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]
Above this rated speed, the wind loads on the rotor blades will be approaching the maximum strength of the electrical machine, and the generator will be producing its maximum or rated power output as the rated wind speed window will have been reached. If the wind speed continues to increase, the wind turbine generator would stop at its cut-out point to prevent mechanical and electrical damage, resulting in zero electrical generation. The application of a brake to stop the generator for damaging itself can be either a mechanical governor or electrical speed sensor.

In terms of ocean energy, another third-generation technology, Portugal has the world's first commercial wave farm, the Aguçadora Wave Park, under construction in 2007. The farm will initially use three Pelamis P-750 machines generating 2.25 MW.[44][45] and costs are put at 8.5 million euro. Subject to successful operation, a further 70 million euro is likely to be invested before 2009 on a further 28 machines to generate 525 MW.[46] Funding for a wave farm in Scotland was announced in February, 2007 by the Scottish Executive, at a cost of over 4 million pounds, as part of a £13 million funding packages for ocean power in Scotland. The farm will be the world's largest with a capacity of 3 MW generated by four Pelamis machines.[47] (see also Wave farm).

A Wind Turbine Generator is what makes your electricity by converting mechanical energy into electrical energy. Lets be clear here, they do not create energy or produce more electrical energy than the amount of mechanical energy being used to spin the rotor blades. The greater the “load”, or electrical demand placed on the generator, the more mechanical force is required to turn the rotor. This is why generators come in different sizes and produce differing amounts of electricity.
A more reliable grid: Even if we're not ready to completely transition to renewable energy sources of power, supplementing the grid with green electricity helps increase grid reliability. You can also produce your own green electricity by installing solar panels or wind turbines at home. If the grid goes down for some reason, you may be able to keep your power on using your on-site renewable power generation system.
The use of a gearbox allows for better matching of the generator speed to that of the turbine but the disadvantage of using a gearbox is that as a mechanical component it is subjected to wear and tear reducing the efficiency of the system. Direct drive however may be more simple and efficient, but the generators rotor shaft and bearings are subjected to the full weight and rotational force of the rotor blades.
Worldwide growth of photovoltaics has averaged 40% per year from 2000 to 2013[35] and total installed capacity reached 303 GW at the end of 2016 with China having the most cumulative installations (78 GW)[36] and Honduras having the highest theoretical percentage of annual electricity usage which could be generated by solar PV (12.5%).[36][35] The largest manufacturers are located in China.[37][38]
Small-scale turbines are expensive (one manufacturer says a typical system costs $40,000 to $60,000 to install), though some of that outlay can be offset by federal and local tax credits. Experts recommend that you buy one certified by the Small Wind Certification Council. Turbine manufacturers include Bergey Wind Power, Britwind and Xzeres Wind; look on their websites for local dealers.
At GE, product evolution is at our core, and we are continuously working to develop the next generation of wind energy. Beginning in 2002 with one wind turbine model, we now offer a full suite of turbines created for a variety of wind environments. We offer increased value to customers with proven performance, reliability, and availability. Our portfolio of turbines feature rated capacities from 1.7 MW to 5.3 MW (Onshore) and 6 MW to 12 MW (Offshore), we are uniquely suited to meet the needs of a broad range of wind regimes. 
Solar contractors face many decisions when it comes to finding the best solar design. One important consideration is determining whether to use module-level power electronics (microinverters or DC optimizers). Once costly specialty products, module-level power electronics have made great strides in the last decade and are rapidly growing in popularity. And there’s good reason for…
Within emerging economies, Brazil comes second to China in terms of clean energy investments. Supported by strong energy policies, Brazil has one of the world’s highest biomass and small-hydro power capacities and is poised for significant growth in wind energy investment. The cumulative investment potential in Brazil from 2010 to 2020 is projected as $67 billion.[155]
The International Geothermal Association (IGA) has reported that 10,715 MW of geothermal power in 24 countries is online, which is expected to generate 67,246 GWh of electricity in 2010.[131] This represents a 20% increase in geothermal power online capacity since 2005. IGA projects this will grow to 18,500 MW by 2015, due to the large number of projects presently under consideration, often in areas previously assumed to have little exploitable resource.[131]
A: A residential solar PV system can cost anywhere from $25,000 to $35,000, on average. Because of the high cost, a power purchase agreement (PPA), loan, or lease are popular options for financing a solar PV system. Naturally, there are benefits and drawbacks with each option. We won’t cover them in detail here, but you can learn more in our article “Financing Options for Solar Power Explained.”
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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