Thursday, August 26, 2010

Solar Energy - A Brief History in the United States

The technology to derive substantial electrical current using light from the sun has been around since the mid 1950's when the first solar cell was created by Daryl Chapin, Calvin Fuller, and Gerald Pearson at Bell Labs - they developed the first solar cell capable of generating enough power from the sun to run everyday electrical equipment. A silicon solar cell was produced that was 6% efficient. They were later able to increase efficiency to eleven percent.

Anyone who is aware of the ability to harness sunlight into electrical energy just has to recall from Jr. High School Science Class that Electricity produced by a solar cell is only good if the sun is shining directly onto the a photovoltaic solar cell.

With basic knowledge that solar cells product Direct (un-fluctuating) current, it stands to reason that there are two, very costly obstacles that stand in the way of practical solar power: 1) how to convert the current from direct current (DC) to Alternating Current (AC) so that it can be used in the common household and 2) how to practically store the energy for use when needed after the sun had set or gone behind the clouds.

By the time solar technology had developed and become less expensive to produce, our nation's infrastructure had already established and built around the standard of AC at 110 volts and 15 amperes. A big expense to the use of solar cells is the requirement for use expensive power inverters to convert it from DC to AC.

With help from Exxon Corporation in 1970, a significantly less costly solar cell was designed by Dr. Elliot Berman. His design decreased the price of solar generated power from $100 per watt to $20 per watt. Although, still costly, this was a giant leap into the feasibility of the use of practical solar power

In 1976, the NASA Lewis Research Center began to install the first of many photovoltaic systems on every continent in the world with the exception of Australia. Those systems provided power for vaccine refrigeration, room lighting, medical clinic lighting, telecommunications, water pumping, grain milling, and classroom television. The project took place from 1976 to 1985, and then again from 1992 to its completion in 1995. By time the project was completed, 83 stand-alone systems were in place. These areas where systems were installed were obviously devoid of practical on-grid systems.

In July of the same year, the U.S. Energy Research and Development Administration which was the predecessor to the U.S. Department of Energy launched the Solar Energy Research Institute. And in 1977, total photovoltaic manufacturing production exceeded 500 kw (kilowatts). This was only enough power to light 5,000, 100-watt light bulbs.

In 1982, the first megawatt-scale PV (photovoltaic) power station went on line in Hisperia, California. The systems capacity was 1-megawatts and was developed by ARCO Solar. The U.S. Department of Energy and an industry consortium began operating Solar One, a 10-megawatt central-receiver demonstration project in California which established the feasibility of power-tower systems. During this same time, an Australian named Hans Tholstrup drove the first solar-powered car - the Quiet Achiever - almost 2,800 miles between Sydney and Perth in 20 days. This was 10 days faster than the first gasoline powered car. Tholstrup is now the founder of a world-class solar car race, Australia's World Solar Challenge.

Two other significant from 1982 which shaped the history of solar energy; Volkswagen of Germany began testing photovoltaic arrays mounted on the roofs of Dasher station wagons which generated 160 watts of electricity for use in the ignition system; and the Florida Solar Energy Center's Southeast Residential Experiment Station began supporting the U.S. Department of Energy's photovoltaics program in the application of systems engineering. Worldwide, photovoltaic production then exceeded 9.3 megawatts.

In 1986 the world's largest solar thermal facility was commissioned in Kramer Junction, California. The solar field contains rows of mirrors that concentrate the sun's energy onto a system of pipes circulating a heat transfer fluid. The heat transfer fluid, used to produce steam, powers a conventional turbine to generate electricity. While

Researchers at the University of South Florida developed a 15.9% efficient thin-film photovoltaic cell made of cadmium telluride, breaking the 15% barrier for this technology, a 7.5-kilowatt prototype dish system that includes an advanced stretched-membrane concentrator began operating in Florida.

The first solar station to distribute electricity produced from solar collectors was Pacific Gas & Electric (PG&E) in 1993, in Kerman, California. The National Renewable Energy Laboratory (formerly the Solar Energy Research Institute) completed construction of its Solar Energy Research Facility and became recognized as the most energy-efficient of all U.S. government buildings in the world.

In 1994 the first solar dish generator to use a free-piston Stirling Engine is hooked up to a utility grid and The National Renewable Energy Laboratory developed a solar cell made of gallium indium phosphide and gallium arsenide. This cell development was the first to achieve a conversion efficiency of above thirty percent.

Two years later, although not in the United States but worth mentioning, a solar-powered airplane, the Icare, flew over Germany. The wings and wings and tail surfaces were covered by 3,000 extremely efficient solar cells. Total surface area was 21 square meters.

The U.S. Department of Energy and an industry consortium begin operating Solar Two - an upgrade to Solar One's concentrating solar power tower. Until the project's end in 1999, Solar Two demonstrated how solar energy can be stored efficiently using molten salt economically so that power can be produced even when the sun isn't shining; it also spurs commercial interest in Molten Salt Power Tower Technology [http://www.energylan.sandia.gov/sunlab/snapshot/stfuture.htm#tower]

On August 6, 1998, a solar-powered, remote-controlled aircraft, "Pathfinder," set a record altitude of 80,000 feet after its 38th consecutive flight in Monrovia, California. This is higher than any prop-job to date.

