Renewable energy
Renewable energy is energy generated from natural resources—such as sunlight wind, rain, tides and geothermal heat—which are renewable (naturally replenished). Renewable energy technologies include solar power, wind power, hydroelectricity, micro hydro, biomass and biofuels.
In 2006, about 18% of global final energy consumption came from renewables, with 13% coming from traditional biomass, such as wood-burning. Hydropower was the next largest renewable source, providing 3%, followed by hot water/heating, which contributed 1.3%. Modern technologies, such as geothermal, wind, solar, and ocean energy together provided some 0.8% of final energy consumption. The technical potential for their use is very large, exceeding all other readily available sources.
Renewable energy technologies are sometimes criticised for being intermittent or unsightly, yet the market is growing for many forms of renewable energy. 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.[8] 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 Geysers 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.
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.[ This level of investment combined with continuing double digit percentage increases each year has moved what once was considered alternative energy to mainstream. Wind was the first to provide 1% of electricity, but solar is not far behind.Some very large corporations such as BP, General Electric, Sharp, and Royal Dutch Shell are investing in the renewable energy sector
Biofuel
Bio-energy" redirects here. For the term bio-energy in the context of non-mechanist philosophy or alternative medicine, see Vitalism.
For articles on specific fuels used in vehicles, see Biogas, Bioethanol, Biobutanol, Biodiesel, Straight vegetable oil, and Wood gas generator.
Biofuel is defined as solid, liquid or gas fuel derived from recently dead biological material and is distinguished from fossil fuels, which are derived from long dead biological material. Theoretically, biofuels can be produced from any (biological) carbon source; although, the most common sources are photosynthetic plants. Various plants and plant-derived materials are used for biofuel manufacturing. Globally, biofuels are most commonly used to power vehicles and cooking stoves. Biofuel industries are expanding in Europe, Asia and the Americas.
Biofuels offer the possibility of producing energy without a net increase of carbon into the atmosphere. This is becuase the plants used in the production of the fuel removed CO2 from the atmosphere; unlike fossil fuels, which return carbon that was stored beneath the surface for millions of years back into the atmosphere. Therefore, biofuel is, in theory, more carbon neutral and less likely to increase atmospheric concentrations of greenhouse gases. (However, doubts have been raised as to whether this benefit can be achieved in practice, see below). The use of biofuels also reduces dependence on petroleum and enhances energy security.
There are two common strategies of producing biofuels. One is to grow crops high in sugar (sugar cane, sugar beet, and sweet sorghum) or starch (corn/maize), and then use yeast fermentation to produce ethyl alcohol (ethanol). The second is to grow plants that contain high amounts of vegetable oil, such as oil palm, soybean, algae, or jatropha. When these oils are heated, their viscosity is reduced, and they can be burned directly in a diesel engine, or they can be chemically processed to produce fuels such as biodiesel. Wood and its byproducts can also be converted into biofuels such as woodgas, methanol or ethanol fuel. It is also possible to make cellulosic ethanol from non-edible plant parts, but this can be difficult to accomplish economically.
Biofuels are discussed as having significant roles in a variety of international issues, including: mitigation of carbon emissions levels and oil prices, the "food vs fuel" debate, deforestation and soil erosion, impact on water resources, and energy balance and efficiency.
Biomass
Biomass refers to living and recently dead biological material that can be used as fuel or for industrial production. Most commonly, biomass refers to plant matter grown to generate electricity or produce biofuel, but it also includes plant or animal matter used for production of fibers, chemicals or heat. Biomass may also include biodegradable wastes that can be burnt as fuel. It excludes organic material which has been transformed by geological processes into substances such as coal or petroleum.
Industrial biomass can be grown from numerous types of plants, including miscanthus, switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane , and a variety of tree species, ranging from eucalyptus to oil palm (palm oil). The particular plant used is usually not very important to the end products, but it does affect the processing of the raw material. Production of biomass is a growing industry as interest in sustainable fuel sources is growing.[citation needed]
Although fossil fuels have their origin in ancient biomass, they are not considered biomass by the generally accepted definition because they contain carbon that has been "out" of the carbon cycle for a very long time. Their combustion therefore disturbs the carbon dioxide content in the atmosphere.
Plastics from biomass, like some recently developed to dissolve in seawater, are made the same way as petroleum-based plastics, are actually cheaper to manufacture and meet or exceed most performance standards. But they lack the same water resistance or longevity as conventional plastics.
