The Benefits of Utilizing Solar Power for Your Home
Abhinav Sidana asked:
When the question arises for utilizing the new sources of energy for your home to reduce the electrical costs, you may be thinking at first about the solar power and you may even question yourself “Is it worthy?” A simple answer for this question is “Yes!” The solar power for home is one of the easiest methods to reduce your home electric bill and by the side you are helping even the environment by installing the solar power for your home in many ways.
The solar power for home uses the sun’s radiation to produce variety of functions which includes cooking and other electricity generation. You are going “Green” by using the solar power which ultimately helps your budget and also the environment. The United States government offers even a tax incentive for those people who install solar power for their home.
When you plan to use the solar power for your home, you really don’t have to rely on many companies for fixing the apparatus. It is one of the easiest ways to change to solar power from the electricity. It will be a freeing experience when you come to know that you are generating power from solar. Since the solar power is very clean and renewable, the upfront costs for installing may be an issue for many people.
When you build a solar power for your home, you need not worry about building it near the power lines or grids. You are free to install it wherever you want provided you keep the solar panel in nature and once fixed you will be having a very clean and renewable source of solar power. Solar energy helps in keeping our environment healthy in many beautiful ways. One million of solar power usage is equal to taking out nearly 1 million of cars out of the city. It helps in reducing the usage of petroleum, natural gas, and also coal for every year.
When the question arises for utilizing the new sources of energy for your home to reduce the electrical costs, you may be thinking at first about the solar power and you may even question yourself “Is it worthy?” A simple answer for this question is “Yes!” The solar power for home is one of the easiest methods to reduce your home electric bill and by the side you are helping even the environment by installing the solar power for your home in many ways.
The solar power for home uses the sun’s radiation to produce variety of functions which includes cooking and other electricity generation. You are going “Green” by using the solar power which ultimately helps your budget and also the environment. The United States government offers even a tax incentive for those people who install solar power for their home.
When you plan to use the solar power for your home, you really don’t have to rely on many companies for fixing the apparatus. It is one of the easiest ways to change to solar power from the electricity. It will be a freeing experience when you come to know that you are generating power from solar. Since the solar power is very clean and renewable, the upfront costs for installing may be an issue for many people.
When you build a solar power for your home, you need not worry about building it near the power lines or grids. You are free to install it wherever you want provided you keep the solar panel in nature and once fixed you will be having a very clean and renewable source of solar power. Solar energy helps in keeping our environment healthy in many beautiful ways. One million of solar power usage is equal to taking out nearly 1 million of cars out of the city. It helps in reducing the usage of petroleum, natural gas, and also coal for every year.
A Detailed Analysis of Power Demand Compensation by Using Photovoltaic Power Generation
s.sankar asked:
Available Information On Photovoltaic Power
There is an enormous supply of articles on the subject of photovoltaic power. Most articles are narrow in scope, perhaps announcing a recent breakthrough or discussing a particular project or application. The internet provides a great deal of information as well, with web sites sponsored by government agencies, industry groups, and manufacturers. We did have some difficulty finding an overview of the subject. Most books on photovoltaics are at least five years old and cover the technical aspect of photovoltaics without providing an assessment of the practicality of using photovoltaics for power generation.
Why Photovoltaic Power Requires Study
The high cost of generating electrical power using photovoltaic cells compared to conventional coal-, gas-, and nuclear-powered generators has kept PV power generation from being in widespread use. Less than 1% of electricity is generated by photovoltaics. However, there are a few applications in which PV power is economical. These applications include satellites, developing countries that lack a power distribution infrastructure, and remote or rugged areas where running distribution lines are not practical. As the cost of photovoltaic systems drops, more applications become economically feasible. The non-polluting aspect of PV power can make it an attractive choice even when conventional generating systems are more economical. The manufacture of photovoltaic systems has increased steadily for the last 25 years. It is inevitable that engineers will be called upon to develop photovoltaic technology or will be involved in projects using this technology. Many existing reports on photovoltaics cover only one facet of the technology and sometimes writers inflate their reports on behalf of the company involved. There is a need for an up-to-date, objective understanding of photovoltaic power generation. With this goal in mind we have created this report.
Photovoltaic Technology
Scientists have known of the photovoltaic effect for more than 150 years. Photovoltaic power generation was not considered practical until the arrival of the space program. Early satellites needed a source of electrical power and any solution was expensive. The development of solar cells for this purpose led to their eventual use in other applications.
Power Output and Efficiency Ratings
The figures given for power output and efficiency of photovoltaic cells, modules, and systems can be misleading. It is important to understand what these figures mean and how they relate to the power available from installed photovoltaic generating systems.
Power Ratings
Photovoltaic power generation systems are rated in peak kilowatts (kWp). This is the amount of electrical power that a new, clean system is expected to deliver when the sun is directly overhead on a clear day. We can safely assume that the actual output will never quite reach this value. System output will be compromised by the angle of the sun, atmospheric conditions, dust on the collectors, and deterioration of the components. When comparing photovoltaic systems to conventional power generation systems, one should bear in mind that the PV systems are only productive during the daytime. Therefore, a 100 kW photovoltaic system can produce only a fraction of the daily output of a conventional 100 kW generator.
Efficiency Ratings
The efficiency of a photovoltaic system is the percentage of sunlight energy converted to electrical energy. The efficiency figures most often reported are laboratory results using small cells. A small cell has a lower internal resistance and will yield a higher efficiency than the larger cells used in practical applications. Additionally, photovoltaic modules are made up of numerous cells connected in series to deliver a usable voltage. Due to the internal resistance of each cell, the total resistance increases and the efficiency drops to about 70% of the single-cell value. Efficiency is higher at lower temperatures. Temperatures used in laboratory measurements may be lower than those in a practical installation.