The tallest Skyscraper in the city that was built in the '90's -- 4 Times Square in New York -- has more energy-efficient features than any other commercial skyscraper. The building includes integrated photovoltaic (BIPV) panels on the 37th through the 43rd floors on the south and west-facing facades to produce a portion of the building's power.

The National Renewable Energy Laboratory (NREL) and Spectrolab, Inc. developed a 32.3% efficient solar cell. This highly efficient cell resulted from the combination of three layers of photovoltaic material into a single cell. This cell was most efficient and practical when used in devices with lenses or mirrors which concentrate the sunlight. These concentrator systems [http://www.environment.gov.au/settlements/renewable/recp/pv/pubs/pv2.pdf] are mounted on trackers which always keep them pointed toward the sun. The NREL also produced a record breaking achievement in the niche of thin-film cells. It increased efficiency more than 1% to 18.8%.

Today, with the price of petroleum topping $126/bbl, more and more people are looking to alternative energy sources to fill their energy needs. From using cooking oil as fuel in diesel cars, to using wind and sun energy at the residential level, people everywhere realize they can no longer depend on the Middle East, or even their own governments to properly regulate energy.

Individuals will need to be proactive in their efforts to supply themselves with energy. Who knows, it may be possible one day we invent automobiles with remove and replace batteries, similar to warehouse forklifts. Spare batteries to be charged via solar panel during the day to replace the spent battery at night. Just in time for the next day's commute to work.

Gene Duckett became interested in Solar Powered gadgets with his first credit card sized, solar-powered calculator purchased from Radio Shack in 1979. Now that he is all grown up and knows what he wants to do with his life, he is combining his interest in Solar Power with the opportunity in the United States to develop energy sources that are independent of foreign sources. That is why he founded http://www.gnpsolar.com His intent is to distribute information about solar power and practical applications to as many homeowners and business owners as possible. He believes that not only should we, as a country, eliminate need for foreign oil but, we should also reduce or eliminate dependency on grid power. When individuals relinquish self sufficiency for daily needs on a wholesale level, then they put themselves in a vulnerable position. Never in recorded history has man been so dependent on his government(s) and to a certain extent big business) for everyday necessities. There is a GOOD reason why the forefathers of the United States intended to LIMIT powers of the government. Those reasons are still valid today. Join in the progressive movement to end dependency on foreign oil and government control of everyday necessities. visit http://www.gnpsolar.com and get on the mailing list for weekly updates on the State of Solar Technology newsletter. There will soon be available valuable resources for converting your home from grid powered, to solar power. There will also be links to suppliers, educational videos, and technological developments. Its free and at the same time will be somewhat entertaining. Please be patient while the website, affiliate links, and company store are being developed. The demand for solar products is going to skyrocket, so these things will be available as quickly as possible. Thank You.

Article by Gene Duckett

Article Source: http://EzineArticles.com/?expert=Gene_Duckett

Monday, August 23, 2010

Electrical Power and Energy

Power is an electrical quantity that is measured in watts, and is the rate at which energy is either being absorbed or produced by a circuit. We know that light bulbs and heaters absorb energy and that the higher their value in watts the more energy they will consume. Likewise, batteries and generators produce energy and the greater their electrical rating the more power they can deliver to the load. The unit of electrical power is the watt with its symbol being a large letter "P" indicating constant DC power or a small letter "p" indicating a time-varying AC power.

Electrical power is related to energy which is the capacity to do work. It can also be defined as the rate of by which energy is transferred. If one joule of work is either absorbed or delivered at a constant rate of one second, then the corresponding power will be equivalent to one watt so power, P can be defined as 1Joule/sec = 1Watt. Then we can say that one watt is equal to one joule per second and electrical power can be defined as the rate of doing work or the transferring of energy.

Equally we can define energy as being watts per second or joules. So if the power is measured in kilowatts (thousands of watts) and the time is measure in hours, then the unit of electrical energy is the kilowatt-hour, (kWh) and 1 kWh is the amount of electricity used by a device rated at 1000 watts in one hour.

Kilowatt-hours are the standard units of energy used by the electricity meter in our homes to calculate the amount of electrical energy we use and therefore how much we pay. So if you switch on an electric fire with an element rated at 1000 watts and left it on for 1 hour you will have used 1 kWh of electricity. If you switched on two electric fires each with 1000 watt elements for half an hour the total consumption would be exactly the same amount of electricity - 1kWh. So, consuming 1000 watts for one hour uses the same amount of power as 2000 watts (twice as much) for half an hour (half the time). Then for a 100 watt light bulb to use 1 kWh or one unit of electrical power it would need to be switched on for a total of 10 hours (10 x 100 = 1000 = 1kWh).