Geothermal power
Geothermal power (from the Greek roots geo, meaning earth, and therm, meaning heat) is energy generated by heat stored beneath the Earth's surface, or the collection of absorbed heat derived from underground in the atmosphere and oceans. Prince Piero Ginori Conti tested the first geothermal generator on 4 July 1904, at the Larderello dry steam field in Italy. The largest group of geothermal power plants in the world is located in The Geysers, a geothermal field in California.As of 2007, geothermal power supplies less than 1% of the world's energy.
"Geothermal" can generally refer to any heat contained in the ground. This article focuses on the generation of power from naturally occurring extraordinary sources of (relatively low grade) underground heat. Information on geothermal heat pump technology and direct exchange geothermal heat pump technology can be found in separate articles on those topics, as can that on deeper and hotter hot dry rock geothermal energy
Hydroelectricity
Hydroelectricity is a form of hydropower, and is the most widely used form of renewable energy. Once a hydro complex is constructed, the project produces no direct waste, and has a considerably different level of carbon dioxide (CO2)--a greenhouse gas--output than fossil fuel powered energy plants. Hydroelectricity supplies an estimated 715,000 MWe or 19% of world electricity, (16% in 2003) accounting for over 63% of the total electricity from renewable sources in 2005.
Although large hydroelectric installations generate most of the world's hydroelectricity, small hydro schemes are particularly popular in China, which has over 50% of world small hydro capacity.
Some jurisdictions do not consider large hydro projects to be a sustainable energy source due to the human, economic and environmental impacts incurred as a result of dam construction and maintenance. Opposition considers hydropower to be an energy source of sometimes great potential when projects can be environmentally and economically effective, however they believe that that potential is currently being exploited in a way that provides neither democratic nor viable alternatives to energy needs.
Solar energy
Solar energy refers to the utilization of the radiant energy from the Sun. Solar power is used interchangeably with solar energy, but refers more specifically to the conversion of sunlight into electricity, either by photovoltaics and concentrating solar thermal devices, or by one of several experimental technologies such as thermoelectric converters, solar chimneys or solar ponds.
Solar energy and shading are important considerations in building design. Thermal mass is used to conserve the heat that sunshine delivers to all buildings. Daylighting techniques optimize the use of light in buildings. Solar water heaters heat swimming pools and provide domestic hot water. In agriculture, greenhouses expand growing seasons and pumps powered by solar cells (known as photovoltaics) provide water for grazing animals. Evaporation ponds are used to harvest salt and clean waste streams of contaminants.
Solar distillation and disinfection techniques produce potable water for millions of people worldwide. Simple applications include clotheslines and solar cookers which concentrate sunlight for cooking, drying and pasteurization. More sophisticated technologies concentrate sunlight for high-temperature material testing, metal smelting and industrial chemical production. A range of experimental solar vehicles provide ground, air and sea transportation
Tidal power
Tidal power, sometimes called tidal energy, is a form of hydropower that converts the energy of tides into electricity or other useful forms of power.
Although not yet widely used, tidal power has potential for future electricity generation. Tides are more predictable than wind energy and solar power. Historically, tide mills have been used, both in Europe and on the Atlantic coast of the USA. The earliest occurrences date from the Middle Ages, or even from Roman times.
Wave power
Wave power refers to the energy of ocean surface waves and the capture of that energy to do useful work — including electricity generation, desalination, and the pumping of water (into reservoirs). Wave power is a form of renewable energy. Though often co-mingled, wave power is distinct from the diurnal flux of tidal power and the steady gyre of ocean currents. Wave power generation is not currently a widely employed commercial technology although there have been attempts at using it since at least 1890.
The world's first commercial wave farm is based in Portugal, at the Aguçadora Wave Park, which consists of three 750 kilowatt Pelamis devices.
The north and south temperate zones have the best sites for capturing wave power. The prevailing westerlies in these zones blow strongest in winter
Wind power
Wind power is the conversion of wind energy into a useful form, such as electricity, using wind turbines. At the end of 2007, worldwide capacity of wind-powered generators was 94.1 gigawatts. Although wind produces about 1% of world-wide electricity use, it accounts for approximately 19% of electricity production in Denmark, 9% in Spain and Portugal, and 6% in Germany and the Republic of Ireland (2007 data). Globally, wind power generation increased more than fivefold between 2000 and 2007.
