Solar Power Electrics

Archive for April, 2010

An alternative energy resource, gaining much market share, is solar power. It is the one that is most well known every day. This involves the manufacturing of solar cells which gather and focus the sun’s energy, and translate it into electricity. In some, hot water can be produced from the sun. As with wind energy, solar energy creates absolutely zero pollution.

One of these renewable energy resources is solar energy. Solar PV cells continue to be manufactured that are often more energy efficient and less costly than previous models from a few years ago. Solar energy plants have been developed in in many nations. They are now more strategically placed in order to improve the national electricity grid. Over time, they are not causing environmental issues as previous placement of solar panels may have caused.

The following sections provide a summary overview of many other renewable energy sources being researched, developed, and deployed throughout the world.

Ocean current energy is discussed by governments and investors as having untapped energy generating potential. A ocean electricity generator in Europe has been in operation for a long time. It is thought to be a great accomplishment. The Irish and Scots are also running pilot facilities.

Hydroelectric power has been with us for a while. At current hydro dams, it is a clean generator of electricity. Because water and gravity is used, it is more effecient than a grid powered by natural gas. There are restrictions to the availability of the right places to set up a large dam. Many river based, or small and localized, hydro generators where created in recently due to this limitation.

Geothermal energy is extremely abundant. Since it lies directly beneath us, we only need drill just a few miles below the earth’s surface to find huge amounts of energy. This energy is produced by the heating of water, trapped in layers of rock, through the earth’s hot molten core. The water turns to steam, which is then used to drive turbines that generate electricity. Great amounts of research and development should be put into geothermal energy tapping.

Biodiesel energy is created out of the oils contained in plants. Most commonly, the retail stockpiles of bio-diesel have been created using rapeseed and sunflower oils. At the time of this writing, biodiesel is typically produced by agricultural corporations or those who want to experiment with renewable energy. Venture interest from companies across the World is on the rise. It burns much better than fossil fuel diesel.

Another renewable energy resource is solar generated electricity. Solar PV cells continue to be manufactured that are often more energy efficient and less costly than previous models from a few years ago. This involves the manufacturing of solar panels which gather and focus the sun’s energy, and translate it into electricity. In other cases, hot water can be produced from the sun. As with wind energy, solar energy creates absolutely zero pollution.

Daniel Stouffer
http://www.articlesbase.com/home-and-family-articles/alternative-green-or-renewable-energy-technologies-711054.html

Solar power is generated when energy is extracted from the suns rays through the use of photovoltaic cells (commonly referred to as solar cells). These cells convert photos (from the suns rays) into electricity, and this process is known as the “photovoltaic effect.”

Many people are beginning to invest in such technologies to avoid rising electricity prices and to help our environment. If every home could be fitted with solar panels, then the strain on power stations would decrease dramatically, which means we wouldn’t be left as dependable on fossil fuels as we currently are.

There are many alternatives to solar power, so why should we invest our money into solar technologies, rather than lets say, home wind turbines, or a geothermal energy system? To answer this, we shall look at the advantages and disadvantages of the technologies above.

Solar Panels:

Advantages – widely available, relatively easy to install, very significant output, a solar panel will pay for itself in two to three years, lifetime of 20 to 30 years, modern cells can harness power on cloudy days, can bring power to remote locations.

Disadvantages – costly to begin with, older technologies won’t work too well if cloudy.

Wind Turbines:

Advantages – fairly cheap for a home turbine, can be used in harsh conditions.

Disadvantages – totally dependent on the wind, small output, larger turbines can be noisy, wind farms are seen by many as eyesores, larger (more effective) turbines can be very expensive.

Geothermal Energy:

Advantages – can aid in the heating of hot water, save money on running your boiler, can supply effective underfloor heating, heat from the ground can be relied upon.

Disadvantages – have to lay hundreds of meters of piping underground, hard to fix a leak, expensive, longer time to heat water than a boiler.

So there we have the advantages and disadvantages of each. Assuming you do not live by a rapid stream or running river (which rules out hydroelectric power), then as you can see from the above text, solar power is your best option. Solar panels offer many more friendly factors and less disadvantages than other technologies.

A proven method is to have more than one of the above technologies installed around a home (all three would be a dream, but also leave a large hole in your wallet). So if you have the spare cash, are interrested in saving money on future electricity bills, care for the environment, and would like to be less dependent on fossil fuels, why not take a deeper look into the world of renewable energy resources.

http://www.clean-energy-ideas.com/solar_panels.html

James Bratley
http://www.articlesbase.com/environment-articles/solar-panels-power-your-home-for-free-106007.html

While some alternative energy solutions for the home require a major investment for their initial installation, there are others which are not so complicated.

Solar lights are relatively simple to acquire and install, and are powered by clean energy. Since they usually require no wiring, they are very simple to set up.

Solar garden lights (or solar landscape lights) are one example of this. Solar garden lights have solar panels embedded into them at the top, facing the sun. Of course one drawback of these is that they might not stay lit forever. The amount of sun they receive will influence how long they last. The specifications of these lights can give you some idea of how long they will stay lit in the dark. But 8-12 hours is not an unusual estimate for a reasonably priced light, which should be plenty of time to get through the night in most circumstances.

Furthermore, these lights usually have sensors so that they turn on automatically at dusk and turn off when the sun starts shining again. This means that you don’t have to run your lights the whole night through, if you don’t need to. Motion sensors are also used in some solar lights, such as those that would be placed along pathways or near the front door, so that the lights turn on when an person or animal is present. This is good for security, and its also good for just seeing where you are going when you walk in a garden or path, or approach a home in the dark.

Solar lighting can also be used in Christmas lights. One might not think that December is the best time of year to utilize solar energy, but I suppose Christmas lights don’t require too much voltage. Since solar powered Christmas lights are not hard to find.

Solar spotlights and floodlights are used in landscaping, among other things. These are used to set out and highlight the best features of a garden or landscape, and again, no wiring required means they are much easier to install than electrical lights. Not to mention cleaner and cheaper.

