The purpose of this report was to analyse the cost of solar power system and the advice to the reader of getting the solar system
Solar Power Systems
TEC3703/MTE3503 - Advance engineering
Department of engineering
Melbourne University
Student name : James
Student ID : 7884936
Contents - Solar power systems
Page no:
.0 Introduction "2"
2.0 Background "2"
2.1 Brief history of photovoltaic energy "2"
2.2 Applications of solar power systems "3"
2.3 Disadvantages of Solar Technology "3"
3.0 How it works
3.1 Solar cells "4"
3.1.1 The Silicon Cell "5"
3.2 Converting Solar to electrical energy "6"
3.3 Energy losses "6"
3.4 Solar Powered systems in modern society "7"
4.0 Social, Environmental and health implications "7"
8
4.1 Solar energy vs. other power sources "8"
4.2 Environmental Benefits "8"
4.3 Health issues "9"
5.0 Economic Viability "10"
5.1 Finding the right size and cost for your power system "11"
5.2 Component Cost "11"
5.2.1 Package deals "12"
5.2.2 Installation Costs "12"
5.3 Cost effectiveness "13"
5.4 Government Rebate scheme "14"
5.5 Input/Output power "15"
5.6 Costs of Photovoltaics Against Other Power Sources "15"
6.0 Bibliography ""
.0 Introduction
The purpose of this report was to analyse the cost of solar power system and the advice to the reader of getting the solar system. This report has considered six important area to look at such at component cost and the warranties on the product and also the cost of the packet.
Solar power works well for most items except large electric appliances that use an electric heat element such as a water heater, clothes dryer and electric stove - for example - or total electric home heating systems. It is not cost effective to use solar power for these items. Conversion to natural gas, propane or other alternatives is usually recommended. Solar power can be used to operate a gas clothes dryer (Maytag, etc) because the electrical requirement is limited to the drum-motor and/or ignito-lighter, but not a HEAT element for drying the clothes, for example.
Using solar power to produce electricity is not the same as using solar to produce heat. Solar thermal principles are applied to produce hot fluids or air. Photovoltaic principles are used to produce electricity. A solar panel (PV panel) is made of the natural element, silicon, which becomes charged electrically when subjected to sun light.
2.0 Background
Solar which also called as photovoltaic cells are a clean renewable source of energy that have been used in stand-alone applications for many years. However, with the growing concern over greenhouse gas emissions and other environmental issues, renewable energy sources such as PV are being increasingly connected to the electricity network.
Now Solar power is the most promising clean energy source for new generations comparing with burning fuel or gas. The sun has been shinning for about 5 billion years and it will continue shinning for another 4 to 5 billion years. Each day the Earth receives ever so much more energy than demanded by the humans. The applications below depict use of photovoltaic systems as an energy source in many interesting ways.
2.1 Brief history of photovoltaic energy
839 - Edmund Becquerel, a French experimental physicist, discovered the photovoltaic effect while experimenting with an electrolytic cell made up of two metal electrodes placed in an electricity-conducting solution--generation increased when exposed to light.
Willoughby Smith discovered photovoltaic effect in selenium in 1873. In 1876, with his student R. E. Day, William G. Adams discovered that illuminating a junction between selenium and platinum also has a photovoltaic effect. These two discoveries were a foundation for the first selenium solar cell construction, which was built in 1877. Charles Fritts first described them in detail in 1883.
Albert Einstein During ( 1900 -)The Author of the most comprehensive theoretical work about the photovoltaic effect was Albert Einstein, who described the phenomenon in 1904. For his theoretical explanation he was awarded a Nobel Prize in 1921. Einstein's theoretical explanation was practically proved by Robert Millikan's experiment in 1916.
In 1932, the photovoltaic effect in cadmium-selenide was observed. Nowadays, CdS belongs among important materials for solar cells production. In 1918, a Polish scientist Czohralski discovered a method for monocrystalline silicon production, which enabled monocrystalline solar cells production. The first silicon monocrystalline solar cell was constructed in 1941.
Bell Laboratories created the first solar cell silicon device with an efficiency of 4% in 1954. In the early 1960's the space programs used PV's in their satellites and still do today.
