Alternative energy and Technology Articles from Mr.white

Solar Best and Worst of 2011

admin — Wed, 11 Jan 2012 13:09:38 +0000

Solyndra, the panel designer/manufacturer publically backed by the government became one of 2011’s top headlines when they sank half a million tax payer dollars. The solar industry took a hit from the exaggeration of the story and the attitude most of the general public adopted after Solyndra went under. The $535 million dollar loan guarantee the government provided left a bad taste in tax payer’s mouths when the company filed for bankruptcy in September. The incident has become politically polarizing with Republicans blaming the Obama administration for awarding loan security based on monetary contribution to the Democratic party instead of merit. The investigation is ongoing, meanwhile, responsibility for the massive loss in tax payer’s dollars has yet to be claimed. Fortunately, the industry showed resilience in growth, surpassing 2010’s 887 installed mW by totaling more than 1,000 mW by the end of the third quarter.

Brightsource Energy is a utility scale installer in Southern California. They have made the top 10 list of Greentech Startups several times since they started in 2004. Investors have ranged from Google to BP and most recently, the U.S. Department of Energy through a $1.6 billion loan guarantee. 2012 promises more growth with over 16,000mW in secured projects.

The third is a literal figure. The price of panels took a 30% drop in the last year. Though this sounds like a good figure (and it is) it has presented its fair share of problems. Many installers and distributors are finding themselves with excess inventory they purchased above market pricing. The forecast for the next couple of years looks better still for consumers: “NRG expects the cost to fall in half again in the next two years, which would make solar power less expensive than retail electricity in roughly 20 states.” (Greentechsolar.com) Bottom line, the price of going solar continues to plummet making it a more accessible and economical option for consumers.

2011 has proven itself as one of the most eventful years in the solar industry. Between the massive drop in panel pricing and the very public downfall of Solyndra, the market continues to adapt and grow.
Solyndra, the panel designer/manufacturer publically backed by the government became one of 2011’s top headlines when they sank half a million tax payer dollars. The solar industry took a hit from the exaggeration of the story and the attitude most of the general public adopted after Solyndra went under. The $535 million dollar loan guarantee the government provided left a bad taste in tax payer’s mouths when the company filed for bankruptcy in September. The incident has become politically polarizing with Republicans blaming the Obama administration for awarding loan security based on monetary contribution to the Democratic party instead of merit. The investigation is ongoing, meanwhile, responsibility for the massive loss in tax payer’s dollars has yet to be claimed. Fortunately, the industry showed resilience in growth, surpassing 2010’s 887 installed mW by totaling more than 1,000 mW by the end of the third quarter.
Brightsource Energy is a utility scale installer in Southern California. They have made the top 10 list of Greentech Startups several times since they started in 2004. Investors have ranged from Google to BP and most recently, the U.S. Department of Energy through a $1.6 billion loan guarantee. 2012 promises more growth with over 16,000mW in secured projects.
The third is a literal figure. The price of panels took a 30% drop in the last year. Though this sounds like a good figure (and it is) it has presented its fair share of problems. Many installers and distributors are finding themselves with excess inventory they purchased above market pricing. The forecast for the next couple of years looks better still for consumers: “NRG expects the cost to fall in half again in the next two years, which would make solar power less expensive than retail electricity in roughly 20 states.” (Greentechsolar.com) Bottom line, the price of going solar continues to plummet making it a more accessible and economical option for consumers.

