far as I know, no manufacturer has ever released data on the actual energy used for the manufacture of PV modules. I propose that the most useful way to structure this debate is to document an enveloping series of total energies, each envelope taking more factors into consideration.

Typically, the energy payback time (the time it takes the system to generate the same amount of energy that it took to manufacture the system) for PV systems is 2 to 5 years. Given that a well-designed and maintained PV system will operate for approximately 30 years, PV systems produce far more energy over their lives than is used in their manufacture. See similar questions...

The payback time of an investment is the period of time required until that investment returns an amount equal to the original investment. This is called the Financial Payback Time. Note that when dealing with money over time, one ought properly to use the standard time value of money calculations (otherwise known as interest). See similar questions...

Then the value of the average energy a PV system generates in N days is (ADPVENERGY * GBERATE * N) Note d The assumption here is that we simply consider the total cost out of pocket to a person, without worrying about a breakdown of those costs. Another assumption is that you are paying cash. If you buy on terms or use your credit card, other individual charges may arise. Then there is the issue of government sponsored rebates. See similar questions...

A photovoltaic module is typically a group of solar cells assembled in a commercial unit ready for installation in a system. It is the form in which most power systems are purchased. Usually the PV module has a specified power rating and guaranteed lifetime (commonly ~20 years). See similar questions...

This again is a question which depends upon where you live. As far as I know there are no grants, rebates or tax incentives for ordinary folk living in Canada. In the UK, the Labour government recently introduced a PV grant for qualifying homeowners. In some American states, I think purchasers of PV are eligible for a percentage rebate. See similar questions...

The costs and benefits of cars extend far beyond an individual driver to society as a whole. But when people talk about payback, they refer only to the net dollars to the driver. Because this question never comes up when people pay a premium for features like leather seats, we point out that millions of people want the "environmental feature" [See J.D. Power and Associates' 2004 report]. Car and Driver's Patrick Bedard writes amusingly but tellingly about this issue. See similar questions...

with cells, There are many manufacturers of PV modules. A look through a business index would be useful. See similar questions...

Comments: A good look at how PV works. Has a discussion of efficiency factors, as well as different cell types. Also some discussion of concentrators. Comments: A how to book with coverage of all the practical issues of setting up a solar electric home. Comments: A classic. This is a good, down to earth, book about all the practical details and decisions of setting up photovoltaic power for a house. See similar questions...

The efficiency of photovoltaic devices has been steadily improving since serious attention began to be paid to them in the 1950's. The first selenium cells built by Fritts were <1% efficient. In 1954, Pearson Fuller and Chapin produced silicon solar cell whose efficiency was 4% to 6%. By the early 1970's silicon solar cells were 10% efficient. See similar questions...

There are ISO standards for some PV measurements, but as far as I can tell the American standards formulated by the ASTM (American Society of Testing and Materials) are the most widely used. Good light sources for this type measurement are extremely expensive and can take a tremendous amount of space, and it's quite common for people without the money or space to use less expensive light sources that aren't quite as good. For that reason, there's no "typical" or "standard" setup. See similar questions...

The payback period can vary widely depending on the technology, and the availability of grants and tax incentives. It also depends on the stability of utility energy prices. Most experts use a conservative 5% yearly inflation rate for utility electric rates. Actual rate increases have at times been much higher. For example, utility inflation rate in California has averaged 6.7% over the last 30 years. See similar questions...

Depending on where you are located, the simple payback (i.e. the time it takes to pay off your solar PV system based on today's electricity rates with no inflation factored in) on a PV system ranges from approximately 8 to 16 years. These are based on the net cost of a system after incentives. Keep in mind however, that the real payback will vary for each system based on your individual circumstances. See similar questions...

There are several ways to approach this question. First note that many of the larger manufacturers are offering 20 year warranties on their modules. The warranties are typically against complete failure, not against slowly falling output. Some companies warranty 90% of rated output for N years and 80% for M years, with various M and N. Second there are the results of lab tests. TISO in Switzerland is one of the few organizations I know who have posted material on the subject. See similar questions...

This again depends on cleanliness. If the material is kept clean, the UV stability is greatly enhanced. I will provide some literature references on this matter with the next few days (it is very late at night and I need to do an extended web search, since I can't send my hard copies). Sintered PTFE such as Fluorilon has been used extensively as a standard for spectrophotometers and spectroradiometers in low-earth orbit space platforms. See similar questions...

Power is the rate of doing work. It is an instantaneous quantity, measured in watts. A watt is 1 joule per second. Energy is power over a period of time. It is measured in watt-seconds, but that unit is too small for everyday use, so the unit kilowatt-hours is more commonly used. Note this is a controversial subject - not because there is any disagreement, but because some people are either lazy, uninformed or misinformed and misuse the terms. See similar questions...

The time required to complete a PV installation will vary widely. The actual installation of a PV system can be completed in 1-3 days, and the chart below outlines the typical timeline for the entire process. See similar questions...

The payback period varies according to the purchase scenario under consideration, cost difference, hours of operation, electrical rates, motor loading, and difference in motor efficiencies. For new purchase decisions, the simple payback on the incremental cost of a continuously operated energy efficient motor can be recovered through energy savings in well under two years. Manufacturers are free to select descriptive terminology for use in identifying and marketing motor lines. See similar questions...

Because of the nature of the descending torque load itself, the magnetic-coupled drive takes advantage of the energy savings with variable speed. Graph] The magnetic-coupled drive will take advantage of the affinity laws on variable torque loads such as centrifugal fans and pumps and does so without altering the voltage or interrupting power to the motor. Even with the motor running continuously, the kW required by the motor changes according to the actual load, i.e. See similar questions...