Again, with solar powered lights, one disadvantage can be the fact that they only stay on for as long as their stored solar electricity permits. In most cases, however, they should last throughout the night if they are receiving sufficient solar energy during the day. You could run into trouble if they are placed in a shady area or if you live in a cloudy climate. They will probably still work, but not as well. Snow can also block sunlight when it covers any photovoltaic surface. But solar lights are often designed in such a way as to let snow slide off of them more easily.

There are plenty of other uses for solar lighting. And they aren’t all for the home owner.

Street lights can be run with solar power. It will be interesting to see how that concept develops, as the world turns its attention more and more toward clean alternative energy solutions. Arguably, it would be dangerous if street lights went out early on days when their solar energy wasn’t sufficient.

But a simple solution would be to use a hybrid system, with a backup battery, a backup power generator, or the like. That way, if the energy from the sun weren’t sufficient one day, the lights would continue to shine nevertheless.

Anna
http://www.articlesbase.com/landscaping-articles/solar-lighting-715728.html

Having an independent power-supply doesn’t have to be that expensive or complicated task anymore, simply because “Make Solar Power Electric” System enable you to do that at minimal cost and effort. The first impression may not reveal that, but this technique can be implemented quite easily by any novice user. Follow this report in order to know more why any of us should use it a.s.a.p.

Some basics

If you want to have such “Make Solar Power Electric” System all you need to do is following one of these ’secret’ guides available on the Web that can teach you how to professionally assemble Solar-Panels. It may sound obvious, but be sure to choose the right guide; make sure it provides clear information including videos, diagrams, and support. Well, here are some key-advantages and tips that can help you to know a little more about this topic.

Main advantages

Finally, when looking for the bottom-line, we easily identify the following benefits:

* Enables us to get an extra income by quickly providing such sys. for others.
* It is now amazingly affordable like never before.
* It is portable and you can take it with you (camping for example).
* Requires no more than a weekend to be installed.
* Made of simple parts/tools found at any local hardware store.

Tip

Use high quality materials – you want your unit to hold for many years ahead, don’t try to save a few dollars here and there and after a few months watch how everything falls apart.

On the bottom line

The reason that turned it extremely effective is the fact that “Make Solar Power Electric” System enables any household to successfully ‘cut’ on their elect. expenses by 80%, at minimal costs, and with excellent results. If we go a little further, it wouldn’t be that hard to discover other benefits provided by this special invention, simply because it is about to change the entire industry forever. Now that we understand how it works the best tip would be to test it as this is the most recommended way that truly enables you to explore the advantages mentioned in this article.

Jason Gilford
http://www.articlesbase.com/diy-articles/quotmake-solar-power-electricquot-system–it-works-period-720182.html

The most innovative water pumping system that can be of use to many people is the solar water pump. Its attributes make it a product of interest ton homeowners, agricultural specialists, farmers, industrial workers, and stewater management employees alike.

An easy to use pump, the solar water pump has become quite popular in many areas of the world. It is especially handy in any area where there is no electricity, or during a power outage. They have been used for home solar water heating systems, for crop irrigation, and to pump water from lake to livestock. Some small villages are using solar water pumps to provide water for everyone who lives in their area.

Think of the potential that solar powered pumps have! No more use of electricity to run them, with the resultant costs. Farmers all across the globe are already aking advantage of the solar powered pumps. Agriculture is taking a hard look at their successes so as to see how these pumps can be put to use elsewhere. This pumping system could work in a small town that has never before had electricity, and give its residents a chance to use some basic farm equipment that they have never been able to have before.

Wastewater management personnel are very curious about how well the solar powered pumps would work for their needs. Submersible wastewater pumps are generally what is used to deal with wastewater. If a company who dealt withsolar pumps was able to come up with a solar powered submersible wastewater pump that was large enough to be used in a municipal setting, companies from everywhere would want to have first chance at buying one. Can you imagine the savings in electrical costs for the businesses and industries that were able to take advantage of the solar pumps to do what electrical pumps are doing for them now?

Solar pump substitutes would more than likely make every lagoon pump builder who ever existed rather sad, as he could well be out of a job if when this happens. But, if he or she were at all interested in technology and progress, they would want to check out the solar lagoon pump Industry would endorse the use of the solar inventions hands down if they could be assured that they would work as flawlessly as the electrical pumps they would be replacing.

What would happen if the sun didn’t shine for a week? How would the solar pumps be able to do their job? There have been steps taken in the solar cell world to make sure this question can be answered. Two ways to store extra energy from the sun that was not needed by the pumps at the time it was taken in by the solar cells have been suggested. One is the use of batteries. The other is having your home or business set up to use electricity occasionally – and to sell the solar electricity that you do not use back to the power company. Whether this happens or not in the future remains to be seen. Research is still being done on solar power and a way to make it feasible for everyone to use. Perhaps in just a few years, you can order your own innovative custom pump system that runs on solar power.

canfieldcustompumps
http://www.articlesbase.com/business-opportunities-articles/innovative-pumping-system-554246.html

You can convert your home into solar power. By using solar system to generate electricity does make your home stand out. Solar energy or renewable energy can help you to save your electricity cost by 60% annually. A single house with 2 solar systems is sufficient for daily power usage. But the problem is a solar power system cost more than $1000. In this article I will show you the way of how you can get a home-made solar system for less than $200.

Earth 4 Energy is a website which offers a web-based program teaches how to build a home-made renewable energy generator. A solar power is enough to produce electricity for 3 heaters. It is also depend on the size of the solar plate. Each house should need at least a 2 kilowatt solar power system. The exceeding of electricity which isn’t use can be sold to a local power utility company.

2 meters are required to record the solar power which being used and another to record how much electricity did the solar system generated. As a result the electricity cost is less than $10 per month which reduces the utility expense by 60%. So you won’t have to worry about how much you have to pay for the bill. A solar system not only helps to keep the environment green but save a lot of money for you. As mentioned earlier, a solar system is costly. Earth 4 Energy is a D.I.Y. home-made solar system the program show you how to build a solar power device for less than $200. In fact you can buy parts from your local store or on the internet.

The program offers an instruction manual and videos show you how to build the system in detail. The process is explained in basic steps. The program is designed for people who have no basic knowledge about renewable power system and does not based on technical content. An experienced person can use the program for new ideas and tweak their skills. Earth 4 Energy offers a cost-effective way to build home-made renewable energy system for every household.

