Solar PV Systems
Almost all the energy we use comes originally from the sun.
Fossil fuels are plant and animal matter that decayed tens of millions of years ago and have been compressed and heated, turning into coal, oil, and gases. Of course, plants get energy from the sun and convert it through photosynthesis. Animals in turn eat plants, converting the stored energy into energy to keep themselves alive.
Wind is created because of differential heating of land and water areas by the sun, creating movement of air from one area to another. Geothermal energy is residual heat of the earth, which was created billions of years ago in the formation of the solar system. So, we can trace all energy back to the source...the nearest star, our sun.
Now we have learned to capture the Sun's energy and use it directly...
Contents |
[edit] When was it Invented
In 1839, Edmond Becquerel discovered that certain materials produced small amounts of electric current when exposed to light. Not long after that, selenium photovoltaic cells were converting light to electricity at 1 to 2 percent efficiency. In 1954, D. M. Chapin, C.S. Fuller and G.L. Pearson, of Bell laboratory, patented a way of making electricity directly from sunlight using silicon-based solar cells. the next year, the Hoffman Electronics-Semiconductor Division announced the first commercial photo voltaic product that was 2.0-percent efficient, priced at $25 per cell, at 14 milliwatts each, or $1,785 per watt (in 1955 dollars). By the mid-1960s, efficiency levels were nearing 10 percent.
We now call this modern-day devices that convert sunlight into energy photovoltaic cells, or "PVs" for short. More commonly, they're known as solar cells. We can find them on calculators, hats, sidewalk lighting systems, and alongside freeways to power phones for stranded motorists.
As an outgrowth of the space exploration and following the energy crises of the 1970s, PV development increased. In 1979, ARCO Solar began construction of the World's largest PV manufacturing facility in Camarillo, California. ARCO Solar was the first company to produce more than 1 megawatt of PV modules in one year. Four years later, ARCO Solar dedicated a 6 megawatt PV facility in central California in the Carrissa Plain. The 120-acre unmanned facility supplied the Pacific Gas and Electric Company utility grid with enough power for about 2,500 homes.
When large collections of PV panels or modules are put together, they can be tied into the electricity grid system. These can supply additional power to areas that need electricity, but costs for new transmission lines and substations are prohibitive. These type of systems are basically Utility-Scale Applications of Photovoltaics.
[edit] Is the site a good place for a PV system?
The property should have clear, unobstructed access to the sun for most of the day and free from shade. The best orientation for a PV system is on a south-facing roof. If your location looks promising, a PV provider can trace the sun's path for you and determine whether your home or business would benefit from a PV system. Typically, composition shingle roofs are the easiest to work with.
[edit] How Much Does a PV System Cost
The cost of a PV system depends on the system's size, equipment options, and labor costs. Prices vary depending on other factors as well, such as the PV provider, whether or not your home is new, if the PV is integrated into the existing roof, and the PV manufacturer. Small systems funded through California's Buy-Down Program have been averaging $7.00 / watt, after rebates. UK customers can find out more on this by reading up on UK solar pv installers websites, such as EvoEnergy.co.uk
[edit] How to use them
In parks, and places where preserving high levels of environment quality is important.
One of the more intriguing recent advances was just announced by Toshiba for the Greatzel cell, a new type of solar panel that consists primarily of titanium dioxide nanocrytals coated with a dye. the new cells could be manufactured by silk-screen printing technologies. At present, at leat seven companies in Japan, Europe, and Australia are developing improved Greatzel cells that may end up gracing cell phones, laptops, and even windows in energy-efficient homes.
BP solar panels quietly and beautifully transform atria, glass roofs, and foor lights into electricity generators. the most impressive products, nevertheless, are PowerWalls, which arrange solar cells in patterns framed by curtain walls erected with traditional glazing techniques.
Powerlight corporation of Berkeley, California, has developed a unique mounting platform that integrates a variety of PV products into rooftops. A foam insulation reduces heating and air-conditioning costs. the light-weight solar by protecting it from the damaging effects of weather.
