PV Gap

Brandon Said:

SOLAR POWER PROJECT!!!!!!!!!!!!!!!!!!!!!!!!!?

We Answered:

Put a rock under glass, and do a temperature rise and fall graph over time. Compare that to the rise and fall graphs of other common materials of similar volume. You can find graphing thermometers relatively cheaply these days. You may want to use concrete drills to drill into the rock and a chunk of concrete, compare those to a block of similar volumes of wood and water.

That is all there is too it.

You are using the principles of geothermal heat storage.

Jessie Said:

solar power project?

We Answered:

We need a storage system so that solar power can be possible. Nobody has invented it yet. If it existed, we could take solar energy in the daytime and use it at night and during cloudy days. This is the gap that stops utilities from making it mass produced.

Jackie Said:

Solar Power Project?

We Answered:

If you plan to build a solar power project, you have a number of basic strategies. Some are worthy of a great mark, some so simple that any jack could do it.
The simplest is to go to the store and buy a 15 watt solar panel with voltage regulator, a battery, and an inverter (Uninteruptible power supply) to convert the battery power to a/c house current.

At the more elaborate end is a series of reflectors mounted so that they concentrate sunlight on a black pipe with water in it that goes to steam, a small model steam engine belted to a 120 volt 60 Hz alternator.

The reflecting collector needs to be mounted on a tracking structure so that the sun can remain focused as the day goes on. There must be a pressure regulator on the top of the system so that the steam engine can be isolated (stopped) without blowing the solar boiler to bits.

Steam released by the engine needs to be recaptured for reuse. There needs to be a way for the operator to see that the water is getting low, and an automatic device to take the pipe out of the focus should it run low on water.

If you go the simple route, buying a panel, you can demonstrate some significant principles by using covers for just one cell, one row of cells.

To make this meaningful you need to have volt and amp meters on your output. You also will want a discrete load such as a rheostat on the output lines to experiment with resistance vs power output. There are enough surprises you can pack into a demonstration to wow the judges. But for goodness sake, know what they are, and why they work that way. Not surprises for YOU!

Velma Said:

how can i power a computer fan via solar power for my science project?

We Answered:

First, pick out a computer fan. They should be marked with the type of voltage they require (such as 120 volts AC, or 12 volts DC), and the maximum amount of current they can draw at full speed (like 100 milliAmps). A fan running with less current, will still run, but will simply spin more slowly.

Try to find a fan that runs on DC voltage and current, as this should simplify your design. Many fans require AC.

Small solar cells typically produce DC voltage and current, which is why your design will be easier if you find a small fan that runs on DC. You may have to connect several solar cells in series to generate enough voltage (for example, if your fan needs 12 volts DC, and your solar cells put out only 6 volts DC, you would have to connect two of them end to end to make a total of 12 volts). You may have to connect several of the solar cells in parallel to generate enough current to make the fan move. It all depends on what voltage and current the fan requires, and how much oomph your solar cells can produce.

If you can only find fans that run on AC current, you will have to add an additional device called an alternator that converts DC current from the solar cells into AC current. Another possiblity is to find solar cells that have an AC output built in.
Good luck, and have fun!

Dave Said:

Mini Solar- Power Project Question?

We Answered:

It can be done.
You need way of moving the Lens or the cup so that all the time sunbeam is focused on the cup.
The advantage of this system is - as you have rightly pointed out- is high temperature.
But there is one disadvantage too. That is, it will give concentrated energy ONLY if the sky is clear. Not even hazy with light cloud. That is why flat solar collectors are used in common solar water heaters.

Shane Said:

I should do my 8th sem BE project on Solar Power.?

We Answered:

There is a pretty good idea that has been out there for a while called a "Minto wheel". What it does is use solar heat to boil a refrigerant (freon, CO2 , propane) in a tubular chamber that resembles a Ferris wheel and the solar heat makes the vapors rise to the top of the wheel and condense the vapors back to a liquid. Since the liquid is heavy it pushes the wheel in circles by gravity , just like a water wheel for grinding grain, and the liquid runs to the bottom of the wheel to be reboiled by the solar heat and do the journey continuously.
The point is this uses solar heat directly and with no moving parts other than the wheel itself , it gets mechanical energy form the heat. The wheel can then be geared to run an electrical generator or a water pump or some useful purpose. The efficiency is quite low, but it is on par with solar cells which only have about 12% daily efficiency anyway. This is an idea that is easy and easy to scale up and get same real power. It might cost 500 dollars for a 100 watt , but maybe only $10,000 for 10 kW . Solar cells cost the same proportionately if you get 100 watts or 10 kW. If it costs 500 dollars for 100w it costs $50,000 for 10 kW. Here is a couple of links on the minto wheel and one model built on youtube:

http://en.wikipedia.org/wiki/Minto_wheel
http://www.youtube.com/watch?v=-fUlKBH1s…

The other thing I could suggest is a thermoelectric generator using solar heat to concentrate heat to a metallic surface. This way you get DC electric directly with no equipment to break or wear out.
http://en.wikipedia.org/wiki/Thermoelect… You can actually buy a thermoelectric picnic cooler and take off the generator from the cooler and construct a solar heater to heat the thermocouple instead of the little electric heater they use. You could get much higher efficiencies using a solar concentrator on the hot side of the thermoelectric device and immerse the cold side in a 5 gallon bucket of water, than the little 5 watt input electric heaters and air cooled cold side they use in the picnic coolers.

And one more idea if you wanted to really impress, is to make a version of magnetohydrodynamics for electric generation. You use the same idea as the Minto wheel, but here you need a fluid that conducts electricity. So you could mix propane (or CO2 or Freon), alcohol and salt water to get a conductive mixture . The alcohol allows the salt water to combine with the water repellent propane or freon. In this idea you would boil the CO2 salt water mixture in black coated copper tubes facing the sun until the pressures were on the order of 800 psi and then the liquid mix is allowed to escape to a receiving vessel (cold side so it condenses the vapors) but it passes thru a square skinny rectangular channel( say if you had a 1/4" copper pipe you would diffuse it to a (3'' wide by 1/16" wide inside opening) that has strong magnets on each side of the copper sheets.

What happens as the high pressure fast moving conductive fluid passes the magnets, the ions separate from the magnetic field and group the negative ions on one side and the positive ions on the other. You install collectors plates (like capacitor plates) just after the magnets to collect the charged ions , which become an electrical flow. This is the same principle as an electric generator where a moving conductor (a copper wire) is moved thru a magnetic field and the ions in the copper wire move away from the opposing magnetic force on one side and move toward an attractive force on the other side.

The only difference of course is you have to move mechanically a solid conductor thru a magnetic field on traditional generators and here you move a liquid conductor with the aid of pressurized CO2 or propane. After the gas liquid mixture passes thru the plate collector, you then have a receiver vessel ( you could even use a air conditioner condenser from a automobile because it can take the pressure and it makes a good cold sink if you put it in water)