Let me show you how to successfully create a solar system for less than $200

Jonathan Valentine
http://www.articlesbase.com/environment-articles/earth-4-energy-review-can-earth-for-energy-really-convert-your-home-to-solar-power-692579.html

Solar panels hold a wealth of benefits, both for individuals and for the world at large. Economically, solar panels promise to lower the cost of electrical power. Environmentally, solar panels can give us cleaner power, sustainable power that will not require further damage to the environment. Solar power can reach remote areas. It can carry education, or urgently needed medical information.

The effects of clouds on a solar panel, though, might diminish those and other promising benefits.

The effects of clouds on a solar panel might make it far less efficient in certain parts of the world and at certain seasons.

For that reason, people who are considering solar panels for their homes are often heard to ask: will clouds affect my solar panels?

Will Clouds Affect My Solar Panels?

Clouds do affect solar panels. The amount of power your solar panels can produce is directly dependent on the level of light they receive.

In full, bright sunlight, solar panels receive maximum levels of light. During those “peak” sunlight hours, your solar panels will produce power at their maximum capacity.

When clouds cover the sun, light levels are reduced. This does not shut down power production, however. If there is enough light to cast a shadow, in spite of the clouds, your solar panels should operate at about half of their full capacity. Thicker cloud cover will reduce operations further. Eventually, with heavy cloud cover, solar panels will produce very little useful power.

The Good News!

The effects of clouds on a solar panel can be surprising good, however. Incredibly, your solar panels will put out their ultimate amount of peak power during cloudy weather!

As the sun moves into a hole between the clouds, your solar panels will see something wonderful. They will see full direct sunlight “plus” reflected light from the clouds! They will drink in more energy than they could on a cloudless day!

The effects of clouds on a solar panel could then produce peaks at or above 50 percent more than its direct-sun output!

Meeting the Challenge

There are ways to meet the cloud challenge.

1. If you often have clouds in the afternoon, but mornings are clear, aim your solar panels slightly toward the east.

2. Be sure you use a large enough battery system to maximize the amount of power stored for use when the clouds arrive.

3. Make sure your controller has plenty of headroom over the rated panel output power so that it can absorb the surges when the sun reflects off the clouds.

Those tricks and more are practiced in cloudy regions of the world where people have sprinted far ahead of the United States in their use of solar panel energy.

Effects of Clouds on a Solar Panel in Germany

Germany is typically a very cloudy country. Read about the climate of Germany, and you will find that it is “temperate and marine; cool, cloudy, wet winters and summers; occasional warm mountain (foehn) wind” according to Nation Master’s website.

In spite of its cloudy climate, though, Germany is by far the world’s biggest user of solar panels. If you lived in Germany, you could sell back to the main power grid all of the excess electricity produced by your solar panels. Why would I even care in such a cloudy climate? If clouds affect my solar panels too much, I would not worry about selling back to the main grid.

In 2006, Germany opened the largest solar park in the world. Germany also has Europe’s most modern solar housing project – a solar village of 50 solar houses that produce more energy than they use!

Will clouds affect my solar panels? Even if I lived in Germany, the effect would not be enough to forego solar power.

Tip: There are few places that are so consistently cloudy that solar power is out of the question. Improvements are being made constantly, and even solar panels small enough to fold into a briefcase can produce helpful amounts of power.

Anna Hart
http://www.articlesbase.com/computers-articles/effects-of-clouds-on-a-solar-panel-136546.html

Technology keeps bringing surprising solutions – “How To: Solar Power Electric” System truly enables you to construct an independent in-house power-supply with your own hands. Very quickly you’ll find out that this technique can be easily duplicated and used for virtually unlimited applications. Need more information? start reading this article and hear more and understand how it can help you.

Some basics

The first step you need to take with this “How To: Solar Power Electric” System is learning how to professionally assemble Solar-Cells by using one of these recommended step-by-step guides. Although many of these guides offer the same thing, it is necessary to choose the right one; check whether it offers the following: clear information, detailed diagrams, video tutorials, and technical support. This way or another, here are several tips & benefits that can help you out.

Main advantages

Undoubtedly most of us can find this solution highly effective:

* Made of simple parts/tools found at any local hardware store.
* It is portable and you can take it with you (camping for example).
* Knowing that we are doing our part to conserve the planet.
* Helps on reducing the amounts of carbon dioxide in the air.
* Enables us to get an extra income by quickly providing such sys. for others.

Tip to go

Always prefer to place the unit on a roof or on other high and isolated area for maximum sunlight exposure of course, but also in order to keep it safe and secure.

Summarizing this article

It isn’t just about saving thousands each year; this powerful “How To: Solar Power Electric” System enables us to preserve our planet. It would be quite easy to find other great advantages provided by this unique ‘machine’, simply because it is innovative. It is advised to simply get it in order for you to enjoy the benefits that it offers.

Jason Gilford
http://www.articlesbase.com/diy-articles/quothow-to-solar-power-electricquot-system–start-right-here-718874.html

Renewable energy

 

Renewable energy sources worldwide at the end of 2006.

Renewable energy is energy generated from natural resources—such as sunlight, wind, rain, tides, and geothermal heat — which are renewable (naturally replenished). In 2006, about 18% of global final energy consumption came from renewables, with 13% coming from traditional biomass, such as wood-burning.Hydroelectricity was the next largest renewable source, providing 3% (15% of global electricity generaiton), followed by solar hot water /heating, which contributed 1.3%. Modern technologies, such as geothermal energy, wind power, solar power and ocean energy together provided some 0.8% of final energy consumption.

Climate change concerns coupled with high oil prices, peak oil and increasing government support are driving increasing renewable energy legislation, incentives and commercialization.European Union leaders reached an agreement in principle in March 2007 that 20 percent of their nations’ energy should be produced from renewable fuels by 2020, as part of its drive to cut emissions of carbon dioxide, blamed in part for global warming. Investment capital flowing into renewable energy climbed from $80 billion in 2005 to a record $100 billion in 2006.

In responce to the G8’s call on the IEA for “guidance on how to achieve a clean, clever and competitive energy future”, the IEA reported that the replacement of current technology with renewable energy could help reduce CO2 emmisions by 50% by 2050, which they claim is of crucial importance because current policies are not sustainable.

