Energy Information

Cuba Leapfrogs The World With Sustainable Solar Energy

In two short years, energy-smart Cuba has bolted past every country on the planet. the World Wildlife Fund (WWF) has declared Cuba to be the only country on the planet that is pproaching sustainable development. Key to this designation is the island?s Revoluci?n Energ?tica, an energy conservation effort launched only two years ago. For two decades, Cuba has been developingrenewable energy and energy-conservation strategies to cope with the fuel shortage. Educating citizens about energy conservation has been one of Cuba?s programs to move toward a more sustainable energy future.

The solutions to Cuba’s energy problems were not easy. Without money, it couldn’t invest in nuclear power and new conventional fossil fuel plants or even large-scale wind and solar energy systems. Instead, the country focused on reducing energy consumption and implementing small-scale renewable energy projects.

Ecosol Solar and Cuba Solar are two renewable energy organizations leading the way. They help develop markets for renewable energy, sell and install systems, perform research, publish newsletters, and do energy efficiency studies for large users.Ecosol Solar has installed 1.2 megawatts of solar photovoltaic in both small household systems (200 watt capacity) and large systems (15-50 kilowatt capacity). In the United States 1.2 megawatts would provide electricity to about 1000 homes, but can supply power to significantly more houses in Cuba where appliances are few, conservation is the custom, and the homes are much smaller.

About 60 percent of Ecosol Solar’s installations go to social programs to power homes, schools, medicals facilities, and community centers in rural Cuba. It recently installed solar photovoltaic panels to electrify 2,364 primary schools throughout rural Cuba where it was not cost effective to take the grid. In addition, it is developing compact model solar water heaters that can be assembled in the field, water pumps powered by PV panels, and solar dryers.

A visit to “Los Tumbos,” a solar-powered community in the rural hills southwest of Havana demonstrates the positive impact that these strategies can have. Once without electricity, each household now has a small solar panel that powers a radio and a lamp. Larger systems provide electricity to the school, hospital, and community room, where residents gather to watch the evening news program called the “Round Table.” Besides keeping the residents informed, the television room has the added benefit of bringing the community together.

“The sun was enough to maintain life on earth for millions of years,” said Bruno Beres, a director of Cuba Solar. “Only when we [humans] arrived and changed the way we use energy was the sun not enough. So the problem is with our society, not with the world of energy.”

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Is Alternative Energy The New Eldorado?

There is money in alternative energy and big corporations are discovering this fact. Not only are existing companies securing their position, new companies that specialize in this new energy source are increasing also. Is there really money to be made or is this the new Eldorado? Many believe that this new form of converting ‘free’ energy has real potential. Let’s look at the most important reasons why.

The energy sources we use today have negative side effects. They cause lots of pollution. The pollution causes acid rain and the earth warm up. Besides these side effects the current reserves are diminishing. The crude oil reserves will last for the next 45 years to come and gas maybe 60 years. The only traditional fuels source that is still in ‘abundance’ is coal. The coal supply will last for the next 300 years. Thus, for everything that runs on a form of crude oil or natural gas we will have to find a good replacement. Many of us think alternative energy is the answer.

Why is alternative energy the answer for our energy problems? There are several reasons why. First it is a clean form of energy that doesn’t cause any harmful effects to the environment. We are realizing that this beautiful planet we live and breathe on needs to cherished. Not only for us but more important for our children. Thus we need to live our lives in a way that is not harmful for our planet. We are doing it right now and need to change that. Alternative energy can be the answer.
Second, these ‘new’ energy sources are available for nearly every one and they are ‘free’. Energy sources like the wind, sunshine and water are for every body and are free to use. We need technology to convert these sources in to useful energy needed for our appliances and transportation. These technologies come with a price tag and one can argue if these investments are worth it. If you feel that the investments are worth it or not, the technology is available. For the individual and for companies there are amazing technologies on the market. Companies that specialize in these energy sources are improving and coming up with new concepts that are better than ever before.

Companies that are developing these technologies are investing in their and our future and can become the next ‘oil barons’. They are not only securing a clean planet, but are also making money. History has taught us that technology is the key for success in the western modern world we live in. These companies that develop these new technologies can sell their knowledge through appliances and services they offer. Consumers and other needing companies are willing to pay for this. You can ask yourself if it is wrong that these companies are making money on something that is ‘free’ for all. When you really think of it, it really is nothing more than what is happening today all around us. It is just plain and simple economy, some one offers a product and another person buys that in exchange for money. Of course the price must be right.

When it comes to making use of alternative energy we need technology to convert the ‘free’ energy sources into forms that we can use. This technology can be expensive, but you will be saving money also. Because many governments are endorsing it, you may profit from tax credits as well or other benefits. Thus, for the right price the investment can be beneficial for all parties.
The hunt for new alternative energy sources is not a hunt for a non-existing golden happy dream. The conversion of alternative energy sources into usable energy is happening today and will be better tomorrow. It is real and here to stay, for a long time.

Renewable Energy

Renewable energy

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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.

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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

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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

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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

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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

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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 km?) 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.

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Portable Solar Chargers

Every day we see new and improved devices that use electricity. And, in increasing watts, the electricity is supplied by rechargeable batteries. The benefits of new battery technologies mean they are being used in new and exciting ways. For example, almost every new and improved small appliance includes current new electronics and the latest software together resulting in more? features for your benefit. The forces of competition conspire to provide you with free, new benefits.

Haven’t times changed? There was a time when every adult had a personal time piece – usually a wrist watch – each person valued and relied on it. Today, a whole generation would rather have a cell phone. A few years ago, we laughed in exasperation at the number of clocks we reset when there was a power failure or in anticipation of the change to or from daylight savings time. Now, the blinking lights are becoming a thing of the past as those devices are improved by additional computer resources so that they use small amounts of battery supplies and their internal programming to take care of these minor chronological? problems? as an automatic function. The point is that we live in households and businesses that have increasing demands for stored electricity – it is just a modern reality and an acceptable trade-off in order to keep our up to date electronics working as expected. Certainly this is one of the motivations for adding solar panels and wind turbines to our homes and businesses. For our portable appliances or devices, we should consider portable solar chargers.

Portable solar chargers come in a variety of sizes and with a wide range of their own features. One of the most important is power generation capacity, the amount of watts that the charger can generate in an hour. This will give you an idea of the kind of devices that the charger will charge for you. Nothing is more frustrating than leaving your favorite device plugged in for hours before you realize that it can’t generate enough electricity to charge that device. This suggests the next important feature. Does the charger include the connectors you need for your devices? Once you know what devices can be charged, you must be sure the charger? has the connectors for your devices. These are the two basic important features.

Portable solar chargers have panels that must be placed where they can convert light into electricity. These panels respond in different ways to different wavelengths of light – from infrared to ultraviolet. The panels are also available in rigid and flexible formats in various sizes. Solar panels are increasingly part of the design of all kinds of consumer goods, the panels may be single purpose photovoltaic sheets or part of your clothes or other accessories.

Rechargeable batteries should be part of your consideration simply because so many of the devices you use, require separate batteries in various formats. AA and AAA are ones you likely use in large quantities although C, D, and nine volt batteries are also very common. A portable solar charger should be part of your personal power generation planning for charging these batteries to keep your devices working well, clean and green.