Renewable energy is energy which comes from natural resources such as sunlight, wind, rain, tides, and geothermal heat, which are renewable (naturally replenished). About 16% of global final energy consumption comes from renewables, with 10% coming from traditional biomass, which is mainly used for heating, and 3. 4% from hydroelectricity. New renewables (small hydro, modern biomass, wind, solar, geothermal, and biofuels) accounted for another 2. 8% and are growing very rapidly.  The share of renewables in electricity generation is around 19%, with 16% of global electricity coming from hydroelectricity and 3% from new renewables. 2] While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas, where energy is often crucial in human development. Climate change concerns, coupled with high oil prices, peak oil, and increasing government support, are driving increasing renewable energy legislation, incentives and commercialization.  New government spending, regulation and policies helped the industry weather the global financial crisis better than many other sectors. [ Main article: Wind power Wind Turbines located outside of Palm Springs, California
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. Typical capacity factors are 20-40%, with values at the upper end of the range in particularly favourable sites. 23] 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 wind turbines to be installed over large areas, 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.   Hydropower See also: Hydroelectricity and Hydropower Grand Coulee Dam is a hydroelectric gravity dam on the Columbia River in the U.
S. state of Washington. The dam supplies four power stations with an installed capacity of 6,809 MW and is the largest electric power-producing facility in the United States. Energy in water 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. 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). •Run-of-the-river hydroelectricity systems derive kinetic energy from rivers and oceans without using a dam.  Solar energy See also: Solar energy, Solar power, and Solar thermal energy Monocrystalline solar cell. Solar energy is the energy derived from the sun through the form of solar radiation. Solar powered electrical generation relies on photovoltaics and heat engines.
A partial list of other solar applications includes space heating and cooling through solar architecture, daylighting, solar hot water, solar cooking, and high temperature process heat for industrial purposes. Solar technologies are broadly characterized as either passive solar or active solar depending on the way they capture, convert and distribute solar energy. Active solar techniques include the use of photovoltaic panels and solar thermal collectors to harness the energy. Passive solar techniques include orienting a building to the Sun, selecting materials with favorable thermal mass or light dispersing properties, and esigning spaces that naturally circulate air.  Biomass Biomass (plant material) is a renewable energy source because the energy it contains comes from the sun. Through the process of photosynthesis, plants capture the sun’s energy. When the plants are burnt, they release the sun’s energy they contain. In this way, biomass functions as a sort of natural battery for storing solar energy. As long as biomass is produced sustainably, with only as much used as is grown, the battery will last indefinitely. 26] In general there are two main approaches to using plants for energy production: growing plants specifically for energy use, and using the residues from plants that are used for other things. The best approaches vary from region to region according to climate, soils and geography.   Biofuel Main article: Biofuel Brazil has bioethanol made from sugarcane available throughout the country. Shown a typical Petrobras gas station at Sao Paulo with dual fuel service, marked A for alcohol (ethanol) and G for gasoline.
Biofuels include a wide range of fuels which are derived from biomass. The term covers solid biomass, liquid fuels and various biogases.  Liquid biofuels include bioalcohols, such as bioethanol, and oils, such as biodiesel. Gaseous biofuels include biogas, landfill gas and synthetic gas. Bioethanol is an alcohol made by fermenting the sugar components of plant materials and it is made mostly from sugar and starch crops. With advanced technology being developed, cellulosic biomass, such as trees and grasses, are also used as feedstocks for ethanol production.
Ethanol can be used as a fuel for vehicles in its pure form, but it is usually used as a gasoline additive to increase octane and improve vehicle emissions. Bioethanol is widely used in the USA and in Brazil. Biodiesel is made from vegetable oils, animal fats or recycled greases. Biodiesel can be used as a fuel for vehicles in its pure form, but it is usually used as a diesel additive to reduce levels of particulates, carbon monoxide, and hydrocarbons from diesel-powered vehicles. Biodiesel is produced from oils or fats using transesterification and is the most common biofuel in Europe.