In 1963, Sharp Corporation developed the first usable photovoltaic module from silicon solar cells. The biggest photovoltaic system at the time, the 242 W module field was set up in Japan. A year later, in 1964, Americans applied a 470 W photovoltaic field in the Nimbus space project.
In 1985, researches of University of New South Wales in Australia have constructed a solar cell with more than 20 % efficiency. BP built a power plant in Sydney, Australia and shortly after another one nearby Madrid. A photovoltaic system was built in Sulawesi, Indonesia for the purposes of a terrestrial satellite station. In 1986, ARCO Solar introduced a G-4000, the first commercial thin film photovoltaic module.
Mostly in Germany, some photovoltaic and renewable energy resources companies have shares listed at the stock exchange. Capital mergers in Germany led to large photovoltaic corporation establishments. During 2000 and production of Japanese producers increased significantly.
2.2 Applications of solar power systems
Solar technologies use the sun's energy and light to provide heat, light, hot water, electricity, and even cooling, for homes, businesses, and industry. Here are just a few of the many possibilities that solar energy are associated with.
Solar Lights
For Street Lights, Commercial lighting, Park lighting systems, and Security lights.
All systems use the latest solar technologies combined with premium quality components to ensure maximum functionality at minimum cost.
Medical Centre uses
Uses of solar power to reduce operating costs at medical center.
The enormous hot water demand for patient care, food service and the hospital laundry was the most cost-effective application for solar energy at the medical center. Solar enery engineered a 4,000 sq. ft. roof-mounted, flat-plate, solar thermal system for domestic and process water heating which provided a full 12-month utilization and an excellent payback.
Solar houses
Photovoltaic systems are in many homes today and are fast becoming a viable solution for providing economical electrical power for lighting, heating, air conditioning and appliances.
Power to go
Not only is solar technology fast developing to power vehicles from A to B, it is being widely used to power vehicles and systems inside vehicles.
From running refrigerators to TV's, or providing light after sunset, solar panels are an excellent way for the outdoor explorer to enjoy both the comforts and essentials of home without consuming costly batteries or running noisy generators.
Remote signs and emergencies
Photovoltaic power can easily meet the demands of information fixtures whether portable, temporary or permanent.
Communications
For telecommunications in remote or temporary locations, or where running direct power would be costly or disruptive, solar electricity is widely recognized as the most practical technology to use.
On the side of the road, in outdoor sites and facilities, and in ever more remote locations such as, desert and mountain areas and third world countries, Solec solar panels can be utilizes for telephones, power transmitters, telemetry systems, TV translators, microwave repeaters and ...
This is a preview of the whole essay
Remote signs and emergencies
Photovoltaic power can easily meet the demands of information fixtures whether portable, temporary or permanent.
Communications
For telecommunications in remote or temporary locations, or where running direct power would be costly or disruptive, solar electricity is widely recognized as the most practical technology to use.
On the side of the road, in outdoor sites and facilities, and in ever more remote locations such as, desert and mountain areas and third world countries, Solec solar panels can be utilizes for telephones, power transmitters, telemetry systems, TV translators, microwave repeaters and more.
2.3 Disadvantages of Solar Technology
There are a few disadvantages of Solar Energy The first is that the sun is not always out and needed for energy to be generated. Secondly the cost of the technology has a rather upfront cost. Generally it will take time for solar energy to replace fossil fuel and gas.
In the evening, or on cloudy days, the photovoltaic cells are essentially useless. If the rays of the sun don't make it to earth with enough potency, the cells have nothing with which to produce energy. These are called dark periods in solar energy collection. Dark periods create one of the most troubling dilemmas in the solar energy promotion. Because of dark periods, photovoliac cells must improve efficiency or share time with fossil fuels, which will supply the energy during dark hours. This means that solar energy is not self reliable, and must be accompanied by fossil fuels to provide sufficient levels of power.
The biggest obstacle to direct replacement of current energy sources by solar energy is the cost of capturing and using it. Most energy in the World is produced by fossil fuels. We use gas to heat our homes and drive our cars. The process of converting these methods to solar energy is not only very costly, but time consuming as well. Current power plants would have to renovate, buying new equipment to collect and transfer the sun's rays into energy. The new power plants would cost millions of dollars to operate, and this, in turn, will be passed on to the consumer.