Making solar panels

admin — Fri, 25 Nov 2011 11:06:23 +0000

Making solar panels is a delicate process, and it is for this reason that major solar advances did not come into play until the lattermost quarter of the last century, when advances in semiconductors and photovoltaic design allowed increasingly efficient and affordable solar cells to be developed.
The creation of solar panels typically involves cutting crystalline silicon into tiny disks less than a centimeter thick. These thin, wafer-like disks are then carefully polished and treated to repair and gloss any damage from the slicing process. After polishing, dopants (materials added to alter an electrical charge in a semiconductor or photovoltaic solar cell) and metal conductors are spread across each disk. The conductors are aligned in a thin, grid-like matrix on the top of the solar panel, and are spread in a flat, thin sheet on the side facing the earth.
To protect the solar panels after processing, a thin layer of cover glass is then bonded to the top of the photovoltaic cell. After the bonding of protective glass, the nearly-finished panel is attached to a subtrate by an expensive, thermally conductive cement. The thermally conductive property of the cement keep the solar panel from becoming overheated; any leftover energy that the solar panel is unable to convert to electricity would otherwise overheat the unit and reduce the efficiency of the solar cells.
Despite these protective measures against the tendancy of solar panels to overheat, it is vital that when installing a solar panel, additional steps should be taken to ensure the solar panel is kept cool. Elevating the solar panel above ground (see solar panel mounts) to let the airflow underneath cool the device.
Amorphous silicon solar panels are a powerful, emerging line of photovoltaics, that differ in output, structure, and manufacture than traditional photovoltaics which use crystalline silicon. Amorphous silicon solar cells, or A-si cells, are developed in a continuous roll-to-roll process by vapor-depositing silicon alloys in multiple layers, with each extremely thin layer specializing in the absorption of different parts of the solar spectrum. The result is record-breaking efficiency and reduced materials cost (A-si solar cells are typically thinner than their crystalline counterparts).
Some Amorphous Solar Panels also come with shade-resistant technology or multiple circuits within the cells, so that if an entire row of cells is subject to complete shading, the circuit won’t be completely broken and some output can still be gained. This is especially useful when installing solar panels on a boat.
The development process of Amorphous Silicon solar panels also renders them much less susceptible to breakage during transport or installation. This can help reduce the risk of damaging your significant investment in a photovoltaic system.

Energy from the Sun

admin — Fri, 25 Nov 2011 10:56:57 +0000

Solar panels have the ability to meet all of our energy needs, but at present we only use a tiny fraction of the energy that the sun has to offer. How much energy does the sun produce? How is it produced? And how much of the sun’s energy can be theoretically harvested via solar cells?
Energy from the sun is caused from thermonuclear expolosions deep within the sun. These explosions fuse atoms of hydrogen into atoms of helium. A tremendous amount of energy is released during the thermonuclear reaction and the sun releases that energy as radiation. This radiation travels through space at the speed of light, and solar panels can make practical use of it. Our sun generates an enourmous amount of energy, and potentially, had we the technology to harvest that sunlight with solar arrays across the solar system, we could harvest huge amounts of energy.
According to our friends at Astronomy Cafe, we calculate the amount of energy given off the sun every hour as:
«3.8 x 10^33 ergs/sec or 3.8 x 10^26 watts of power, an amount of energy each second equal to 3.8 x 10^26 joules. In one hour, or 3600 seconds, [the Sun] produces 1.4 x 10^31 Joules of energy or 3.8 x 10^23 kilowatt-hours.»
The sun produces more energy every hour than the entire energy needs of human civilization from the beginning of time. Solar panels will help us harvest increasing amounts of this abundance of energy to meet our energy needs in the future.

Do you know what a solar panel is?

admin — Fri, 25 Nov 2011 10:46:46 +0000

Solar panels are typically constructed with cystalline silicon, which is used in other industries (such as the microprocessor industry), and the more expensive gallium arsenide, which is produced exclusively for use in photovoltaic (solar) cells.
Other, more efficient solar panels are assembled by depositing amorphous silicon alloy in a continuous roll-to-roll process. The solar cells created from this process are called Amorphous Silicon Solar Cells, or A-si. Solar Panels constructed using amorphous silicon technology are more durable, efficient, and thinner than their crystalline counterparts.
For very important solar projects, such as space probes that have to rely on solar energy, very-high efficiency solar cells are constructed from gallium arsenide by a process called molecular beam epitaxy. Solar cells constructed by this process have several p-n junction diodes, each designed to be maximally efficient at absorbing a given part of the solar spectrum. This solar panels are much more efficient than conventional types, but the process and materials involved make them far too expensive for everyday applications.
The newest solar panels function on the molecular or quantum level, and represent an exciting new technology coming into play. These solar panels are created by implanting carbon nanotubes or quantum dots into a treated plastic. Unlike silicon-based solar panels, these solar panels do not have to be constructed in a clean room, and therefore production costs are somewhat dimished.
The practical applications of solar panels constructed from plastics are staggering – they could be overlayed onto a laptop screen to provide continous power, or provide supplemental power to any number of outdoor appliances. The primary hurdle for this new technology is efficiency, and these ‘plastic’ solar panels have an operational efficiency of about .11% of their silicon-based counterparts. The only short-term solution to this energy problem is for these plastic solar panels to generate electricity from light outside the visible spectrum of light. Some highly-experimental plastic solar panels have been made to absorb infrared energy, and if a solar panel is made that can absorb both infrared energy and light from the visible spectrum, the operational efficiency could increase up to thirty percent.

