Solar power | Wikipedia audio article
Solar. Power is the conversion of, energy from, sunlight into, electricity either. Directly. Using, photovoltaics. Pv. Indirectly. Using, concentrated. Solar, power or, a combination. Concentrated. Solar power systems. Use lenses or, mirrors and, tracking, systems to focus, a large area, of sunlight into. A small beam. Photovoltaic. Cells. Convert, light into an electric, current using the photovoltaic, effect. Photovoltaics. Were. Initially, solely, used as a source of electricity, for, small and medium-sized, applications. From the calculator, powered, by a single, solar, cell to remote homes powered by an off-grid rooftop. PV system. Commercial. Concentrated. Solar power plants. Were first developed, in the 1980s. The. 392. Megawatts, even, per installation, is, the largest. Concentrating. Solar power plant, in the world located. In the Mojave, Desert of California. As. The. Cost of solar electricity has. Fallen the, number of grid connected, solar, PV, systems, has grown into the millions, and utility, scale solar power. Stations. With hundreds, of megawatts are, being built. Solar. PV, is rapidly, becoming an inexpensive. Low-carbon. Technology. To harness renewable. Energy, from the Sun the. Current, largest, photovoltaic, power. Station. In the world is the, 850. Megawatts, longyang, Shah dam solar, park in Ching, hai China. The. International. Energy Agency. Projected. In 2014. That under its high. Renewables. Scenario. By, 2050. Solar. Photovoltaics. And. Concentrated. Solar power would, contribute, about 16. And 11%, respectively. Of, the worldwide, electricity. Consumption, and, solar would be the world's, largest source. Of electricity. Most. Solar, installations. Would be in China and India, in, 2017. Solar. Power provided. 1.7. Percent of, total worldwide. Electricity. Production growing. At 35, percent per, annum. Topic. Mainstream. Technologies. Many. Industrialized. Nations. Have installed, significant. Solar power capacity. Into their grids to supplement. Or provide, an alternative. To conventional energy. Sources while. An increasing, number of less developed nations. Have turned to solar to reduce dependence on, expensive. Imported, fuels see, solar power by country. Long-distance. Transmission allows. Remote renewable. Energy, resources, to displace, fossil, fuel consumption. Solar. Power plants. Use one of two technologies. Photovoltaic. PV. Systems. Use solar, panels either, on rooftops, or in ground mounted, solar, farms, converting. Sunlight directly, into, electric, power. Concentrated. Solar, power CSP, also. Known as. Concentrated. Solar thermal. Plants. Use solar, thermal energy to make steam, that, is thereafter, converted. Into electricity. By, a turbine. Topic. Photovoltaics. A solar. Cell or photovoltaic, cell. PV, is a device, that converts light into electric. Current, using the photovoltaic, effect. The. First solar, cell was, constructed. By Charles, Fritts in the 1880s. The. German, industrialist. Ernst Werner von Siemens was, among those who recognized. The importance, of this discovery. In. 1931. The, German engineer, Bruno, Lange developed. A photocell. Using, silver solenoid, in place of copper oxide. Although the prototype, selenium. Cells converted. Less than 1%, of incident, light into, electricity. Following. The work of Russell, in the 1940s. Researchers, Gerald. Pearson Calvin. Fuller and Darrell Chaplin created, the silicon, solar cell, in, 1954. These. Early, solar cells, cost. 286. United. States dollars, per watt and reached efficiencies. Of 4.5. To 6 percent the, array of a photovoltaic, power. System. Or PV, system, produces. Direct, current, DC power, which fluctuates with, the sunlights intensity. For. Practical, use this usually, requires conversion. To certain, desired, voltages. Or alternating, current, AC, through, the use of inverters. Multiple. Solar cells, are connected inside, modules. Modules. Are wired together to, form a raised then, tied to an inverter which, produces. Power at the desired voltage, and for AC the, desired, frequency phase. 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 backups. Such. Standalone. Power systems. Permit, operations. At night and at other times of limited sunlight. Topic. Concentrated. Solar power. Concentrated. Solar power, CSP. Also. Called. Concentrated. Solar, thermal, users. Lenses, or mirrors and, tracking, systems to concentrate. Sunlight then, use the resulting, heat to generate electricity, from, conventional. Steam driven turbines. A. Wide. Range of concentrating. Technologies. Exists. Among the best known are the parabolic, trough the, compact, linear Fresnel reflector.