Converting Sunlight to Electricity
A typical photovoltaic cell consists of semiconductor material (usually silicon) having a pn junction as shown in Figure 1.
Figure 1.Implementation of solar cells
Sunlight striking the cell raises the energy level of electrons and frees them from their atomic shells. The electric field at the pn junction drives the electrons into the n region while positive charges are driven to the p region. A metal grid on the surface of the cell collects the electrons while a metal back-plate collects the positive charges .
Light Generates
Electron and Hole
p-Type
n-Type
Thin Film Technology
Thin-film solar cells are manufactured by applying thin layers of semiconductor materials to a solid backing material. The composition of a typical thin-film cell is shown in Figure 2. Sunlight entering the intrinsic layer generates free electrons. The p-type and n-type layers create an electric field across the intrinsic layer. The electric field drives the free electrons into the ntype layer while positive charges collect in the p-type layer. The total thickness of the p-type, intrinsic, and n-type layers is about one micron. Although less efficient than single- and polycrystal silicon, thin-film solar cells offer greater promise for large-scale power generation because of ease of mass-production and lower materials cost. Thin-film is also suitable for building-integrated systems because the semiconductor films may be applied to building materials such as glass, roofing, and siding .
Fig.2.
Using thin films instead of silicon wafers greatly reduces the amount of semiconductor material required for each cell and therefore lowers the cost of reducing photovoltaic cells. Gallium arsenide (GaAs), copper indium diselenide (CuInSe2), cadmium telluride (CdTe) and titanium dioxide (TiO2) are materials that have been used for thin film PV cells. Titanium dioxide thin films have been recently developed and are interesting because the material is transparent and can be used for windows.
Tin Oxide Tin oxide is a conductive material that is transparent when in a thin layer. Tin oxide is used in place of a metallic grid for the top layer of thin film photovoltaic sheets .
Amorphous Silicon (a-Si) Amorphous (uncrystallized) silicon is the most popular thin-film technology. It is prone to degradation and produces cell efficiencies of 5-7%. Double- and triple-junction designs raise efficiency to 8-10%. The extra layers capture different wavelengths of light. The top cell captures blue light, the middle cell captures green light, and the bottom cell captures red light. Variations include amorphous silicon carbide (a-SiC), amorphous silicongermanium (a-SiGe), microcrystalline silicon (mc-Si), and amorphous silicon-nitride (a-SiN)
.
Cadmium Telluride (CdTe) and Cadmium Sulphide (CdS) Photovoltaic cells using these materials are under development by BP Solar and Solar Cells Inc .
Poly-crystalline Silicon Poly-crystalline silicon offers an efficiency improvement over amorphous silicon while still using only a small amount of material.
Concentrating Collectors
By using a lens or mirror to concentrate the sun’s rays on a small area, it is possible to reduce the amount of photovoltaic material required. A second advantage is that greater cell efficiency can be achieved at higher light concentrations. To accommodate the higher currents in the photocells, a larger metallic grid is used. For example, in a system with a 22X concentration ratio, the grid covers about 20% of the surface of the solar cell. To prevent this from blocking 20% of the sunlight, a prism is used to redirect sunlight onto the photovoltaic material, as shown in Figure 3. A second problem is the higher temperatures of a concentrating system. The cells may be cooled with a heat sink or the heat can be used to heat water .
Fig.3.
Only direct sunlight, not scattered by clouds or haze, can be concentrated. Therefore, the concentrating collectors are less effective in locations that are frequently cloudy or hazy, such as coastal areas .
How much power is available from the sun?
Sunlight reaches the Earth’s outer atmosphere at strength of 1367 watts per square meter, defined as AM0, or “air mass zero.” Atmospheric losses reduce the sun’s power to about 1000 W/m2 when the sun is directly overhead on a cloudless day . Figure 4 shows the average daily sunlight falling on a square meter surface which has been tilted toward the southern horizon at an angle equal to the latitude of the location. Note that diffused as well as direct sunlight is considered, making this map applicable to flat plate collectors.
Fig.4.Average daily sunlight in kWh/m2
Conversion Efficiency
The most efficient PV modules usually employ single-crystal silicon cells, with efficiencies up to 15%. Poly-crystalline cells are less expensive to manufacture but yield module efficiencies of about 11%. Thin-film cells are less expensive still, but give efficiencies to about 8% and suffer greater losses from deterioration.
Production Considerations
In the past, low-grade silicon was bought from semiconductor manufacturers for use in building solar cells. With improvements in the manufacturing process, silicon manufacturers are able to consistently produce the more profitable semiconductor-grade silicon. As a result, it is becoming difficult to buy low-grade silicon. There has been much discussion about building a production facility dedicated to the production of silicon for solar cells.
Photovoltaic Applications
Photovoltaic power generation has been most useful in remote applications with small power requirements where the cost of running distribution lines was prohibitive. As PV power becomes more affordable, the use of photovoltaics for grid-connected applications is increasing. However, the high cost of PV modules and the large area they require continue to be obstacles to using PV power to supplement existing electrical utilities. An interesting approach to both of these problems is the integration of photovoltaics into building materials.
Building-Integrated Systems
Building-integrated photovoltaic (BIPV) systems offer advantages in cost and appearance by incorporating photovoltaic properties into building materials such as roofing, siding, and glass. When BIPV materials are substituted for conventional materials in new construction, the savings involved in the purchase and installation of the conventional materials are applied to the cost of the photovoltaic system. BIPV installations are architecturally more attractive than roof mounted PV structures.