Biofuels provided 2. 7% of the world’s transport fuel in 2010.  Renewable energy can be particularly suitable for developing countries. In rural and remote areas, transmission and distribution of energy generated from fossil fuels can be difficult and expensive. Producing renewable energy locally can offer a viable alternative Renewable energy projects in many developing countries have demonstrated that renewable energy can directly contribute to poverty alleviation by providing the energy needed for creating businesses and employment.
Renewable energy technologies can also make indirect contributions to alleviating poverty by providing energy for cooking, space heating, and lighting. Renewable energy can also contribute to education, by providing electricity to schools.  A non-renewable resource is a natural resource which cannot be produced, grown, generated, or used on a scale which can sustain its consumption rate, once depleted there is no more available for future needs. Also considered non-renewable are resources that are consumed much faster than nature can create them.
Fossil fuels (such as coal, petroleum, and natural gas), types of nuclear power (uranium) and certain aquifers are examples. In contrast, resources such as timber (when harvested sustainably) or metals (which can be recycled) are considered renewable resources Natural resources such as coal, petroleum, oil and natural gas take thousands of years to form naturally and cannot be replaced as fast as they are being consumed. Eventually natural resources will become too costly to harvest and humanity will need to find other sources of energy.
At present, the main energy source used by humans are non-renewable fossil fuels, as a result of continual use since the first internal combustion engine in the 17th century, the fuel is still in high demand with conventional infrastructure fitted with the combustion engine.  Radioactive fuel Further information: Uranium depletion The use of nuclear technology requires radioactive fuel. Uranium ore is present in the ground at relatively low concentrations and mined in 19 countries. 2] The uranium resource is used to create plutonium, uranium-238 is fissionable and can be transmuted into fissile plutonium-239 in a nuclear reactor. Nuclear fuel is used for the production of nuclear weapons and in nuclear power stations to create electricity. Nuclear power provides about 6% of the world’s energy and 13–14% of the world’s electricity.  Nuclear technology is a volatile and contaminating source of fuel production, with the expense of the nuclear industry predominantly reliant on subsidies.
The radioactive waste the nuclear industry collects is highly hazardous, for a prolonged period and storage has risks of containment. Radioactive fuel continues to be controversial and unresolved industry.  Renewable resources Further information: Renewable resource and Renewable energy Natural resources, called renewable resources, are replaced by natural processes and forces of the natural environment. There are intermittent and reoccurring renewables, and recyclable materials, which are utilised during a cycle across a certain amount of time, and can harnesse any number of cycles.
Soil, water, forests, plants, and animals are all renewable resources as long as they are adequately conserved. Solar, wind, wave, and geothermal energies are based on renewable resources. Renewable resources such as the movement of water (hydropower, tidal power and wave power from ocean surface waves), wind (used for wind power), geothermal heat (used for geothermal power); and radiant energy (used for solar power) are practically infinite and cannot be depleted, unlike their non-renewable counterparts, which are likely to run out if not used sparingly.
Potential wave energy on our coastlines, can provide 1/5 of world demand. Hydroelectric power can supply 1/3 of our total energy global needs. Geothermal energy can provide 1. 5 more times the energy we need. There is enough wind to power the planet 30 times over, wind power could power all of humanity’s needs alone. Solar currently supplies only 0. 1% of our world energy needs, but there is enough out there to power humanity’s needs 4,000 times over, the entire global projected energy demand by 2050.   Economic models
In economics, a non-renewable resource is defined as a good where greater consumption today implies less consumption tomorrow.  David Ricardo in his early works analysed the pricing of exhaustible resources, where he argued that the price of a mineral resource should increase over time. He argued that the spot price is always determined by the mine with the highest cost of extraction, and mine owners with lower extraction costs benefit from a differential rent. The first model is defined by Hotelling’s rule, which is a 1931 economic model of non-renewable resource management by Harold Hotelling.