The, Stirling, dish and the solar, power tower. Various. Techniques, are used to track the Sun and focus, light in. All of these systems are working fluid, is heated by, the concentrated. Sunlight and, is then used for power generation or. Energy, storage. Thermal. Storage efficiently. Allows up to 24. Hour electricity. Generation, a parabolic, trough, consists. Of a linear parabolic, reflector. That concentrates. Light onto a receiver positioned. Along the reflectors. 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 access. Parabolic. Trough systems, provide, the best land-use factor, of any solar technology. The. Segs, plants. In California and, a key owners Nevada, solar, one near, Boulder City Nevada, are representatives. Of this technology, compact. Linear Fresnel reflectors. Are CSP, plants, which use many thin mirrors strips instead, of parabolic, mirrors to concentrate sunlight. Onto two tubes with working, fluid, this. Has the advantage, that flat, mirrors, can be used which are much cheaper than parabolic. Mirrors and that more reflectors, can be placed in the same amount of space allowing. More of the available sunlight. To, be used. Concentrating. Linear, Fresnel reflectors. Can be used in either large or more compact, plants, the Stirling, solar dish can be a parabolic. Concentrating. Dish with a Stirling, engine which, normally, drives an electric generator. The. Advantages. Of Stirling. Solar, over photovoltaic, cells. A higher efficiency, of converting, sunlight into electricity and. Longer, lifetime. Parabolic. Dish systems, give the highest efficiency, among, CSP. Technologies. The. 50, kilowatts, big dish in Canberra Australia. Is an example, of this technology. A solar, power tower uses, an array of tracking, reflectors. Heliostats. To concentrate. Light on a central, receiver, atop a tower, power. Towers. Can achieve higher thermal, to electricity, conversion. Efficiency. Than linear tracking, CSP. Schemes, and better energy storage, capability. Than dish stirling technologies. The. PS 10 solar, power plant, and PS 20, solar, power plants, are examples, of this technology. Topic. Hybrid. Systems. A hybrid. System, combines. CPV. And CSP, with, one another or with other forms, of generations. Such as diesel wind, and biogas. The. Combined, form, of generation. May enable the system to modulate, power output. As a function of demand, or at least reduce, the fluctuating. Nature, of solar power and the consumption, of non-renewable, fuel. Hybrid. Systems, are most often found on, Islands. See, PV CSP. System. A novel, solar, CPV. CSP. Hybrid, system, has been proposed, combining. Concentrator. Photovoltaics. With. The non PV, technology. Of concentrated. Solar power or also known as concentrated. Solar thermal. Iscc, system. The. Hacý Armel power station, in algeria is an example, of combining, CSP. With a gas turbine, where, a 25. Megawatt, CSP. Parabolic. Trough array supplements. Are much larger. 130. Megawatts. Combined, cycle gas turbine. Plant. Another. Example, is the yazd power station. In Iran. Pvt. System. Hybrid. PV, T also, known as photovoltaic, thermal. Hybrid, solar collectors. Convert, solar radiation. Into thermal and electrical, energy. Such. A system. Combines, a solar, PV module. With a solar, thermal collector. In a complementary. Way. See. PV, T system. A concentrated. Photovoltaic. Thermal. Hybrid, CP, VT, system, is similar to a PV, T system, it. Uses. Concentrated. Photovoltaics. CPV. Instead, of conventional, PV. Technology. And combines, it with a solar thermal collector. PV. Diesel, system. It. Combines, a photovoltaic system. With, a diesel generator. Combinations. With other renewables. Are possible, and include wind, turbines. PV. Thermoelectric. System. Thermoelectric. Or thermo. Voltaic. Devices. Convert, a temperature. Difference, between dissimilar. Materials. Into, an electric, current. Solar. Cells, use, only the high-frequency part, of the radiation. While the low-frequency, heat. Energy is wasted. Several. Patents, about the use of thermoelectric. Devices in, tandem, with solar, cells have, been filed the idea, is to increase the, efficiency of the combined, solar. Thermoelectric. System, to convert the solar radiation, into, useful electricity. Topic. Development, and. Deployment. You. Topic. Early. Days. The, early development. Of solar technologies. Starting in the 1860s. Was, driven by an expectation, that, coal would soon become scarce. Charles. Fritts installed. The world's, first rooftop. Photovoltaic, solar. Array, using, 1%. Efficient, selenium, cells on a New York City, roof, in 1884. However. Development, of, solar technologies. Stagnated. In the early 20th, century in, the face of the increasing, availability. Economy. And utility. Of coal and petroleum, in.
1974. It was estimated that, only six, private homes, in all of North America were, entirely, heated. Or cooled by, functional. Solar, power systems. The. 1973. Oil embargo, and. 1979. Energy crisis. Caused a reorganization. Of energy, policies, around the world and brought renewed attention, to, developing solar, technologies. Deployment. Strategies. Focused, on incentive, programs, such as the federal photovoltaic. Utilization. Program in the u.s. and the sunshine, program, in Japan other. Efforts. Included. The formation, of research, facilities in, the United, States Surrey, now, NREL. Japan, NEDO, and, Germany. Fraunhofer eyes. Between. 1970. And 1983. Installations. Of photovoltaic, systems. Grew rapidly but. Falling oil prices in. The early 1980s. Moderated. The growth of photovoltaics. From. 1984. To 1996. Topic. Mid-1990s. To early, 2010. 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, deployment in. Europe. Topic. Current. Status. For, several years worldwide. Growth. Of solar PV was, driven by European, deployment. But has since shifted to, Asia especially China. And Japan and, to a growing number of countries, and regions all, over the world including but, not limited to, Australia. Canada, Chile. India. Israel Mexico. South. Africa. South, Korea, Thailand. And the United States. Worldwide. Growth, of photovoltaics, has. Averaged, 40 percent per year from 2000. To 2013, and. Total, installed, capacity reached. 303. Gigawatts, at the end of 2016. With China having, the most cumulative. Installations. 78. Gigawatts, and Honduras. Having, the highest theoretical. Percentage, of annual electricity usage. Which could be generated. By solar PV. 12.5. Percent. The. Largest. Manufacturers. Are located, in China. Concentrated. Solar power, CSP. Also, started, to grow rapidly, increasing. Its capacity. Nearly, tenfold from. 2004. To 2013. Albeit. From a lower level and involving, fewer countries, than solar, PV, as. Of. The end of 2013. Worldwide, cumulative. CSP. Capacity. Reached 3,000. 425. Megawatts. Topic. Forecasts. In, 2010. The, International Energy. Agency, predicted. That global, solar, PV, capacity could. Reach 3,000. Gigawatts, or 11% of, projected, global electricity. Generation, by, 2050. Enough. To generate. 4,500. Terawatt-hours, of, electricity. Four. Years later in, 2014. The, agency, projected, that under, its high.