Basic information on wind energy and wind power technology, resources, and issues of concern.

admin — Mon, 13 Jun 2011 09:23:16 +0000

Wind Energy and Wind Power

Wind is a form of solar energy. Winds are caused by the uneven heating of the atmosphere by the sun, the irregularities of the earth’s surface, and rotation of the earth. Wind flow patterns are modified by the earth’s terrain, bodies of water, and vegetative cover. This wind flow, or motion energy, when «harvested» by modernwind turbines, can be used to generate electricity.

How Wind Power Is Generated

The terms «wind energy» or «wind power» describe the process by which the wind is used to generate mechanical power or electricity. Wind turbines convert the kinetic energy in the wind into mechanical power. This mechanical power can be used for specific tasks (such as grinding grain or pumping water) or a generator can convert this mechanical power into electricity to power homes, businesses, schools, and the like.

Wind Turbines

Wind turbines, like aircraft propeller blades, turn in the moving air and power anelectric generator that supplies an electric current. Simply stated, a wind turbine is the opposite of a fan. Instead of using electricity to make wind, like a fan, wind turbines use wind to make electricity. The wind turns the blades, which spin a shaft, which connects to a generator and makes electricity.

Wind Turbine Types

Modern wind turbines fall into two basic groups; the horizontal-axis variety, like the traditional farm windmills used for pumping water, and the vertical-axis design, like the eggbeater-style Darrieus model, named after its French inventor. Most large modern wind turbines are horizontal-axis turbines.

Turbine Components

Horizontal turbine components include:

blade or rotor, which converts the energy in the wind to rotational shaft energy;
a drive train, usually including a gearbox and a generator;
a tower that supports the rotor and drive train; and
other equipment, including controls, electrical cables, ground support equipment, and interconnection equipment.

Wind turbine diagram – click for enlarged image.

Turbine Configurations

Wind turbines are often grouped together into a single wind power plant, also known as a wind farm, and generate bulk electrical power. Electricity from these turbines is fed into a utility grid and distributed to customers, just as with conventional power plants.

Wind Turbine Size and Power Ratings

Wind turbines are available in a variety of sizes, and therefore power ratings. The largest machine has blades that span more than the length of a football field, stands 20 building stories high, and produces enough electricity to power 1,400 homes. A small home-sized wind machine has rotors between 8 and 25 feet in diameter and stands upwards of 30 feet and can supply the power needs of an all-electric home or small business. Utility-scale turbines range in size from 50 to 750 kilowatts. Single small turbines, below 50 kilowatts, are used for homes, telecommunications dishes, or water pumping.

See Wind Energy Photos page for wind turbine photographs.

Wind Energy Resources in the United States

Wind energy is very abundant in many parts of the United States. Wind resources are characterized by wind-power density classes, ranging from class 1 (the lowest) to class 7 (the highest). Good wind resources (e.g., class 3 and above, which have an average annual wind speed of at least 13 miles per hour) are found in many locations (see United States Wind Energy Resource Map). Wind speed is a critical feature of wind resources, because the energy in wind is proportional to thecube of the wind speed. In other words, a stronger wind means a lot more power.