It shows that efficient exploitation of a nonrenewable and nonaugmentable resource would, under otherwise stable conditions, lead to a depletion of the resource. The rule states that this would lead to a net price or “Hotelling rent” for it that rose annually at a rate equal to the rate of interest, reflecting the increasing scarcity of the resources. The Hartwick’s rule provides an important result about the sustainability of welfare in an economy that uses non-renewable source. 85% of the energy used in the world today is produced using non-renewable energy sources.
This percentage is forecast to remain the same through 2030 unless something changes drastically such as the widespread enactment of legislation, breakthroughs in energy technology or the development of abundant, inexpensive new energy sources. Non-renewable fuels are also known as a€? fossil fuelsa€? because they are the fossilized remains of plants and animals which died up to 300 million years ago and became buried beneath the surface of the earth and the ocean floors. Time, pressure and heat transformed this material into hydrocarbons which we burn to extract energy.
We will never run out of fossil fuels, but at some point, the cost of recovering a fuel, say a barrel of oil, will exceed the profits to be made from selling that barrel of oil. At that point we will lose that fuel as an energy source. The big question is a€? How soon will this happen? a€?. Going green is easier than you think. There are little things you can do every day to help reduce greenhouse gases and make a less harmful impact on the environment. Taking care of the Earth is not just a responsibility — it’s a privilege. In that spirit, HowStuffWorks came up with 10 things you can do to help save the Earth. 1. ¬ Pay attention to how you use water. The little things can make a big difference. Every time you turn off the water while you’re brushing your teeth, you’re doing something good. Got a leaky toilet? You might be wasting 200 gallons of water a day [Source: EPA]. Try drinking tap water instead of bottled water, so you aren’t wasting all that packaging as well. Wash your clothes in cold water when you can. 2. Leave your car at home.
If you can stay off the road just two days a week, you’ll reduce greenhouse gas emissions by an average of 1,590 pounds per year [Source: EPA]. Combine your errands — hit the post office, grocery store and shoe repair place in one trip. It will save you gas and time. 3. Walk or ride your bike to work, school and anywhere you can. You can reduce greenhouse gases while burning some calories and improving your health. If you can’t walk or bike, use mass transit or carpool. Every car not on the road makes a difference. 4. Recycle.
You can help reduce pollution just by putting that soda can in a different bin. If you’re trying to choose between two products, pick the one with the least packaging. If an office building of 7,000 workers recycled all of its office paper waste for a year, it would be the equivalent of taking almost 400 cars off the road [Source: EPA]. 5. Compost. Think about how much trash you make in a year. Reducing the amount of solid waste you produce in a year means taking up less space in landfills, so your tax dollars can work somewhere else.
Plus, compost makes a great natural fertilizer. Composting is easier than you think. 6. Change your light bulbs. Compact fluorescent light bulbs (CFLs) last 10 times longer than a standard bulb and use at least two-thirds less energy. If you’re shopping for new appliances or even home electronics, look for ENERGY STAR products, which have met EPA and U. S. Department of Energy guidelines for energy efficiency. In 2006, the ENERGY STAR program saved energy equivalent to taking 25 million cars off the road and saved Americans $14 billion in utility costs [Source: ENERGY STAR]. Learn more about proper disposal of CFLs. ) 7. Make your home more energy efficient (and save money). Clean your air filters so your system doesn’t have to work overtime. Get a programmable thermostat so you aren’t wasting energy when you aren’t home. When you go to bed, reduce the thermostat setting — you won’t miss those extra degrees of heat or air conditioning while you’re asleep. 8. Maintain your car. Underinflated tires decrease fuel economy by up to three percent and lead to increased pollution and higher greenhouse gas emissions [Source: EPA].
Underinflation also increases tire wear, so it will save you money in the long run if you’re good about checking your tire pressure. 9. Drive smarter. Slow down — driving 60 miles per hour instead of 70 mph on the highway will save you up 4 miles per gallon. [Source: Consumer Guide Automotive]. Accelerating and braking too hard can actually reduce your fuel economy, so take it easy on the brakes and gas pedal. 10. Turn off lights when you’re not in the room and unplug appliances when you’re not using them. It only takes a second to be environmentally conscious.