Six Easy Steps To Estimate Cost of a Solar Power System
Solar power energy systems are not inexpensive. That said it’s important to compare them within context of other types of home improvement projects. Home buyers and realtors view a solar photovoltaic or solar hot water heating system as a significant value-added improvement – similar to adding a deck or remodeling your kitchen. Plus unlike a deck or kitchen remodel, you also gain one-up on your power bills.

Solar power systems often get an additional financial boost as well: many jurisdictions and utilities across the USA offer attractive financial incentives to drive down the upfront capital costs associated with a solar power system.

Here are some foolproof ways to estimate the cost of a solar photovoltaic or solar thermal system and to figure out if a solar energy system makes sense for you. Let’s start with a home photovoltaic (PV) system.

Step 1: Estimate your home’s electricity needs
To get started, it’s good to have a sense of how much electricity you use. You’ll have a better point for comparison if you find out how many kilowatt hours (kWh) you use per day, per month, per year. Your utility bill should include that information.

Of course, the utility bill will also display your costs and many utilities include a graph that displays how your monthly energy use/cost varies throughout the year. That helps you estimate where your highest energy use is and at what time of year.

New Home Construction
If you are constructing a new home, then you’ll need to estimate your demand based on the type of equipment you plan to install and your home’s square footage. The pross call this “your load”.

To figure out your anticipated load, create a table to record the watt use for each appliance. Each appliance – be it a water heater, electric light, computer, or refrigerator – should have a nameplate that lists its power rating in watts. Or you can get the information from the manufacturer’s website.

Some labels list amperage and voltage only; to obtain watts multiply the two together (amperage x voltage = watts). In another column, record the number of hours each appliance is expected to operate. Then multiple the watts and hours together to estimate watt-hours used per day. Since it’s hard to anticipate all electric loads (it may get tedious scouting out every toothbrush and mobile phone cell charger), you might want to add a multiplier of 1.5 to be safe.

Step 2: Anticipate the future
In 2005, average residential electricity rates across the USA ranged from about 6 to nearly 16 cents per kilowatt hour depending on where you lived. Average retail and commercial electricity rates have increased roughly 30% since 1999 and the upward trend will likely continue especially as costs for the coal and hydropower used to generate that electricity rise as well. So think about your home electricity needs and present and future cost in relation to one another.

Step 3: How much sun do you get?
The Florida Solar Energy Center has conducted a study to examine how a 2-kW photovoltaic system would perform if installed on a highly energy efficient home across the continental USA (http://www.fsec.ucf.edu/en/publications/html/FSEC-PF-380-04/).

The study accounted for all factors that impact a PV system’s performance such as the temperature effect on the photovoltaic cells, the amount of sun peak hours in various regions, and the efficiency of inverter to convert solar derived energy from DC to AC.

As the study implies, solar photovoltaic systems work just about anywhere in the US. Even in the Northeast or in “rainy Seattle”, a pv system can pencil out if designed and installed properly. In New York or New Jersey, a one kilowatt system should produce about 1270 kilowatt hours of electricity per year, in Seattle, a one kilowatt system should produce about 1200 kilowatt hours per year. In the Southwest, of course, those ratios will be much greater.

Solar contractors in your area can help determine the best size for your solar photovoltaic system.

Step 4: Size your system
In general, solar photovoltaic systems sized between 1 to 5 kilowatts are usually sufficient to meet the electricity needs of most homes. One advantage of grid-tied systems is that you can use solar PV to supplement or offset some of your electricity needs; therefore you can size your system to match your budget and always add to the system later if needed.

Also as a side note, here’s a rule of thumb to remember to help you estimate the physical space your PV system might need: one square foot yields 10 watts. So in bright sunlight, a square foot of a conventional photovoltaic panel will produce 10 watts of power. A 1000 watt system, for example, may need 100 – 200 square feet of area, depending on the type of PV module used.

Step 5: Know your rebates
Many states and local jurisdictions offer rebates, tax credits and other types of incentives to homeowners for installing residential photovoltaic and solar domestic water systems. To view a comprehensive database of the incentives available for renewable energy visit http://www.dsireusa.org.

At the Federal Level, you can take advantage of a 30% tax credit (of up to $2,000) for the purchase of a residential solar system at least until December 31, 2008.

