At the Global Environmental Leadership Conference presented by Newsweek, California Governor Arnold Schwarzenegger made an address and delivered very strong words to U.S. automakers. The Governor wanted automakers to make changes to reduce harmful exhaust greenhouse gasses emitted by their vehicle models. He also commented to a billboard in Detroit, which criticizes him for mandating the vehicle exhaust emissions standards in California that car makers, especially Michigan-based automakers are unwilling to meet.
Here is some part of Schwarzenegger’s speech.
“I have to say that I am somewhat amazed to be here, and the reason is because three and a half years ago when I ran for governor I was followed around by environmental protestors with signs. They didn’t like my Humvees and Hummers, and my SUVs, or anything that I did. As a matter of fact, when I promised that I would improve the environment when I became governor, they didn’t believe that either. So here we are, three and a half years later, and I’m on the cover of Newsweek as one of the big environmentalists. Only in America, that’s all I can say.
But let me tell you something; even though I love being on the cover of Newsweek, but there should have been some other people on that cover as well, and those are people that were my partners in the Legislature. They have worked very hard, they were incredible partners, and I’m talking here about, first of all, Assembly Speaker Fabian Núñez and Senator Perata. I invited both of them to come here but they couldn’t make it, but I just wanted to thank them publicly for being such great environmentalists and such great leaders in the environment. So let’s give them a big hand, even though they’re not here.
And I want to thank also someone that is here with us today, and this is Assemblywoman Fran Pavley. She has been such a great, great warrior.
Let me tell you something; this is the real deal. This is the real deal. This woman has been fighting for the environment way before I ever became governor, and she has really been the author of these very important legislations, and she has worked with our office, and she is a team player. And this is, you can see here, she’s a Democrat. Also the Speaker is a Democrat. Senator Perata is a Democrat. So this is what I’m talking about, working together in a bipartisan or post-partisan way, and this is how we get things done, because we work what is best for the people of California and for America. So thank you again to Assemblywoman Pavley. (Applause)
Now, I know this is an environmental conference, but I do want to start talking first about bodybuilding. And the reason is because bodybuilding is another passion of mine, as you probably know, and it has similarities there. Bodybuilding used to have a very sketchy image. As a matter of fact, so much so that some people that worked out seriously and pumped weights didn’t admit they were doing bodybuilding. As a matter of fact, say in the old days, some of the very famous Hollywood actors like Kirk Douglas, Clint Eastwood, Charles Bronson, and the list goes on and on, they all worked out with weights, but they never admitted it publicly because they didn’t want to be associated with the gymnasiums that were like dungeons and that had fanatics, and that had weird people training in there. That is the kind of an image that it had.
But we changed that, we consciously changed that. And what we did was, we came out with a book called Pumping Iron—I know a lot of you are familiar with that, especially the students—then the movie Pumping Iron, and that changed bodybuilding, the image of bodybuilding, dramatically. As a matter of fact, the perception of bodybuilding began to change and it became more and more hip and more and more attractive. And then all of a sudden, everyone wanted to exercise. As a matter of fact, today you can go to any place in the world and you will find a bodybuilding gymnasium or a place where you can do weight resistance training, and you can go into any gymnasium and you will find ordinary people talking about their abs, their lats, their deltoids, body fat, and all those kinds of things. So this is how much it changed. It became mainstream, it became sexy, attractive.
And this is exactly what has to happen with the environmental movement. Like bodybuilders, environmentalists were thought of as kind of weird and fanatics also. You know, the kind of serious tree huggers. Environmentalists were no fun; they were like prohibitionists at a fraternity party. (Applause)
So someone the other day just showed me a cartoon that was of a car salesman in a showroom talking to this couple. And the car salesman pointed at the car and said, “This car runs on an ordinary gasoline-powered engine, and then when it feels a little guilt, when it senses guilt, it switches over to battery power.” Now, that’s funny, it’s a cartoon. But let me tell you something; there’s a lot of truth to that. For too long the environmental movement had been powered by guilt.
But I believe that this is about to switch over from being powered by guilt to being powered by something much more positive, much more dynamic, something much more capable of bringing about major change. You know the kind of guilt I’m talking about; the smokestacks belching pollution that are powering our Jacuzzis and our big-screen TVs, and in my case powering my private airplanes. So it is too bad, of course, that we can’t all live simple lives like the Buddhist monks in Tibet. But you know something? That’s not going to happen.
