The time will arrive when the industry of Europe will cease to find those natural resources, so necessary for it. Petroleum springs and coal mines are not inexhaustible but are rapidly diminishing in many places. Will man, then, return to the power of water and wind? Or will he emigrate where the most powerful source of heat sends its rays to all? History will show what will come.[35]
Climate change concerns coupled with high oil prices and increasing government support are driving increasing rates of investment in the sustainable energy industries, according to a trend analysis from the United Nations Environment Programme. According to UNEP, global investment in sustainable energy in 2007 was higher than previous levels, with $148 billion of new money raised in 2007, an increase of 60% over 2006. Total financial transactions in sustainable energy, including acquisition activity, was $204 billion.[64]
The advantage of this approach in the United States is that many states offer incentives to offset the cost of installation of a renewable energy system. In California, Massachusetts and several other U.S. states, a new approach to community energy supply called Community Choice Aggregation has provided communities with the means to solicit a competitive electricity supplier and use municipal revenue bonds to finance development of local green energy resources. Individuals are usually assured that the electricity they are using is actually produced from a green energy source that they control. Once the system is paid for, the owner of a renewable energy system will be producing their own renewable electricity for essentially no cost and can sell the excess to the local utility at a profit.

Reliance on rare earth minerals for components has risked expense and price volatility as China has been main producer of rare earth minerals (96% in 2009) and had been reducing its export quotas of these materials.[56] In recent years, however, other producers have increased production of rare earth minerals and China has removed its reduced export quota on rare earths leading to an increased supply and decreased cost of rare earth minerals, increasing the viability of the implementation of variable speed generators in wind turbines on a large scale.[57]
A parabolic trough consists of a linear parabolic reflector that concentrates light onto a receiver positioned along the reflector's focal line. The receiver is a tube positioned along the focal points of the linear parabolic mirror and is filled with a working fluid. The reflector is made to follow the sun during daylight hours by tracking along a single axis. Parabolic trough systems provide the best land-use factor of any solar technology.[13] The SEGS plants in California and Acciona's Nevada Solar One near Boulder City, Nevada are representatives of this technology.[14][15]
I wouldn’t consider myself a creative type.  Never painted a picture, never felt confident in color or fabric choices.  But I did get a real creativity boost living off-grid in northern New Mexico, raising children on one income in a home with caught water, gardening at 7600 feet in a climate that gets REALLY cold.  We built a house called an earthship from recycled materials and earth. 
If you want to purchase a rooftop solar system for your home, federal tax credits and other state, local, or utility incentives can offset some of the upfront cost. There are also several financing options available for homeowners, including energy-saving mortgages, home equity, Property Assessed Clean Energy Loans, and more traditional bank loans.
According to the International Energy Agency, new bioenergy (biofuel) technologies being developed today, notably cellulosic ethanol biorefineries, could allow biofuels to play a much bigger role in the future than previously thought.[41] Cellulosic ethanol can be made from plant matter composed primarily of inedible cellulose fibers that form the stems and branches of most plants. Crop residues (such as corn stalks, wheat straw and rice straw), wood waste and municipal solid waste are potential sources of cellulosic biomass. Dedicated energy crops, such as switchgrass, are also promising cellulose sources that can be sustainably produced in many regions of the United States.[42]
At Bodine-Scott, our renewable energy options have helped dozens of local homes and businesses reduce their utility bills and any negative environmental impact from the use of traditional energy sources. Our technicians are NABCEP-certified experts, and we keep all of our staff informed and up to date on the latest developments in the solar industries. Our average customer sees a 50 percent reduction in utility costs, to say nothing of the invaluable reduction in environmental impact that comes from using clean energy. If you are serious about making an investment in the future of your home and the Earth, contact us today to speak with one of our renewable energy experts.