Wind power is growing at the rate of 30 percent annually, with a worldwide installed capacity of over 100 GW, and is widely used in several European countries and the United States. The manufacturing output of the photovoltaics industry reached more than 2,000 MW in 2006, and photovoltaic (PV) power stations are particularly popular in Germany. Solar thermal power stations operate in the USA and Spain, and the largest of these is the 354 MW SEGS power plant in the Mojave Desert. The world’s largest geothermal power installation is The Gevsers in California, with a rated capacity of 750 MW. Brazil has one of the largest renewable energy programs in the world, involving production of ethanol fuel from sugar cane, and ethanol now provides 18 percent of the country’s automotive fuel. Ethanol fuel is also widely available in the USA.

While there are many large-scale renewable energy projects and production, renewable technologies are also suited to small off-grid applications, sometimes in rural and remote areas, where energy is often crucial in human development. Kenya has the world’s highest household solar ownership rate with roughly 30,000 small (20–100 watt) solar power systems sold per year.

Some renewable energy technologies are criticised for being intermittent or unsightly, yet the market is growing for many forms of renewable energy.

Main renewable energy technologies

Three energy sources

The majority of renewable energy technologies are directly or indirectly powered by the sun. The Earth-Atmosphere system is in equilibrium such that heat radiation into space is equal to incoming solar radiation, the resulting level of energy within the Earth-Atmosphere system can roughly be described as the Earth’s “climate.” The hydrosphere (water) absorbs a major fraction of the incoming radiation. Most radiation is absorbed at low latitudes around the equator, but this energy is dissipated around the globe in the form of winds and ocean currents. Wave motion may play a role in the process of transferring mechanical energy between the atmosphere and the ocean through wind stress. Solar energy is also responsible for the distribution of precipitation which is tapped by hydroelectric projects, and for the growth of plants used to create biofuels.

Renewable energy flows involve natural phenomena such as sunlight, wind, tides and geothermal heat, as the International Energy Agency explains:

“Renewable energy is derived from natural processes that are replenished constantly. In its various forms, it derives directly from the sun, or from heat generated deep within the earth. Included in the definition is electricity and heat generated from solar, wind, ocean, hydropower, biomass, geothermal resources, and biofuels and hydrogen derived from renewable resources.”

Each of these sources has unique characteristics which influence how and where they are used.

Wind power

 Vestas V80 wind turbines

Airflows can be used to run wind turbines. Modern wind turbines range from around 600 kW to 5 MW of rated power, although turbines with rated output of 1.5–3 MW have become the most common for commercial use; the power output of a turbine is a function of the cube of the wind speed, so as wind speed increases, power output increases dramatically. Areas where winds are stronger and more constant, such as offshore and high altitude sites, are preferred locations for wind farms.

Since wind speed is not constant, a wind farm’s annual energy production is never as much as the sum of the generator nameplate ratings multiplied by the total hours in a year. The ratio of actual productivity in a year to this theoretical maximum is called the capacity factor. Typical capacity factors are 20-40%, with values at the upper end of the range in particularly favourable sites. For example, a 1 megawatt turbine with a capacity factor of 35% will not produce 8,760 megawatt-hours in a year, but only 0.35×24x365 = 3,066 MWh, averaging to 0.35 MW. Online data is available for some locations and the capacity factor can be calculated from the yearly output.

Globally, the long-term technical potential of wind energy is believed to be five times total current global energy production, or 40 times current electricity demand. This could require large amounts of land to be used for wind turbines, particularly in areas of higher wind resources. Offshore resources experience mean wind speeds of ~90% greater than that of land, so offshore resources could contribute substantially more energy. This number could also increase with higher altitude ground-based or airborne wind turbines.

Wind power is renewable and produces no greenhouse gases during operation, such as carbon dioxdie and methane.

Water power

Energy in water (in the form of kinetic energy, temperature differences or salinity gradients) can be harnessed and used. Since water is about 800 times denser than air, even a slow flowing stream of water, or moderate sea swell, can yield considerable amounts of energy.

 

One of 3 PELAMIS P-750 Ocean Wave Power engines in the harbour of Peniche/ Portugal.

There are many forms of water energy:

·         Hydroelectric energy is a term usually reserved for large-scale hydroelectric dams. Examples are the Grand Coulee Dam in Washington State and the Akosombo Dam in Ghana.

·         Micro hydro systems are hydroelectric power installations that typically produce up to 100 kW of power. They are often used in water rich areas as a Remote Area Power Supply (RAPS). There are many of these installations around the world, including several delivering around 50 kW in the Solomon Islands.

·         Damless hydro systems derive kinetic energy from rivers and oceans without using a dam.

·         Ocean energy  describes all the technologies to harness energy from the ocean and the sea:

o   Marine current power. Similar to tidal stream power, uses the kinetic energy of marine currents

o   Ocean thermal energy  conversion (OTEC) uses the temperature difference between the warmer surface of the ocean and the colder lower recesses. To this end, it employs a cyclic heat engine. OTEC has not been field-tested on a large scale.

o   Tidal power captures energy from the tides. Two different principles for generating energy from the tides are used at the moment:

o   Tidal motion in the vertical direction — Tides come in, raise water levels in a basin, and tides roll out. Around low tide, the water in the basin is discharged through a turbine, exploiting the stored potential energy.

o   Tidal motion in the horizontal direction — Or tidal stream power. Using tidal stream generators, like wind turbines but then in a tidal stream. Due to the high density of water, about eight-hundred times the density of air, tidal currents can have a lot of kinetic energy. Several commercial prototypes have been build, and more are in development.

·         Wave power  uses the energy in waves. Wave power machines usually take the form of floating or neutrally buoyant structures which move relative to one another or to a fixed point. Wave power has now reached commercialization.

·         Saline gradient power,  or osmotic power, is the energy retrieved from the difference in the salt concentration between seawater and river water. Reverse electrodialysis (RED), and Pressure retarded osmosis (PRO) is in research and testing phase.

·         Deep lake water cooling,  although not technically an energy generation method, can save a lot of energy in summer. It uses submerged pipes as a heat sink for climate control systems. Lake-bottom water is a year-round local constant of about 4 °C.