3.0 How it works
Photovoltaic is the scientific term for " solar electricity" . Energy-which means electricity from light. The more light a photovoltaic cell gets means the more electricity that cell can be produce. These cells when connected together, laminated and framed, are called a 'solar modules/panels' or 'PV (photovoltaic) modules'. These modules are designed to produce electricity at convenient direct current (DC) voltages for storing in a battery or being directly converted into typical 120-230 volt alternating current (120 VAC).
This section will look at solar panels and how they convert the sun's energy directly into electricity. The solar cells that you see on calculators and satellites are photovaltic cells, these cells convert sunlight directly into electricity. Once used almost exclusively in space, photovoltaics are used more and more in less exotic ways. They could even power a person's home.
The modularity and flexibility of solar electricity allows users to have system tailored to specific needs and preferences.
Aside from full or partial power, solar electricity may serve as a power source for a specific job. This could be electricity for a well pump, patio or street lighting or for a home security system or even a backyard waterfall. Typically, such systems consist of one of more modules and charge controller accompanied by a battery or batteries.
PV systems are composed of several individual components including arrays (multiple connected modules), inverters, controls, safety disconnects, and batteries. By assembling differing sizes of components together, systems can be built with varied power outputs to meet the demands of various loads.
3.1 Solar cells
Photovoltaic (PV) cells are made of special materials called semi conductors such as silicon, which is currently the most commonly used. Basically, when light strikes the cell, a certain portion of it is absorbed within the semiconductor material. This means that the energy of the absorbed light is transferred to the semiconductor. The energy knocks electrons loose, allowing them to flow freely. PV cells also all have one or more electric fields that act to force electrons freed by light absorption to flow in a certain direction. This flow of electrons is a current, and by placing metal contacts on the top and bottom of the PV cell, we can draw that current off to use externally. For example, the current can power a calculator. This current, together with the cell's voltage (which is a result of its built-in electric field or fields), defines the power (or wattage) that the solar cell can produce.
3.1.1 The Silicon Cell
Silicon has some special chemical properties, especially in its crystalline form. An atom of silicon has 14 electrons, arranged in three different shells. The first two shells, those closest to the centre, are completely full. The outer shell, however, is only half full, having only four electrons. A silicon atom will always look for ways to fill up its last shell (which would like to have eight electrons). To do this, it will share electrons with four of its neighbour silicon atoms. It's like every atom holds hands with its neighbours, except that in this case, each atom has four hands joined to four neighbours. That's what forms the crystalline structure, and that structure turns out to be important to this type of PV cell as can be seen in figure 3.a.
Figure 3.a Silicon Crystal Lattice with do pant Atoms.
Pure silicon is a poor conductor of electricity because none of its electrons are free to move about, as electrons are in good conductors such as copper. Instead, the electrons are all locked in the crystalline structure. The silicon in a solar cell is modified slightly so that it will work as a solar cell. Silicon solar cells are made using either single crystal wafers, polycrystalline wafers or thin films.
Single crystal wafers are sliced, (approx. 1/3 to 1/2 of a millimetre thick), from a large single crystal ingot which has been grown at around 1400 °C, which is a very expensive process. The silicon must be of a very high purity and have a near perfect crystal structure (see figure 3 (b)).
(a)
a) Single Crystal solar cells in panel
(b)
b) Polycrystalline solar panel
(c)
c) a-Si solar panel
Figure 3b. Different types of Silicon solar cells
Single crystal silicon isn't the only material used in PV cells. Polycrystalline silicon is also used in an attempt to cut manufacturing costs, although resulting cells aren't as efficient as single crystal silicon. Amorphous silicon, which has no crystalline structure, is also used, again in an attempt to reduce production costs. Other materials used include gallium arsenide, copper indium dieseline and cadmium telluride. Since different materials have different band gaps, they seem to be "tuned" to different wavelengths, or photons of different energies. One way efficiency has been improved is to use two or more layers of different materials with different band gaps. The higher band gap material is on the surface, absorbing high-energy photons while allowing lower-energy photons to be absorbed by the lower band gap material beneath. This technique can result in much higher efficiencies. Such cells, called multi-junction cells, can have more than one electric field.
