PV Gap

Bonnie Said:

Is it technically possible to collect solar power in orbit and transmit it to earth ?

We Answered:

Yes, technically possible and it even has been done on a small scale by converting the raw electricity into a beam of microwaves. At the receiving end, the microwaves are converted back into raw electricity. On a small scale, this is used in smart RFID tags used by stores to tag pilferable items. The radio beam powers the circuit in the tag so it can transmit a reply. There is no power source in the tag itself. They deactivate the tag by causiing an overload which burns out the circuitry. The problem with large scale is one of focus of beam over large distances. The beam would have to be very strong to transmit usable power, and if the beam strayed, would cause heat damage, especially to living things, cooking them much like a microwave oven does.

Leah Said:

I want to buy an Electric Power Generator and im not 100% sure how they work.?

We Answered:

If you don't care how much it costs, your best (as in quietest and least obtrusive) option is a heap of solar panels, a fat battery bank and a multi-kilowatt inverter.

Anything that gives you electricity OUT is going to require a substantially greater amount of energy IN.  Gasoline, wind, sunlight... always more in than out, the proportion depending on which one you use (wind will be most efficient).  You cannot get something for nothing.  I wrote a blues about it once.

Edit:  You don't really understand your own needs.  You say you need 5000 watts, but that's a measure of power (like horsepower).  How much time each day do you need it?  What you need to calculate is how many kilowatt-hours you need per day (like gallons per day).

This makes a huge difference.  If you are running a 3000 watt well pump for a total of 20 minutes a day, that's 1 kilowatt-hour (3000 watts * 1/3 hour) a day or an average of just 42 watts.  If you are running a 5000-watt light show for 12 hours a day, that's 60 kWh/day.... 60 times as much energy.

Determining the required size of the various generating options, batteries and so forth are way beyond the scope of Y!A, so you should go pick up something like "Home Power" magazine and start reading up.

Norman Said:

I heard about a solar powered generator, can someone provide some info on this, are they legit?

We Answered:

Yes, they are legit: read this article:

If you've ever found yourself without power in the middle of a storm, especially with today's unpredictable weather patterns, you may have also wondered whether it would be worthwhile investment.

Who would find the technology of a solar power generator useful?

There are many benefits of having a solar generator available for powering the necessities and even those things you just want to function when you're experiencing a power outage.

Reasons to have a solar power generator might include:

Life support - An elderly person, child, or person who is on oxygen or other life supporting machines that require power
Being able to power appliances, cook, work, and function normally during a power outage
Medical facilities can power essential equipment during a power outage, saving lives and preserving supplies
Saving on food – Residents lose hundreds of dollars and restaurants lose thousands of dollars of food every year when a natural disaster strikes and they are without power to keep the refrigerator and freezer operational. A solar generator would save a lot of money.
Solar power generators can be used virtually anywhere including in a home, business, boat, cabin, tent, desert, and many other climates and locations throughout the world.
Solar generators are available in several sizes and wattages. Your purpose for having a solar generator and the number of watts you'll need to keep your home or business up and running will determine how big your generator will need to be and how much it will cost.

The general rule of thumb when considering the cost of a solar generator is to assume the more wattage it produces, the more money it will cost to purchase.

Cost of Solar Powered Generators

The most expensive part of a solar powered generator is the solar panel system. The power inverter and the deep cycle batteries required to operate a solar generator aren't as expensive, but necessary.

The price range for a solar powered generator varies from a mere $30.00 all the way up to a whopping $50,000.

If you want to recharge your camera or small hand-held device, the small generator at the price point of around $30 will be just right. However, if you are looking to power an entire building or home that has no power at all, you should expect to spend up to $50,000 for a solar generator that can handle the job.

The price range for a small generator would run between $750 and $2,100. This is the most popular size and the most affordable for most people.

Portable solar powered generators can be very small, as in a few inches across. However, the larger units can run as large as 20 feet long and would need special transportation to get it to its destination.

No matter what size generator you have, it must be installed in a location where it gets direct sunlight whenever possible. The greatest disadvantage of solar power generators of course, is that they do require direct sunlight to be able to convert and store the sun's energy for later use.