So we now know that the unit of power is the watt with the power absorbed by an electrical circuit being given as the product of the voltage, V and the current, I which gives:

P (watts) = V (volts) x I (amperes)

Also, by substituting Ohm's Law into the equation above we can also define a constant DC power as being:

P (watts) = I^2 (amperes squared) x R (resistance)

or

P (watts) = V^2 (voltage squared) / R (resistance)

Then there are three possible formulas for calculating electrical power in a circuit. If the calculated power is positive, (+P) then the circuit or component absorbs the power. But if the calculated power is negative, (-P) the circuit or component delivers power in other words it is a source of energy.

Power Rating

Electrical components are given a "power rating" in watts that indicates the maximum rate at which the component coverts the electrical energy into another form of energy such as heat, light or motion. For example, a 1/4W resistor, a 100W light bulb etc. So energy is used by electrical devices to convert one form of power to another so for example, an electrical motor will covert electrical energy into a mechanical force.

Electrical motors and other electrical systems have an efficiency rating defined as the ratio of power converted into work to the total power consumed by the device. Efficiency is expressed as a decimal fraction but is generally defined as a percentage value such as 85% efficient. So we can define efficiency as being equal to power output divided by power input x 100%.

The efficiency of an electrical device or motor will always be less than one (100%) due to electrical and mechanical losses. If an electrical device has an efficiency rating of 85% then only 85% of the input power is transformed into mechanical work the other 15% is lost in heat or other losses.

Domestic electrical appliances such as washing machines, driers, fridges and freezers also have energy efficiency ratings that indicate their energy usage and cost. These ratings are given as "A" for efficient and "G" for less efficient.

So remember, the more energy efficient is the device, the less energy it will consume and the more money you will save as well as being helpful to the environment.

Learn more about electrical power and energy and lots of other good basic electronics tutorials at http://www.electronics-tutorials.ws.

Article by Wayne Storr

Article Source: http://EzineArticles.com/?expert=Wayne_Storr

Sunday, August 22, 2010

In The Industrial Electricity World, Time Is Money. We're On Your Side.

When it comes to the Industrial world, Vacaville Electric knows "Time is Money." We realize it may be a deadline for a new facility, new equipment being implemented into an existing system, or general maintenance. Vacaville Electric will be there at all hours to help you get the production moving.

Call Tom Jackson of Vacaville Electric at 707-448-8222.

Saturday, August 21, 2010

Big Changes Are Coming To Our Industry. We're Ready. Are You?

We can help you be ready. "Carbon footprint," "greenhouse emissions" and "global warming" are not just news stories. They are concerns that are driving change in electrical technology, revolutionizing our industry.

"Green" technology often translates into huge savings on electricity. Generating electricity from the sun is a technology we all know well. Whether you’re powering a pocket calculator, satellite, or your home, solar electricity, also known as photovoltaics, can get the job done.

Give us a call today to see how we can help you be "green" and save money at the same time!

Did you know?

Enough sunlight falls on the earth's surface each minute to meet world energy demand for an entire year.






The cost of electricity is going up (both in dollars and in environmental and health impacts) and it doesn’t show any signs of doing otherwise. About half of the energy in the American grid is coal generated. Electric energy is an intermediate form of energy. It is produced in thermal power stations (where fuel oil, gas, coal, biomass, etc. are burnt), in hydroelectric power stations and nuclear power stations. Smaller quantities are produced by wind, photovoltaic solar panels, sea tides, etc.

Call Tom Jackson of Vacaville Electric at 707-448-8222 to answer any of your solar questions.

Friday, August 20, 2010

Did You Know?

Benjamin Franklin was the first to name the two types of charges, calling one positive and the other negative. He also established the convention that the charge that moves is associated with electrons, and that it has a negative sign. He assumed that electricity flows from positively charged to negatively charged regions.


Electric current is composed of moving charges. In metals, it is the free electrons that move, so the current is negative. In semiconductors, currents may be either positive or negative, due to the movement of holes and free electrons. Electric potential is a voltage. Charges flow when there is a potential difference applied between two different points. This potential difference creates a pressure that causes the charges to move, just like a pump does water. Potential differences are created from power sources such as batteries or generators, and are measured in units called volts. Volts are named after Italian physicist Alessandro Volta.

Current is measured in amperes or amps, for short. It is named after the French physicist Andre Marie Ampere. An ampere is equal to one coulomb of charge per second, which is in magnitude a billion billion of electrons. The coulomb is named after another French physicist, Charles Coulomb.

Thursday, August 19, 2010

Vacaville Electric Blog

Welcome to the New Vacaville Electric Blog
We hope to not only Inform but, to Entertain you!

Vacaville Electric is a full service Electrical Contractor based in Vacaville, California. Some of our company specialties include Residential, Commercial, Industrial, Service & Maintenance, Design, Lighting and Solar. When you need an electrician, you can count on us. Whether you are a Business Owner, a Contractor, a Property Owner, or a Homeowner, we facilitate the smooth completion of your project. Working well with other trades, we look out for the owner's intrests, delivering affordable quality every time. We always welcome new challenges and look forward to working with you.

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