3.2 Converting Solar to electrical energy
Silicon in a solar cell has impurities (other atoms mixed in with the silicon atoms), changing the way things work. Impurities are something undesirable, but in this case, the solar cell wouldn't work without it. These impurities are actually put there on purpose. Consider silicon with an atom of phosphorous here and there, maybe one for every million silicon atoms. Phosphorous has five electrons in its outer shell, not four. It still bonds with its silicon neighbour atoms, but in a sense, the phosphorous has one electron that doesn't have anyone to hold hands with. It doesn't form part of a bond, but there is a positive proton in the phosphorous nucleus holding it in place as seen in figure 3a.
The interesting part starts when you put N-type silicon together with P-type silicon. Remember that every PV cell has at least one electric field. Without an electric field, the cell wouldn't work, and this field forms when the N-type and P-type silicon are in contact. Suddenly, the free electrons in the N side, which have been looking all over for holes to fall into, see all the free holes on the P side, and there's a mad rush to fill them in. To understand the operation of a PV cell, we need to consider both the nature of the material and the nature of sunlight. Solar cells consist of two types of material, often p-type silicon and n-type silicon. Light of certain wavelengths is able to ionise the atoms in the silicon and the internal field produced by the junction
Figure 3c The Photovoltaic Effect in a Solar Cell
separates some of the positive charges ("holes") from the negative charges (electrons) within the photovoltaic device. The holes are swept into the positive or p-layer and the electrons are swept into the negative or n-layer. Although these opposite charges are attracted to each other, most of them can only recombine by passing through an external circuit outside the material because of the internal potential energy barrier. Therefore if a circuit is made (see figure 3c) power can be produced from the cells under illumination, since the free electrons have to pass through the load to recombine with the positive holes. The amount of power available from a PV device is determined by ;the type and area of the material; the intensity of the sunlight; and the wavelength of the sunlight.
Single crystal silicon solar cells, for example cannot currently convert more than 25% of the solar energy into electricity, because the radiation in the infrared region of the electromagnetic spectrum does not have enough energy to separate the positive and negative charges in the material.
Polycrystalline silicon solar cells have an efficiency of less than 20% at this time and amorphous silicon cells, are presently about 10% efficient, due to higher internal energy losses than single crystal silicon.
Before now, our silicon was all electrically neutral. The extra protons in the phosphorous balanced our extra electrons out. Missing electrons (holes) were balanced out by missing protons in the boron. When the holes and electrons mix at the junction between N-type and P-type silicon, however, that neutrality is disrupted. Not all free electrons fill every hole if they did, then the whole arrangement wouldn't be very useful at the junction, however, they do mix and form a barrier, making it harder for electrons on the N side to cross to the P side. Eventually, equilibrium is reached, and we have an electric field separating the two sides. This electric field acts as a diode, allowing (and even pushing) electrons to flow from the P side to the N side, but not the other way around. It's like a hill -- electrons can easily descend down the hill (to the N side), but can't climb it (to the P side).
3.3 Energy losses
Visible light is only part of the electromagnetic spectrum. Electromagnetic radiation is not monochromatic -- it is made up of a range of different wavelengths, and therefore energy levels.
Light can be separated into different wavelengths, and we can see them in the form of a rainbow. Since the light that hits our cell has photons of a wide range of energies, it turns out that some of them won't have enough energy to form an electron-hole pair. They'll simply pass through the cell as if it were transparent. Still other photons have too much energy. Only a certain amount of energy, measured in electron volts (eV) and defined by our cell material (about 1.1 eV for crystalline silicon), is required to knock an electron loose. We call this the band gap energy. A photon has more energy the required amount then the extra energy is lost (unless a photon has twice the required energy, and can create more than one electron-hole pair, but this effect is not significant). These two effects alone account for the loss of around 70 percent of the radiation energy incident on our cell.
Material with a really low band gap can use more photons because the band gap also determines the strength (voltage) of our electric field, and if it's too low, then what is made up in extra current (by absorbing more photons), is lost by having a small voltage. Remember that power is voltage times current. The optimal band gap, balancing these two effects, is around 1.4 eV cell made from a single material.