Solar energy use

 

Monocrystalline solar cell

In this context, “solar energy” refers to energy that is collected from sunlight. Solar energy can be applied in many ways, including to:

•           Generate electricity by heating trapped air which rotates turbines in a Solar updraft tower.

•           Generate electricity in geosynchronous orbit using solar power satellites.

•           Generate electricity using photovoltaic solar cells.

•           Generate electricity using concentrated solar power.

•           Generate hydrogen using photoelectrochemical cells.

•           Heat and cool air through use of solar chimneys.

•           Heat buildings, directly, through passive solar building design.

•           Heat foodstuffs, through solar ovens.

•           Heat water or air for domestic hot water and space heating needs using solar-thermal panels.

•           Solar air conditioning

Biofuel

Plants use photosynthesis to grow and produce biomass. Also known as biomatter, biomass can be used directly as fuel or to produce liquid biofuel. Agriculturally produced biomass fuels, such as biodiesel, ethanol and bagasse (often a by-product of sugar cane cultivation) can be burned in internal combustion engines or boilers. Typically biofuel is burned to release its stored chemical energy. Research into more efficient methods of converting biofuels and other fuels into electricity utilizing fuel cells is an area of very active work.

Liquid biofuel

 

Information on pump, California.

Liquid biofuel is usually either a bioalcohol such as ethanol fuel or a bio-oil such as biodiesel and straight vegetable oil. Biodiesel can be used in modern diesel vehicles with little or no modification to the engine and can be made from waste and virgin vegetable and animal oil and fats (lipids). Virgin vegetable oils can be used in modified diesel engines. In fact the Diesel engine was originally designed to run on vegetable oil rather than fossil fuel. A major benefit of biodiesel is lower emissions. The use of biodiesel reduces emission of carbon monoxide and other hydrocarbons by 20 to 40%.

In some areas corn, cornstalks, sugarbeets, sugar cane, and switchgrasses are grown specifically to produce ethanol (also known as grain alcohol) a liquid which can be used in internal combustion engines and fuel cells. Ethanol is being phased into the current energy infrastructure. E85 is a fuel composed of 85% ethanol and 15% gasoline that is sold to consumers. Biobutanol is being developed as an alternative to bioethanol. There is growing international criticism about biofuels from food crops with respect to issues such as food security, environmental impacts (deforestation) and energy balance.

Solid biomass

 

Sugar cane  residue can be used as a biofuel

Solid biomass is mostly commonly usually used directly as a combustible fuel, producing 10-20 MJ/kg of heat.

Its forms and sources include wood fuel,  the biogenic portion of municipal solid waste, or the unused portion of field crops. Field crops may or may not be grown intentionally as an energy crop,  and the remaining plant byproduct used as a fuel. Most types of biomass contain energy. Even cow manure still contains two-thirds of the original energy consumed by the cow. Energy harvesting via a bioreactor is a cost-effective solution to the waste disposal issues faced by the dairy farmer, and can produce enough biogas to run a farm.

With current technology, it is not ideally suited for use as a transportation fuel. Most transportation vehicles require power sources with high power density, such as that provided by internal combustion engines. These engines generally require clean burning fuels, which are generally in liquid form, and to a lesser extent, compressed gaseous phase. Liquids are more portable because they have high energy density, and they can be pumped, which makes handling easier. This is why most transportation fuels are liquids.

Non-transportation applications can usually tolerate the low power-density of external combustion engines, that can run directly on less-expensive solid biomass fuel, for combined heat and power. One type of biomass is wood, which has been used for millennia in varying quantities, and more recently is finding increased use. Two billion people currently cook every day, and heat their homes in the winter by burning biomass, which is a major contributor to man-made climate change global warming. The black soot that is being carried from Asia to polar ice caps is causing them to melt faster in the summer. In the 19th century, wood-fired steam engines were common, contributing significantly to industrial revolution unhealthy air pollution. Coal is a form of biomass that has been compressed over millennia to produce a non-renewable, highly-polluting fossil fuel.

Wood and its byproducts can now be converted through process such as gasification into biofuels such as woodgas, biogas,  methanol or ethanol fuel; although further development may be required to make these methods affordable and practical. Sugar cane residue, wheat chaff, com cobs and other plant matter can be, and are, burned quite successfully. The net carbon dioxide emissions that are added to the atmosphere by this process are only from the fossil fuel that was consumed to plant, fertilize, harvest and transport the biomass.

Processes to harvest biomass from short-rotation poplars and willows, and perennial grasses such as switchgrass, phalaris, and miscanthus, require less frequent cultivation and less nitrogen than from typical annual crops. Pelletizing miscanthus and burning it to generate electricity is being studied and may be economically viable.

Biogas

Biogas can easily be produced from current waste streams, such as: paper production, sugar production, sewage, animal waste and so forth. These various waste streams have to be slurried together and allowed to naturally ferment, producing methane gas. This can be done by converting current sewage plants into biogas plants. When a biogas plant has extracted all the methane it can, the remains are sometimes better suitable as fertilizer than the original biomass.

Alternatively biogas can be produced via advanced waste processing systems such as mechanical biological treatment. These systems recover the recyclable elements of household waste and process the biodegradable fraction in anaerobic digesters.

Renewable natural gas is a biogas which has been upgraded to a quality similar to natural gas. By upgrading the quality to that of natural gas, it becomes possible to distribute the gas to the mass market via gas grid.

Geothermal energy

 

Krafla Geothermal Station in northeast Iceland

Geothermal energy is energy obtained by tapping the heat of the earth itself, usually from kilometers deep into the Earth’s crust. It is expensive to build a power station but operating costs are low resulting in low energy costs for suitable sites. Ultimately, this energy derives from heat in the Earth’s core. The government of Iceland states: “It should be stressed that the geothermal resource is not strictly renewable in the same sense as the hydro resource.” It estimates that Iceland’s geothermal energy could provide 1700 MW for over 100 years, compared to the current production of 140 MW. Radioactive elements in the earth’s crust continuously decay, replenishing the heat. The International Energy Agency classifies geothermal power as renewable.