Most wind power is generated in the form of electricity. Large scale wind farms are connected to electrical grids. Individual turbines can provide electricity to isolated locations. In windmills, wind energy is used directly as mechanical energy for pumping water or grinding grain.
Wind energy is plentiful, renewable, widely distributed, clean, and reduces greenhouse gas emissions when it displaces fossil-fuel-derived electricity. Therefore, it is considered by experts to be more environmentally friendly than many other energy sources. The intermittency of wind seldom creates problems when using wind power to supply a low proportion of total demand. Where wind is to be used for a moderate fraction of demand, additional costs for compensation of intermittency are considered to be modest.
source:http://en.wikipedia.org/wiki/Renewable_energy
The Secret World of Energy - The Evolution and Use of the - World's Energy Systems
by McLamb
Updated 4-17-2008
The amount of sunlight hitting Earth's surface each year can supply nearly 36,000 times the amount of energy currently provided by total world oil consumption. (Image: NOAA)
Every minute enough of the Sun's energy reaches the Earth's surface to meet the world's energy demands for a whole year. Combine this powerful energy source (the very source of life for our planet) with other readily available energy sources like wind, moving water and heat from within the Earth (geothermal heat), it almost seems incredulous that our human population depends on the burning of fossil fuels to meet nearly all of its energy demands. And this picture doesn't look like it will change very much in the near future.
Why fossil fuels? The fossil fuels we largely depend on today are coal, oil and natural gas. They are called non-renewable energy sources. But if you think about it, that description is actually another way of saying we use them faster than they form. Over 100,000 times faster to be exact! So how did we ever decide this would be the primary energy resource to power human development and progress?
It all goes back to human mastery of fire to provide warmth, light and a means of preparing more palatable and easily digestible foods. To the early humans, fire was the equivalent of having a little sun with them wherever they needed or wanted to go. With this energy available at anytime and anyplace, humans could begin to spread about the world and thrive, regardless of the climate or amount of sunlight available. It provided the power for humans to begin their mastery of Earth as a species, less vulnerable to extinction than all other animal species, yet with a greater ability to bring about change -- for good or bad.
Impact of The Industrial Revolution
It was coal that fueled the Industrial Revolution, forever changing the way people would live and utilize energy. While this propelled human progress to extraordinary levels, it came with extraordinary costs to our environment and ultimately the health of all living things. It would not be until the mid 20th century that people began to understand our energy policies needed to change. (Photo: University of Ireland, Galway)
It was wood -- a renewable biomass energy source -- that was unquestionably the first fuel used for fire. Although the fossil fuel coal had been used as a fuel since 1,000 B.C., it wasn't until the arrival of the Industrial Revolution from the mid -1700s through the 1800s that coal began to replace biomass as the primary source of energy.
The Industrial Revolution also marks the beginning of an era when the world human population started to explode. Indelibly tied together, both energy consumption and population growth have experienced exponential growth with few exceptions since the beginning of the Industrial Revolution. As the population increased, energy demands increased with greater intensity. Naturally, as the population grew and industry advanced, the demand for energy increased exponentially.
Coal: the First Mass Use of Fossil Fuels
"Indelibly tied together, both energy consumption and population growth have experienced exponential growth… since the beginning of the Industrial Revolution."
Why coal? Coal can provide much more energy over longer periods of time than wood or any other biomass product. Forests were also diminishing in many regions because they were being consumed for fuel, particularly in England -- where the Industrial Revolution started. Coal was in ample supply. It very quickly made industrial and economic sense to use coal to supply the rapidly increasing energy demand for a growing and progressing human population.
Since coal and other fossil fuels to be discovered -- oil and natural gas -- seemed to exist in infinite supplies, human progress and achievement centered around the exploitation of these resources. Not only had we learned to use fire to meet our energy demands, but we had become dependent on fossil fuels to supply the fire!
Oil & Natural Gas
The fossil fuels oil and natural gas combined currently provide most of our energy needs. Although they have been used in some form for thousands of years, the massive consumption of them did not start until the late 1800s and early 1900s following their discovery in large quantities in shallow oil reservoirs. In the U.S., the discovery that sparked the oil boom was in Titusville, Pennsylvania, in 1859 when Edwin L. Drake drilled the world's first oil well that launched the modern petroleum industry. This high energy fuel set the stage for the expansion of industry, but it also led to the development of the automobile. At this time, few considered the non-renewable nature of these fossil fuels and the amounts that would be used in the future.