Anaerobic digestion, geothermal power, wind power, small-scale hydropower, solar energy, biomass power, tidal power, wave power, and some forms of nuclear power (ones which are able to "burn" nuclear waste through a process known as nuclear transmutation, such as an Integral Fast Reactor, and therefore belong in the "Green Energy" category). Some definitions may also include power derived from the incineration of waste.
The windwheel of Hero of Alexandria (10 AD – 70 AD) marks one of the first recorded instances of wind powering a machine in history.[2][3] However, the first known practical wind power plants were built in Sistan, an Eastern province of Persia (now Iran), from the 7th century. These "Panemone" were vertical axle windmills, which had long vertical drive shafts with rectangular blades.[4] Made of six to twelve sails covered in reed matting or cloth material, these windmills were used to grind grain or draw up water, and were used in the gristmilling and sugarcane industries.[5]
The most significant barriers to the widespread implementation of large-scale renewable energy and low carbon energy strategies are primarily political and not technological. According to the 2013 Post Carbon Pathways report, which reviewed many international studies, the key roadblocks are: climate change denial, the fossil fuels lobby, political inaction, unsustainable energy consumption, outdated energy infrastructure, and financial constraints.[155]
Japan and China have national programs aimed at commercial scale Space-Based Solar Power (SBSP). The China Academy of Space Technology (CAST) won the 2015 International SunSat Design Competition with this video of their Multi-Rotary Joint design. Proponents of SBSP claim that Space-Based Solar Power would be clean, constant, and global, and could scale to meet all planetary energy demand.[56] A recent multi-agency industry proposal (echoing the 2008 Pentagon recommendation) won the SECDEF/SECSTATE/USAID Director D3 (Diplomacy, Development, Defense) Innovation Challenge.[57]
A few localities have exploited the attention-getting nature of wind turbines by placing them on public display, either with visitor centers around their bases, or with viewing areas farther away.[59] The wind turbines are generally of conventional horizontal-axis, three-bladed design, and generate power to feed electrical grids, but they also serve the unconventional roles of technology demonstration, public relations, and education.
A recent UK Government document states that "projects are generally more likely to succeed if they have broad public support and the consent of local communities. This means giving communities both a say and a stake".[194] In countries such as Germany and Denmark many renewable projects are owned by communities, particularly through cooperative structures, and contribute significantly to overall levels of renewable energy deployment.[195][196]
In its 2014 edition of the Technology Roadmap: Solar Photovoltaic Energy report, the International Energy Agency (IEA) published prices for residential, commercial and utility-scale PV systems for eight major markets as of 2013 (see table below).[2] However, DOE's SunShot Initiative has reported much lower U.S. installation prices. In 2014, prices continued to decline. The SunShot Initiative modeled U.S. system prices to be in the range of $1.80 to $3.29 per watt.[76] Other sources identify similar price ranges of $1.70 to $3.50 for the different market segments in the U.S.,[77] and in the highly penetrated German market, prices for residential and small commercial rooftop systems of up to 100 kW declined to $1.36 per watt (€1.24/W) by the end of 2014.[78] In 2015, Deutsche Bank estimated costs for small residential rooftop systems in the U.S. around $2.90 per watt. Costs for utility-scale systems in China and India were estimated as low as $1.00 per watt.[79]
The price breakdown really surprised Tom D. He was enjoying a nice solar installation presentation at a kiosk at Costco when the numbers came out. Two-thirds of the overall cost was installation. Tom got online and found Wholesale Solar. He didn't have much construction experience and had no electrical experience. But after conversations with our solar experts, he felt confident to take on the project.