Renewables. Scenario. Solar. Power could supply, 27. Percent of global electricity. Generation. By, 2050. 16, percent, from PV, and 11%, from, CSP. Topic. Photovoltaic. Power. Stations. The, desert, sunlight, solar farm is a 550. Megawatts. Power plant in Riverside, County California, that. Uses, thin film CDT. Modules. Made by First Solar as of. November, 2014, the. 550. Megawatt, topaz, solar farm, was the largest photovoltaic, power. Plant in, the world, this. Was surpassed by the. 579. Megawatt. Solar star, complex. The. Current, largest, photovoltaic, power. Station. In the world is longyang, char dam solar, Park in Ghana County, Ching, hai China. Topic. Concentrating. Solar. Power stations. Commercial. Concentrating. Solar power, CSP. Plants. Also called, solar. Thermal, power, stations. Were. First developed. In the 1980s. The. 377. Megawatts. Even, per solar power facility. Located. In California's. Mojave Desert. Is the world's, largest solar, thermal power, plant, project, other. Large. CSP. Plants, include, the SOL nova solar, power station. 150. Megawatts, the, andasol solar, power station. 150. Megawatts, and extra, soul solar, power station. 150. Megawatts, all in Spain. The. Principal, advantage, of CSP, is the ability to efficiently, add thermal, storage allowing. The dispatching, of electricity. Over up to a 24, hour period. Since. Peak electricity. Demand, typically, occurs at about 5:00 p.m., many, CSP. Power plants, use three to five hours of thermal, storage. Topic. Economics. You. Topic. Cast. The, typical, cost factors. For solar power include, the costs, of the modules, the frame to hold them wiring, inverters. Labor, cost, any land, that might be required the, grid connection. Maintenance. And the solar installation. That location, will receive. Adjusting. For inflation it. Cost 96. Dollars per watt for a solar module, in the mid-1970s. Process. Improvements. And a very large boost, in production. Have brought that figure, down to 68, cents, per watt in February, 2016. According, to data from Bloomberg. New Energy Finance. Palo. Alto California. Signed. A wholesale, purchase, agreement, in 2016. That secured, solar, power for, 3.7, cents per kilowatt, hour and, in. Sunny Dubai, large-scale. Solar, generated. Electricity, sold, in 2016. For just 2.9, nine cents. Per kilowatt, hour, competitive. With any form, of fossil based electricity. And, cheaper. Than most. Photovoltaic. Systems. Use no fuel and modules, typically, last 25. To 40 years, thus.
Capital. Costs, make up most of the cost of solar power. Operations. And maintenance costs. For new utility-scale. Solar, plants. In the US are estimated. To be nine percent, of the cost of photovoltaic electricity. And. 17, percent of the cost of solar thermal electricity. Governments. Have created. Various, financial. Incentives. To encourage the use of solar power such, as feed-in. Tariff programs. Also. Renewable, portfolio. Standards. Impose, a government, mandate, that utilities. Generate, or acquire a certain percentage. Of renewable power regardless of, increased, energy procurement. Costs, in, most. States, RPS. Goals, can be achieved by any combination. Of solar, wind biomass. Landfill. Gas. Oshin, geothermal. Municipal. Solid waste. Hydroelectric. Hydrogen. Or fuel, cell technologies. Topic. Levelized. Cost, of electricity. The PV, industry is. Beginning, to adopt levelized, cost, of electricity, LCOE. As the unit of cost. The. Electrical. Energy generated is. Sold in units, of kilowatt, hours, kWh. As, a. Rule, of thumb and, depending, on the local insulation. One watt peak of installed, solar PV, capacity generates. About one to two kilo, watt hours of electricity, per year, this. Corresponds. To a capacity. Factor of around 10, to 20 percent. The. Product, of the local, cost of electricity, and, the insulation, determines. The break-even point, for solar power the. International. Conference on, solar, photovoltaic. Investments. Organized, by EPIA, has, estimated that PV, systems, will pay back their investors, in 8 to 12 years as a, result. Since. 2006. It has been economical. For investors, to install, photovoltaics. For. Free in return for a long term power purchase, agreement. 50%. Of commercial, systems, in the United, States were installed, in this manner in. 2007. And over 90%, by. 2009. She, Jiang Wang has said that as of 2012. Unsubsidized. Solar, power is already competitive. With, fossil fuels. In India Hawaii, Italy. And Spain. He. Said we, are at a tipping point, no. Longer, a renewable, power sources, like solar, and wind a, luxury, of the rich. They. Are now starting to compete, in the real world, without, subsidies. Solar. Power will, be able to compete, without subsidies. Against, conventional. Power sources. In half the world by, 2015. Topic. Current. Installation. Prices. 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 8 major markets. As of 2013, see. Table below. However. Doz SunShot. Initiative has, reported. Much lower US installation. Prices. In. 2014. Prices, continued, to decline the. SunShot, initiative modeled. U.s. system, prices, to be in the range of one dollar and eighty cents, to three dollars and twenty-nine cents, per watt other. Sources. Identify. Similar, price ranges, of one dollar and seventy cents, to three dollars and 50 cents, for the different, market, segments, in the US and in the highly, penetrated. German, market, prices. For residential, and small commercial, rooftop. Systems, of up to 100. Kilowatts, declined, to one dollar and 36. Cents per watt one, euro and 24, cents per W by the end of 2014. In. 2015. Deutsche, Bank estimated. Costs, for small residential. Rooftop, systems, in the u.s. around two, dollars and ninety cents, per watt.