Three types of power plants are used to generate power from geothermal energy: dry steam, flash, and binary. Dry steam plants take steam out of fractures in the ground and use it to directly drive a turbine that spins a generator. Flash plants take hot water, usually at temperatures over 200 °C, out of the ground, and allows it to boil as it rises to the surface then separates the steam phase in steam/water separators and then runs the steam through a turbine. In binary plants, the hot water flows through heat exchangers, boiling an organic fluid that spins the turbine. The condensed steam and remaining geothermal fluid from all three types of plants are injected back into the hot rock to pick up more heat.

The geothermal energy from the core of the Earth is closer to the surface in some areas than in others. Where hot underground steam or water can be tapped and brought to the surface it may be used to generate electricity. Such geothermal power sources exist in certain geologically unstable parts of the world such as Chile, Iceland, New Zealand, United States, the Philippines and Italy. The two most prominent areas for this in the United States are in the Yellowstone basin and in northern California. Iceland produced 170 MW geothermal power and heated 86% of all houses in the year 2000 through geothermal energy. Some 8000 MW of capacity is operational in total.

There is also the potential to generate geothermal energy from hot dry rocks. Holes at least 3 km deep are drilled into the earth. Some of these holes pump water into the earth, while other holes pump hot water out. The heat resource consists of hot underground radiogenic granite rocks, which heat up when there is enough sediment between the rock and the earths surface. Several companies in Australia are exploring this technology.

Renewable energy commercialization

Costs

Source                         2001 energy costs                              Potential future energy cost

Electricity

Wind                           4–8 ¢/kWh                                                      3–10 ¢/kWh

Solar photovoltaic       25–160 ¢/kWh                                                            5–25 ¢/kWh

Solar thermal               12–34 ¢/kWh                                                  4–20 ¢/kWh

Large hydropower      2–10 ¢/kWh                                                    2–10 ¢/kWh

Small hydropower       2–12 ¢/kWh                                                    2–10 ¢/kWh

Geothermal                 2–10 ¢/kWh                                                    1–8 ¢/kWh

Biomass                       3–12 ¢/kWh                                                    4–10 ¢/kWh

Coal (comparison)       4 ¢/kWh         

Heat

Geothermal Heat         0.5–5 ¢/kWh                                                   0.5–5 ¢/kWh

Biomass — heat          1–6 ¢/kWh                                                      1–5 ¢/kWh

Low Temp Solar Heat 2–25 ¢/kWh                                                    2–10 ¢/kWh

All costs are in 2001 US$-cent per kilowatt-hour.

New generation of solar thermal plants

The 11 megawatt PS10 solar power tower in Spain produces electricity from the sun using 624 large movable mirrors called heliostats.

Aerial view of one of the SEGS plants.

Since 2004 there has been renewed interest in solar thermal power stations and two plants were completed during 2006/2007: the 64 MW Nevada Solar One and the 11 MW PS10 solar power tower in Spain. Three 50 MW trough plants were under construction in Spain at the end of 2007 with 10 additional 50 MW plants planned. In the United States, utilities in California and Florida have announced plans (or contracted for) at least eight new projects totaling more than 2,000 MW.

In developing countries, three world bank projects for integrated CSP/combined-cycle gas-turbine power plants in Egypt, Mexico, and Morocco were approved during 2006/2007.

There are several solar thermal power plant in the Mojave Desert which supply power to the electricity grid. Solar Energy Generating Systems (SEGS) is the name given to nine solar power plants in the Mojave Desert which were built in the 1980s. These plants have a combined capacity of 354 MW making them the largest solar power installation in the world.

World’s largest photovoltaic power plants

Several large photovoltaic power plants have been completed in Spain in 2008: the Parque Fotovoltaico Olmedilla de Alarcon (60 MW), Parque Solar Merida/Don Alvaro (30 MW), Planta solar Fuente Alamo (26 MW), Planta fotovoltaica de Lucainena de las Torres (23.2 MW), Parque Fotovoltaico Abertura Solar (23.1 MW), Parque Solar Hoya de Los Vincentes (23 MW), the Solarpark Calveron (21 MW), and the Planta Solar La Magascona (20 MW).

First Solar 40 MW PV Array installed by JUWI Group in Waldpolenz, Germany

Waldpolenz Solar Park, which will be the world’s largest thin-flim photovoltaic (PV) power system, is being built at a former military air base to the east of Leipzig in Germany. The power plant will be a 40-megawatt solar power system using state-of-the-art thin film technology, and should be finished by the end of 2009. 550,000 First Solar thin-film modules will be used, which will supply 40,000 MWh of electricity per year.

Topaz Solar Farm is a proposed 550 MW solar photovoltaic power plant which is to be built northwest of California Valley in the USA at a cost of over $1 billion. Built on 9.5 square miles (25 km2) of ranchland, the project would utilize thin-film PV panels designed and manufactured by OptiSolar in Hayward and Sacramento. The project would deliver approximately 1,100 gigawatt-hours (GWh) annually of renewable energy. The project is expected to begin construction in 2010, begin power delivery in 2011, and be fully operational by 2013.

High Plains Ranch  is a proposed 250 MW solar photovoltaic power plant which is to be built by Sun Power in the Carrizo Plain, northwest of California Valley.

However, when it comes to renewable energy systems and PV, it is not just large systems that matter. Building-Integrated Photovoltaics or “onsite” PV systems have the advantage of being matched to end use energy needs in terms of scale. So the energy is supplied close to where it is needed.

Environmental and social considerations

While most renewable energy sources do not produce pollution directly, the materials, industrial processes, and construction equipment used to create them may generate waste and pollution. Some renewable energy systems actually create environmental problems. For instance, older wind turbines can be hazardous to flying birds.

Land area required

Another environmental issue, particularly with biomass and biofuels, is the large amount of land required to harvest energy, which otherwise could be used for other purposes or left as undeveloped land. However, it should be pointed out that these fuels may reduce the need for harvesting non-renewable energy sources, such as vast strip-mined areas and slag mountains for coal, safety zones around nuclear plants, and hundreds of square miles being strip-mined for oil sands. These responses, however, do not account for the extremely high biodiversity and endemism of land used for ethanol crops, particularly sugar cane.

