can thrive on arsenic ? a discovery that upends long-held assumptions about the basis of life here on Earth and elsewhere. Image: Science/AAAS

Although Gliese 581g is the most Earthlike planet to be discovered to date, it's unclear whether the planet is habitable. Just because the planet is relatively similar in mass to Earth doesn't mean it can host life. Although Earth and Venus are about the same mass and size, the surface of Venus is too unbearably hot for life to survive there.

In fact, the hardest part about the quest to find life elsewhere in the universe may be confirming whether an Earth-sized planet is habitable. The only way to find that out is by studying the planet’s atmosphere, an area of research that Sara Seager, the Ellen Swallow Richards Professor of Planetary Science in MIT’s Department of Earth, Atmospheric and Planetary Sciences and professor of physics, has pioneered over the past 15 years. Although Seager has mostly studied the atmospheres of massive exoplanets known as “hot Jupiters,” which are too hot and gaseous to host life, she considers these observations as valuable practice for studying smaller exoplanets.

“We are just testing the waters, because we are only now getting the data and practicing how to interpret that data,” Seager explains of studying super-Earths, or planets that are up to 10 times the mass of Earth. “I look to these planets as practice cases for when we find the Earths, which is important, because a lot of the time with exoplanets, things are different from what you’d expect,” she says. In fact, despite all the excitement surrounding the discovery of Gliese 581g, Seager doesn’t believe this is a good planet for follow-up observations because there is significant uncertainty about its density, composition and atmosphere.

Studying the atmospheres of Earth candidates like Gliese 581g is expected to be challenging in part because these planets have thin atmospheres, and current telescope technology may not enable researchers to collect enough detailed data to confirm signs of life, according to a paper that Seager co-authored and that was published in September in the Annual Reviews of Astronomy and Astrophysics. Despite this limitation, Seager is trying to learn as much as possible about recently discovered midsized planets with the hope that this knowledge will lead to better observational techniques for studying Earthlike exoplanets that are even smaller than Gliese 581g.

Millions of models

During the 1990s, researchers didn’t think it would be possible to study the atmospheres of the hot Jupiters that they were beginning to discover. But that changed in 2002, when the Hubble Space Telescope detected an exoplanet’s atmosphere as it transited, or passed in front of its host star. During a transit, the molecules in a planet’s atmosphere absorb some of the starlight that passes through the atmosphere. Researchers can identify those molecules by studying the changes in the spectrum, or rainbow of colors emitted in the light that radiates from the star’s electromagnetic waves. Because lab experiments have determined what kinds of molecules are absorbed at certain wavelengths, scientists study spectra patterns to pinpoint the types of molecules that may exist in a planet’s atmosphere. They can also learn how much heat an exoplanet radiates and absorbs by observing it as it passes behind its host star, an event known as an occultation.

As researchers began to collect data from these events, they started to develop computer models to interpret the data. Seager and former MIT postdoctoral researcher Nikku Madhusudhan pioneered the so-called “million-model approach,” a technique that uses computer programs to combine variables, such as a planet's temperature throughout its atmosphere, with different amounts of the most stable and prominent molecules that exist in planetary atmospheres, including methane and water vapor. The programs then analyze millions of combinations of these variables to find a range that most closely matches the data. This allows researchers to determine the most likely composition of the atmosphere.

Seager’s technique has allowed researchers to characterize the atmospheres of dozens of hot Jupiters to date. In addition to identifying the molecules that make up those atmospheres, they have learned the temperature of these planets’ day and night sides, and how those temperatures change at different altitudes. Most recently, Seager, Madhusudhan and their colleagues studied the atmosphere of GJ 436b, an exo-Neptune, and found that it didn’t contain the high levels of methane that scientists expected for a planet with its temperature.

Waiting game

Seager is also working with Leslie Rogers, a graduate student in MIT’s Department of Physics, to explore the range of pressures and temperatures that would enable liquid water — a requirement for all life on Earth — to exist inside a planet or on its surface. By pinpointing the variables that are most important for liquid water to exist, such as the distance between a planet and its host star, Seager and Rogers hope to develop more realistic models to study Earth candidates.

But it remains to be seen whether there will be enough decent data to plug into such models, according to Drake Deming, a senior scientist at NASA’s Goddard Space Flight System, who says that even though Seager’s technique has been useful for interpreting hot Jupiters, the approach requires extremely high-quality data. The James Webb Space Telescope, scheduled to be deployed in 2014, is expected to more easily obtain better data of exoplanet atmospheres, but Drake says it’s likely that the telescope won’t be sensitive enough to study Earthlike planets. He estimates that confirming the existence of a true Earth twin could “take years, probably decades, because we don’t have the techniques or the technology to do so.”

Despite these technical challenges, Seager remains optimistic and is focused on tackling what she sees as the biggest hurdle for future atmospheric research: identifying biosignature gases that don’t exist on Earth. That possibility became much more realistic with the recent announcement that NASA researchers had discovered a bacterium that can grow from a diet of arsenic and thus doesn’t share the biological building blocks traditionally associated with all life forms. While arsenic isn’t a biosignature gas, Seager says the finding is a reminder that there are likely unrecognized biosignature gases produced by organisms that may exist in configurations that weren’t previously thought possible.

Although each of the more than 500 exoplanets that have been detected to date — with the possible exception of Gliese 581g — are too hot to support molecules that could sustain life, Seager is preparing for the possibility of detecting unknown biosignature gases in the future. To do so, she is reviewing all the byproducts that Earth organisms produce, calculating the likelihood that those byproducts can accumulate in an atmosphere and creating models of the types of planetary environments that could sustain such signatures.
This story is republished courtesy of MIT News (http://web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.