Costs. For utility, scale systems. In China and India were estimated. As low as one dollar per, watt. Topic. Grid, parity. Grid. Parity the, point at which the cost of photovoltaic electricity, is. Equal, toward cheaper, than the price of grid power is more easily achieved, in areas, with abundant Sun, and high costs, for electricity, such, as in California. And Japan, in. 2008. The, levelized, cost, of electricity for, solar PV was, 25, cents, per kilowatt, hour or, less in most of the OECD. Countries. By. Late 2011, the, fully-loaded, cost, was predicted, to fall below 15, cents, per kilowatt. Hour for most of the OECD. And to reach 10 cents per kilowatt, hour in sunnier, regions. These. Cost, levels, are driving, three emerging, trends, vertical. Integration, of the supply chain origination. Of Power Purchase, Agreements. PPAs, by, solar, power companies. And unexpected. Risk for traditional, power generation. Companies, grid, operators, and wind turbine, manufacturers. Grid, parity was first reached in Spain in 2013. Hawaii, and other islands, that otherwise use fossil fuel, diesel, fuel to produce electricity. And, most, of the u.s. is expected to, reach grid parity by 2015. In. 2007. General, electrics, 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. Topic. Productivity. By location. The, productivity. Of solar power in a region, depends, on solar, irradiance, which, varies, through the day and is influenced. By latitude, and climate, the. Locations. With highest annual solar. Irradiance, lie, in the arid tropics, and subtropics. Deserts. Lying in low latitudes, usually. Have few clouds and can receive sunshine. For more than 10 hours a day, these. Hot deserts, form, the global, Sun Belt circling. The world, this, belt consists. Of extensive. Swaths of land in, northern Africa, southern, Africa, Southwest. Asia Middle, East and Australia as, well as the much smaller deserts. Of North and South America. Africa's. Eastern Sahara, Desert, also, known as the Libyan desert has, been observed, to be the sunniest place on earth according, to NASA. Different. Measurements. Of solar, irradiance, direct. Normal irradiance. Global. Horizontal. Irradiance, a mapped below. Topic. Self-consumption. In cases, of self consumption, of the solar energy the payback time is calculated. Based on how much electricity, is, not purchased, from the grid, for. Example. In Germany, with electricity, prices. Of 25 cents, per kilowatt, hour and insulation. Of 900. Kilo watt hours, per kilowatt, one, kwp. Will save. 225. Euros per year and with an installation, cost of. 1700. Euros per, KW, P the system, cost will be returned, in less than 7 years. However. In, many cases the. Patterns, of generation. And consumption, do, not coincide and, some are all of the energy, is fed back into the grid, the. Electricity. Is sold and at other times when. Energy is taken from the grid electricity. Is bought, the. Relative, costs, and prices, obtained, affect, the economics. In many. Markets, the price paid for sold, PV, electricity is. Significantly. Lower than the price of bought, electricity. Which, incentivizes. Self, consumption. Moreover. Separate. Self consumption, incentives. Have been used in eg. Germany. And Italy grid. Interaction. Regulation. Has also included. Limitations. Of grid feed and in some regions, in Germany, with high amounts of installed, PV, capacity. By. Increasing. Self consumption, the, grid feed-in, can be limited, without curtailment. Which wastes, electricity. 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, however. Batteries. Are expensive, and profitability. May, require, provision, of other services from. Them besides self consumption. Increase. Hot. Water storage, tanks. With electric, heating, with heat pumps, or resistance, heaters. Can provide low-cost storage. For self-consumption. Of solar power. 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. Topic. Energy. Pricing. And incentives. The, political, purpose, of incentive, policies, for PV is to facilitate, an initial, small scale deployment. To begin to grow the industry even. Where the cost of PV is significantly. Above grid parity, to allow the industry, to achieve the economies, of scale necessary. To reach grid parity. The. Policies, are implemented, to promote, national, energy independence. High-tech. Job creation, and reduction, of co2 emissions. Three, incentive. Mechanisms. Are often used in combination, as investment. Subsidies the. Authorities, refund, part of the cost of installation, of the system the, electricity. Utility. Buys PV, electricity from. The producer, under a multi-year, contract, at a guaranteed, rate and solar, renewable. Energy, certificates. Sree, cease. Topic. Rebates. With, investment. Subsidies the. Financial. Burden, falls upon the taxpayer, while, with feed-in, tariffs, the extra, cost is distributed. Across the utilities. Customer, bases. While. The investment. Subsidy, may be simpler, to administer. The main argument. In favor of feed-in, tariffs, is the encouragement, of quality. Investment. Subsidies are, paid out as a function, of the nameplate capacity of. The installed, system and they're independent of its actual, power yield, over time, thus rewarding, the overstatement. Of power and tolerating. Poor durability, and maintenance. Some. Electric, companies, offer rebates, to their customers, such, as Austin, Energy in Texas, which offers two dollars and 50 cents per watt installed, up to. $15,000. Topic. Net, metering. In, net metering, the price of the electricity. Produced, is the same as the price supplied, to the consumer, and the consumer is. Billed on the difference, between production. And consumption. Net. Metering, can usually be, done with no changes. To standard, electricity. Meters, which, accurately, measure power in both directions, and, automatically. Report, the difference, and because it allows homeowners and, businesses, to generate electricity, at, a different, time from consumption. Effectively. Using, the grid as a giant storage, battery. With. Net metering, deficits. Are billed each month while surpluses. Are rolled over to the following month. Best. Practices. Call for perpetual, rollover. Of kWh. Credits. Excess. Credits, upon termination of, service are, either lost or paid for it or ape ranging, from wholesale, to retail rate. Or above as can be excess, annual, credits, in. New. Jersey annual. Excess, credits, are paid at the wholesale, rate as a leftover.