So ladies and gentlemen, I don’t think that any movement has ever made it and has ever made much progress based on guilt. Guilt is passive, guilt is inhibiting, and guilt is defensive. You remember the commercials a number of years ago, the commercials specifically of a Native American who sees what we have done to the environment and then a year runs down his cheek. You all remember that? Well, let me tell you something; that approach didn’t work, because successful movements are built on passion, they’re not built on guilt. They’re built on passion, they’re built on confidence, and they’re built on critical mass. And often, they’re built on an element of alarm that galvanizes action.
The environmental movement is, to use a popular term, about the tipping point. It’s about to get to the tipping point. There’s a tipping point, and I believe the tipping point will be occurring when the environmental movement is no longer seen as a nag or as a scold, but as a positive force in people’s lives. Now, I don’t know when that tipping point occurs, but I know where—in California. In California, we are doing everything that we can to tip the balance on the environment.
Now, first, let me start with government policy. I don’t want to go into all the initiatives that we have passed and all the laws that we have passed, because that was already eloquently explained by John when he introduced me. But there are two things that stick out that have gotten us the most attention.
1. We passed a law to cap greenhouse gas emissions by 25 percent by the year 2020. That basically means we are rolling back the greenhouse gases to the 1990 level by the year 2020, and then we go 80 percent below that by the year 2050.
2. I ordered a 10 percent cut in the carbon content of transportation fuels.
Now, do I believe that the standards that California sets will solve global warming? Of course not. But what we are doing is applying leverage so that at some point the whole environmental thing tips. That’s what we are trying to do. It’s like a seesaw. You walk up to it and then slowly it tips the other way. That is what we are trying to do. California, as you know, is big, California is powerful, and what we do in California has unbelievable impact and it has consequences. As a matter of fact, when you look at the globe, California is a little spot, but the kind of power of influence that we have on the rest of the world is an equivalent of whole huge continent.
We are sending the world a message. What we are saying is that we are going to change the dynamic on greenhouse gas and on carbon emissions. We are taking actions ourselves. We are not waiting for anyone, we are not waiting for the federal government or for Washington. We are creating our own partnerships. We are partnering with Great Britain, we are partnering with provinces in Canada, with states in the United States, with the western states, with the northeastern states. And you know something? Every year we are adding more and more partners to our team. We are increasing the momentum for change.
Now, there’s a billboard in Michigan that accuses me of costing the car industry 85 billion dollars. They say because of our new carbon fuel standards I cost them 85 billion dollars. The billboard says “Arnold to Michigan—drop dead.” The fact of the matter is, what I’m saying is, Arnold to Michigan—get off your butt. Get off your butt and join us. (Applause)
In fact, California may be doing more to save US automakers than anyone else, because what we are doing is we are pushing them to make changes, to make the changes so they can sell their cars in California. And we all know—let’s be honest—that if they don’t change, someone will. The Japanese will, the Chinese will, the South Koreans will, the Germans will, they all will. So what I want to do is, I want to prevent that from happening. I want them to sell their cars in California. I believe strongly in American technology, and I think in the end it will be technology that will ultimately save Detroit.
Now, California, for instance, has already a car company that’s called Tesla Motors. Tesla Motors has just designed and produced a car that’s called the Tesla Roadster. It’s 100 percent electric. Now, why is it that a car company that has never produced a car before is already producing a car with zero emissions—zero emissions—and Detroit is still lagging behind? Now, this car, let me tell you something, is a very sexy looking car. It’s really cool. I mean, I test drove it. It goes from 0 to 60 in 4 seconds. It drives 130 miles an hour, and it has 250 miles on a charge, and then the recharging only takes 3 1/2 hours. Now, that’s what I call cool. And the car cost 100,000 dollars—to be exact, 98,000 dollars—and it is so popular, it sold out immediately. And now the second version is being produced, and that car, the cost will drop down to 50,000 dollars.
So we can see where that is heading, economics tells us where this is heading. It’s like the cell phones. I remember when I bought a cell phone, the first cell phone, which was kind of a radio phone, 20 years ago. It was 1,600 dollars. The next version I bought a few years later was 1,200, and the next one was 750. I just recently bought a cell phone for my daughter and it was below 90 dollars. Now, because of the costs that have dropped down, almost everyone can afford a cell phone, and the same thing is going to happen to the environmental Technologies in cars. Government can give a push by setting standards, so California is giving the nation and the world a push.”
Well, Let us just wait and see if Detroit and other Michigan automakers like Chrysler Group, maker of Jeep models with quality Jeep vent visor can meet California’s emission standards in the near future.
Lisa Ziegler
http://www.articlesbase.com/automotive-articles/arnold-schwarzeneggers-address-to-detroit-automakers-132593.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
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