The Prediction that Startled the World
M. King Hubbert (1903-1989) startled the world in 1949 with his prediction that fossil fuels would not be able to meet world energy demands in the relatively near future. Hubbert, a widely acclaimed geophysicist, was a world authority on the estimation of energy resources and on the prediction of their patterns of discovery and depletion.
It wasn't until M. King Hubbert predicted in 1949 that the fossil fuel era would be very short-lived that we began to realize we would one day soon have to rely on other energy sources. Though Hubbert startled the world with his calculated assessment, he followed it in 1956 with the prediction that US oil production would peak around 1970 and decline thereafter. This peak period of world oil discovery and exploitation has become known as Hubbert's Peak.
Indeed, US oil production began to decline in 1971. Since then, world energy use has risen almost 70 percent. Today, more than 50 percent of oil consumed by the US is imported from other nations. According to the US Department of Energy, US dependence on imported oil will reach 64 percent by 2020. World oil use will continue to grow exponentially particularly as developing countries become more industrialized.
In the late 1990s, renowned geophysicist Kenneth S. Deffeyes -- Professor Emeritus at Princeton University -- predicted world oil production decline would occur by 2005; however, many scientists believe the actual decline of oil is now 2020-2040, with the US using 2015 as the projected start of the decline.
By the time the world began to heed Hubbert's prediction, the use of fossil fuels had become so firmly interwoven into human progress and economy that changing this energy system would drastically alter the very way we have lived our lives. Certainly, the production and consumption costs of changing our energy systems have greatly discouraged the development and use of alternate energy resources.
As much as we are now all aware of the impending depletion of our primary fossil fuel reserves -- and the fact that we would like to see renewable and cleaner energy sources take their place -- alternative energy will be challenged to take over as a primary energy supplier for human consumption by the end of this century. It is also widely believed that we will not see alternative fuels become mainstream until fossil fuels become too expensive to produce and consume. And that will happen in the relative near term! The immediate importance of renewables is that their use extends the life of the fossil fuels and provides cleaner alternatives to the fossil fuels.
The good news is that energy abounds all around us, energy resources that we haven't even begun to consider, and we now have a natural mandate to begin developing them before the fossil fuels disappear. One thing for sure, the human race will not just one day start living in the dark and without power because we used the last drop of oil or lump of coal. And scientists are working on it in ways you probably haven't even considered.
Can Alternative Energy Meet the Demand?
Despite exceptional progress in the development and application of alternative energy, increasing worldwide energy consumption is making it difficult for these new energy resources to replace fossil fuels. Alternative energy today meets only about 12.78% of the world's power demands -- including combustible renewables and wastes – (Source: IEA, 2007), and that's with nearly 6.8 billion people living on the planet. In 100 years, the population is expected to double. That's over 13 billion people living on the planet... at the same time... using the same power sources! The demand for energy then will be five times greater than what it is now. Considering current projections for world energy demand increases, by 2030, renewable energy is expected to meet only 8% of the world demand, according to the Energy Information Agency (link to http://www.eia.doe.gov). Yet, the World Renewable Energy Network says that 70 percent of the world's energy could come from renewable sources by 2070 through innovation and advanced effort.
Energy and potential energy exist in everything. Energy is basically without form and cannot be seen, but we see and feel its effects. Electricity is not energy, but rather it is created from energy. Energy captured from the sun, the burning of fossil fuels, water currents and wind is used to create electricity and provide power for our homes, businesses and transportation. It is the release of energy from the burning of wood or other combustible materials that causes the heat and fire used to help meet today's power requirements.
Understanding Energy
In simple terms, energy is motion, the force created through the movement of the tiniest particles of matter as well as the very largest objects in the universe. Even light from the sun is made up of tiny submicroscopic particles called photons -- which literally means visible-light particles -- the movement of which is energy. These particles travel in waves at different frequencies (wavelengths) to create what is called radiant energy, a.k.a. electromagnetic energy. Radiant energy also exists in non-visible forms such as infrared and ultraviolet radiation (oh, those sunburns!), X-rays and gamma rays.