Credits, When a customer, terminates, service. Topic. Feed-in-tariffs. Fit. 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. The. Complexity. Of approvals, in California. Spain, and Italy has, prevented comparable. Growth to Germany, even though, the return on investment is. Better, in. Some, countries, additional. Incentives. Are offered for BIPV, compared. To standalone, PV. France. Plus, 16. Euro cents, per kilowatt, hour compared. To semi integrated. Or plus he you are. 0.27. Per kilowatt, hours, compared, to standalone. Italy. Plus he you are, 0.04. To. 0.01. Hours. Germany. Plus 0 euros, o, 5. Per, kilowatt, hour for, sods only. Topic. Solo. Renewable. Energy, credits, SRECs. Alternatively. SRECs. Allow. For a market, mechanism to, set the price of the solar generated. Electricity, subsidy. In. This, mechanism, a renewable, energy production, or consumption, target. Is set and the utility, more technically, the load serving, entities is, obliged, to purchase, renewable energy. Or face a fine, alternative. Compliance payment. Or ACP. The. Producer, is credited, for an SRE, see for every 1000. Kilo, watt hours of electricity, produced. If. The utility buys, this SR EC, and retires it they avoid paying the ACP. In. Principle. This system, delivers, the cheapest, renewable, energy, since, the all solar facilities. Are eligible, and can be installed in the most economic. Locations. Uncertainties. About the future, value of SRECs. Have. Led to long term SR EC, contract, markets, to give clarity to the prices, and allows solar developers. To pre-sell, and hedge their credits.
Financial. Incentives, for photovoltaics, differ. Across countries, including. Australia, China. Germany. Israel. Japan and, the United States and even across states within the US. The. Japanese, government, through its Ministry. Of International, Trade and Industry ran. A successful, program. Of subsidies, from, 1994. To 2003. By. The end of, 2004. Japan, led the world and installed, PV, capacity with. Over 1.1. Gigawatts. In, 2004. The, German government, introduced, the first large-scale, feed-in. Tariff, system under, the German, Renewable, Energy Act which, resulted, in explosive. Growth of PV, installations. In Germany, at. The outset. The fit was over 3x, the retail, price or 8x the industrial, price. The. Principle. Behind the German system is a 20-year, flat rate contract. The, value, of new contracts. Is programmed, to decrease, each year, in order to encourage the industry to pass on lower costs, to the end-users, the. Program, has been more, successful than, expected. With over 1 gigawatt, installed, in, 2006. And political. Pressure is mounting to, decrease the tariffs to lessen the future, burden, on consumers. 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 program 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 EU. Are. 0.55. Per kilowatt, hours, for building integrated, systems. California. Greece, France. And Italy have, 30 to 50 percent more insulation, than Germany, making them financially. More attractive. The. Greek domestic. Solar. Roof. Program. Adopted. In June 2009. For, installations. Up to 10 kilowatts has, internal, rates of return of 10 to 15 percent at, current, commercial, installation. Costs, which furthermore. Is tax-free. In. 2006. California. Approved that California. Solar Initiative, offering. A choice of investment. Subsidies or, fit for small and medium, systems, and a fit for large systems. The. Small system, fit of 39, cents, per kilowatt, hour far less than EU countries, expires, in just five years and, the alternate. Epbb. Residential. Investment, incentive. Is modest, averaging. Perhaps, 20%. Of cost, all. California. Incentives. Are scheduled, to decrease, in the future depending, as a function, of the amount of PV. Pasi installed. At. The end of, 2006. The Ontario, Power Authority, OPA. Canada, began its standard, offer program, a precursor, to the Green Energy Act and, the first in North America, for distributed. Renewable, projects, of less than 10 megawatts. The. Feed-in tariff, guaranteed. A fixed, price of 42. Cents, CDN, per kilowatt, hour over. A period of 20 years. Unlike. Net metering, all the electricity. Produced, was sold to the OPA at the given rate. Topic. Grid, integration. The, overwhelming. Majority of, electricity, produced, worldwide, is used immediately, since, storage, is usually, more expensive and. Because traditional. Generators. Can adapt to demand. However. Both solar, power and wind power a variable. Renewable, energy, meaning, that all available, output, must be taken, whenever it is available, by moving through transmission. Lines to where it can be used now. Since. Solar, energy, is not available at, night storing.
Its Energy, is potentially. An important, issue particularly. In off-grid, and for future, 100%. Renewable, energy scenarios. To have continuous. Electricity. Availability. Solar. Electricity, is, inherently, variable. And predictable, by time of day location. And seasons. In. Addition. Solar, is intermittent. Due today night, cycles. And unpredictable. Weather, how. Much of a special, challenge solar, power is in any given electric, utility. Varies, significantly. In. A, summer peak utility. Solar, is well matched to daytime, cooling, demands. In. Winter. Peak utilities. Solar. Displaces. Other forms, of generation. Reducing. Their capacity, factors. In. An, electricity. System, without grid, energy storage. Generation. From stored, fuels, coal, biomass. Natural. Gas nuclear, must. Be go up and down in reaction, to the rise and fall of solar, electricity, see, load following power plant. While. Hydroelectric. And natural, gas plants. Can quickly follow solar, being intermittent. Due to the weather coal biomass, and, nuclear, plants, usually take considerable. Time to respond, to load and can only be scheduled, to follow the predictable, variation. Depending. On local circumstances. Beyond. About 20, to 40 percent of total generation, grid, connected, intermittent. Sources, like solar tend, to require investment. In some combination of grid interconnection. Energy, storage or, demand-side. Management. Integrating. Large amounts, of solar power with existing, generation. Equipment has caused issues in, some cases. For. Example in Germany. California. And Hawaii, electricity. Prices, have been known to go negative when, solar is generating. A lot of power, displacing. Existing, base load generation. Contracts. Conventional. Hydroelectricity. Works, very well in conjunction with solar, power water can be held back or released from a reservoir, behind a dam as required. Where. A suitable. River is not available. Pumped-storage. Hydroelectricity. Uses. Solar power to pump water to a high reservoir, on sunny days then, the energy, is recovered, at night and in bad weather by releasing, water via, a hydroelectric, plant, to, a low reservoir, where the cycle can begin again. However. This, cycle, can lose 20%. Of the energy to round-trip, in efficiencies. This, plus the construction. Costs, add to the expense, of implementing. High levels, of solar power. Concentrated. Solar, power plants. May use thermal, storage to, store solar, energy, such, as in high-temperature, molten. Salts. These. Salts, are an effective storage, medium, because, they are low cost have, a high specific, heat capacity. And can deliver heat at temperatures, compatible. With conventional. Power systems. This. Method, of energy, storage, is used for example by the solar to power station. Allowing, it to store. 1.44. Terajoules. In it 68 cubic, meters storage, tank enough, to provide full output for, close to thirty nine hours, with an efficiency, of about 99%. In, standalone, PV, systems, batteries. Are traditionally. Used to store excess, electricity. With. Grid-connected, photovoltaic. Power. System. Excess, electricity. Can be sent to the electrical, grid, net. Metering and fee, tariff, programs, give these systems, a credit for the electricity, they produce. This. Credit offsets, electricity. Provided, from the grid when the system, cannot meet demand, effectively.
