File Name: solar energy and its applications .zip
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 solar 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 s. As the cost of solar electricity has fallen, the number of grid-connected solar PV systems has grown into the millions and utility-scale photovoltaic 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 Pavagada Solar Park , Karnataka, India with a generation capacity of MW. The International Energy Agency projected in that under its "high renewables" scenario, by , solar photovoltaics and concentrated solar power would contribute about 16 and 11 percent, 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. 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:. 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 s.
Atalla developed the process of silicon surface passivation by thermal oxidation at Bell Labs. The array of a photovoltaic power system , or PV system, produces direct current DC power which fluctuates with the sunlight's intensity. For practical use this usually requires conversion to certain desired voltages or alternating current AC , through the use of inverters.
Many residential PV systems are connected to the grid wherever available, especially in developed countries with large markets. 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.
Concentrated solar power CSP , also called "concentrated solar thermal", uses 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 dish Stirling and the solar power tower.
Various techniques are used to track the sun and focus light. In all of these systems a working fluid is heated by the concentrated sunlight, and is then used for power generation or energy storage. 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.
Compact Linear Fresnel Reflectors are CSP-plants which use many thin mirror 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 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. 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.
A hybrid system combines C PV and CSP with one another or with other forms of generation 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. The early development of solar technologies starting in the s was driven by an expectation that coal would soon become scarce.
In the mids 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.
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.
In , Tokelau became the first country to be powered entirely by photovoltaic cells, with a 1 MW system using batteries for nighttime power. Concentrated solar power CSP also started to grow rapidly, increasing its capacity nearly tenfold from to , albeit from a lower level and involving fewer countries than solar PV.
This was surpassed by the MW Solar Star complex. Commercial concentrating solar power CSP plants, also called "solar thermal power stations", were first developed in the s. The principal advantage of CSP is the ability to efficiently add thermal storage, allowing the dispatching of electricity over up to a hour period. The typical cost factors for solar power include the costs of the modules, the frame to hold them, wiring, inverters, labour cost, any land that might be required, the grid connection, maintenance and the solar insolation that location will receive.
Process improvements and a very large boost in production have brought that figure down to 68 cents per watt in February , according to data from Bloomberg New Energy Finance. And in sunny Dubai large-scale solar generated electricity sold in for just 2. 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 9 percent of the cost of photovoltaic electricity, and 17 percent of the cost of solar thermal electricity.
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 , ocean, geothermal, municipal solid waste , hydroelectric, hydrogen, or fuel cell technologies. The electrical energy generated is sold in units of kilowatt-hours kWh.
The product of the local cost of electricity and the insolation determines the break-even point for solar power. Shi Zhengrong has said that, as of , unsubsidised solar power is already competitive with fossil fuels in India, Hawaii, Italy and Spain. He said "We are at a tipping point. No longer are renewable power sources like solar and wind a luxury of the rich. They are now starting to compete in the real world without subsidies". In its 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 see table below.
In , prices continued to decline. The SunShot Initiative modeled U. Grid parity, the point at which the cost of photovoltaic electricity is equal to or 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.
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 ,  Hawaii and other islands that otherwise use fossil fuel diesel fuel to produce electricity, and most of the US is expected to reach grid parity by The productivity of solar power in a region depends on solar irradiance , which varies through the day and is influenced by latitude and climate.
It also depends on the temperature, and the local soiling conditions. 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 ten hours a day. In cases of self-consumption of 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 0. 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.
Germany and Italy. 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. 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 CO 2 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 multiyear contract at a guaranteed rate, and Solar Renewable Energy Certificates SRECs.
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 favour 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 are independent of its actual power yield over time, thus rewarding the overstatement of power and tolerating poor durability and maintenance.
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 roll over of kWh credits.
In New Jersey, annual excess credits are paid at the wholesale rate, as are left over credits when a customer terminates service. 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 this mechanism, renewable energy production or consumption target is set, and the utility more technically the Load Serving Entity is obliged to purchase renewable energy or face a fine Alternative Compliance Payment or ACP.
In principle, this system delivers the cheapest renewable energy since all solar facilities are eligible and can be installed in most economic locations. Uncertainties about the future value of SRECs have led to long-term SREC contract markets to give clarity to their prices and allow solar developers to pre-sell and hedge their credits.
Applications of Solar Energy
July 12, Our sun is the source of all life on Earth, and solar energy is useful to us in many different ways. The sun creates two main types of energy — light and heat — that we can harness for many activities ranging from photosynthesis in plants to creating electricity with photovoltaic PV cells to heating water and food. So, what are some uses of solar energy? Let's explore seven common uses and benefits of sunlight in our daily lives.
Once production of your article has started, you can track the status of your article via Track Your Accepted Article. Help expand a public dataset of research that support the SDGs. The Society was founded in and is now incorporated as a non-profit educational and scientific institution. With participation encompassing Through its publications and its sponsorship of technical conferences, the Society provides a world forum for the active consideration of solar energy. Solar Energy welcomes manuscripts presenting information not previously published in journals on any aspect of solar energy research , development , application , measurement or policy.
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 solar 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 s. As the cost of solar electricity has fallen, the number of grid-connected solar PV systems has grown into the millions and utility-scale photovoltaic power stations with hundreds of megawatts are being built.
Solar power is the key to a clean energy future. Every day, the sun gives off far more energy than we need to power everything on earth. Solar panels produce electricity by transforming the continuous flow of energy from the sun to electricity. No harmful emissions are released into the air when electricity is produced by solar panels. As a renewable energy source, the only limitation of solar power is our ability to turn it into electricity in an efficient and cost-effective way.
The discussions in this book cover varied aspects of solar energy in use around the globe. Chapters 1 through 6, deal with Solar Energy in over pages addressed by 15 experts from academia, NASA, and practicing professionals from the U. Global interest in solar energy is apparent not only from the current usage but also from the untapped resources and its potential for greater usage. Rao, K.
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