The building-integrated products manufactured by Atlantis Energy of Grass Valley, California, offers custom glass PV laminates, which turn windows into micro-power plants.
[edit] Types of Solar PV Systems
- When large collections of PV panels or modules are put together , they can be tied into the electricity grid system. These can supply additional power to areas that need electricity, but costs for new transmission lines and substations are prohibitive . These type of systems are basically Utility -Scale Application of Photovoltaics.
- Solar photovoltaic cells are small, square -shape panel semiconductors manufactured in thin film layers from silicon and other conductive materials. When sunlight strikes the PV cell, chemical reactions release electrons, generating electric current. The small current from individual PV cells, which are installed in modules, power individual homes and businesses, or can be plugged into the bulk electricity grid.
- Solar PV has come a long way since its early origins in the space program powering satellites and other extraterrestrial Vehicles more than four decades ago. The technology has come down to earth and now is the first power supply choice for much of the developing world. They are also appearing on rooftops and years around our state to provide power during daylight hours.
- There are two primary PV markets. Off-grid systems are used where the cost of a PV system is cheaper than stringing electrical power lines long distance from the local utility. Grid-connected PV systems usually cannot complete directly with the cost of utility-produced power. However, with the changing deregulated marketplace, many people are considering grid-connected PV systems. If the PV system provides more power than the home or business uses, additional electricity is fed back into the grid for other people to use . This effectively spins an electricity meter backward in what is known as "net metering."
Types of PV Systems
- Photovoltaics or solar cells can be purchased in two formats: as a stand-alone module that is attached to your roof or on a separate system, or using intergrated roofing materials with dual functions -- that as a regular roofing shingle and as a solar cell making electricity.
- Because they do not produce polluting air emissions or water effluents, solar PV systems are prime candidates for supplying electricity at locations where such environmental impacts are unacceptable; for example, in parks and places where preserving high levels of envinronmental quality is important.
[edit] The benefits of solar electricity
Cut your carbon footprint:
- Solar electricity is green, renewables energy and doesn't release any harmful carbon dioxide (CO2) or other pollutants. A typical home PV system could save around 1200 kg of CO2 per year - that's around tonnes over its lifetime.
Cut your electricity bills:
- Sunlight is free, so once you've paid for the initial installation your electricity costs will be greatly reduced. A typical home PV system can produce around 40% of the electricity a household uses in a year.
Sell electricity back to the Grid:
- If your system is producing more electricity than you need, or when you can't use it, someone else can use it - and you could make a bit of money.
Store electricity for a cloudy day:
- If your home isn't connected to the national grid you can't store excess electricity in batteries to use when you need it.
[edit] Is solar electricity suitable for my home?
Do you have a sunny place to put it? You'll need a roof or wall that faces within 90 degrees of south, and isn't overshadowed by trees or buildings. If the surface is in shadow for parts of the day, your system will generate less energy.
Is your roof strong enough? Solar panel are not light and the roof must be strong enough to take their weight, especially if the panel is placed on top of existing tiles. If in doubt, ask a construction expert or an installer.
Do you need planning permission? In England and Scotland, you don't need planning permission for most home solar electricity systems, as long as they're below a certain size - but you should check with your local planning officer if your home is a listed building, or is in a conversation area or World Heritage Site.
- The electricity generated is used to power your appliances around the home and any surplus is exported to the grid. This means you will benifit whatever the time of year. Overall the UK, up to 850 kilo Watt hours (kwh) of power can be generated annually from every KW installed and this can be either offset from your bill or exported directly to the grid.
- Not only wil you experience a reduction in your electricity bills but PV will also minimise the impact of rising energy costs over the coming years.
- Solar systems have no moving parts, are moiseless and require very minimal maintenance.
- You are investing in a highly reliable system which has a typical lifetime of 25-30 years.
- An energy saving solar installation adds value to your property and addresses energy efficiency aspects of the HIPS when selling.
- The PV Home connects seamlessly into your existing frid connection.
- By generating your own solar energy you will reduce your dependence on the commercial electricity providers.
- A reduction of your carbon footprint on the planet by 482kg for every KW of solar PV installed per annum.
