admin answers:

I think the only down side is that no electricity is generated at night.

As for other answer mentioned energy used to produce panel, here is a interesting fact:

The energy payback time (i.e., the time it takes for a PV system to generate the same amount of energy that it took to manufacture the system) for PV systems is 2 to 5 years. Since a well-designed and maintained PV system will operate for more than 20 years, and a system without moving parts will operate for close to 30 years, PV systems produce far more energy over their useful life than we use to manufacture them.

admin answers:

Nope. The only solar power that works adequately all through the night is solar therm. The sun’s heat melts salt. The molten salt boils water, water produces steam drives a turbine connected to a generator. Since the salt gets VERY hot and takes a long time to cool down a MSR solar therm reactor [as opposed to a MSR Thorium nuclear reactor] can operate all night long.

An offset is a financial instrument – it is like a stock certificate; it is in fact a commodity forward and the commodity is electricity. It allows you to spend credits produced in generating solar power on electricity generated from the grid. In this case you are not generating energy from the solar cells but from some other electricity plant. You are just getting your electricity for free by spending your offsets.

Not sure but I think a hospital will require large amounts of electricity – too much for solar cells to produce????

admin answers:

The electric utilities can’t hold us hostage the way the petroleum companies do – because you have more choices with electricity.
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If electricity prices get too steep, you can put up your own solar panels, or your own windmill, and make your own electricity. Or you can go to Home Depot right now and buy a generator that makes electricity from a natural gas hookup.
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Sure, solar panels and windmills are expensive, but you’d do it if you got mad enough at your electric bills. Utilities would be nuts to let prices get high enough for this to happen.
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Right now, electric utilities love the idea of electric cars. For the first time, they have people willing to buy electricity in the middle of the night. My own utility (here in Michigan) gave me a free electric car charger for my garage, and a special half-rate for overnight charging.
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Here’s a study that shows there’s enough electricity available overnight for nearly everyone to switch to electric cars:
http://www.sciencedaily.com/releases/2006/12/061211221149.htm

admin answers:

You could certainly do some physics experiments with sound waves:

– Resonant frequencies of open and closed pipes, as a function of length. Can use cheap (black ABS plastic) pipe, at the plumbing isle of a Home Depot store.

– Resonant frequencies of guitar strings as a function of length, tension, mass of string.

Resonant frequencies of a cavity like a hollow-body (acoustic) guitar or violin. Compare how “harsh” the violin string sounds alone (without wood body), vs. The much more pleasing sound when the string’s harmonics are filtered by the resonance of the hollow-body.

– Resonant frequencies in a room in your house. There are multiple resonant modes, in a room with parallel walls, closed door. These are “standing waves”, so by moving the microphone to different points in the room, some points will have maximum intensity & other points will be a “null”.

Gadgets to use – Resonances: Use a variable-frequency sine generator, audio amplifier, speaker to generate the frequencies.

Gadgets to use to observe frequencies of guitar strings: You could use an oscilloscope and microphone to measure frequency. Can also observe harmonic structure of sound (shape of waveform, vs. Sinewave, as observed on an oscilloscope).

There are many possibilities. I’d recommend reading an introductory book on “musical acoustics”. For example, Chapters 1 of “Master Handbook of Acoustics” by Everest ($ 20), explains the basics of sound waves.

Note: As you compete in science fairs in subsequent years, you can continue to expand your investigation of sound waves to increasing levels of sophistication.

-> For example, you can investigate properties of human hearing — how our binaural hearing can determine the distance and angular location of a sound source. Ben Burtt at Lucas Film did pioneering work in this field, to create the 3D “soundfields” in the original Star Wars film.

-> As another example, you can investigate the relationship between construction techniques used to build violins, and subtle changes in the sound produced by the best violins.

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admin answers:

Coal is primarily used as a solid fuel to produce electricity and heat through combustion. World coal consumption is about 6.2 billion tons annually, of which about 75% is used for the production of electricity.[citation needed] China produced 2.38 billion tons in 2006 and India produced about 447.3 million tons in 2006. 68.7% of China’s electricity comes from coal. The USA consumes about 1.053 billion tons of coal each year, using 90% of it for generation of electricity. The world in total produced 6.19 billion tons of coal in 2006.