For example, United Solar Corporation produces photovoltaic shingles that replace normal asphalt shingles. Each PV shingle replaces a seven-foot long row of asphalt shingles, and any roofer can install them. Normally, only one-third of a roof needs to be covered with PV panels to produce sufficient power for the average home. Glass manufactured with photovoltaic properties is available for use in skylights and windows. The architect can select from several colors of transparent photovoltaic glass. The tint color and depth is controlled by the type and amount of semiconductor material used in the construction of the photovoltaic glass.
Off-Grid Applications
The majority of photovoltaic power generation applications are remote, off-grid applications. These include communication satellites, terrestrial communication sites, remote homes and villages, and water pumps. These are sometimes hybrid systems that include an engine-driven generator to charge batteries when solar power is insufficient.
Grid-Connected Applications
In grid-connected application, the DC power from solar cells runs through an inverter and feeds back into the distribution system. Grid-connected systems have demonstrated an advantage in natural disasters by providing emergency power capabilities when utility power was interrupted. Although PV power is generally more expensive than utility-provided power, the use of grid connected systems is increasing.
The Economics Of Photovoltaic Power Generation
Photovoltaic efficiency and manufacturing costs have not reached the point that photovoltaic power generation can compete with conventional coal-, gas-, and nuclear-powered facilities. The cost of photovoltaic power (when storage is not required) is two to four times that of conventionally produced power. It is difficult to define this relationship precisely due to wide variations in the cost of producing and distributing conventional electrical power and other variables. Due to the wide range of these variables, some applications of photovoltaic power are economically superior to conventional systems.
Conclusion
However, large variations in cost of conventional electrical power, and other factors, such as cost of distribution, create situations in which the use of PV power is economically sound. PV power is used in remote applications such as communications, homes and villages in developing countries, water pumping, camping, and boating. Grid connected applications such as electric utility generating facilities and residential rooftop installations make up a smaller but more rapidly expanding segment of PV use. Furthermore, as technological advances narrow the cost gap, more applications are becoming economically feasible at an accelerating rate.
Available Information On Photovoltaic Power
There is an enormous supply of articles on the subject of photovoltaic power. Most articles are narrow in scope, perhaps announcing a recent breakthrough or discussing a particular project or application. The internet provides a great deal of information as well, with web sites sponsored by government agencies, industry groups, and manufacturers. We did have some difficulty finding an overview of the subject. Most books on photovoltaics are at least five years old and cover the technical aspect of photovoltaics without providing an assessment of the practicality of using photovoltaics for power generation.
Why Photovoltaic Power Requires Study
The high cost of generating electrical power using photovoltaic cells compared to conventional coal-, gas-, and nuclear-powered generators has kept PV power generation from being in widespread use. Less than 1% of electricity is generated by photovoltaics. However, there are a few applications in which PV power is economical. These applications include satellites, developing countries that lack a power distribution infrastructure, and remote or rugged areas where running distribution lines are not practical. As the cost of photovoltaic systems drops, more applications become economically feasible. The non-polluting aspect of PV power can make it an attractive choice even when conventional generating systems are more economical. The manufacture of photovoltaic systems has increased steadily for the last 25 years. It is inevitable that engineers will be called upon to develop photovoltaic technology or will be involved in projects using this technology. Many existing reports on photovoltaics cover only one facet of the technology and sometimes writers inflate their reports on behalf of the company involved. There is a need for an up-to-date, objective understanding of photovoltaic power generation. With this goal in mind we have created this report.
Photovoltaic Technology
Scientists have known of the photovoltaic effect for more than 150 years. Photovoltaic power generation was not considered practical until the arrival of the space program. Early satellites needed a source of electrical power and any solution was expensive. The development of solar cells for this purpose led to their eventual use in other applications.
Power Output and Efficiency Ratings
The figures given for power output and efficiency of photovoltaic cells, modules, and systems can be misleading. It is important to understand what these figures mean and how they relate to the power available from installed photovoltaic generating systems.
Power Ratings
Photovoltaic power generation systems are rated in peak kilowatts (kWp). This is the amount of electrical power that a new, clean system is expected to deliver when the sun is directly overhead on a clear day. We can safely assume that the actual output will never quite reach this value. System output will be compromised by the angle of the sun, atmospheric conditions, dust on the collectors, and deterioration of the components. When comparing photovoltaic systems to conventional power generation systems, one should bear in mind that the PV systems are only productive during the daytime. Therefore, a 100 kW photovoltaic system can produce only a fraction of the daily output of a conventional 100 kW generator.
Efficiency Ratings
The efficiency of a photovoltaic system is the percentage of sunlight energy converted to electrical energy. The efficiency figures most often reported are laboratory results using small cells. A small cell has a lower internal resistance and will yield a higher efficiency than the larger cells used in practical applications. Additionally, photovoltaic modules are made up of numerous cells connected in series to deliver a usable voltage. Due to the internal resistance of each cell, the total resistance increases and the efficiency drops to about 70% of the single-cell value. Efficiency is higher at lower temperatures. Temperatures used in laboratory measurements may be lower than those in a practical installation.
Converting Sunlight to Electricity
A typical photovoltaic cell consists of semiconductor material (usually silicon) having a pn junction as shown in Figure 1.
Figure 1.Implementation of solar cells
Sunlight striking the cell raises the energy level of electrons and frees them from their atomic shells. The electric field at the pn junction drives the electrons into the n region while positive charges are driven to the p region. A metal grid on the surface of the cell collects the electrons while a metal back-plate collects the positive charges .