In the U.S., crops grown for biofuels are the most land- and water-intensive of the renewable energy sources. In 2005, about 12% of the nation’s corn crop (covering 11 million acres (45,000 km²) of farmland) was used to produce four billion gallons of ethanol—which equates to about 2% of annual U.S. gasoline consumption. For biofuels to make a much larger contribution to the energy economy, the industry will have to accelerate the development of new feedstocks, agricultural practices, and technologies that are more land and water efficient. Already, the efficiency of biofuels production has increased significantly and there are new methods to boost biofuel production.

Hydroelectric dams

The major advantage of hydroelectric systems is the elimination of the cost of fuel. Other advantages include longer life than fuel-fired generation, low operating costs, and the provision of facilities for water sports. Operation of pumped-storage plants improves the daily load factor of the generation system. Overall, hydroelectric power can be far less expensive than electricity generated from fossil fuels or nuclear energy, and areas with abundant hydroelectric power attract industry.

However, there are several major disadvantages of hydroelectric systems. These include: dislocation of people living where the reservoirs are planned, release of significant amounts of carbon dioxide at construction and flooding of the reservoir, disruption of aquatic ecosystems and birdlife, adverse impacts on the river environment, potential risks of sabotage and terrorism, and in rare cases catastrophic failure of the dam wall.

Hydroelectric power is now more difficult to site in developed nations because most major sites within these nations are either already being exploited or may be unavailable for other reasons such as environmental considerations.

Wind farms

Wind power  is one of the most environmentally friendly sources of renewable energy

A wind farm, when installed on agricultural land, has one of the lowest environmental impacts of all energy sources:

•           It occupies less land area per kilowatt-hour (kWh) of electricity generated than any other energy conversion system, apart from rooftop solar energy, and is compatible with grazing and crops.

•           It generates the energy used in its construction in just 3 months of operation, yet its operational lifetime is 20–25 years.

•           Greenhouse gas emissions and air pollution produced by its construction are tiny and declining. There are no emissions or pollution produced by its operation.

•           In substituting for base-load coal power, wind power produces a net decrease in greenhouse gas emissions and air pollution, and a net increase in biodiversity.

•           Modern wind turbines are almost silent and rotate so slowly (in terms of revolutions per minute) that they are rarely a hazard to birds.

Studies of birds and offshore wind farms in Europe have found that there are very few bird collisions. Several offshore wind sites in Europe have been in areas heavily used by seabirds. Improvements in wind turbine design, including a much slower rate of rotation of the blades and a smooth tower base instead of perchable lattice towers, have helped reduce bird mortality at wind farms around the world. However older smaller wind turbines may be hazardous to flying birds. Birds are severely impacted by fossil fuel energy; examples include birds dying from exposure to oil spills, habitat loss from acid rain and mountaintop removal coal mining, and mercury poisoning.

Other issues

Sustainability

Renewable energy sources are generally sustainable in the sense that they cannot “run out” as well as in the sense that their environmental and social impacts are generally more benign than those of fossil. However, both biomass and geothermal energy require wise management if they are to be used in a sustainable manner. For all of the other renewables, almost any realistic rate of use would be unlikely to approach their rate of replenishment by nature.

Transmission

If renewable and distribution generation were to become widespread, electric power transmission and electricity distribution systems might no longer be the main distributors of electrical energy but would operate to balance the electricity needs of local communities. Those with surplus energy would sell to areas needing “top ups”. That is, network operation would require a shift from ‘passive management’ — where generators are hooked up and the system is operated to get electricity ‘downstream’ to the consumer — to ‘active management’, wherein generators are spread across a network and inputs and outputs need to be constantly monitored to ensure proper balancing occurs within the system. Some governments and regulators are moving to address this, though much remains to be done. One potential solution is the increased use of active management of electricity transmission and distribution networks. This will require significant changes in the way that such networks are operated.

However, on a smaller scale, use of renewable energy produced on site reduces burdens on electricity distribution systems. Current systems, while rarely economically efficient, have shown that an average household with an appropriately-sized solar panel array and energy storage system needs electricity from outside sources for only a few hours per week. By matching electricity supply to end-use needs, advocates of renewable energy and the soft energy path believe electricity systems will become smaller and easier to manage, rather than the opposite.

Controversy over nuclear power as a renewable energy source

In 1983, physicist Bernard Cohen proposed that uranium is effectively inexhaustible, and could therefore be considered a renewable source of energy. He claims that fast breeder reactors, fueled by uranium extracted from seawater, could supply energy at least as long as the sun’s expected remaining lifespan of five billion years. Nuclear energy has also been referred to as “renewable” by the politicians George W. Bush, Charlie Crist,  and David Sainsbury.

Inclusion under the “renewable energy” classification could render nuclear power projects eligible for development aid under various jurisdictions. However, it has not been established that nuclear energy is inexhaustible, and issues such as peak uranium and uranium depletion are ongoing debates. No legislative body has yet included nuclear energy under any legal definition of “renewable energy sources” for provision of development support. Similarly, statutory and scientific definitions of renewable energies usually exclude nuclear energy. Commonly sourced definitions of renewable energy sources often omit or explicitly exclude nuclear energy sources as examples.Nuclear fission is not regarded as renewable by the U.S. DOE on the website “What is Energy?”

There are also environmental concerns over nuclear power, including the dangerous environmental hazards of nuclear waste and concerns that development of new plants cannot happen quickly enough to reduce CO2 emissions, such that nuclear energy is neither efficient nor effective in cutting CO2 emissions.

ADVANTAGES AND DISADVANTAGES OF RENEWABLE ENERGY:

There are many energy sources today that are extremely limited in supply. Some of these sources include oil, natural gas, and coal. It is a matter of time before they will be exhausted.

Estimates are that they can only meet our energy demands for another fifty to seventy years. So in an effort to find alternative forms of energy, the world has turned to renewable energy sources as the solution. There are many advantages and disadvantages to this.

Renewable energy sources consist of solar, hydro, wind, geothermal, ocean and biomass. The most common advantage of each is that they are renewable and cannot be depleted. They are a clean energy, as they don’t pollute the air, and they don’t contribute to global warming or greenhouse effects. Since their sources are natural the cost of operations is reduced and they also require less maintenance on their plants. A common disadvantage to all is that it is difficult to produce the large quantities of electricity their counterpart the fossil fuels are able to. Since they are also new technologies, the cost of initiating them is high.

