The tables above are for HAWTs, the regular horizontal “wind mill” type we are all familiar with. For VAWTs the tables can be used as well, but you have to convert their dimensions. Calculate the frontal area (swept area) of the VAWT by multiplying height and width, or for a curved egg-beater approximate the area. Now convert the surface area to a diameter, as if it were a circle: Diameter = √(4 • Area / Pi). That will give you a diameter for the table. Look up the energy production for that diameter and your average annual wind speed and do the following:
In 2015, Ross wrote an op-ed for Time magazine about his city’s planned transition to renewables. “A town in the middle of a state that recently sported oil derricks on its license plates may not be where you’d expect to see leaders move to clean solar and wind generation,” he wrote. Lest readers get the wrong idea, he felt compelled to explain: “No, environmental zealots have not taken over City Council.”
Cleaner air and water: Burning fossil fuels releases greenhouse gases (GHG) into the atmosphere. GHG contribute to global climate change, rising sea levels and unpredictable weather patterns that can be costly in terms of human and economic losses. Burning fossil fuels also releases contaminants in to the air and water near the power generation source. Alternative energy sources can produce the same electricity in a greener way. You can shrink your carbon footprint, help curb climate change and reduce air and water pollution when you choose renewable electricity.
In the mid-1990s, development of both, residential and commercial rooftop solar as well as utility-scale photovoltaic power stations, began to accelerate again due to supply issues with oil and natural gas, global warming concerns, and the improving economic position of PV relative to other energy technologies. In the early 2000s, the adoption of feed-in tariffs—a policy mechanism, that gives renewables priority on the grid and defines a fixed price for the generated electricity—led to a high level of investment security and to a soaring number of PV deployments in Europe.
Wind energy research dates back several decades to the 1970s when NASA developed an analytical model to predict wind turbine power generation during high winds. Today, both Sandia National Laboratories and National Renewable Energy Laboratory have programs dedicated to wind research. Sandia’s laboratory focuses on the advancement of materials, aerodynamics, and sensors. The NREL wind projects are centered on improving wind plant power production, reducing their capital costs, and making wind energy more cost effective overall. The Field Laboratory for Optimized Wind Energy (FLOWE) at Caltech was established to research renewable approaches to wind energy farming technology practices that have the potential to reduce the cost, size, and environmental impact of wind energy production. The president of Sky WindPower Corporation thinks that wind turbines will be able to produce electricity at a cent/kWh at an average which in comparison to coal-generated electricity is a fractional of the cost.
In 2007, General Electric's Chief Engineer predicted grid parity without subsidies in sunny parts of the United States by around 2015; other companies predicted an earlier date: the cost of solar power will be below grid parity for more than half of residential customers and 10% of commercial customers in the OECD, as long as grid electricity prices do not decrease through 2010.
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.”
Several initiatives are being proposed to mitigate distribution problems. First and foremost, the most effective way to reduce USA’s CO2 emissions and slow global warming is through conservation efforts. Opponents of the current US electrical grid have also advocated for decentralizing the grid. This system would increase efficiency by reducing the amount of energy lost in transmission. It would also be economically viable as it would reduce the amount of power lines that will need to be constructed in the future to keep up with demand. Merging heat and power in this system would create added benefits and help to increase its efficiency by up to 80-90%. This is a significant increase from the current fossil fuel plants which only have an efficiency of 34%.
The generator, which is approximately 34% of the wind turbine cost, includes the electrical generator, the control electronics, and most likely a gear box (e.g. planetary gear box), adjustable-speed drive or continuously variable transmission component for converting the low-speed incoming rotation to high-speed rotation suitable for generating electricity.
In the 1980s and early 1990s, most photovoltaic modules provided remote-area power supply, but from around 1995, industry efforts have focused increasingly on developing building integrated photovoltaics and power plants for grid connected applications (see photovoltaic power stations article for details). Currently the largest photovoltaic power plant in North America is the Nellis Solar Power Plant (15 MW). There is a proposal to build a Solar power station in Victoria, Australia, which would be the world's largest PV power station, at 154 MW. Other large photovoltaic power stations include the Girassol solar power plant (62 MW), and the Waldpolenz Solar Park (40 MW).
Green marketing is the sale of green power in competitive markets, where consumers have the option to choose from a variety of suppliers and service offerings, much like they can choose between long-distance telephone carriers. The key difference between green marketing and green pricing is that with green marketing, you are actually switching electricity providers.
Coal is our dirtiest source of energy. It releases more harmful pollutants into the atmosphere than any other energy source and produces a quarter of the nation’s global warming emissions. If we are going to effectively reduce air pollution and address global warming, we need to shut down the oldest, dirtiest coal plants—and not build new ones to replace them.
Many companies are taking the push for 100 percent renewables seriously because they see it as good business — not just today, but for the long term. At the time of publication, 152 companies of various sizes have made a commitment to go 100 percent renewable through RE100. Big names like Apple and Google have already met their targets, while other companies are looking out further into the future, some as far as 2040. That timeline indicates companies are looking beyond today’s prices and present-day marketing benefits.