Light Generates
Electron and Hole
p-Type
n-Type
Thin Film Technology
Thin-film solar cells are manufactured by applying thin layers of semiconductor materials to a solid backing material. The composition of a typical thin-film cell is shown in Figure 2. Sunlight entering the intrinsic layer generates free electrons. The p-type and n-type layers create an electric field across the intrinsic layer. The electric field drives the free electrons into the ntype layer while positive charges collect in the p-type layer. The total thickness of the p-type, intrinsic, and n-type layers is about one micron. Although less efficient than single- and polycrystal silicon, thin-film solar cells offer greater promise for large-scale power generation because of ease of mass-production and lower materials cost. Thin-film is also suitable for building-integrated systems because the semiconductor films may be applied to building materials such as glass, roofing, and siding .
Fig.2.
Using thin films instead of silicon wafers greatly reduces the amount of semiconductor material required for each cell and therefore lowers the cost of reducing photovoltaic cells. Gallium arsenide (GaAs), copper indium diselenide (CuInSe2), cadmium telluride (CdTe) and titanium dioxide (TiO2) are materials that have been used for thin film PV cells. Titanium dioxide thin films have been recently developed and are interesting because the material is transparent and can be used for windows.
Tin Oxide Tin oxide is a conductive material that is transparent when in a thin layer. Tin oxide is used in place of a metallic grid for the top layer of thin film photovoltaic sheets .
Amorphous Silicon (a-Si) Amorphous (uncrystallized) silicon is the most popular thin-film technology. It is prone to degradation and produces cell efficiencies of 5-7%. Double- and triple-junction designs raise efficiency to 8-10%. The extra layers capture different wavelengths of light. The top cell captures blue light, the middle cell captures green light, and the bottom cell captures red light. Variations include amorphous silicon carbide (a-SiC), amorphous silicongermanium (a-SiGe), microcrystalline silicon (mc-Si), and amorphous silicon-nitride (a-SiN)
.
Cadmium Telluride (CdTe) and Cadmium Sulphide (CdS) Photovoltaic cells using these materials are under development by BP Solar and Solar Cells Inc .
Poly-crystalline Silicon Poly-crystalline silicon offers an efficiency improvement over amorphous silicon while still using only a small amount of material.
Concentrating Collectors
By using a lens or mirror to concentrate the sun’s rays on a small area, it is possible to reduce the amount of photovoltaic material required. A second advantage is that greater cell efficiency can be achieved at higher light concentrations. To accommodate the higher currents in the photocells, a larger metallic grid is used. For example, in a system with a 22X concentration ratio, the grid covers about 20% of the surface of the solar cell. To prevent this from blocking 20% of the sunlight, a prism is used to redirect sunlight onto the photovoltaic material, as shown in Figure 3. A second problem is the higher temperatures of a concentrating system. The cells may be cooled with a heat sink or the heat can be used to heat water .
Fig.3.
Only direct sunlight, not scattered by clouds or haze, can be concentrated. Therefore, the concentrating collectors are less effective in locations that are frequently cloudy or hazy, such as coastal areas .
How much power is available from the sun?
Sunlight reaches the Earth’s outer atmosphere at strength of 1367 watts per square meter, defined as AM0, or “air mass zero.” Atmospheric losses reduce the sun’s power to about 1000 W/m2 when the sun is directly overhead on a cloudless day . Figure 4 shows the average daily sunlight falling on a square meter surface which has been tilted toward the southern horizon at an angle equal to the latitude of the location. Note that diffused as well as direct sunlight is considered, making this map applicable to flat plate collectors.
Fig.4.Average daily sunlight in kWh/m2
Conversion Efficiency
The most efficient PV modules usually employ single-crystal silicon cells, with efficiencies up to 15%. Poly-crystalline cells are less expensive to manufacture but yield module efficiencies of about 11%. Thin-film cells are less expensive still, but give efficiencies to about 8% and suffer greater losses from deterioration.
Production Considerations
In the past, low-grade silicon was bought from semiconductor manufacturers for use in building solar cells. With improvements in the manufacturing process, silicon manufacturers are able to consistently produce the more profitable semiconductor-grade silicon. As a result, it is becoming difficult to buy low-grade silicon. There has been much discussion about building a production facility dedicated to the production of silicon for solar cells.
Photovoltaic Applications
Photovoltaic power generation has been most useful in remote applications with small power requirements where the cost of running distribution lines was prohibitive. As PV power becomes more affordable, the use of photovoltaics for grid-connected applications is increasing. However, the high cost of PV modules and the large area they require continue to be obstacles to using PV power to supplement existing electrical utilities. An interesting approach to both of these problems is the integration of photovoltaics into building materials.
Building-Integrated Systems
Building-integrated photovoltaic (BIPV) systems offer advantages in cost and appearance by incorporating photovoltaic properties into building materials such as roofing, siding, and glass. When BIPV materials are substituted for conventional materials in new construction, the savings involved in the purchase and installation of the conventional materials are applied to the cost of the photovoltaic system. BIPV installations are architecturally more attractive than roof mounted PV structures.
For example, United Solar Corporation produces photovoltaic shingles that replace normal asphalt shingles. Each PV shingle replaces a seven-foot long row of asphalt shingles, and any roofer can install them. Normally, only one-third of a roof needs to be covered with PV panels to produce sufficient power for the average home. Glass manufactured with photovoltaic properties is available for use in skylights and windows. The architect can select from several colors of transparent photovoltaic glass. The tint color and depth is controlled by the type and amount of semiconductor material used in the construction of the photovoltaic glass.