There are also other losses. Our electrons have to flow from one side of the cell to the other through an external circuit. We can cover the bottom with a metal, allowing for good conduction, but if we completely cover the top, then photons can't get through the opaque conductor and we lose all of our current (in some cells, transparent conductors are used on the top surface, but not in all). If we put our contacts only at the sides of our cell, then the electrons have to travel an extremely long distance (for an electron) to reach the contacts. Remember, silicon is a semiconductor -- it's not nearly as good as a metal for transporting current. Its internal resistance is fairly high, and high resistance means high losses. To minimize these losses, a metallic contact grid that shortens the distance that electrons have to travel while covering only a small part of the cell surface covers our cell. Even so, the grid, which can't be too small, blocks some photons or else its own resistance will be too high.
3.4 Solar Powered systems in modern society
For most of the eighties and early nineties the major markets for solar panels were remote area power supplies and consumer products (watches, toys and calculators). However in the mid nineties a major effort was launched to develop building integrated solar panels for grid connected applications. Rooftop PV is now driving the development of the market in Japan, Europe and the USA. Japan currently has a program that aims to build 70,000 solar homes, installing 400MW of PV by 2000 and installing 4600MW by 2010. In Europe several countries are supporting the construction of solar homes, with the European parliament proposing a 1,000MW scheme. In the USA, President Clinton announced a Solar Roofs Program, that aims to install solar panels on one million roofs in America by 2010.
Electric Fences
Electric fences are widely used in agriculture to prevent stock or predators from entering or leaving an enclosed field. These fences usually have one or two 'live' wires that are maintained at about 500 volts DC. These give a painful, but harmless shock to any animal that touches them. This is generally sufficient to prevent stock from pushing them over. These fences are also used in wildlife enclosures and secure areas. They require a high voltage but very little current and they are often located in remote areas where the cost of electric power is high. These requirements can be met by a photovoltaic system involving solar cells, a power conditioner and a battery.
Remote Lighting Systems
Lighting is often required at remote locations where the cost of power is too high to consider using the grid. Such applications include security lighting, navigation aids (eg buoys and beacons), illuminated road signs, railway crossing signs and village lighting. Solar cells are suited to such applications, although a storage battery is always required in such systems. They usually consist of a PV panel plus a storage battery, power conditioner and a low voltage, high efficiency DC fluorescent lamp. These systems are very popular in remote areas, especially in developing countries and this is one of the major applications of solar cells.
Telecommunications and Remote Monitoring Systems
Good communications are essential for improving the quality of life in remote areas. However the cost of electric power to drive these systems and the high cost of maintaining conventional systems has limited their use. Photovoltaics has provided a cost-effective solution to this problem through the development of remote area telecommunications repeater stations. These typically consist of a receiver, a transmitter and a PV based power supply system. Thousands of these systems have been installed around the world and they have an excellent reputation for reliability and relatively low costs for operation and maintenance.
Similar principles apply to solar powered radios and television sets, emergency telephones and monitoring systems. Remote monitoring systems may be used for collecting weather data or other environmental information and for transmitting it automatically via radio to the home base.
Solar Powered Water Pumping
There are more than 10,000 solar powered water pumps in use in the world today. They are widely used on farms and outback stations in Australia to supply water to livestock. In developing countries they are used extensively to pump water from wells and rivers to villages for domestic consumption and irrigation of crops. A typical PV-powered pumping system consists of a PV array that powers an electric motor, which drives a pump. The water is often pumped from the ground or stream into a storage tank that provides a gravity feed. No energy storage is needed for these systems. PV powered pumping systems are widely available from agricultural equipment suppliers and they are a cost-effective alternative to agricultural wind turbines for remote area water supply.
Water Treatment Systems
In remote areas electric power is often used to disinfect or purify drinking water. Photovoltaic cells are used to power a strong ultraviolet light that can be used to kill bacteria in drinking water. This can be combined with a solar powered water pumping system.
Desalination of brackish water can be achieved via PV powered reverse osmosis systems. These are used in arid parts of Australia to produce fresh water from artesian supplies.
