Solar Energy

I mean when light hits the solar panel where does the energy go and what does it become? Be specific.

Visible light from the sun is in the form of photon before hitting the solar panel. In a silicon solar panel, the photon is caught by the semiconductor material. Energy equivalent of the photon is then used to excite an electron from the semiconductor molecule. The aggregate of free flowing electrons form the current in a closed electric circuit.

The efficency of conversion from sun light to electricity is not 100%. The majority of light energy hitting the solar panel is dissipated in the form of heat. As technology advances, the conversion efficiency is improving, hence reducing the cost of solar energy.

Solar Incorporated wants to know which solar panel collects energy in the most efficient way. Three different brands are placed in the sun and voltage readings are taken every 15 minutes for three hours. This is an example of which step of the Scientific Method?

analyze the results

conduct the experiment

form a conclusion

research the question

experiment

I have a solar energy panel that works in every room except mine. I have those severely bright, energy efficient bulbs and it doesn’t work at all.
What do I do? Is the bulbs really causing this? Why?

You should still get some output but you do expect less under an energy efficient bulb even though it looks brighter. This is because old bulbs give out a lot of ‘light’ in the infrared that you can’t see. Which is completely wasted if you want it as a light bulb, but a solar panel may still harvest some of this energy!

Your solar panel is probably made of silicon. This has a ‘band gap’ of about 1.1 eV so any light with a wavelength shorter than about 1.1-1.2 microns be able to generate electricity. (shorter wavelength means higher energy)

Energy efficient bulbs give off the vast majority of their energy in the visible light range, which is about 0.45-0.8 microns. The spectrum looks something like this:
http://holeman.org/spectra/fluorescent%20-%2065%20watt%20CFL%20-%20%20spectrum.jpg

It’s hardly giving out any energy in the range from about 800-1100 nm, which is where the solar panel is most efficient at converting light into electricity (each photon can make 1 electron, which will give a specific amount of output power – any excess photon energy is wasted heating up the panel). The panel should still catch those photons and turn them into electricity, but it’ll make far less current.

By contrast a non energy efficient light spectrum looks like this:
http://www.sciencebuddies.org/mentoring/project_ideas/Phys_img039.jpg

It’s giving off a good chunk of its energy as light in the range 800-1100nm which the solar panel can efficiently harvest into electricity. As a lightbulb though, this energy is being wasted because you can’t see light of those wavelengths!

I was just thinking about it. A solar panel cannot get energy from sunlight at night because there is MUCH less light. If there is an overcast, the same concept should apply. If the sun appears to be shining brighter than usual, would the panel be able to receive more energy?

As indicated in the reference sites I’ve listed, there is actually very little variation in the sun’s intensity on a day to day basis. However, scientists claim that over the last 60 years or so, that the sun has been at the hottest temperatures and burning the brightest than it ever has.

But the real solar energy is in the light, not the temperature. Hence, the PHOTOvoltaic cells that are a part of today’s solar collectors and panel. They say that solar energy can actually be collected at the North Pole as long as the Sun is shining.

NO we can use solar panel for satalites not for rockets. A rocket or rocket vehicle is a missile, aircraft or other vehicle which obtains thrust by the reaction of the rocket to the ejection of fast moving fluid from a rocket engine. Chemical rockets work by the action of hot gas produced by the combustion of the propellant against the inside of combustion chambers and expansion nozzles. This generates forces that accelerate the gas to extremely high speed and exert a large thrust on the rocket (since every action has an equal and opposite reaction). Now the funny answer 4 u please send rockets only on sunny day…….. tks

Not really.

Your monthly costs will go down but it requires a large upfront investment.
The overall costs to produce energy via solar panels are slightly greater.

There are other benefits though.

If I buy a 60W solar panel is that how much electricity produces? In what time period? And if so how many kWh’s would that be equal to?

60W would be the RATE at which it produces electricity (W, watt, is a measure of power not energy).

kWh is the measure of energy which is equal to 1000W of generating power running for 1 hour.

that means it would take your 60W generator (assuming that it is running at that level based on environmental factors) 16 2/3 hours running at that level to general 1 kWh. (that would probably be about 2 days assuming 8 hours of good sunlight per day)

Discuss any issues/opportunities in marketing solar energy panel in the targeted foreign country such as the United Kingdom.

I would suggest reading about advantages and disadvantages of solar panels. Here’s the link if interested

http://renewableenergyarticles.blogspot.com/2010/01/main-advantages-and-disadvantages-of.html

I am doing a science project and I need to find out if solar panels are an environmentally feasible way to heat a pool compared to the #2 diesel that is currently being used. Is there a calculator that I could use to see how much energy a solar panel uses?

What you need is a solar pool heater. It is a series of plastic panels that you run your pool water through using your existing pool pump. As the water runs through them, they get heated by the sun, just like if you leave a hose in the yard, the water inside gets very hot. Since you are using your existing pool pump, no extra electricity is used. You can see some data on it at http://www.hi-tecsolar.com/whysolar.html.

To size a system, you use anywhere from 70% to 100% of the pool’s surface area to determine how many panels. A 10′ x 40′ pool is 400 sq ft, it would need anywhere from 280 to 400 sq ft of panels. That kit will cost less than $2000, and can heat the pool to around 10 degrees F higher than the air temp. http://www.altestore.com/store/Solar-Pool-Heaters-and-Pumps/Unglazed-Solar-Pool-Heating/Guardian-Solar-Pool-Heating/Leveredge-Guardian-Pool-Heating-Package-400-SqFt/p7353/.

This is MUCH more cost effective than using solar electric panels to power an electric pool heater. Depending on what fuel is currently used to heat the pool, a system can pay for itself in a year or two.

A solar panel is going to produce from 5 to 10 Watts on a sunny day during peak sunlight.