Off-Grid Applications
The majority of photovoltaic power generation applications are remote, off-grid applications. These include communication satellites, terrestrial communication sites, remote homes and villages, and water pumps. These are sometimes hybrid systems that include an engine-driven generator to charge batteries when solar power is insufficient.
Grid-Connected Applications
In grid-connected application, the DC power from solar cells runs through an inverter and feeds back into the distribution system. Grid-connected systems have demonstrated an advantage in natural disasters by providing emergency power capabilities when utility power was interrupted. Although PV power is generally more expensive than utility-provided power, the use of grid connected systems is increasing.
The Economics Of Photovoltaic Power Generation
Photovoltaic efficiency and manufacturing costs have not reached the point that photovoltaic power generation can compete with conventional coal-, gas-, and nuclear-powered facilities. The cost of photovoltaic power (when storage is not required) is two to four times that of conventionally produced power. It is difficult to define this relationship precisely due to wide variations in the cost of producing and distributing conventional electrical power and other variables. Due to the wide range of these variables, some applications of photovoltaic power are economically superior to conventional systems.
Conclusion
However, large variations in cost of conventional electrical power, and other factors, such as cost of distribution, create situations in which the use of PV power is economically sound. PV power is used in remote applications such as communications, homes and villages in developing countries, water pumping, camping, and boating. Grid connected applications such as electric utility generating facilities and residential rooftop installations make up a smaller but more rapidly expanding segment of PV use. Furthermore, as technological advances narrow the cost gap, more applications are becoming economically feasible at an accelerating rate.
The Economics of Photovoltaic Power Generation
s.sankar asked:
A European Photovoltaic Industry Association survey covering the 1990-1994 time period showed that approximately three-fourths of PV applications involved remote locations. Remote applications include satellites, remote telecommunications sites, remote homes and villages, water pumping, camping, and boating . Remote applications can become economically feasible because of the expense of constructing distribution lines and power losses sustained in transmission of conventional power. PV facilities may be located at the point of power consumption and do not require the purchase or delivery of fuel. If a remote site requires a dependable power source or has large loads, a hybrid system may be a better option. This may consist of photovoltaic cells and a diesel generator charging a bank of batteries. In such a hybrid system, the PV cells reduce the amount of fuel consumed. The batteries reduce the runtime required of the generator. Charging the batteries during generator runtime permits the generator to operate in a more efficient load range.
Peak Load Relief
In warm-climate areas, peak load demands occur on sunny days due to heavy use of air conditioners. This coincides with the productive period for photovoltaic power. By locating photovoltaic collectors at the end of a distribution line, a power utility may be able to defer the construction of additional conventional generating capacity as well as defer an upgrade of the distribution line.
Photovoltaic System Components
We often see the cost of photovoltaic modules reported in dollars per watt. At the retail level, the cost of photovoltaic modules is currently about $5/watt. But photovoltaic modules account for only 25% to 50% of the cost of a PV system. To achieve substantial cost reduction, the expense of system components will need to be addressed. Also, poor component efficiencies can compromise the total system efficiency. PV systems can have efficiencies as low as 50% due to losses in inverters, batteries, and system voltage drops.
Green Power
Economic feasibility is not always the determining factor in selecting a power generation system. With interest in green (ecologically friendly) power growing, both consumers and providers of electrical power are turning to the use of photovoltaics in spite of its higher cost.
Industry Forecasts
A 1996 study published by the International Energy Agency (IEA), concluded that demand for alternative energy would grow strongly, yet renewable sources would only account for about 1% of total energy produced in 2010. This does not include hydropower, which would constitute about 3% of the energy supply. The World Energy Council estimates that renewable power could provide 5-8% of the total energy demand by 2020, but only with continued support for research and development .Figure .1 shows the practical implementation of photovoltaic system
Fig.1. A view of PV system
Major Manufacturers
The five companies listed below are major producers of photovoltaic modules. All have been involved in products for aerospace as well as land-based systems including thin-film technology. Some have achieved this status by recent buyouts of established PV manufacturers.
Siemens Solar
Siemens Solar is the largest manufacturer of photovoltaic cells. The parent company, Siemens, is a diversified producer of electrical equipment, involved in all types of electrical power generation, with an established worldwide marketing and distribution system.
Applications of Photovoltaic Power
Distinct advantages to PV power, such as zero pollution and absence of the need to transport fuel to the generating site, make it attractive in many applications. As efficiency improvements and manufacturing cost reductions inch PV power toward economic parity with conventional power, these applications become more numerous. This economic trend is reflected in the recent expansions of manufacturing capacity and the acquisitions of PV manufacturers by larger corporations. The use of photovoltaic as the sole source of electrical power requires the use of batteries or other storage. The cost of electrical storage prevents PV generation from replacing conventional power generation. PV systems with electrical storage are only feasible for low-power, remote applications. For remote applications requiring more power, a hybrid system may be practical. This may consist of photovoltaic cells and a diesel generator charging a bank of batteries. In such a hybrid system, the PV cells reduce the amount of fuel to be transported to the site. The batteries also reduce the runtime required of the generator, and charging the batteries during generator runtime permits the generator to be operated in a more efficient load range .
Conclusion
Photovoltaic efficiency and manufacturing costs have not reached the point that photovoltaic power generation can replace conventional coal-, gas-, and nuclear-powered generating facilities. For peak load use (no battery storage), the cost of photovoltaic power is around two to four times as much as conventional power. (Cost comparisons between photovoltaic power and conventionally generated power are difficult due to wide variations in utility power cost, sunlight availability, and numerous other variables.)