Advantages and Disadvantages of Wind-Generated Electricity

A Renewable Non-Polluting Resource

Wind energy is a free, renewable resource, so no matter how much is used today, there will still be the same supply in the future. Wind energy is also a source ofclean, non-polluting, electricity. Unlike conventional power plants, wind plants emit no air pollutants or greenhouse gases. According to the U.S. Department of Energy, in 1990, California’s wind power plants offset the emission of more than 2.5 billion pounds of carbon dioxide, and 15 million pounds of other pollutants that would have otherwise been produced. It would take a forest of 90 million to 175 million trees to provide the same air quality.

Cost Issues

Even though the cost of wind power has decreased dramatically in the past 10 years, the technology requires a higher initial investment than fossil-fueled generators. Roughly 80% of the cost is the machinery, with the balance being site preparation and installation. If wind generating systems are compared with fossil-fueled systems on a «life-cycle» cost basis (counting fuel and operating expenses for the life of the generator), however, wind costs are much more competitive with other generating technologies because there is no fuel to purchase and minimal operating expenses.

Environmental Concerns

Although wind power plants have relatively little impact on the environment compared to fossil fuel power plants, there is some concern over the noiseproduced by the rotor blades, aesthetic (visual) impacts, and birds and bats having been killed (avian/bat mortality) by flying into the rotors. Most of these problems have been resolved or greatly reduced through technological development or by properly siting wind plants.

Supply and Transport Issues

The major challenge to using wind as a source of power is that it is intermittentand does not always blow when electricity is needed. Wind cannot be stored (although wind-generated electricity can be stored, if batteries are used), and not all winds can be harnessed to meet the timing of electricity demands. Further, good wind sites are often located in remote locations far from areas of electric power demand (such as cities). Finally, wind resource development may compete with other uses for the land, and those alternative uses may be more highly valued than electricity generation. However, wind turbines can be located on land that is also used for grazing or even farming.

The History of Solar Panels and Solar Energy.

admin — Fri, 10 Jun 2011 11:32:44 +0000

For the answer to that question we can rely on the wisdom of the ages:

A wise man once said that in order to know where we’re going we need to know where we’ve been.

So let’s follow that wise man’s advice and take a look at the history of solar power.

To keep this as simple as possible, we’ll break things down into three easily digestible portions based on the three main types of solar:

1. Passive solar

2. Solar Thermal

3. Solar Electric (Photovoltaics)

Passive Solar

The Greeks and Romans Get Active With Passive Solar

Passive solar power is pretty simple, it doesn’t require any fans, pumps, or panels.

It just means using part of your home to collect the sun’s energy. Not surprisingly, passive solar is the first stop in our journey into the history of solar power.

Archaeological evidence shows that the ancient Greeks were building their homes in grid patterns to utilize the heat and light of the sun in the fifth century BC.

Socrates sang the praises of passive solar power when he wrote that «In houses that look toward the south, the sun penetrates the portico in winter».

The playwright Aeschylus was a little more elitist in his solar power observations, noting that only primitives «lacked knowledge of houses turned to face the winter sun, dwelling beneath the ground like swarming ants in sunless caves.»

Zing!

Meanwhile, Back in America…

In the twelfth century AD the Pueblo Indians built Acoma (the «Sky City»). Each building had a south facing adobe wall which absorbed the sun’s heat all day and then heated the interior of the house at night.

Early Spanish settlers in America also built their homes with the main portion of the house facing south. They closed their shutters at night to keep in the warmth that the sun had provided during the day.

20th Century Passive

What about the ‘modern’ history of solar power?

In the early 20th century an observant city planner in Britain said that «every house should have its face turned to the sun, whence comes light, sweetness and health».

In the 1930’s German architect Hannes Meyer said that a house should be viewed as a «storage cell for the heat of the sun». In fact, throughout the 1930’s Germany spearheaded a resurgence in solar home building.

Passive Solar: Our Friend When Times Get Tough

The history of solar power has followed a similar pattern since the time of the ancient Greeks.

When fuel is expensive or hard to come by, we think passive solar is the greatest thing since sliced bread.
When fuel is cheap and abundant we ditch passive solar faster than you can say «baseboard heating».

Well, I’m no fortune teller but I think we’ll be getting friendly with our old friend passive solar again in the near future.

Solar Thermal

Piping Hot Water? Yes Please!