Trading, With the grid instead of storing excess, electricity. Credits. Are normally, rolled over from month to month and, any remaining, surplus. Settled, annually. When. Wind and solar are a small, fraction of the grid power other generation. Techniques, can adjust their output, appropriately. But as these forms, of variable, power grow, additional. Balance on the grid is needed, as. Prices. Are rapidly, declining, PV. Systems, increasingly. Use rechargeable, batteries. To store a surplus, to be later used at night. Batteries. Used for grid storage stabilize, the electrical. Grid by leveling, out peak loads usually, for several minutes and in rare cases for, hours, in. The future, less expensive. Batteries could play an important, role on the electrical, grid as they can charge during, periods, when generation. Exceeds, demand and, feed the stored energy into, the grid when demand is higher than generation. Although. Not permitted, under the US National, Electric, Code it, is technically, possible to, have a plug-and-play. PV. Micro, inverter a recent. Review article. Found that careful, system, design, would enable such systems, to meet all technical. Though not all safety, requirements. There. Are several companies, selling, plug-and-play, solar. Systems, available, on the web but there is a concern, that if people install, their own it will reduce the enormous employment. Advantage, solar has over fossil fuels common, battery technologies. Used, in today's home, PV, systems, include, the valve regulated, lead, acid, battery a modified, version of, the conventional. Lead acid, battery, nickel, cadmium and, lithium ion batteries. Lead. Acid, batteries, are currently, the predominant. Technology. Used in small-scale. Residential. PV systems. Due, to their high reliability, low. Self, discharge, and investment, and maintenance costs. Despite shorter, life time and lower energy density. However. Lithium-ion. Batteries. Have the potential to replace lead, acid, batteries, in the near future as they are being intensively. Developed and. Lower prices are expected due, to economies, of scale, provided. By large production, facilities. Such as the gigafactory one. In. Addition. The li-ion batteries. Of plug-in, electric cars, may, serve as a future, storage, devices, in, a vehicle to grid system. Since. Most vehicles. Are parked an average of 95, percent of, the time their, batteries, could be used to let electricity.
Flow From the car to the powerlines, and back other. Rechargeable. Batteries, used for distributed. PV systems. Include, sodium. Sulfur, and vanadium redox, batteries. Two, prominent, types of a molten, salt and a flow battery, respectively. The combination. Of wind and solar PV, has, the advantage. That the two sources, complement. Each other because, the peak operating times. For each system occur, at different times, of the day and year, the. Power generation. Of such solar hybrid, power systems. Is therefore, more constant. And fluctuates, less, than each of the two component, subsystems. Solar. Power, is seasonal. Particularly. In northern, southern, climates, away, from the equator, suggesting. A need for long-term seasonal. Storage in a medium, such as hydrogen, or pumped, hydroelectric. The. Institute. For solar energy supply. Technology. Of the University. Of Kassel pilot, tested, a combined, power plant, linking, solar, wind, biogas. And hydro, storage to provide load, following power from, renewable, sources research. Is also undertaken. In this field of artificial. Photosynthesis. It. Involves. The use of nanotechnology. To store solar electromagnetic. Netic energy in, chemical bonds. By splitting, water to produce hydrogen, fuel, or then combining, with carbon, dioxide to. Make biopolymers. Such as methanol. Many. Large, national. And regional research. Projects. On artificial. Photosynthesis. Are now trying to develop techniques. Integrating. Improved, light capture, quantum, coherence methods. Of electron, transfer and, cheap catalytic. Materials. That operate, under a variety of, atmospheric. Conditions. Senior. Researchers. In the field have, made the public policy, case for a global project on artificial. Photosynthesis. To address critical, energy security. And environmental sustainability. Issues. You. Topic. Environmental. Impacts. Unlike. Fossil fuel-based. Technologies. Solar, power does not lead to any harmful, emissions during, operation. But the production, of the panel's leads to some amount of pollution. Topic. Greenhouse. Gases. The, lifecycle. Greenhouse gas. Emissions, of solar power in, the range of 22. To 46, gram, g per, kilowatt-hour. KWh. Depending. On if solar thermal, or solar, pv is being analyzed, respectively. With. This potentially. Being decreased, to 15 grams, per kilowatt, hour in the future. For. Comparison. Of weighted, averages, a combined, cycle gas fired, power plant, emits, some 400.