Wind-to-rotor efficiency (including rotor blade friction and drag) are among the factors impacting the final price of wind power. Further inefficiencies, such as gearbox losses, generator and converter losses, reduce the power delivered by a wind turbine. To protect components from undue wear, extracted power is held constant above the rated operating speed as theoretical power increases at the cube of wind speed, further reducing theoretical efficiency. In 2001, commercial utility-connected turbines deliver 75% to 80% of the Betz limit of power extractable from the wind, at rated operating speed.[needs update]
Green energy, however, utilizes energy sources that are readily available all over the world, including in rural and remote areas that don't otherwise have access to electricity. Advances in renewable energy technologies have lowered the cost of solar panels, wind turbines and other sources of green energy, placing the ability to produce electricity in the hands of the people rather than those of oil, gas, coal and utility companies.
The world of small wind turbines is much like the wild-west of a century ago: Anything goes, and no claim is too bold. Wind turbine manufacturers will even routinely make claims that are not supported by the Laws of Physics. Energy production claims are often exaggerated, as are power curves. In fact, this is the rule, not the exception. Those manufacturers that tell the truth are the exception. Many manufacturers have never tested their wind turbines under real-world conditions. Some have never tested their turbine before selling it to unsuspecting customers. We are not joking! Because we sell grid-tie inverters for small wind turbines we have a front-row seat when it comes to actual operation of turbines of many makes and models. It turns out that some do not work; they self-destruct within days, and sometimes run away and blow their inverter within seconds after being turned onfor the first time (clearly nobody at the factory bothered to ever test it).
Turbines used in wind farms for commercial production of electric power are usually three-bladed. These have low torque ripple, which contributes to good reliability. The blades are usually colored white for daytime visibility by aircraft and range in length from 20 to 80 meters (66 to 262 ft). The size and height of turbines increase year by year. Offshore wind turbines are built up to 8(MW) today and have a blade length up to 80 meters (260 ft). Usual tubular steel towers of multi megawatt turbines have a height of 70 m to 120 m and in extremes up to 160 m.
America is embracing renewables, slowly. In 2016, Massachusetts passed a law promoting a huge investment in wind and hydropower; the first megawatt is expected to hit the grid in 2020. Early this year New York State announced plans to spend 12 years building the infrastructure for a $6 billion offshore wind power industry. Hawaii has pledged to be powered entirely by renewable energy—in 2045. Atlanta’s goal is 2035 and San Francisco’s is 2030. Typically, plans to convert to sustainable energy stretch on for decades.
These include E-glass/carbon, E-glass/aramid and they present an exciting alternative to pure glass or carbon reinforcements. that the full replacement would lead to 80% weight savings, and cost increase by 150%, while a partial (30%) replacement would lead to only 90% cost increase and 50% weight reduction for 8 m turbine. The world currently longest wind turbine rotor blade, the 88.4 m long blade from LM Wind Power is made of carbon/glass hybrid composites. However, additional investigations are required for the optimal composition of the materials 
Heat pumps and Thermal energy storage are classes of technologies that can enable the utilization of renewable energy sources that would otherwise be inaccessible due to a temperature that is too low for utilization or a time lag between when the energy is available and when it is needed. While enhancing the temperature of available renewable thermal energy, heat pumps have the additional property of leveraging electrical power (or in some cases mechanical or thermal power) by using it to extract additional energy from a low quality source (such as seawater, lake water, the ground, the air, or waste heat from a process).
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.
While a single dramatic victory against something like the dirty Keystone XL pipeline can be nice to imagine, the truth is this is how we’re going to win: fighting at every level and with every tool we’ve got. We can’t stop until governments and fossil fuel corporations finally get the message that we need to put our dirty past behind us and fully commit to a clean future that works for all of us moving forward.
Biomass is biological material derived from living, or recently living organisms. It most often refers to plants or plant-derived materials which are specifically called lignocellulosic biomass. As an energy source, biomass can either be used directly via combustion to produce heat, or indirectly after converting it to various forms of biofuel. Conversion of biomass to biofuel can be achieved by different methods which are broadly classified into: thermal, chemical, and biochemical methods. Wood remains the largest biomass energy source today; examples include forest residues – such as dead trees, branches and tree stumps –, yard clippings, wood chips and even municipal solid waste. In the second sense, biomass includes plant or animal matter that can be converted into fibers or other industrial chemicals, including biofuels. Industrial biomass can be grown from numerous types of plants, including miscanthus, switchgrass, hemp, corn, poplar, willow, sorghum, sugarcane, bamboo, and a variety of tree species, ranging from eucalyptus to oil palm (palm oil).
The reliability of small wind turbines is (still) problematic. Even the good ones break much more frequently than we would like, and none will run for 20 years without the need to replace at least some part(s). Despite their apparent simplicity, a small wind turbine is nowhere near as reliable as the average car (and even cars will not run for 20 years without stuff breaking). If you are going to install a small wind turbine you should expect that it will break. The only questions are when and how often.
Wind power - Air flow on the earth's surface can be used to push turbines, with stronger winds producing more energy. High-altitude sites and areas just offshore tend to provide the best conditions for capturing the strongest winds. According to a 2009 study, a network of land-based, 2.5-megawatt wind turbines in rural areas operating at just 20% of their rated capacity could supply 40 times the current worldwide consumption of energy.
Many residential PV systems are connected to the grid wherever available, especially in developed countries with large markets. In these grid-connected PV systems, use of energy storage is optional. In certain applications such as satellites, lighthouses, or in developing countries, batteries or additional power generators are often added as back-ups. Such stand-alone power systems permit operations at night and at other times of limited sunlight.