Solar energy makes use of the sun’s energy. It is advantageous because the systems can fit into existing buildings and it does not affect land use. But since the area of the collectors is large, more materials are required. Solar radiation is also controlled by geography. And it is limited to daytime hours and non-cloudy days.

Wind energy uses the power of the wind to produce electricity. Although it is the largest job producer, it is reliant on strong winds. Wind turbines are large and, although you can use the area under them for farming, many consider them unattractive looking. They are also very noisy to operate. In addition, they threaten the wild bird population.

Hydroelectric energy uses water to produce power. This is the most reliable of all the renewable energy sources. On the down side, it affects ecology and causes downstream problems. The decay of vegetation along the riverbed can cause the buildup of methane. Methane is a contributing gas to greenhouse effect. Dams can also alter the natural river flow and affect wildlife. Colder, oxygen poor water can be released into the river, killing fish. And the release of water from the dam can cause flooding.

Geothermal energy uses steam from the Earth’s ground to generate power. It uses smaller land areas than other power plants. They can run 24 hours per day, every day of the year. Disadvantages are that it is very site specific and, along with the heat from the Earth, it can also bring up toxic chemicals when obtaining the steam. Drilling geothermal reservoirs and finding them can be an expensive task.

Biomass electricity is produced through the energies from wood, agricultural and municipal waste. It helps save on landfill waste but transportation can be expensive and ecological diversity of land may be affected. In addition, its process needs to be made simpler.

Ocean energy is a clean and abundant energy form. It does, however, have high costs. Ocean thermal energy also requires close to a forty degree Fahrenheit difference in water temperature year round. In addition, construction and laying pipes can cause damage to the ecosystem.

There are many advantages to the use of renewable energy sources. There are also some disadvantages. The fact is energy demands will continue to increase. Through research and development, as well as, new technologies, the hope is many of the disadvantages of renewable sources of energy can be eliminated and we can successfully incorporate it into our power supplies.

                                                 

N.Sankari
http://www.articlesbase.com/electronics-articles/renewable-energy-707358.html

Installing a solar power system isn’t as hard as many people may think, however we have made a few solar panels so far and this article is an overview of how to do it properly at the lowest cost. Below are some of the things you need to focus on if you’re looking to make your own solar panel all by yourself.

If you’re a novice in this field you might end up being overwhelmed by all the information that lays everywhere on the Internet. You will need a solid manual that teaches you step-by-step how to put a solar system together without failing, in fact some guides will give you the information you need but aren’t as detailed as they should be. Look for one that contains illustrated diagrams that are easy to comprehend. Some proven records are essential as well as they only reflect the fact that even a DIY novice is able to build their own solar panel with ease without having to get any headaches or even worse give up.

Long story short — lets have a look at what you need to know even before deciding to install a fully functional solar power system that will suit your needs:

1. Understanding how a solar power system works. Even before you go about purchasing all the required parts for your DIY project you need to have a clear overall picture of how a solar power system works and what each part is supposed to do. That is why a solid DIY guide will be necessary, that you can read through to get the main idea before going to your local power parts supplier.

2. Where to buy all the necessary components. Most people might think that building a solar panel is quite costly however not anymore since all the necessary parts don’t cost you more than two hundred dollars. There’s nothing to worry about because a proper guide will not only teach you how to properly install the power system but where to get the best components you’ll need at the lowest price.

3. Installing the power system. This part can only be achieved by following a blueprint. (A guide that has proven to work for others). You need to look for one that has a tech support as well just in case of any troubleshooting. Seriously we were a bit skeptical when we’ve built our first solar panels but it can be done with ease even by a novice and it doesn’t take weeks either.

4. Additional components. Lastly when your system is put in place you’ll need a charge controller to check the amount of electricity that your system is generating and not only but a few storage batteries for the electricity that is not consumed. Everyone should know that a system is incomplete without these two elements (they don’t cost much either)

Now you have an overview of how to install a proper power system that can drastically reduce your energy bills. You might want to find a guide that explains every step in detail including how to generate electricity using wind turbines in the cloudy days right in your own backyard.

Installing a solar power system isn’t as hard as many people may think, however we have made a few solar panels so far and this article is an overview of how to do it properly at the lowest cost. Below are some of the things you need to focus on if you’re looking to make your own solar panel all by yourself.

If you’re a novice in this field you might end up being overwhelmed by all the information that lays everywhere on the Internet. You will need a solid manual that teaches you step-by-step how to put a solar system together without failing, in fact some guides will give you the information you need but aren’t as detailed as they should be. Look for one that contains illustrated diagrams that are easy to comprehend. Some proven records are essential as well as they only reflect the fact that even a DIY novice is able to build their own solar panel with ease without having to get any headaches or even worse give up.

Long story short — lets have a look at what you need to know even before deciding to install a fully functional solar power system that will suit your needs:

1. Understanding how a solar power system works. Even before you go about purchasing all the required parts for your DIY project you need to have a clear overall picture of how a solar power system works and what each part is supposed to do. That is why a solid DIY guide will be necessary, that you can read through to get the main idea before going to your local power parts supplier.

2. Where to buy all the necessary components. Most people might think that building a solar panel is quite costly however not anymore since all the necessary parts don’t cost you more than two hundred dollars. There’s nothing to worry about because a proper guide will not only teach you how to properly install the power system but where to get the best components you’ll need at the lowest price.

3. Installing the power system. This part can only be achieved by following a blueprint. (A guide that has proven to work for others). You need to look for one that has a tech support as well just in case of any troubleshooting. Seriously we were a bit skeptical when we’ve built our first solar panels but it can be done with ease even by a novice and it doesn’t take weeks either.

4. Additional components. Lastly when your system is put in place you’ll need a charge controller to check the amount of electricity that your system is generating and not only but a few storage batteries for the electricity that is not consumed. Everyone should know that a system is incomplete without these two elements (they don’t cost much either)

Now you have an overview of how to install a proper power system that can drastically reduce your energy bills. You might want to find a guide that explains every step in detail including how to generate electricity using wind turbines in the cloudy days right in your own backyard.

Alex