To, 599. Grams per. Kilowatt, hour an oil-fired, power plant. 893. Grams, per, kilowatt, hour a coal-fired power, plant. 915. To, 994. Grams, per kilowatt, hour or, with carbon, capture and storage some, 200. Grams per kilowatt, hour and, a geothermal high-temp. Power plant 91. To, 122. Grams per. Kilowatt, hour. The. Lifecycle, emission, intensity, of hydro, wind and nuclear power are lower than Soler's as of 2011. As published, by the IPCC. And, discussed, in the article, lifecycle. Greenhouse gas. Emissions, of energy sources. Similar. To all energy sources, were their total life cycle emissions primarily. Lay in the construction. And transportation phase. The, switch to low-carbon, power in the manufacturing. And transportation of. Solar devices, would further reduce carbon, emissions. BP. Solar, owns two factories. Built by salar x1, in Maryland, the other in Virginia, in which all of the energy, used to manufacture solar. Panels, is produced, by solar panels, a one. Kilowatt, system eliminates. The burning of approximately. 170. Pounds, of coal 300. Pounds of carbon dioxide from. Being released into the atmosphere and. Saves, up to 105. Gallons of, water consumption. Monthly. The u.s. National. Renewable Energy, Laboratory. NREL. In harmonizing. The disparate, estimate. Of lifecycle, GHG. Emissions, for solar PV found. That the most critical parameter. Was the solar insulation. Of the site GHG. Emissions, factors, for PV solar are inversely, proportional. To insulation. For. A site with insulation, of. 1700. Kilo watt hours, per meter, to per years typical. Of southern Europe, NREL. Researchers. Estimated. GHG. Emissions, of 45, g co2e. Per kilowatt. Hour, using. The same assumptions. At Phoenix, USA. With insulation, of. 2400. Kilo, watt hours per meter - per years the, GHG emissions. Factor, would be reduced, to 32. Grams of co2 e per, kilowatt, hour the new zealand parliamentary. Commissioner. For the environment found. That the solar PV would have little impact on, the country's, greenhouse, gas emissions. The. Country, already generates. 80%. Of its electricity from, renewable. Resources, primarily. Hydroelectricity. And geothermal and, national. Electricity, usage. Peaks on winter, evenings whereas, solar, generation, Peaks, on summer afternoons, meaning, a large uptake, of solar PV would, end up displacing. Other renewable, generators.
Before, Fossil, fuelled power plants. Topic. Energy. Payback. The, energy, payback time, EP, bt of a power generating. System, is the time required, to generate as, much energy as is consumed, during, production and, lifetime, operation. Of the system, due. To improving, production, technologies. The payback, time has been decreasing, constantly. Since the introduction, of PV, systems, in the energy, market. In. 2000. The energy, payback time of, PV, systems, was estimated. As 8 to 11 years and in, 2006. This was estimated. To be one point five to, three point five years, for crystalline, silicon. PV systems. And 1 to 1.5 years. For thin film technologies. S. Europe. These, figures, fell to. 0.75. To, 3.5. Years in 2013. With an average of about two, years for crystalline, silicon. PV and, sis systems, another, economic measure, closely. Related to the energy payback time is, the energy, returned, on energy invested, er. Oei or energy, return, on investment. EROI, which, is the ratio of electricity, generated. Divided. By the energy, required, to build and maintain the, equipment this, is not the same as the economic, return on investment. ROI which. Varies, according, to local energy, prices, subsidies. Available, in metering, techniques, with, expected. Lifetimes, of 30 years, the ER Oei of PV systems, are in the range of 10 to 30 thus, generating. Enough energy over, their lifetimes, to reproduce, themselves many. Times, 6, to 31, reproductions. Depending. On what type of material balance. Of system, boss and the geographic, location, of the system. You. Topic. Water, use. Solar. Power includes. Plants, with among the lowest water, consumption, per, unit of electricity. Photovoltaic. And. Also, power plants, with among the highest water consumption. Concentrating. Solar power with, wet cooling systems. Photovoltaic. Power. Plants. Use very little water for, operations. Life. Cycle. Water consumption. For, utility, scale operations. Is estimated. To be twelve gallons per megawatt, hour for, flat panel PV solar. Only. Wind power which, consumes, essentially. No water during, operations. Has, a lower water consumption. Intensity. Concentrating. Solar, power plants. With wet cooling systems, on the other hand, have the highest water consumption. Intensities. Of any conventional. Type of electric, power plant only, fossil. Fuel plants, with carbon, capture and storage may, have higher water intensities. A. 2013. Study comparing. Various sources, of electricity, found, that the median water consumption. During, operations. Of concentrating. Solar, power plants. With wet cooling was 810. Garr MW. HR, for power tower plants, and 890. Gallons, MW. HR, for trough plants. This. Was higher than the operational. Water consumption, with cooling, towers, for nuclear. 720, gallons, MW. HR, Col. 530. Gallons. MW. HR, or natural, gas. 210. A. 2011. Study, by the National Renewable Energy, Laboratory. Came, to similar, conclusions for. Power plants, with cooling, towers, water, consumption. During, operations. Was. 865. Gallons. MW. HR, for CSP, trough. 786. Gallons, MW. HR, for CSP, tower. 687. Gallons, MW. HR, for coal. 672. Gallons. MW. H for nuclear, and. 198. Gallons, MW. HR, for natural, gas the. Solar, Energy Industries Association. Noted. That the Nevada solar, one trough, CSP. Plant consumes. 850. Gallons, MW. HR. The. Issue of water consumption. Is heightened, because CSP. Plants, are often located in arid environments. Where water is scarce, in. 2007. The US Congress, directed. The Department, of Energy, to report on ways to reduce water consumption. By CSP. The. Subsequent. Report, noted, that dry cooling, technology. Was available that, although, more expensive to. Build and operate could, reduce water consumption. By CSP. By 91. To 95, percent a. Hybrid. Wet/dry, cooling, system, could reduce water consumption. By 32. To 58, percent a. 2015. Report, by, NREL. Noted, that of the 24, operating. CSP. Power plants, in the US for, used dry cooling, systems. The. For dry cooled systems. Were the three power plants. At the even per solar power facility. Near Barstow, California and. The Genesis, solar, energy, project, in Riverside, County California a. 15. CSP. Projects. Under construction or, development in.