Cloudy days or extended periods of inclement weather will prevent you from being able to recharge your generator.

Despite the drawbacks, a generator powered by the sun is an excellent supplemental power source or a great alternative power source in the case of an emergency.

Cody Said:

Making a Solar Powered Generator?

We Answered:

The first question to ask is how much power will be required. Sunlight has an average of 2 watts per cubic centemeter. Solar cells are only 10% efficient, so the cells will only generate 200 milliwatts per cubic centemeter. Roughly speaking, a pair of solar cells capable of running the average toaster would be about 2 by 4 feet.

Of course, this is why batteries are always a part of a solar array because it is easier to store electrical power and use it later. Batteries can either be connected in series or parallel. A series conncetion links the negative terminal of one battery to the positive terminal of the other. It is like a group of elephants marching along holding each other's tail. The circuit is tapped by holding the trunk of the lead elephant and the tail of the last elephant. This circuit maximizes voltage. The other connection is a parallel connection. All the elephants hold trunks and their tails are tied together. This circuit is tapped by holding any elephant's trunk and any elephant's tail. Electrical engineers refer to the terminals as "rails". The DC circuit will have a positive rail and a negative rail.

Next comes something loosely referred to as an inverter circuit. It changes the DC output from the batteries to 60 hertz AC current needed by most appliances. The AC output voltage is also fixed around 120 volts. Because of this, a parallel battery circuit might be the best choice of an input to the AC/DC inverter/converter. A parallel circuit has a voltage fixed at the maximum output of any single battery on the rail; the advantage is this circuit stores lots of current. It's like pouring water out of a bucket connected to 10 other buckets. The bucket won't drain until one has the equivalent of 10 bucket's worth of water.

Therefore the trick is going to be finding an inverter which will produce 120 volt AC around 60 hertz. Just such a circuit is available in automotive shops. These are the sorts of things which allow campers to run AC appliances off their car battery. Inverters are very easy to get and also cheap. They are designed to run off a 12 volt source (current is not an issue here). Depending on your power requirements, 12 volt car batteries can be used, or smaller motorcycle batteries if space and weight are conciderations. Remember, the input voltage is going to have to be 12 V DC.

The major cost of this system is going to be the solar pannels. Solar technology is still rather crude and uncommon (READ: inefficient and expensive). Some distributors manufacture blanket style cells which lay on top of a a dashboard and charge a car battery. These would be perfect to use with an automotive inverter circuit. Just hook the solar pannel to the battery and the battery to the inverter. Sunlight will go in one end and AC current will emerge from the other. A DC voltmeter is going to be very helpful in determining the polarity of the DC hookup. This is going to be between the output of the solar cells and the input and output to/from the battery (batteries) and the input to the inverter. In fact the whole section up to this point is going to be a parallel connection. The positive terminal from the solar cell(s) will run directly to the positive terminal on the batteries and then on to the positive input terminal on the inverter. This is going to be the positive rail. All positive terminals of solar cells and batteries will be connected directly to this rail. The rail will then run to the positive input terminal of the inverter. Likewise, the negative rail will be connected exactly the same for all the negative terminals.

This is going to look somewhat like a ladder design, each rail will be opposetly charged (positive or negative) and all solar cells and batteries will be connected like the rungs on the ladder. The important thing is to get the polarity right. If the negative terminal of a barrety or solar cell is accidently connected to the positive rail, a short circuit will result. Depending on the power generated, it can be anything from a nusciance to a disaster. Always remember, electrical engineering is very much like chemistry - each is not something to get involved with if one does not know what they are doing!

Finally, I'm sure there are a number of formulas available which will allow one to calculate things such as how much power can be generated, how long the batteries will need to be charged and how long AC power can be tapped. If this circuit is hooked up correctly and works successfully, perhaps just taking notes on the preformance might be more entertaining - and accurate as well. Most scientific formulas are based on incredibly simple situations. As more elements are added to a design, the less reliable an approach based on pure calculations becomes.

Hope this helps. have fun and remember to be careful!