Pretty much, can solar panel’s support the entire houses electrical needs generally, because I know sometimes the owner’s can sell unused electricity back, any ideas or any ideas on how much the average home uses in kWh

It all depends on how you define ‘needs’. Could you have enough lighting and enough power to keep the fridge running? Easy that. A passive solar water heater would produce enough hot water for showers and cleaning, no problem there. If the majority of the folks now living on this planet had all that they’d be dancing in the streets. Heating and air conditioning is another subject. Both of these are energy hogs so they require an entirely different approach that at the current state of the art is beyond the average homeowners ability. If cities, counties and states demanded that all homes have solar water heaters and solar panels a whale of a lot of electricity could be generated on site. Expensive? True, but for a century state and local governments have demanded that every home must have electricity, running water and flush toilets. I imagine when those rules were set there were ‘teabaggers’ who complained that ‘government’ had no right to demand such an imposition’. Yeah, the government does have that right so lets move past that. As a nation we’re going to have to set some priorities, priorities that insist on the ‘greatest good for the greatest number’. Burning coal and oil and also wasting electricity on outdoor advertising signs, excessive lighting and mal-insulated buildings can’t continue. Such things as single pane windows are going to have to go as will the will the 150 year old incandescent light bulb…energy hogs in general will have to go. The US will have to move as rapidly as possible to public utilities that produce electric power via solar and wind. Private energy companies who have deals with coal producers simply aren’t going to fold up their coal burning electrical plants on their own. The government is going to have to shut them down. Tax money, instead of paying for a bloated military should be used to build a 21st century electrical grid based on solar and wind to take care of the electric overload that homes and business can’t produce on their own. All other electrical needs can be produced by conventional power as stand by units. Tax breaks and subsidies and direct cash grants could make this happen. We did far more than that in WW2 in less than a years time. Very doable technically…politically, that’s a different story!

China seems to have the insight into seeing that green energy is the wave of the future and will ultimately will be more cost effective than relying on the world dwindling non-renewable resources. Will this set a dramatic new precedent for the USA, who has been dragging its feet?

Nothing like good old fashioned competition to get the ball rolling on an idea.

i got a 20 watt solar panel and a 120v pump.the thing is that most electronics have a piece that reduces electricity into the voltage the part wants.will the solar panel make the pump work.

20 watts is not much power. That would run a small DC fountain pump. For anything larger, you would have to match the power rating of the pump.

There is an entire forum devoted to solar water pumping here http://www.wind-sun.com/ForumVB/forumdisplay.php?f=10 . If you browse around, you may find what you’re looking for. The people there are pumping larger volumes, to water cattle, irrigate, or fill cisterns.

I want the solar panel to charge the battery.
how long will it take to charge the battery ?
how can i control the out put volts from the battery?
and if i can control the volts how long will the battery charge last if i’m charging a phone or sumin at 5v.
how can i prevent battery over charging.?
battery= 12V 3.4Ah 3.4amp.
solar palen = 5W 12V

If the panel hasn’t a reverse protector diode, add one. You should use a 12V1A Shottky diode.
For safety, you should also run a 1 A or so fuse in series. You should also consider a charge controller.

A 5W panel practically may output 300ma. It might practically take around two days of normal sunlight to fully charge that battery with that panel, longer if you don’t have that much sun.

I have a solar panel that puts out 100v, .5 amps in full sun. Before I thought it would charge a 12v battery without a solar charger but then I talked to someone and they said that it was wasting a lot of power and could potentially hurt the battery. A second part to this question is what happens if I put it on a 72v battery without a controller. Thanks!
Hmm. The answers are fairly interesting. The voltage of the solar panel drops to the voltage of the battery when I connect it because of the very little amps the solar panel has. Thanks for the answers!

The solar panel is capable of 1/2 Amp output. If you hook it to a 12V battery directly and the battery is discharged it will want more than 1/2 Amp and pull the voltage down until the battery is charged to a certain level. Eventually the battery will try to charge up to 100V which will definitely damage the battery. If you use a regulator circuit running off the solar panel that outputs 12V then you will have a constant voltage circuit which will still be limited to 1/2A or whatever the regulator is capable of outputting. Of course you can’t just go out and connect 100V to any voltage regulator it has to be capable of running from 100V and dropping the voltage to 12V like the original charger that comes with the battery. The same explanation applies to a 72V battery. You have to limit the output voltage to 72V or risk overcharging the battery.

If australia began to use only solar energy to power the country, what do you think would happen? Also, what would happen to the other energy sources we are currently using and all the power lines? And how would we be able to make sure that important buildings like hospitals always have power?
Please answer, best question gets full points.

<<And how would we be able to make sure that important buildings like hospitals always have power?>>

Any alternative energy source that is ‘intermittent’ solar or wind will be built with a storage mechanism, so that when the sun is not shining or the wind is not blowing, you will still have power. If a country were to rely fully on a technology like solar, they would set it up so that while the sun is shining, they would produce much more energy than they need. They would store the rest of the energy using technologies such as molten salt storage, creating hydrogen through electrolysis of water, or just simple batteries.

Likely, a country will never rely fully on one source of energy like this.

I would like to offset my air conditioning bills by purchasing a solar panel setup. I guess the questions that need answered are these:

How much power does a central air unit use? 220 Volts / 8 Amps Sound about right?

How large of a solar array will I need to power this non-stop during peak daylight/sunlight hours?

If your state offers "New Metering" look into installing a grid-tie system. You won’t need to rely on batteries storing the energy your panels produce and if you produce more energy than you consume one month the utility company will actually credit your account for that surplus. I would recommend Global Solar Center as a good starting point (http://www.globalsolarcenter.com/). They will provide you with a free solar quote and inform you of all the incentives you’ll be eligible for, your estimated annual savings, payback period etc… They’ll provide you with all the info you’ll need to make a smart decision. Whether or not the system powers your entire central units consumption, at the end of the day you will be saving on your monthly utility bill. Your location will be a major factor as far as feasibility goes but you should definitely start by visiting that site.

what type of engineer is responsible in creating green technology and solar energy?

MECHANICAL ENGINEER