The Original Post is Located Here: Six Easy Steps to Estimate Cost of a Solar Power System

Cell phones, computers, MP3 players, kitchen stoves, and irons all have one thing in common: They need electricity. And in the future, more and more cars will also be fuelled by electric power. If the latest forecast from the World Energy Council WEC can be believed, global electricity requirements will double in the next 40 years. At the same time, prices for the dwindling resources of petroleum and natural gas are climbing.

“Rising energy prices are making alternative energy sources increasingly cost-effective. Sometime in the coming years, renewable energy sources, such as solar energy, will be competitive, even without subsidization,” explains Dr. Arnold Gillner, head of the microtechnology department at the Fraunhofer Institute for Laser Technology in Aachen, Germany. “Experts predict that grid parity will be achieved in a few years. This means that the costs and opportunities in the grid will be equal for solar electricity and conventionally generated household electricity.” Together with his team at the Fraunhofer Institute for Laser Technology ILT in Aachen, this researcher is developing technologies now that will allow faster, better, and cheaper production of solar cells in the future. “Lasers work quickly, precisely, and without contact. In other words, they are an ideal tool for manufacturing fragile solar cells. In fact, lasers are already being used in production today, but there is still considerable room for process optimization.” In addition to gradually improving the manufacturing technology, the physicists and engineers in Aachen are working with solar cell developers – for example, at the Fraunhofer Institute for Solar Energy Systems ISE in Freiburg – on new engineering and design alternatives.

New production technologies allow new design alternatives
At “Laser 2009” in Munich, the researchers will be demonstrating how lasers can drill holes into silicon cells at breathtaking speed: The ILT laser system drills more than 3,000 holes within one second. Because it is not possible to move the laser source at this speed, the experts have developed optimized manufacturing systems which guide and focuses the light beam at the required points. “We are currently experimenting with various laser sources and optical systems,” Gillner explains. “Our goal is to increase the performance to 10,000 holes a second. This is the speed that must be reached in order to drill 10,000 to 20,000 holes into a wafer within the cycle time of the production machines.”

The tiny holes in the wafer – their diameter is only 50 micrometers – open up undreamt-of possibilities for the solar cell developers. “Previously, the electrical contacts were arranged on the top of the cells. The holes make it possible to move the contacts to the back, with the advantage that the electrodes, which currently act as a dark grid to absorb light, disappear. And so the energy yield increases. The goal is a degree of efficiency of 20 percent% in industrially-produced emitter wrap-through (EWT) cells, with a yield of one-third more than classic silicon cells,” Gillner explains. The design principle itself remains unchanged: In the semi-conductor layer, light particles, or photons, produce negative electrons and positive holes, each of which then wanders to the oppositely poled electrodes. The contacts for anodes and cathodes in the EWT cells are all on the back, there is no shading caused by the electrodes, and the degree of efficiency increases. With this technique, it may one day be possible to use unpurified “dirty” silicon to manufacture solar cells that have poorer electrical properties, but that are cheaper.

Drilling holes into silicon cells is only one of many laser applications in solar cell manufacturing. In the EU project Solasys – Next Generation Solar Cell and Module Laser Processing Systems – an international research team is currently developing new technologies that will allow production to be optimized in the future. ILT in Aachen is coordinating the six million euro project. “We are working on new methods that make the doping of semiconductors, the drilling and the surface structuring of silicon, the edge isolation of the cells, and the soldering of the modules more economical,” project coordinator Gillner explains. For example, “selective laser soldering” makes it possible to improve the rejection rates and quality of the contacting, and so reduce manufacturing costs. Until now, the electrodes were mechanically pressed onto the cells, and then heated in an oven. “But silicon cells often break during this process,” Gillner knows. “Breakage is a primary cost factor in production.” On the other hand, however, with “selective laser soldering” the contacts are pressed on to the cells with compressed air and then soldered with the laser. The mechanical stress approaches zero and the temperature can be precisely regulated. The result: Optimal contacts and almost no rejects.