And what about heat? Heat is created by the kinetic energy -- or motion -- of all the tiny atoms and molecules in a gas, liquid or solid (yes, molecules can even move about in solids). The motion of any object possesses kinetic energy, and the larger and faster the motion of the object, the more kinetic energy it possesses.
Any object has the potential to start moving and gain kinetic energy. Take gravity and Newton's Apple, for instance. The apple on the tree is being acted upon by the force of gravity, but it is only when the apple falls from the tree does it possess kinetic energy. When the apple is hanging it has potential energy, which is also the same as stored energy or energy for future release. The potential energy is converted to kinetic energy when the apple falls.
Energy Dynamics & Environmental Health
By understanding the secret lives of energy -- how it exists, how it is created, how it acts and even where it can be found, we can better understand how to tap the world of energy available to meet our continuously increasing energy demands. The issues really aren't about energy at all, but about how we try to get it and use it! The specific issues concern the fuels we use to create energy. All fuels have to go through either a chemical or physical change to create energy, whether it's the burning of oil (chemical) or the boiling of water (physical).
Yet, while using fuels such as fossil fuels as energy resources, not only is their kinetic energy potential released, but the very carbon molecules that make these fuels such powerful energy sources are also released. The end result is pollution, pollution that not only causes health problems but also directly contributes to today's global warming trends. The costs of these side-effects cannot be calculated but can only be measured in terms of the costs of lives and quality of living, environmental health, and climatic change.
A Global Perspective
Already, the world is making progress in tapping alterative forms of energy from solar, wind and water, to nuclear, biomass, geothermal and even new forms of fossil fuels. Currently, hydroelectric energy -- which is the kinetic energy of falling or moving water, is the world's largest source of renewable energy. Over 80 percent of the world's renewable energy is hydroelectric. Hydroelectric is followed by solar energy, biomass and wind in that order.
* Includes Geothermal, solar, wind, etc.
(Source: IEA World Energy Statistics 2007 Edition)
But let's this put this in its proper perspective. According to recently released data by the International Energy Agency (IEA), fossil fuels currently provide 81.0 percent of the world's primary energy supplies! Biomass and other combustible renewables and waste account for 10.0 percent, and nuclear energy accounts for 6.3 percent. Hydro (moving water) alone accounts for 2.2 percent with all other renewable resources meeting .5 (five-tenths) of a percent of the world's total energy appetite.
Total world electricity demand -- which is part of the total world energy demand -- still depends primarily on fossil fuels but to a somewhat lesser extent. Hydro and other renewable energy sources account for 18.2 percent of the world's total electricity needs. Fossil fuels still account for well over half of the world's electricity supplies – 66.6 percent according to the IEA, while nuclear energy supplies 15.2% of the world's electricity.
The Alternatives
Renewable energy is the ultimate replacement for any non-renewable source. Certainly, the day will come when this fossil fuel era will pass and eventually fade totally into the history books. And what will life be like then? Even more important perhaps is what we will have to do -- and even endure -- to get there.
Despite nuclear energy's role as a significant power supply source, it is highly unlikely it will survive past the 21st century if that long. Many people are against it, storage of its highly radioactive wastes is difficult and costly, there are not enough ores available to maintain continued production of nuclear energy as it is being done today, and most of today's nuclear plants will reach the end of their life-span within the next 50 years.
Wind and hydro are two low-cost renewable energy sources that have been used for many generations. While hydro (right) provides about 2.3 percent of the world's total energy demands -- by far the greatest source of renewable energy, wind power technology (left) has become a far more efficient renewable energy source. The challenge to using wind power primarily exists with location.
While hydro, solar, wind (a very efficient energy source), geothermal are currently our most promising forms of renewable energy to develop for future use, there are sources that many scientists classify in the "surprise category" that theoretically hold great promise. These sources range from the mining of methane hydrates (a fossil fuel that exists under the oceans and are very difficult to reach and dangerous) and hydrogen fusion from simple H2O -- the same process that powers our Sun and all the stars of the universe, to sources we have yet to discover. The startling potential of hydrogen fusion is so great that the US government has launched an initiative to study whether it's feasible within the next 35 years to develop and use what's known as fusion energy.
And, yes, there are other fossil fuels that some scientists believe may be able to help contribute to the current energy pressures, but these forms have a low net energy yield, are difficult to process, and have serious pollution side-effects. They are oil shale and tar sands. Still, it appears unlikely that these forms will ever be used as significant sources of energy.