The US as of March 2015. Six were wet systems, seven, were dry systems, one, hybrid and, one unspecified. Although. Many older, thermoelectric. Power plants with, once-through. Cooling or, cooling, ponds, use more water than CSP. Meaning. That more water passes. Through their systems, most, of the cooling water returns, to the water body, available. For other uses and, they consume, less water by evaporation. For. Instance, the median, coal power plant, in the US with once-through, cooling uses. Thirty six thousand, three hundred and 50 gallons, MW. HR but only, 250. Gallons, MW. H are less, than 1%, is lost through evaporation. Since. The, 1970s. The majority, of us power plants. Have used, recirculating. Systems, such as cooling, towers, rather than once-through systems. Topic. Other issues. One, issue that has often raised concerns. Is the use of cadmium, CD. A toxic, heavy metal, that has the tendency to accumulate. In ecological food, chains. It. Is used as semiconductor. Component. In cadmium, telluride, solar, cells, and as buffer layer for certain, cigs cells in the form of CDs. The. Amount of cadmium, used in thin film PV, modules, is relatively, small 5, to 10 grams per square meter, and with proper recycling, and, emission, control, techniques, in place the cadmium emissions from. Module production can, be almost zero. Current. PV, technologies. Lead to cadmium, emissions of. 0.3. To, 0.9. Microgram. Per kilowatt-hour. Over, the whole lifecycle. Most. Of these emissions, arise through, the use of coal power for the manufacturing. Of the modules, and coal and lignite combustion. Leads to much higher emissions, of cadmium. Lifecycle. Cadmium, emissions from. Coal is 3.1. Microgram. Per kilowatt-hour. Lignite. 6.2. And natural, gas, 0.2. Microgram. Per kilowatt. Hour, in. A, lifecycle, analysis. It has been noted, that if electricity. Produced, by photovoltaic, panels. Were used to manufacture the, modules, instead, of electricity. From burning, coal cadmium. Emissions from. Coal power usage, in the manufacturing. Process could. Be entirely, eliminated. In the case of crystalline, silicon, modules, the solder, material, that joins together the copper strings, of the cells contains. About. 36%. Of lead PB. Moreover. The, paste used, for screen printing front. And back contacts. Contains, traces, of PB, and sometimes, C D as well it. Is estimated that about, 1,000. Metric tonnes, of PB, have been used for 100. Gigawatts of CC, solar modules. However. There, is no fundamental. Need for lead in soldier alloy some, media sources, have reported that, concentrated. Solar power plants. Have injured, or killed large, numbers, of birds due, to intense, heat from the concentrated. Sun rays, this. Adverse, effect, does not apply to PV, solar power, plants. And some of the claims may have been overstated. Or exaggerated. A 2014. Published, life cycle, analysis, of land used for various, sources, of electricity, concluded. That the large-scale, implementation, of. Solar and wind potentially. Reduces, pollution related. Environmental. Impacts. The. Study found that the land use footprint. Given, in square, meter years, per megawatt hour M to a per, megawatt, hour was. Lowest, for wind natural. Gas and rooftop, PV with. 0.26. 0.49. And. 0.59. Respectively. And followed, by utility, scale solar, PV. With 7.9. For. CSP, the, footprint, was 9 and 14, using. Parabolic. Troughs and solar towers, respectively. The. Largest, footprint, had coal-fired. Power plants, with 18 meters to a per megawatt, hour. Topic. Emerging. Technologies. You. Topic. Concentrator. Photovoltaics. Concentrator. Photovoltaics. CPV. Systems. Employ, sunlight. Concentrated. Onto photovoltaic. Surfaces. For the purpose, of electrical. Power production. Contrary. To conventional photovoltaic. Systems. It uses, lenses, and curved mirrors, to focus sunlight onto small but, highly efficient, multi-junction.
Solar, Cells. Solar. Concentrators. Of all varieties, may be used and these are often mounted on a solar tracker, in order to keep the focal, point upon, the cell as the Sun moves across the sky. Luminescent. Solar, concentrators. When combined, with a PV solar cell, can, also be regarded as a si PV system. Concentrated. Photovoltaics, are. Useful, as they can improve, efficiency of, PV, solar panels, drastically. In addition, most, solar, panels, on spacecraft are, also made of high efficient, multi, Junction photovoltaic. Cells. To derive electricity. From sunlight when, operating. In the inner solar system. Topic. Flow, to voltaics. Floater. Voltaics, are, an emerging, form of pv systems, that float on the surface of irrigation, canals, water, reservoirs. Quarry, lakes and tailing, ponds. Several. Systems exist. In France India. Japan Korea. The United, Kingdom, and the United States. These. Systems, reduce the need of valuable. Land area, safe, drinking, water that would otherwise be, lost through, evaporation and. Show a higher efficiency, of solar energy conversion, as, the panels are kept at a cooler temperature, than they would be on land although. Not, floating other, dual, used facilities. With solar, power include, fisheries. Equals, equals, see also.