A European Photovoltaic Industry Association survey covering the 1990-1994 time period showed that approximately three-fourths of PV applications involved remote locations. Remote applications include satellites, remote telecommunications sites, remote homes and villages, water pumping, camping, and boating . Remote applications can become economically feasible because of the expense of constructing distribution lines and power losses sustained in transmission of conventional power. PV facilities may be located at the point of power consumption and do not require the purchase or delivery of fuel. If a remote site requires a dependable power source or has large loads, a hybrid system may be a better option. This may consist of photovoltaic cells and a diesel generator charging a bank of batteries. In such a hybrid system, the PV cells reduce the amount of fuel consumed. The batteries reduce the runtime required of the generator. Charging the batteries during generator runtime permits the generator to operate in a more efficient load range.
Peak Load Relief
In warm-climate areas, peak load demands occur on sunny days due to heavy use of air conditioners. This coincides with the productive period for photovoltaic power. By locating photovoltaic collectors at the end of a distribution line, a power utility may be able to defer the construction of additional conventional generating capacity as well as defer an upgrade of the distribution line.
Photovoltaic System Components
We often see the cost of photovoltaic modules reported in dollars per watt. At the retail level, the cost of photovoltaic modules is currently about $5/watt. But photovoltaic modules account for only 25% to 50% of the cost of a PV system. To achieve substantial cost reduction, the expense of system components will need to be addressed. Also, poor component efficiencies can compromise the total system efficiency. PV systems can have efficiencies as low as 50% due to losses in inverters, batteries, and system voltage drops.
Green Power
Economic feasibility is not always the determining factor in selecting a power generation system. With interest in green (ecologically friendly) power growing, both consumers and providers of electrical power are turning to the use of photovoltaics in spite of its higher cost.
Industry Forecasts
A 1996 study published by the International Energy Agency (IEA), concluded that demand for alternative energy would grow strongly, yet renewable sources would only account for about 1% of total energy produced in 2010. This does not include hydropower, which would constitute about 3% of the energy supply. The World Energy Council estimates that renewable power could provide 5-8% of the total energy demand by 2020, but only with continued support for research and development .Figure .1 shows the practical implementation of photovoltaic system
Fig.1. A view of PV system
Major Manufacturers
The five companies listed below are major producers of photovoltaic modules. All have been involved in products for aerospace as well as land-based systems including thin-film technology. Some have achieved this status by recent buyouts of established PV manufacturers.
Siemens Solar
Siemens Solar is the largest manufacturer of photovoltaic cells. The parent company, Siemens, is a diversified producer of electrical equipment, involved in all types of electrical power generation, with an established worldwide marketing and distribution system.
Applications of Photovoltaic Power
Distinct advantages to PV power, such as zero pollution and absence of the need to transport fuel to the generating site, make it attractive in many applications. As efficiency improvements and manufacturing cost reductions inch PV power toward economic parity with conventional power, these applications become more numerous. This economic trend is reflected in the recent expansions of manufacturing capacity and the acquisitions of PV manufacturers by larger corporations. The use of photovoltaic as the sole source of electrical power requires the use of batteries or other storage. The cost of electrical storage prevents PV generation from replacing conventional power generation. PV systems with electrical storage are only feasible for low-power, remote applications. For remote applications requiring more power, a hybrid system may be practical. This may consist of photovoltaic cells and a diesel generator charging a bank of batteries. In such a hybrid system, the PV cells reduce the amount of fuel to be transported to the site. The batteries also reduce the runtime required of the generator, and charging the batteries during generator runtime permits the generator to be operated in a more efficient load range .
Conclusion
Photovoltaic efficiency and manufacturing costs have not reached the point that photovoltaic power generation can replace conventional coal-, gas-, and nuclear-powered generating facilities. For peak load use (no battery storage), the cost of photovoltaic power is around two to four times as much as conventional power. (Cost comparisons between photovoltaic power and conventionally generated power are difficult due to wide variations in utility power cost, sunlight availability, and numerous other variables.)
Jay Rockefeller: ‘Clean Coal Is Dirty’
climatebrad asked:
On January 21, 2009, Sen. Jay Rockefeller (D-WV) used his question time during the Senate Finance Committee confirmation hearing of Timothy Geithner for Secretary of the Treasury to deliver a discourse on coal power.
SuperCapitalism is a great book.
variablast asked:
This was a surprise to me. It turns out that one of the best ways to view the changes in our culture since the 70s is through considering the importance of consumers, investors, and the impact of corporate competition on Democracy. This book is intelligent, meaningful, relevant, and might find a place in your book shelf, because it needs to find a place in your mind.
I hope to post another reply on this topic. Corporate competition creates lobbyists that shift our democracy to focusing on their concerns exclusively in the real time of politics. Let it be known that that is not going to serve you well.
Clean coal my ***! Nuclear power is much more meaningful than coal, and carbon based fuels have no hope in a safe and environmentally friendly future. Coal doesn’t even bring about as much power! You can cut use, but you’d do better to increase it ten fold and replace coal power plants with nuclear ones. This is common knowledge amongst physicists in my experience, but if your opinion differs, please justify it in the comment section.
Take care.
XCEL ENERGY SAINT PAUL POWER PLANT DEMOLITION! DOCUMENTARY
JNew asked:
The 570 foot tall smokestack at the St. Paul XCEL ENERGY coal power plant gets BLOWN UP! I decided to film a documentary about it.
