Enhanced geothermal systems (EGS) are a new type of geothermal power technologies that do not require natural convective hydrothermal resources. The vast majority of geothermal energy within drilling reach is in dry and non-porous rock.[161] EGS technologies "enhance" and/or create geothermal resources in this "hot dry rock (HDR)" through hydraulic stimulation. EGS and HDR technologies, such as hydrothermal geothermal, are expected to be baseload resources which produce power 24 hours a day like a fossil plant. Distinct from hydrothermal, HDR and EGS may be feasible anywhere in the world, depending on the economic limits of drill depth. Good locations are over deep granite covered by a thick (3–5 km) layer of insulating sediments which slow heat loss.[162] There are HDR and EGS systems currently being developed and tested in France, Australia, Japan, Germany, the U.S. and Switzerland. The largest EGS project in the world is a 25 megawatt demonstration plant currently being developed in the Cooper Basin, Australia. The Cooper Basin has the potential to generate 5,000–10,000 MW.
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:
Besides the greening of fossil fuel and nuclear power plants, another option is the distribution and immediate use of power from solely renewable sources. In this set-up energy storage is again not necessary. For example, TREC has proposed to distribute solar power from the Sahara to Europe. Europe can distribute wind and ocean power to the Sahara and other countries. In this way, power is produced at any given time as at any point of the planet as the sun or the wind is up or ocean waves and currents are stirring. This option however is probably not possible in the short-term, as fossil fuel and nuclear power are still the main sources of energy on the mains electricity net and replacing them will not be possible overnight.

Other renewable energy technologies are still under development, and include cellulosic ethanol, hot-dry-rock geothermal power, and marine energy.[156] These technologies are not yet widely demonstrated or have limited commercialization. Many are on the horizon and may have potential comparable to other renewable energy technologies, but still depend on attracting sufficient attention and research, development and demonstration (RD&D) funding.[156]

Manufacturers often claim that their vertical axis turbine is superior to a horizontal one, because it always faces the wind. So does any horizontal axis turbine, thanks to their tail or yaw mechanism. If the airflow is such that wind directions change drastically from one second to the next it means you have lots of turbulence, and that means it is a poor place to put any wind turbine, HAWT or VAWT.


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.
Max daily output is at 1.4KW. It also works when there is only the wind power, getting single power. Closed maintenance-free ball bearings ensure not only lightness, high efficiency and low wear. The series of wind turbine with high-quality aluminum alloy and stainless steel parts, the machine is not only light weight, small size, shape is also better than similar products.
In conclusion, I would say that however great the scientific importance of this discovery may be, its practical value will be no less obvious when we reflect that the supply of solar energy is both without limit and without cost, and that it will continue to pour down upon us for countless ages after all the coal deposits of the earth have been exhausted and forgotten.[36]

Al Gore says the reason is innovation. “The cost-reduction curve that came to technologies like computers, smartphones and flat-panel televisions has come to solar energy, wind energy and battery storage,” he says. “I remember being startled decades ago when people first started to explain to me that the cost of computing was being cut in half every 18 to 24 months. And now this dramatic economic change has begun to utterly transform the electricity markets.”


Renewable energy is energy that is collected from renewable resources, which are naturally replenished on a human timescale, such as sunlight, wind, rain, tides, waves, and geothermal heat.[3] Renewable energy often provides energy in four important areas: electricity generation, air and water heating/cooling, transportation, and rural (off-grid) energy services.[4]
Subsequently, Spain, Italy, Greece—that enjoyed an early success with domestic solar-thermal installations for hot water needs—and France introduced feed-in tariffs. None have replicated the programmed decrease of FIT in new contracts though, making the German incentive relatively less and less attractive compared to other countries. The French and Greek FIT offer a high premium (EUR 0.55/kWh) for building integrated systems. California, Greece, France and Italy have 30–50% more insolation than Germany making them financially more attractive. The Greek domestic "solar roof" programme (adopted in June 2009 for installations up to 10 kW) has internal rates of return of 10–15% at current commercial installation costs, which, furthermore, is tax free.
As suppliers of inverters for turbines good, bad, and just plain ugly, we have pretty well seen it all when it comes to turbine failure. We can tell you unequivocally that you get what you pay for. Depending on your sense of adventure that can be good or bad; if you plan to go cheap, plan on (you) being the manufacturer’s R&D department and test center. Being a really good do-it-yourselfer with an understanding of wind turbines, alternators, and all things electric will come in very handy too. Just in case you do not believe us, you can read about it in this Green Power Talk thread. There are more threads with similar content on the forum, just browse around a little.
Consumers throughout the United States have a third green power option: Renewable Energy Certificates (RECs or sometimes "green tags"). A REC represents the environmental attributes or benefits of renewable electricity generation (usually one credit = one kilowatt-hour). RECs can be purchased in almost any quantity and are usually available from someone other than your electricity provider. What you pay for is the benefit of adding clean, renewable energy generation to the regional or national electricity grid. The overall environmental benefit of purchasing a green pricing or green marketing product versus RECs is exactly the same. RECs provide a "green" option for people in any state, but are ideal for people who live in states where green pricing and green marketing options are not available. 
Sustainable energy is energy that is consumed at insignificant rates compared to its supply and with manageable collateral effects, especially environmental effects. Another common definition of sustainable energy is an energy system that serves the needs of the present without compromising the ability of future generations to meet their energy needs.[1] Not all renewable energy is sustainable. While renewable energy is defined as energy sources that are naturally replenished on a human timescale, sustainable (often referred to as 'clean') energy must not compromise the system in which it is adopted to the point of being unable to provide for future need. The organizing principle for sustainability is sustainable development, which includes the four interconnected domains: ecology, economics, politics and culture.[2] Sustainability science is the study of sustainable development and environmental science.[3]
Most in the industry agree that 11 m/s (24.6 mph) makes for a good rated wind speed. Go above it and very soon the turbine should be hard at work to protect itself from destruction, by furling, governing, or shutting down. Those that do not will likely face a short and tortured life. If we agree on 11 m/s, an equation for a realistic rated power number is as follows:
List of books about renewable energy List of countries by electricity production from renewable sources List of geothermal power stations Lists of hydroelectric power stations List of largest hydroelectric power stations List of people associated with renewable energy List of renewable energy companies by stock exchange List of renewable energy organizations List of renewable energy topics by country List of U.S. states by electricity production from renewable sources
While many renewable energy projects are large-scale, renewable technologies are also suited to rural and remote areas and developing countries, where energy is often crucial in human development.[13] Former United Nations Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity.[14] As most of renewables provide electricity, renewable energy deployment is often applied in conjunction with further electrification, which has several benefits: Electricity can be converted to heat (where necessary generating higher temperatures than fossil fuels), can be converted into mechanical energy with high efficiency and is clean at the point of consumption.[15][16] In addition to that electrification with renewable energy is much more efficient and therefore leads to a significant reduction in primary energy requirements, because most renewables don't have a steam cycle with high losses (fossil power plants usually have losses of 40 to 65%).[17]