Provided by Massachusetts Institute of Technology (news : web)

Rate this story - 5 /5 (1 vote)

View the original article here

Is Your Home Pollution Free?

Is Your Home Pollution Free? | Lifeofearth.org HomeGreen CommunityTake ActionGreen ImagesGreen VideosGreen NewsDonate HereResourcesLifeofearth.orgAstronomyEnvironmentEarthGlobal-WarmingActivistHealthMens-HealthWomens-HealthPollutionAir PollutionSoil PollutionWater PollutionPublicationGlobal Warming BookRecyclingGreen-GuideWildlifeWorldAgricultureEconomicNatural-DisasterTravel Sponsored LinksSponsored LinksSponsored LinksIs Your Home Pollution Free?February 3rd, 2010 | Mac

Impure and polluted air inside your home can be dangerous and result in asthma and bring on symptoms of allergy as well. The American Lung Association offers these suggestions to help keep the air clean at home:

Don’t allow anyone to smoke in your home.Have your home tested for radon gas.High levels of humidity can have negative repercussions. Make sure your home’s humidity level is below 50 per cent. Install a dehumidifier if you stay in a high-humidity zone.Have all the pipes and drains of your home examined. If a tap is dripping, or a pipe is leaking, have it fixed rightaway as it will attract mold.Get into the habit of covering all your food items – whether it is lying outside or stashed away in the refrigerator. You will be warding off cockroaches and thanking your stars.Open windows and doors to let out stale smells, but do not use candles or sprays to hide odours as it just becomes worse.Go for organic household products as they do not have any side-effects. Most chemical products contain toxics which harm human beings.
Related PostsHave A Green DiwaliPollution in China Affecting RainfallThe Sky Is Not Falling: Pollution In Eastern China Cuts Light, Useful RainfallOrganic Carbon Compounds Emitted By Trees Affect Air QualityIndoor Air Pollution Create Problems for Rural Areas Flyash: Air PollutionAcid Rain: Air PollutionSmog: Air PollutionAir Pollution May Harm Children From Day OneWhat’s In Our Air?Pollution
Tags: Air-Pollution, Asthma, Home-Pollution, Pollution Leave a ReplyClick here to cancel reply.

Name (required)

Mail (will not be published) (required)

Website

Search Free Articles By Keyword... Choose Your Language...By N2HWe will keep You Updated...Sign up to receive breaking news
as well as receive other site updates!Join Us With...  Sponsored LinkImportant Links...

Featured Video
For more videos CLICK HERE Archives March 2010February 2010January 2010December 2009November 2009October 2009September 2009August 2009July 2009June 2009May 2009April 2009March 2009February 2009January 2009December 2008November 2008October 2008July 2008June 2008May 2008April 2008March 2008February 2008December 2007October 2007September 2007August 2007July 2007June 2007May 2007 Our Creation Classified DirectoryHealth DirectoryJobs Directory Pages Climate ChangeEnergy ConservationEnvironmentForest ConservationFossil FuelsGlobal CoolingGlobal WarmingGreenhouse GasesLiving EarthNatural DisastersOzone LayerPollutionRecyclingSearch ResultWildlife Conservation Categories ActivistAgricultureAir PollutionAstronomyEarthEconomicEnvironmentGlobal Warming BookGlobal-WarmingGreen-GuideHealthMens-HealthNatural-DisasterPollutionPublicationRecyclingSoil PollutionTravelWater PollutionWildlifeWomens-HealthWorld Recent Posts World Kidney Day 2010

World kidney day, a joint initiative of the International Society of Nephrology and the International... 

CAG To Audit Water Pollution In India

CAG To Audit Water Pollution In India, The government’s official auditor Comptroller and Auditor... 

Green Energy Projects to Damage Environment

Projects to develop renewable energy sources including solar and wind power are paradoxically damaging... 

The Case for Global Warming Stronger Than Ever

One of the many crimes that climate scientists have been accused of lately is that they claim absolute... 

Going To London

Going to London? Wow! It sounds like a dream come true. But have you ever thought what makes your trip... 

Recent CommentsHI!!!!!!!!!!!! i love lruing at this site! and i love dinos!!!!!!! Inspite of many thoughts, well researched articles still fetch in subscribers like me. You showed broad understanding of the subject exemplary work. You have gained a new subscriber. Please keep up the good work and I look forward to more of your interesting posts. Passage Cry,opinion paint heavy weak interesting this board themselves essential deny application plastic husband gentleman throw wh Land Pollution August 11th, 2009 | Mac Land Pollution is the degradation of Earth’s land surfaces often caused by human activ Tag Cloud

Air-PollutionAmericaAstronomyAtmosphereAustraliaCaliforniaCancerCarbon-DioxideChinaClimateClimate-ChangeDiseasesEarthEconomyEnergyEnvironmentFamilyFossil-FuelsGlobal-WarmingGreenhouseGreenhouse-GasesHealthIndiaJapanLondonNatural-DisasterOzonePeoplePlanetPollutionPopulationPublicationRecyclingReduceResearchReuseScientistsSoil-PollutionTravelTravel-TipsUnited-StatesWater-PollutionWeatherWildlifeWorld

WP Cumulus Flash tag cloud by Roy Tanck and Luke Morton requires Flash Player 9 or better.

Designed by RDJ Inc.

View the original article here