When coal is used for electricity generation, it is usually pulverized and then burned in a furnace with a boiler. The furnace heat converts boiler water to steam, which is then used to spin turbines which turn generators and create electricity. The thermodynamic efficiency of this process has been improved over time. “Standard” steam turbines have topped out with some of the most advanced reaching about 35% thermodynamic efficiency for the entire process, which means 65% of the coal energy is waste heat released into the surrounding environment. Old coal power plants, especially “grandfathered” plants, are significantly less efficient and produce higher levels of waste heat.

The emergence of the supercritical turbine concept envisions running a boiler at extremely high temperatures and pressures with projected efficiencies of 46%, with further theorized increases in temperature and pressure perhaps resulting in even higher efficiencies.[8]

Other efficient ways to use coal are combined cycle power plants, combined heat and power cogeneration, and an MHD topping cycle.

Approximately 40% of the world electricity production uses coal. The total known deposits recoverable by current technologies, including highly polluting, low energy content types of coal (i.e., lignite, bituminous), might be sufficient for 300 years’ use at current consumption levels, although maximal production could be reached within decades (see World Coal Reserves, below).

A more energy-efficient way of using coal for electricity production would be via solid-oxide fuel cells or molten-carbonate fuel cells (or any oxygen ion transport based fuel cells that do not discriminate between fuels, as long as they consume oxygen), which would be able to get 60%–85% combined efficiency (direct electricity + waste heat steam turbine).[citation needed] Currently these fuel cell technologies can only process gaseous fuels, and they are also sensitive to sulfur poisoning, issues which would first have to be worked out before large scale commercial success is possible with coal. As far as gaseous fuels go, one idea is pulverized coal in a gas carrier, such as nitrogen. Another option is coal gasification with water, which may lower fuel cell voltage by introducing oxygen to the fuel side of the electrolyte, but may also greatly simplify carbon sequestration.

I hope i helped…

admin answers:

Could it be imaginable, that Saturn is a generator for the sun?

No. If it were as you say, then it would be igniting other bodies also in the solar system (including Earth).

A very suitable and testable explanation for the production of energy in the Sun was already proposed in the early 20th century by Arthur Eddington. If you have an alternative, testable explanation, then please describe it so that it can be tested. Http://www.youtube.com/watch?v=b240PGCMwV0#t=0m37s

How can we know exactly what’s inside Saturn?

“Exactly”? We can’t.
But you can look at what happens in the parts we can see (above the surface) and compare with predictions of what would be expected for different kinds of things in the deep. Http://www.youtube.com/watch?v=b240PGCMwV0

Read this: http://en.wikipedia.org/wiki/Saturn#Internal_structure
and follow the links there.

admin answers:

I would address your question by saying that yes, I would certainly install it if I owned a home that I intended to stay in for at least 10 years. I think it takes a while before you make the money back on the installation investment. I wish I had it… Maybe my next house!

Solar Energy Advantages
Saves you money
After the initial investment has been recovered, the energy from the sun is practically FREE.
The recovery/ payback period for this investment can be very short depending on how much electricity your household uses.
Financial incentives are available form the government that will reduce your cost. (visit www.dsireusa.org to find out about incentives available in the state you live in!).
If your system produces more energy than you use, your utility company can buy it from you, building up a credit on your account! This nifty little scheme is called “net-metering”.