The Sun, no doubt, holds the greatest potential to meet the world's energy demands. But it will take a change in the technological, political and economic landscape for it to be realized. Still, the most plausible answer for our indefinite energy needs lies in a cohesive, sensible and ecologically sustainable combination of the resources available to us. The incentives must be there to be successful -- political, economic, and human intelligence -- and success can be achieved only through the use of renewable energy in ways that will ensure the healthy sustainability of Earth's life systems. As Nobel Laureate Sir George Porter so eloquently said in the late 1960s, "I have no doubt that we will be successful in harnessing the sun's energy If sunbeams were weapons of war, we would have had solar energy centuries ago."
Did You Know?
- Sunlight is made up of tiny particles of energy called photons. The amount of this energy hitting the Earth's surface in one year is equivalent to the energy provided by 935 trillion barrels of oil. The current annual world consumption of oil equals about 26 billion barrels!
- In 2006, 5,370 metric tons of hard coal were produced to help meet world energy demands. That is an 8.8 % increase over the previous year & 92% growth over the past 25 years. (Source: World Coal Institute
- Reservoirs of hot liquid with temperatures greater than about 350°F are the most common type of geothermal energy sources. (Source: Hawaiian Electric Company)
- To lock up the eight billion tons of carbon released into the atmosphere each year would require planting a forest four times the area of the United States. (Source: Whole Systems Foundation)
Source: http://www.ecology.com/features/secretworldofenergy/index.html
Energy Innovators: 4 creative solutions to energy problems
By Paul Davidson, USA TODAY
The nation is turning to alternative energy as never before amid concerns about global warming and runaway fossil-fuel prices.
Wind and solar power, for example, each grew 45% last year, while the U.S. consumed 633,000 barrels of ethanol a day in June, up 43% from a year earlier.
But alternative energy has not broken into the mainstream because of myriad roadblocks. Solar energy, for example, is expensive. Wind power is available only when the wind blows.
But hundreds of companies are working to overcome the obstacles. Through June, venture capital investments in alternative energy companies this year totaled $980 million, up 92% from a year earlier, says Dow Jones VentureSource. Here are four technologies that show promise:
Thin-film solar panels:
Printing process cuts down on the cost of silicon, a key material
Here's one way to bring down the price of solar energy: make churning out solar panels as easy as printing a newspaper.
That's precisely what start-up Nanosolar has done. The company says it's poised to be the first among dozens of manufacturers to make solar competitive in price with conventional electricity.
While solar-system costs have fallen, they're still about 20 cents to 30 cents per kilowatt hour, or more than twice the price of electricity from your local utility.
That's largely because traditional solar-system makers use expensive silicon as a semiconductor to generate electricity from sunlight.
Thin-filmmakers have pushed down costs by using a tiny fraction of the semiconductor. But most still employ a slow and expensive condensation method to attach the semiconductor onto a base. Yet with production volumes rising, solar energy generally is expected to be competitive with grid electricity in 2010 or after.
Nanosolar, a Northern California company, says it can achieve that next year because of its printing process.
It embeds tiny semiconductor particles in ink, then coats a layer of it onto mile-long rolls of aluminum foil, which is later cut into solar panels. The company says it can turn out panels at a rate of 100 feet a minute, 20 times faster than typical thin-filmmakers at a tenth of the cost.
"It's all about higher throughput," to more cost-efficiently leverage fixed labor and equipment costs, Nanosolar CEO Martin Roscheisen says.
In December, Nanosolar opened a factory in San Jose that's capable of pumping out 430 megawatts of solar capacity a year, nearly the size of an average coal-fired power plant. It plans to produce huge solar panels for cities and other utility-scale users this year and target businesses and homes next year.
Consultant Paul Maycock of Photovoltaic Energy Systems says Nanosolar's systems "could be one of the more exciting products" in solar energy's history.
But he says the company has not delivered the production volumes it promised a few years ago. Roscheisen would not discuss its output, noting Nanosolar is private.
E-Coal:
No greenhouse gas in coal substitute
Imagine an electricity source that kind of looks like coal and packs all of coal's energy punch but is cheaper and produces no greenhouse gas emissions.
That's what Seattle-based NewEarth Renewable Energy says it developed with E-Coal. It's biomass made from plants or other organic waste and heated to boost its energy content.