And I do believe I’m the first person to do so 
Wind Power Battery Storage System
Munya Chinongoza asked:
There is a new Canadian technology could make wind power a much more reliable source of energy with their new wind power battery storage system. VRB Power Systems Inc. (www.vrbpower.com) is a company in Vancouver that has developed a large-scale storage unit which allows it to a hold significant amount of power.
These batteries could be the solution to the main problem that we have with wind, the fact that it is unpredictable. Five percent of the electricity produced in Saskatchewan comes from wind. Wind power would be a great alternative to using coal if they could only predict the amount of wind they would be receiving.
Hydro offers a dependable power supply to meet basic industrial and residential needs. Wind adds to the mix of hydro and gas however it does not do it consistently. Wind can decide to blow at night when there is no demand for it at all, or it may decide to be unavailable when people actually need it.
Although coal is a much more dependable resource, it has a huge downside and that is the amount of pollution that it sends off into the atmosphere. To use clean coal technology would be very expensive. The new power plant that might be built in Saskatchewan will cost roughly $1.5 billion to produce 300 MW of power that we could actually use.
If they decided to spend the same amount of money on wind the plant would be able to give off 1,000 MW of power. However unfortunately for the reasons that have been already stated they can not rely on wind power to satisfy the people’s basic needs. It would be wonderful if we could store large amounts of wind power and then use it when it is necessary. Although storing wind power in batteries is not feasible, the VRB wind power battery storage system technology just may allow it to be possible of us to do so.
There is a new Canadian technology could make wind power a much more reliable source of energy with their new wind power battery storage system. VRB Power Systems Inc. (www.vrbpower.com) is a company in Vancouver that has developed a large-scale storage unit which allows it to a hold significant amount of power.
These batteries could be the solution to the main problem that we have with wind, the fact that it is unpredictable. Five percent of the electricity produced in Saskatchewan comes from wind. Wind power would be a great alternative to using coal if they could only predict the amount of wind they would be receiving.
Hydro offers a dependable power supply to meet basic industrial and residential needs. Wind adds to the mix of hydro and gas however it does not do it consistently. Wind can decide to blow at night when there is no demand for it at all, or it may decide to be unavailable when people actually need it.
Although coal is a much more dependable resource, it has a huge downside and that is the amount of pollution that it sends off into the atmosphere. To use clean coal technology would be very expensive. The new power plant that might be built in Saskatchewan will cost roughly $1.5 billion to produce 300 MW of power that we could actually use.
If they decided to spend the same amount of money on wind the plant would be able to give off 1,000 MW of power. However unfortunately for the reasons that have been already stated they can not rely on wind power to satisfy the people’s basic needs. It would be wonderful if we could store large amounts of wind power and then use it when it is necessary. Although storing wind power in batteries is not feasible, the VRB wind power battery storage system technology just may allow it to be possible of us to do so.
Earthjustice & Kansas Governor Talk Clean Energy
FiresideProduction asked:
Fireside Production is there when the non-profit, Earthjustice hosts Kansas Governor Kathleen Sebelius in Denver, Colorado for the forum, “Out of Kansas — A National Clean Energy Agenda.” Governor Sebelius speaks about her stand against new coal-fired power plants in her state and her push for renewable energy alternatives.
4000 Mw Ultra Power Project - Sasan
asked:
I am a proud citizen of this nation which has made great strides in many fields including the power sector.
The Sasan 4000 MW ultra power project is certainly a boon for the nation given its immense potential and long-term implications for power self-reliance. However, there are inherent complications and problems that require immediate attention compelling me to write this note.
You would be aware that Union Government has given coal linkage for the proposed 4000 MW power project in Sidhi in Madhya Pradesh to give boost to the ultra mega power projects program being undertaken by the union power ministry. Coal ministry has allocated Moher, Moher-Amlori Extension and Chhtrasal coal blocks with combined reserves of about 800 million tonnes to this project to meet its coal requirement. The Sasan power project is planned as a pit head power plant at an estimated cost of Rs 16,000 crore.
The intent and action in this regard has been extremely novel, however, there are some tricky issues calls for immediate attention and prudent interventions by the government.
If one looks at the long-term calculations some startling facts come to light. One, it is apparent that there is a huge windfall for the promoter Anil Dhirubhai Ambani Group vis a vis volume of the coal that is being made available to it. It is common knowledge that the 4000 MW plant would require upto 20 MT of coal per year. If we take the life of the PPA of 25 years, and it is a simple calculation, only upto 500 MT of coal would be consumed. What would be the fate of the rest volume of the coal? Would this precious natural resource become a tool for a private operator to fill its coffers? These are scary thoughts and as someone who swears by every bit of natural resources that Mother India carries in her womb, I am alarmed because this would mean both financial and natural loss to the Government of India. Hence I submit that the entire additional volume be monitored and should be made available on easy (and not ruthlessly commercial) terms to the people of the country. The government should play the role of an active referee here and should ensure that the coal price is lower than that offered by the Coal India Limited. It is also of importance to note that government should spare no efforts to ensure that the linked coal mine does not fall prey to the coal mafia prevalent in the region.
Two, there is a pressing need to bring in a policy issue also here given the high-decibel talk on natural resources these days. I wish to understand what is the government policy vis a vis utilization of coal (like in gas) and how does it ensure that the excess coal be utilized judiciously during the course of the Power Purchase Agreement (PPA) or thereafter?
The operator may rightly argue that it incurs a cost in developing the mines and hence needs to recover that cost as well. Anyone who understand the nuances of this business would reckon that this cost could be easily recovered through the power tariff’s variable charge. The variable mine cost for the additional quantity, in fact, would be negligible. I am pained to point at the lack of clarity on the policy front on this count. For unlike in the E&P business where beyond a threshold much of the hydrocarbon is actually for the benefit of the government, in this instance a small royalty is all that the government will end up earning. Isn’t that a grave disregard for a premium and limited natural resource?