It will save you money on your electricity bill if you have one at all.
Solar energy does not require any fuel.
It’s not affected by the supply and demand of fuel and is therefore not subjected to the ever-increasing price of gasoline.
The savings are immediate and for many years to come.
The use of solar energy indirectly reduces health costs.
Environmentally friendly
Solar Energy is clean, renewable (unlike gas, oil and coal) and sustainable, helping to protect our environment.
It does not pollute our air by releasing carbon dioxide, nitrogen oxide, sulphur dioxide or mercury into the atmosphere like many traditional forms of electrical generation does.
Therefore Solar Energy does not contribute to global warming, acid rain or smog.
It actively contributes to the decrease of harmful green house gas emissions.
It’s generated where it is needed.
By not using any fuel, Solar Energy does not contribute to the cost and problems of the recovery and transportation of fuel or the storage of radioactive waste.
Independent/ semi-independent
Solar Energy can be utilized to offset utility-supplied energy consumption. It does not only reduce your electricity bill, but will also continue to supply your home/ business with electricity in the event of a power outage.
A Solar Energy system can operate entirely independently, not requiring a connection to a power or gas grid at all. Systems can therefore be installed in remote locations (like holiday log cabins), making it more practical and cost-effective than the supply of utility electricity to a new site.
The use of Solar Energy reduces our dependence on foreign and/or centralized sources of energy, influenced by natural disasters or international events and so contributes to a sustainable future.
Solar Energy supports local job and wealth creation, fuelling local economies.
Low/ no maintenance

Solar Energy systems are virtually maintenance free and will last for decades.
Once installed, there are no recurring costs.
They operate silently, have no moving parts, do not release offensive smells and do not require you to add any fuel.
More solar panels can easily be added in the future when your family’s needs grow.

More about Solar energy advantages disadvantages

Solar Energy Disadvantages

The initial cost is the main disadvantage of installing a solar energy system, largely because of the high cost of the semi-conducting materials used in building one.
The cost of solar energy is also high compared to non-renewable utility-supplied electricity. As energy shortages are becoming more common, solar energy is becoming more price-competitive.
Solar panels require quite a large area for installation to achieve a good level of efficiency.

The efficiency of the system also relies on the location of the sun, although this problem can be overcome with the installation of certain components.
The production of solar energy is influenced by the presence of clouds or pollution in the air.
Similarly, no solar energy will be produced during nighttime although a battery backup system and/or net metering will solve this problem. See www.dsireusa.org for details on how net metering allows you to save electricity and money.
As far as solar powered cars go – their slower speed might not appeal to everyone caught up in today’s rat race.

As you can see there are many Solar Energy Advantages
Disadvantages can be found in any product or system, but it
is important to know that they can be managed in this case.

admin answers:

What you are asking about is not only possible, it has been in use in limited applications for a while. These devices are based on the Peltier–Seebeck and Thomson effects:
http://en.wikipedia.org/wiki/Peltier-Seebeck_effect

Thermoelectric generators have been used on deep space probes for several decades:
http://en.wikipedia.org/wiki/Radioisotope_thermoelectric_generator

These devices use radioactive materials as a heat source. The Soviet Union also used similar devices to power remote beacons and lighthouses:
http://www.bellona.no/bellona.org/english_import_area/international/russia/navy/northern_fleet/incidents/31772

There are also small thermoelectric devices designed to work at lower temperatures for common applications:
http://www.dts-generator.com/gen-txe.htm

admin answers:

If it were me, I’d buy a power inverter for the van, and use it to run the computer and printers. They’re available at most truck stops, auto parts stores, etc. If you combine that with a couple of small solar panels that plug into the cigarette lighters and charge the batteries, you shouldn’t need to run the motor more than a few hours a day to charge the van batteries.

Buy a deep cycle battery, and keep an eye on the power levels. You don’t say how remote the location is. If getting help or a jump is a problem when you run completely out of battery to start the van, buy a small generator for emergency starting. Like they said, they’re not at all expensive. You could probably set up the whole thing for less than $500.

Good luck.

admin answers:

Hi there … You can get a whole house generator which will cover all your needs for between $3-8000 or you cab get a portable one and have a swtich fitted to your house so that you basically plug it in….
Here in florida… I have two … A small 1000w and a bigger 8000 watt. The higher the watts the more it will run in your house. For example .. The only things the 8000w wont run in my house is the air conditioning and the stove…. It will run everything else….. It cost $1300
The 1000 w will run the refrigerator… And a few lights… Or the tv and lights and fans … It cost…. $299.
There is also the thing called starting watts… The 8000 wat gernerator has a starting watt of 13500. What this means is that when certain electrila appliances start they need more electricity than when they are constantly running… Like acceleration in a car… More gas to get up to speed…
The site below has a section sizing your generator and it wexplains how to work out what you need…