The Future
The market for photovoltaic cells is presently growing at about 30% per year, and the cost of panels is declining continuously in real terms (figure 9), due to both new technologies and mass production. There are confident predictions from leading PV manufacturers in USA, Japan and Europe that the price of PV power will be competitive with mains electricity within 10 years.
These predictions generally refer to power at the panel, and do not take into account the various other system costs mentioned above. The price of the balance of systems components are not declining as rapidly as the cost of panels, so the total system costs will decline more slowly. This factor is encouraging research into appliances that can be used directly from the panels, and do not need to rely on inverters and battery storage. Integrating panels into buildings also reduces the balance of systems costs.
5.0 Economic Viability
The purpose of this report was to analyse cost of most solar power system and to advice, the readers to think which solar power systems to get and there budget. While doing on the research in this area, is important for other who wants to get the renewable solar energy it to look at the size and cost for power system. Also the component cost, installations cost, cost effectiveness, the cash back offer and the power produce and warranties of the system. The information used in this report was research on the internet and other recourses
5.1 Finding the right size and cost for your power system
The exact sizing of solar is not terribly risky, since solar modules can be added any time, and since a backup generator can supplement charging if there is a shortfall. There is some flexibility because the power you receive varies with the sunshine of each year and with seasonal changes in weather. Your own flexibility in energy usage, plus use of a backup generator allows you to adapt to temporary shortages, while the automatic charge control manages any overproduction.
We caution against the temptation to start with generator, batteries and inverter, but postpone solar modules until later. If you can, start with enough solar modules required to do the job, since this is where most of your power originates. If budget requires, perhaps start with half or a third of the panels, and add the rest in subsequent years. This will help avoid battery problems and save many generator hours. Solar charging is what made home power systems practical! Solar power is modular. When the family grows or the cabin becomes a full time home, you add more solar modules. If you need to upgrade a charge control or AC inverter. But two things are more permanent decisions: choice of battery voltage, and selection of a Power centre. Consider your long term objective in making these decisions
5.2 Component Cost ""
Inverters transform the direct current (DC) generated by the PV array into the alternating current (AC) used for most residential and industrial purposes. To date, inverters typically average around 10 percent of total system cost. As with module costs, inverter costs are useful for tracking inverter technological improvement and market penetration. Inverters come in sizes from 250 watts (about $300) to over 8,000 watts (about $6,000).
Solar panel which convert sunlight into direct current (DC) electricity, which was come in size from 5 watts (about $155) to over 150 watts (about $1390) and has a lifetime of over twenty years. The purpose of solar regulators is to regulate the current from the solar panels to prevent the batteries from overcharging. The solar regulators are coming in amount of 5 Amps to 60 Amps is cost around $59 to $649. Batteries that are used in solar power systems are designed to be discharged over a long period of time and recharged hundreds or thousands of times. Which cost around at $185 to $859 from the different type amount of voltage and capacity rate? The cost of each component could be higher because depend on the brand name of choice.
5.2.1 Package deals
Solazone Generator 1000
Typically this 1000 watt Solar Power System will generate sufficient electricity to power lights & medium-sized appliances in a 2 - 3 bedroom home, or about 60% of your electricity bill in a typical energy-efficient home.
What you get -
2 - BP 80 Watt Solar Panels
2 - Solazone 6-module Array Frames (adjustable)
- Latronics PV Edge 1500w Grid Interactive Inverter
All wiring, conduit, safety switches, circuit breakers, signage and labour
Net price for total system installed, including GST is $ 10,800
Solazone Generator 1500
This is our most popular solar power system. Typically this 1500 watt Solar Power System will generate sufficient electricity to power lights & medium-sized appliances in a 3 - 4 bedroom home, or approximately 100% of your electricity bill in a typical energy-efficient home.
What you get -
8 - BP 80 watt Solar Panels
3 - Solazone 6-module Array Frames (adjustable)
- Latronics PV Edge 1500w Grid Interactive Inverter
All wiring, conduit, safety switches, circuit breakers, signage and labour
Net price for total system installed, including GST is $ 14,800
5.2.2 Installation Costs"
Installation costs represent nearly all balance-of system components such as wiring, mounting system, junction boxes, and other materials, as well as labour costs and equipment needed for installation. In addition, installation costs are particularly useful for tracking market penetration and commercialization since they are indicative of the level of acceptance of PV products and familiarity with use. Because installation costs are so heavily dependent on end-market commercialization, we would expect installation costs to be the last cost centre to experience significant cost reductions.