Solar thermal refers to the direct conversion of sunlight to heat. The main application of solar thermal has been the heating of our water for showers and other household fun.

In the 1760’s Swiss naturalist Horace de Saussure built an insulated, black, glass-covered box. He then put it in the sun and watched the temperature of his «hot box» climb to 228°F.

How did it work?

Well, the sunlight easily passed through the glass top and was absorbed by the black interior of the box and converted to heat.

Once converted to heat, the sun’s energy was trapped in the box by the glass lid that had allowed the sunlight in so easily.

To simplify: sunlight gets in > turns into heat > can’t get out

This brilliantly simple tool would be the key to countless hot showers over the next few centuries.

But first things first.

In the nineteenth century people began painting metal water tanks black and putting them in the sun to heat up their water.

These early water heaters were cheaper than heating water by burning coal or wood but they took all day to heat up and lost their heat every night.

Enter Clarence Kemp.

In 1891 Kemp patented a new solar water heater that combined the black water tank idea with the «hot box» idea of Horace de Saussure. The glass casing of the water tank increased its ability to collect and retain the sun’s heat.

Kemp saucily titled his invention «The Climax» and began taking orders.

The next revolution in solar thermal occurred in 1909 when William J. Bailey patented a solar water heater that separated the heating portion which was exposed to the sun and the storage tank which was kept in the house.

This allowed the water to heat up faster (because a smaller amount was exposed to the sun at one time) and keep its heat longer (because the storage tank wasn’t exposed to the nighttime cold).

Cheap natural gas and electricity put a dent in the solar water heater market but whenever fuel prices spiked, solar thermal became popular again (sound familiar?).

In 1839 a nineteen year old by the name of Alexandre-Edmond Becquerel discovered the photovoltaic effect.

This effect is the physical process through which a solar cell converts sunlight into electricity.

The basis for the modern solar cell, however, can more directly be traced back to William Grylls Adams.

Back in 1876, Mr. Adams discovered that selenium generated an electric current when exposed to light.

This important day in solar power history proved that a solid material could change light into electricity without heat or moving parts.

I assume it also gave William some bragging rights over his brother John who discovered Neptune.

Yes, that’s right, the man who invented solar electricity had a brother who discovered a planet .

So, what has your family done for the world of science and technology lately?

The selenium solar cells were revolutionary but they were not efficient enough to power electrical equipment.

That chapter of solar panel history wouldn’t begin until 1953 when Bell Laboratories employee Gerald Pearson made a solar cell with silicon instead of selenium. The solar cell was finally ready to be put to work.

Unfortunately the solar cell was put to work powering toy subs and model airplanes because any major use of the technology was seen as being prohibitively expensive.

How expensive?

About $300 per watt (a power plant cost 50¢ a watt to build).

Could this be the end for our hero the solar cell? Is it doomed by its hefty price tag?

Nope.

It seems there was a little thing called the Cold War going on at the time. Satellites were the new surveillance tool in this fight but they needed a reliable power source.

Can you see how this might affect solar panel history?

That’s right, us regular people looked at the $300 per watt cost of the solar cell and said «No thank you».

Uncle Sam just said «Where did I put my checkbook?».

This was a turning point in the history of solar panels. The technology developed under the guiding hand of the military industrial complex until, by the late 1960’s, solar cells became the accepted power source for satellites.

Accessible solar electricity on earth seemed as distant as ever, however, until Dr. Elliot Berman designed a solar cell using cheaper materials in the early 70’s. This brought the price down to $20 per watt and made solar feasible in remote locations like off-shore rigs and lighthouses.

The following years saw solar power used by the Coast Guard and the railway companies. Solar panels also began to be used in the developing world for pumping water as well as powering lights, televisions, and radios.

As the price of solar cells has dropped over the years the use of solar electric panels has become feasible for more situations. This includes buildings that are far from power lines, bus shelters, and call boxes.

More people all the time are also using solar power for their homes. The solar cell industry has increased 200 fold over the last twenty years.

We may be entering a whole new era in the history of solar panels. As fuel prices skyrocket people’s interest in solar electricity is increasing.