"We can produce (clean) fuels that are pound-for-pound replacements for coal," NewEarth CEO Ahava Amen says.
In 2004, after making a small fortune in cosmetics, Amen and some former associates reunited to tackle global warming.
They hunted for a substitute for coal, the biggest greenhouse gas producer. Biomass emits carbon dioxide when burned but absorbs the same amount in its lifetime. Yet it yields a third to half of coal's energy, raising fuel costs and limiting the size of current biomass power plants. NewEarth boosts its energy content by placing the biomass in an oxygen-deprived chamber and heating it to 250 degrees.
The resulting solid is condensed, and unwanted gases and moisture are removed. The heating process was invented decades ago, but Amen says NewEarth has made it cost-efficient. It's using as its feedstock a fast-growing plant, Nile reed.
Because the energy value equals coal's, he says, there's no need to spend millions to upgrade plant boilers. Plus, he says, E-Coal costs 5% to 40% less than regular coal. Initially, a utility likely would blend a small amount of E-Coal with its coal. But Amen says a plant's entire fuel stock can be replaced. He says he's negotiating with dozens of utilities.
Larry Joseph, former U.S. Energy Department official and investor in the company, says utilities are very cautious and want clear evidence they're not going to harm their equipment.
Algenol:
Company uses algae to make ethanol more eco-friendly
Corn-based ethanol is getting slammed for straining the world's food supply and contributing to global warming by encouraging the plowing of grasslands.
Cellulosic ethanol, a more eco-friendly version derived from switch grass or wood chips, is several years away. Maryland-based Algenol says it can solve the problems by making ethanol from algae, starting next year.
The start-up recently agreed to license its technology to BioFields, which plans to build an $850 million saltwater algae farm in Mexico's Sonoran Desert and churn out 100 million gallons of ethanol the first year. It will sell the gasoline substitute to Mexico's state-run oil monopoly.
A handful of companies are working on turning the abundant marine organism into biodiesel. That requires growing algae and killing them to extract their oil, a time-consuming and expensive process.
Algenol adds enzymes to the organisms to enhance their normally limited ability to convert sugar into ethanol, a waste product. To maximize ethanol production, the algae are placed in regions with abundant sunlight and grown in 50-foot long tubes filled with seawater. Ethanol is captured as a gas in the bottle and condensed to a liquid. Since algae aren't destroyed, the same ones keep yielding ethanol, holding down costs.
Algenol CEO Paul Woods says production costs are half those of corn-based ethanol, and the fuel will wholesale for $1 less than gasoline. His goal: Woods wants to build 20 plants in sunny areas such as Texas and Florida to generate 20 billion gallons of ethanol by 2020. "We don't have any limitations, because we're not competing with the food supply," Woods says.
Philip Pienkos, of the National Renewable Energy Laboratory, says Algenol's goal is "definitely doable." But he says there will still be a need for fuels with higher energy content than ethanol.
Compressed air:
Facilities put stored air to work when wind dies
Wind farms are sprouting across the country as wind energy costs become competitive with those of coal-fired power plants. But there's a rub: no wind, no electricity.
Batteries can store electricity generated by wind for use on a day when the wind doesn't blow. But they're expensive.
PSEG Global, a sister company of a New Jersey utility, says it has the answer. It recently teamed with energy storage pioneer Michael Nakhamkin to market compressed-air technology.
Here's how it works: During off-peak hours, wind turbines compress air that's stored in underground caverns or in more expensive above-ground tanks. The air is released at peak periods to run turbines and generate power when gusts flag.
The nation's only compressed-air generator was built in Alabama in 1991. PSEG says it has improved on the technology and hopes to deploy it with power providers.
PSEG says its advanced system can transform the industry. It's about half the price of batteries, partly because it uses off-the-shelf power-industry parts rather than customized compressed-air gear.
The technology is more than 25% cheaper than current systems, says Stephen Byrd, president of PSEG Energy Holdings.
Also, it can generate electricity in five minutes, vs. current systems that take 20 minutes. That's vital if the wind suddenly stops blowing. "It really is likely to further enable the growth of renewable" energy, Byrd says.
While the system is largely designed to supplement intermittent wind or solar power, it can be used to stockpile cheap electricity at night and use it midday when the grid is strained.
Energy consultant Stow Walker says it sounds promising, but finding suitable underground storage can be challenging.
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