Three, there is another critical issue that I wish to emphasize here. We have recently heard much hoopla over the capital expenditure estimates by a company for gas explorations. Taking a cue from the same case, I am of the opinion that the government should ensure that operator be made to commit the running expenses for the mine upfront. It is also of immense significance to note here that much like in the Gas Sales Purchase Agreement (GSPA), the PPA in the power project should ensure that the mining risk should rest entirely on investor and in the case of mine failure alternate fuel must be supplied by ADAG at the cost charged for coal from captive mine. The GSPA for the gas industry had a similar clause.
Four, the government may also want to ensure that the best possible technology is used in design, operation and maintenance of the coal mine.
Also given the stakes involved I would want the government to closely monitor the progress of the project at each level. Given the multiplicity of interests that are associated with voluminous projects, like in any other business, I urge the government to ensure strict surveillance at each stage of the critical power project.
Five, in case there is coal available on expiry of PPA and no agreement is reached for sale of power with the off-taker government must have the right to take possession of the power plant as well as the coal mine.
As a proud citizen, I am certain good sense would prevail and government would do every bit to ensure that no vagueness is left in this critical project. All these issues must be addressed through a transparent process. Any leniency on this could spell big perils for the critical power sector and may even derail the project
I am a proud citizen of this nation which has made great strides in many fields including the power sector.
The Sasan 4000 MW ultra power project is certainly a boon for the nation given its immense potential and long-term implications for power self-reliance. However, there are inherent complications and problems that require immediate attention compelling me to write this note.
You would be aware that Union Government has given coal linkage for the proposed 4000 MW power project in Sidhi in Madhya Pradesh to give boost to the ultra mega power projects program being undertaken by the union power ministry. Coal ministry has allocated Moher, Moher-Amlori Extension and Chhtrasal coal blocks with combined reserves of about 800 million tonnes to this project to meet its coal requirement. The Sasan power project is planned as a pit head power plant at an estimated cost of Rs 16,000 crore.
The intent and action in this regard has been extremely novel, however, there are some tricky issues calls for immediate attention and prudent interventions by the government.
If one looks at the long-term calculations some startling facts come to light. One, it is apparent that there is a huge windfall for the promoter Anil Dhirubhai Ambani Group vis a vis volume of the coal that is being made available to it. It is common knowledge that the 4000 MW plant would require upto 20 MT of coal per year. If we take the life of the PPA of 25 years, and it is a simple calculation, only upto 500 MT of coal would be consumed. What would be the fate of the rest volume of the coal? Would this precious natural resource become a tool for a private operator to fill its coffers? These are scary thoughts and as someone who swears by every bit of natural resources that Mother India carries in her womb, I am alarmed because this would mean both financial and natural loss to the Government of India. Hence I submit that the entire additional volume be monitored and should be made available on easy (and not ruthlessly commercial) terms to the people of the country. The government should play the role of an active referee here and should ensure that the coal price is lower than that offered by the Coal India Limited. It is also of importance to note that government should spare no efforts to ensure that the linked coal mine does not fall prey to the coal mafia prevalent in the region.
Two, there is a pressing need to bring in a policy issue also here given the high-decibel talk on natural resources these days. I wish to understand what is the government policy vis a vis utilization of coal (like in gas) and how does it ensure that the excess coal be utilized judiciously during the course of the Power Purchase Agreement (PPA) or thereafter?
The operator may rightly argue that it incurs a cost in developing the mines and hence needs to recover that cost as well. Anyone who understand the nuances of this business would reckon that this cost could be easily recovered through the power tariff’s variable charge. The variable mine cost for the additional quantity, in fact, would be negligible. I am pained to point at the lack of clarity on the policy front on this count. For unlike in the E&P business where beyond a threshold much of the hydrocarbon is actually for the benefit of the government, in this instance a small royalty is all that the government will end up earning. Isn’t that a grave disregard for a premium and limited natural resource?
Three, there is another critical issue that I wish to emphasize here. We have recently heard much hoopla over the capital expenditure estimates by a company for gas explorations. Taking a cue from the same case, I am of the opinion that the government should ensure that operator be made to commit the running expenses for the mine upfront. It is also of immense significance to note here that much like in the Gas Sales Purchase Agreement (GSPA), the PPA in the power project should ensure that the mining risk should rest entirely on investor and in the case of mine failure alternate fuel must be supplied by ADAG at the cost charged for coal from captive mine. The GSPA for the gas industry had a similar clause.
Four, the government may also want to ensure that the best possible technology is used in design, operation and maintenance of the coal mine.
Also given the stakes involved I would want the government to closely monitor the progress of the project at each level. Given the multiplicity of interests that are associated with voluminous projects, like in any other business, I urge the government to ensure strict surveillance at each stage of the critical power project.
Five, in case there is coal available on expiry of PPA and no agreement is reached for sale of power with the off-taker government must have the right to take possession of the power plant as well as the coal mine.
As a proud citizen, I am certain good sense would prevail and government would do every bit to ensure that no vagueness is left in this critical project. All these issues must be addressed through a transparent process. Any leniency on this could spell big perils for the critical power sector and may even derail the project
Lou Anne Wallace at a Power Plant Hearing in Wise County, VA
AppalachianVoices asked:
Local resident Lou Wallace at a public hearing in Wise County, VA, regarding Dominion Resources’ proposal to build a new coal-fired power plant near the community of St. Paul