Laser technology means more efficient thin film cells
Laser technology is also helping to optimize the manufacture of thin film solar cells. The extremely thin film packages made of semiconducting oxide, amorphous silicon, and metal that are deposited onto the glass panels still have a market share of only ten percent. But as Gillner knows, “This could be higher, because thin film solar cells can be used anywhere that non-transparent glass panels can be mounted, for example, on house facades or sound-insulating walls. But the degrees of efficiency are comparable low at five to eight percent, and the production costs are comparatively high.” The laser researchers are working to improve these costs. Until now, the manufacturers have used mechanical methods or solid-state lasers in the nanosecond range in order to structure the active layers on the glass panels. In order to produce electric connections between the semiconductor and the metal, grooves only a few micrometers wide must be created. At the Fraunhofer-Gesellschaft booth at “Laser 2009” the ILT researchers will be demonstrating a 400-watt ultrashort pulse laser that processes thin-film solar modules ten times faster than conventional diode-pumped solid-state lasers. “The ultrashort pulse laser is an ideal tool for ablating thin layers: It works very precisely, does not heat the material and, working with a pulse frequency of 80 MHz, can process a 2-by-3 meter glass panel in under two minutes,” Gillner reports. “The technology is still very new, and high-performance scanning systems and optical systems adapted to the process must be developed first. In the medium term, however, this technology will be able to reduce production costs.”

The rise of laser technology in solar technology is just taking off, and it still has a long way to go. “Lasers simplify and optimize the manufacture of classic silicon and thin-film cells, and they allow the development of new design alternatives,” Gillner continues. “And so laser technology is making an important contribution towards allowing renewable energy sources to penetrate further into the energy market.”

Fraunhofer-Gesellschaft. “Lasers Are Making Solar Cells Competitive” ScienceDaily

The Original Post is Located Here: Lasers Are Making Solar Cells Competitive

Solar Energy Collectors

Harnessing the power of the sun’s ray to create energy to power our house is very appealing. But the question is, “Is everything about solar energy good?”

Looking at the current price of fossil fuel-based electricity, it is quite impractical to convert into solar energy system. However, with the growing concern on the state of the earth, there is really a need to find other means of energy aside from what power plants are using right now. Where do you place yourself?

Whether you are an advocate of clean energy or simply care about where your finances go, looking at the pros and cons of residential solar energy system will help you decide on whether to convert or not.

Advantages
Solar energy is free. Did you know that the earth absorbs 174 pettawatts of solar radiation? This means that we have more than enough source of free energy to power every house in the world. Unfortunately, most of our energy is still drawn from oil, gas and coal. But in recent years, there is a steady increase of demand for alternative and renewable energy like solar power. It is estimated that the demand for alternative sources of energy will increase by 53% between 1999 and 2020.

Solar energy is clean, renewable and sustainable. Because the energy created from the sun’s rays does not produce byproducts like those from fossil fuel power plants (sulfur dioxide, nitrogen oxide, mercury or carbon dioxide), it does not contribute to pollution. Accordingly, the increase in the use of solar energy and other alternative forms of energy will decrease the demand for greenhouse gases-producing power plants.

The price of photovoltaic cells is steadily decreasing. The demand for solar panels has risen by 57% in the United States in 2007 and is steadily increasing on a monthly basis. The increase in demand results to the improvement of solar technology as a whole. The prices of photovoltaic cells have declined on the average of 4% every year over the past 15 years.

Solar panels can be installed on most rooftops, eliminating the problem of finding a suitable place for installation. Solar panels require little or no maintenance. The original photovoltaic cells technology is used for most satellites orbiting our earth today which are not maintained at all. Many solar panel manufacturers give 25 to 40 years warranty on their products.

Because most areas of the country receive a substantial amount of sunlight throughout the year, solar panels can be installed anywhere.

Many states in the country give tax credits and rebates to households who want to install solar energy system. Check with your state government the cost of these incentives.

Disadvantages
While the prices of PV cells are in constant decline, the cost of installation is substantially high compared to the current electric cost. But the good thing is, after your initial cash out, you don’t have to pay every month on electric bills for the rest of your life.

On areas cities and areas with heavy pollution problem, solar energy may not work as fine. Weather can also affect the efficiency of solar energy. If it is raining, overcast weather or if there is a hurricane, the solar panels’ efficiency is decreased.

You are only producing energy during day time.

These are general pros and cons you might encounter when considering the conversion to solar energy system. It would be best if your decision is based on location, cost, budget, rebates, tax credits and practicality.
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The Original Post is Located Here: Solar Energy – The Advantages and Disadvantages