5.3 Cost effectiveness"
The current cost of solar panels, and other renewable energy systems, means that grid-interactive systems are not as cost effective as relying purely on the grid for electricity. In spite of this, many people are choosing to install grid-interactive solar systems, as they do not create any greenhouse gases when generating electricity, unlike coal-fired power plants. Numerous studies have demonstrated that the equivalent amount of electricity used to make a solar panel is generated by the panel within the first two years of operation, hence a solar panel will repay its greenhouse gas 'debt' within this time.
Prices for grid interactive systems can start from as little as $2000 for a pair of solar panels and a small inverter. A system capable of running an average suburban home would cost around $20,000 to $25,000, and would include a solar array of 1.5 to 2 kilowatts and an inverter to suit.
5.4 Government Rebate scheme"
The Australian Commonwealth Government's Photovoltaic Rebate Program (PVRP) was introduced to encourage the long-term use of solar technology thus decreasing Australia's greenhouse gas emissions. The government will pay a rebate of $5.00 per installed watt of solar power which is capped at $7,500.00 per household. On a standard 1500-watt system, this equates to approximately 40% of the total system cost. However, there is no restriction on the size of the system. Householders wishing to add to an existing solar power system are eligible for a rebate of $2.50 per Watt, with a minimum extension size of 450W. This rebate is capped at $2,500 (or 1 kW).
5.5 Input/Output power
Grid Interactive System
This is costs of common size grid interactive solar power systems. The systems are sized by the maximum power they produce. The calculations use an average daily solar radiation. The power production figure shown clearly power produced by the solar array, which is: (number of panels) x (rated output of each panel) x (average sun hours per day).
Example: 24 x 85W x 5.65hrs/day = 11.5 kWh/Day.
The actual output for a grid interactive system accounts for inverter efficiency and temperature losses, and is based on the guaranteed output of the solar panels. This is the figure to look at when selecting a system size as this is the actual amount of power the system will charge into your house and electricity grid each day.
Stand Alone System
This is the costs of common size autonomous solar power systems. The systems are sized by the maximum power they produce. The power production figure is the 'apparent' power produced by the solar array, which is: (number of panels) x (rated output of each panel) x (wintertime equivalent sun hours per day).
Example: 24 x 85W x 5.65hrs/day = 11.5 kWh/Day.
The actual output for an autonomous system accounts losses associated with temperature, inverter efficiency, battery and battery charger efficiencies and is based on the guaranteed output of the solar panels. This is the figure to look at when selecting a system size as this is the actual amount of power at 240 volts the system will feed into your house each day.
5.6 Costs of Photovoltaics Against Other Power Sources
You should look not just at the initial cost, but also at the costs of running the power source for the whole intended lifetime of the equipment (10 years, 20 years, etc).
Points to consider:
Photovoltaics' running costs are more or less zero, at least until you have to trade in a battery.
Grid extension can also have a high initial cost, depending on how far a line has to be extended, and how many users can share this cost. Don't forget the costs of transformers and safety equipment too. The running costs here are low, but not zero.
A diesel generator can be quite a low initial cost, but running costs can be high, especially if fuel and regular maintenance are needed at a very remote site. And like all engines, it can need special replacement parts that can be very expensive (or impossible) to supply at short notice.
Primary batteries have an extremely high running cost (the electricity costs around 100x times that of mains electricity) and the cost of sending someone out to replace batteries in a remote area can be high too. Don't forget the cost of disposing of used batteries responsibly too. And if a primary battery runs out before someone has come to replace it, the equipment stops functioning, and that costs money too.
6.0 Bibliography
Reference:
http://www.solardyne.com/comsolsys.html
http://www.bpsolar.com
http://home.earthlink.net/~fradella/green.htm
http://www.solazone.com.au/SOLPOWER.htm
http://www.sustainable.com.au/renewable.html#cashback
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