Previously, the largest U.S. city fully powered by renewables was Burlington, Vermont (pop. 42,000), home to Senator Bernie Sanders, the jam band Phish and the original Ben & Jerry’s. Georgetown’s feat is all the more dramatic because it demolishes the notion that sustainability is synonymous with socialism and GMO-free ice cream. “You think of climate change and renewable energy, from a political standpoint, on the left-hand side of the spectrum, and what I’ve done is toss all those partisan political thoughts aside,” Ross says. “We’re doing this because it’s good for our citizens. Cheaper electricity is better. Clean energy is better than fossil fuels.”

Some people, including Greenpeace founder and first member Patrick Moore,[67][68][69] George Monbiot,[70] Bill Gates[71] and James Lovelock[72] have specifically classified nuclear power as green energy. Others, including Greenpeace's Phil Radford[73][74] disagree, claiming that the problems associated with radioactive waste and the risk of nuclear accidents (such as the Chernobyl disaster) pose an unacceptable risk to the environment and to humanity. However, newer nuclear reactor designs are capable of utilizing what is now deemed "nuclear waste" until it is no longer (or dramatically less) dangerous, and have design features that greatly minimize the possibility of a nuclear accident. These designs have yet to be commercialized. (See: Molten salt reactor)
Many of the largest operational onshore wind farms are located in the USA and China. The Gansu Wind Farm in China has over 5,000 MW installed with a goal of 20,000 MW by 2020. China has several other "wind power bases" of similar size. The Alta Wind Energy Center in California is the largest onshore wind farm outside of China, with a capacity of 1020 MW of power.[141] Europe leads in the use of wind power with almost 66 GW, about 66 percent of the total globally, with Denmark in the lead according to the countries installed per-capita capacity.[142] As of February 2012, the Walney Wind Farm in United Kingdom is the largest offshore wind farm in the world at 367 MW, followed by Thanet Wind Farm (300 MW), also in the UK.
The first three are active solar systems, which use mechanical or electrical devices that convert the sun's heat or light to another form of usable energy. Passive solar buildings are designed and oriented to collect, store, and distribute the heat energy from sunlight to maintain the comfort of the occupants without the use of moving parts or electronics.
Renewable electricity production, from sources such as wind power and solar power, is sometimes criticized for being variable or intermittent, but is not true for concentrated solar, geothermal and biofuels, that have continuity. In any case, the International Energy Agency has stated that deployment of renewable technologies usually increases the diversity of electricity sources and, through local generation, contributes to the flexibility of the system and its resistance to central shocks.[191]
A 1.5 (MW) wind turbine of a type frequently seen in the United States has a tower 80 meters (260 ft) high. The rotor assembly (blades and hub) weighs 22,000 kilograms (48,000 lb). The nacelle, which contains the generator, weighs 52,000 kilograms (115,000 lb). The concrete base for the tower is constructed using 26,000 kilograms (58,000 lb) reinforcing steel and contains 190 cubic meters (250 cu yd) of concrete. The base is 15 meters (50 ft) in diameter and 2.4 meters (8 ft) thick near the center.[43]
The W03083 Firman generator is perfect in and The W03083 Firman generator is perfect in and around the RV on the campsite while powering small appliances or while at home. Its Fuel Economy Mode reduces fuel consumption and promotes engine efficiency. It uses an OHV electric start engine (Max-Pro Series) for longer life higher performance and lower maintenance. ...  More + Product Details Close
A turbine that produces around 5 kW worth of energy can produce approximately 8,000 kWh per year, assuming there are decent winds to power it. Given ideal conditions, you will be able to recoup your investment in three to five years, depending on your monthly energy consumption and other related factors. If, however, your property doesn’t get enough wind then it may take a little more time to recover your initial investment.
Hydropower is produced in 150 countries, with the Asia-Pacific region generating 32 percent of global hydropower in 2010. For countries having the largest percentage of electricity from renewables, the top 50 are primarily hydroelectric. China is the largest hydroelectricity producer, with 721 terawatt-hours of production in 2010, representing around 17 percent of domestic electricity use. There are now three hydroelectricity stations larger than 10 GW: the Three Gorges Dam in China, Itaipu Dam across the Brazil/Paraguay border, and Guri Dam in Venezuela.[48]
A good match between generation and consumption is key for high self consumption, and should be considered when deciding where to install solar power and how to dimension the installation. The match can be improved with batteries or controllable electricity consumption.[94] However, batteries are expensive and profitability may require provision of other services from them besides self consumption increase.[95] Hot water storage tanks with electric heating with heat pumps or resistance heaters can provide low-cost storage for self consumption of solar power.[94] Shiftable loads, such as dishwashers, tumble dryers and washing machines, can provide controllable consumption with only a limited effect on the users, but their effect on self consumption of solar power may be limited.[94]
Only a quarter of the worlds estimated hydroelectric potential of 14,000 TWh/year has been developed, the regional potentials for the growth of hydropower around the world are, 71% Europe, 75% North America, 79% South America, 95% Africa, 95% Middle East, 82% Asia Pacific. However, the political realities of new reservoirs in western countries, economic limitations in the third world and the lack of a transmission system in undeveloped areas, result in the possibility of developing 25% of the remaining potential before 2050, with the bulk of that being in the Asia Pacific area.[102] There is slow growth taking place in Western counties, but not in the conventional dam and reservoir style of the past. New projects take the form of run-of-the-river and small hydro, neither using large reservoirs. It is popular to repower old dams thereby increasing their efficiency and capacity as well as quicker responsiveness on the grid.[103] Where circumstances permit existing dams such as the Russell Dam built in 1985 may be updated with "pump back" facilities for pumped-storage which is useful for peak loads or to support intermittent wind and solar power. Countries with large hydroelectric developments such as Canada and Norway are spending billions to expand their grids to trade with neighboring countries having limited hydro.[104]

The Stirling solar dish combines a parabolic concentrating dish with a Stirling engine which normally drives an electric generator. The advantages of Stirling solar over photovoltaic cells are higher efficiency of converting sunlight into electricity and longer lifetime. Parabolic dish systems give the highest efficiency among CSP technologies.[18] The 50 kW Big Dish in Canberra, Australia is an example of this technology.[14]

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