The generator, which is approximately 34% of the wind turbine cost, includes the electrical generator,[38][39] the control electronics, and most likely a gear box (e.g. planetary gear box),[40] adjustable-speed drive or continuously variable transmission[41] component for converting the low-speed incoming rotation to high-speed rotation suitable for generating electricity.

^ Jump up to: a b Werner, Jürgen H. (2 November 2011). "Toxic Substances In Photovoltaic Modules" (PDF). postfreemarket.net. Institute of Photovoltaics, University of Stuttgart, Germany - The 21st International Photovoltaic Science and Engineering Conference 2011 Fukuoka, Japan. p. 2. Archived from the original (PDF) on 23 September 2014. Retrieved 23 September 2014.


In the case of crystalline silicon modules, the solder material, that joins together the copper strings of the cells, contains about 36 percent of lead (Pb). Moreover, the paste used for screen printing front and back contacts contains traces of Pb and sometimes Cd as well. It is estimated that about 1,000 metric tonnes of Pb have been used for 100 gigawatts of c-Si solar modules. However, there is no fundamental need for lead in the solder alloy.[141]

With feed-in tariffs, the financial burden falls upon the consumer. They reward the number of kilowatt-hours produced over a long period of time, but because the rate is set by the authorities, it may result in perceived overpayment. The price paid per kilowatt-hour under a feed-in tariff exceeds the price of grid electricity. Net metering refers to the case where the price paid by the utility is the same as the price charged.
If you do install an anemometer and measure the wind over one or more years, you should compare the annual average wind speed obtained from your anemometer data to the annual average of the nearest airport or meteo-station for that same year. This will tell you if your site is more or less windy than that airport or meteo-station, and by how much. Then compare that year’s data  to the long-term annual average wind speed, and you will know what to expect over the long term, corrected for your particular site. It will not be exact, but it will make your short-term anemometer data much more useful.

I contacted many different solar installation companies looking for someone who operates in my area (150 miles west of San Antonio) and Soleil Energy Solutions was the only one willing to make the trip out here. Fortunately for me, they’re also a great company to work with.I was able to deal directly with the owners of the company, Abbas and Jennifer, and their customer service is top notch. They had a customized assessment the day after I contacted them which included the size of system best suited for my home and energy consumption, the cost of the system with all the rebates and tax rebates I qualified for, and the amount of money I’d save on my light bill. They also offered me multiple financing options and guided me through that whole process. I had a ton of questions throughout the entire process and whether I emailed them or texted them after business hours, I got a response right away.They took care of everything for me including securing the rebates and city permits so I didn’t really have to do anything. The crew they had doing the actual solar panel and backup battery installation are all veterans, which I really appreciated because of their attention to detail. They were very courteous and they made sure the panels added to the curb appeal of my house as far as their placement.I’m really excited to finally have a solar panel system for my home and I’d definitely recommend Soleil to anyone who’s interested in switching to solar too.... read more


United Nations' Secretary-General Ban Ki-moon has said that renewable energy has the ability to lift the poorest nations to new levels of prosperity.[14] In October 2011, he "announced the creation of a high-level group to drum up support for energy access, energy efficiency and greater use of renewable energy. The group is to be co-chaired by Kandeh Yumkella, the chair of UN Energy and director general of the UN Industrial Development Organisation, and Charles Holliday, chairman of Bank of America".[147]
Many residential PV systems are connected to the grid wherever available, especially in developed countries with large markets.[10] 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.
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