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.

So we will be moving to a home out in CA, the desert part where its usually 100* Degrees. So we definitly want to get solar panels to reduce energy costs considering we will have AC all day and heating in winter. But we only to plan to live there about 2- 3years. Can you move solar panels to another house?

Sure you can! They don’t have to be mounted to the house, that is where they are usually put to take up less space and not be shaded by buildings, but if you have a large property, they can be mounted on stands. Alternately, I am sure they can mount them on the roof in a way that minimizes the damage and can easily be removed and the roof repaired.

I think the system is a great investment and the cost of moving them can be minimal, depending if you can haul them yourself. Anyways, I just wanted to include a link to some more info on solar panels http://homepower.com/basics/solar/

around here, there’s overcast more often in the morning, than the rest of the day.
in that case, you’d want them to face south, and a little west, to catch more of the afternoon sun.
as to what part of the roof, the part that’s not under a tree.
(i have a nice south facing roof, over my garage, that’s at just the right angle, that’s shaded much of the day by my neighbor’s trees. and he really likes those trees.)

Science project…researching solar cars.

There have been a few truly solar powered cars as university projects. But in general, no car/solar panel combination is efficient enough to run completely solar powered.

Solar panels are currently used to lower the strain of the alternator in recharging the battery, and are used extensively on motor homes and the like. The same process could be applied to a hybrid car, although a solar panel itself is not generally aesthetically appealing (this may change with the advent of flexible solar panels.)

where do you get parts? can you salvage stuff from a junkyard?
from bought or salvaged parts

What type? Electric, hot water or hot air? I built a hot water panel (4′x8′) around 25 years ago from hardware store parts. It was more of an experimental project than a practical application but it worked. I used it to pre-heat or temper the intake water to the water heater. I made the frame out of 2×6 lumber with a plywood back, insulated with regular fiberglas roll insulation and used corrugated roofing as the heat collector. I ran 1/2" copper pipe vertically across the width of the collector and used 3/4" copper with T fittings for the top and bottom headers. Inside the house I had a circulating pump and an old hot water heater tank for storage. The pump was triggered by a fan switch mounted to the underside of the corrugated heat collector. With a slow flow rate the panel would boil water. It eventually fell into disrepair and I junked it. I believe if I ever got the urge to build another solar project, I’d go with a hot air collecter for use in the winter time. Free energy from the sun is a fascinating hobby and when put to practical use can be very rewarding.

ok 2 solar panels, the first (sp1) is just outside of the earths atmosphere. the second solar panel (sp2) is 20km away towards the sun…..what is the difference between the power output of each solar panel?
my friends says it would be tiny, but i say there sould be at least a usable difference? (i know it would be small-but not tiny?)

who is right? please quote any numbers? im looking for the actual difference between the two power outputs..many thanks in advance….:)

Well, after doing the math and crunching some numbers, I have to admit the difference is a lot more than I thought it would be.

Lets suppose your panel further from the sun receives 1000 watts of power from the sun.

1000 = x / 150000000^2
x = 2.25 * 10^19

Decreasing the 150 million by 20, instead of 1000 watts of power reaching your panel, you now have

Power = 2.25 * 10^19 / 149000080 ^2 = 1013.4 watts.

A difference of 1.34%

Lets suppose your panel is 25% efficient, and your voltage out is regulated to 100 volts.

The two panels would produce
1000 * 0.25 / 100 = 2.5 amps
and
1013.4 * 0.25 / 100 = 2.5335 amps

… a measurable amount, but not what I would call signifficanty more.

Hello all and thank you for helping!

I’m building a solar panel with solar cells from ebay and I wanted to know what supplies will I need other than 1.Solar Cells 2.Soldering Gun 3.Solder 4.Flux Pen 5.Tabbing 6.Tabbing Wire 7.Bus Wire 8. Materials for the frame 9.12 Volt Batteries

What kind of power inverter do I need if I’m trying to charge 12 Volt Car Batteries? I need these supplies to be-able to handle a moderate amount of power because I want to keep adding on cells to my panel. I pretty much know how to make the panel but what all do I need to connect the home built Solar Panel to the batteries? I’m willing to spend around $500.00 to $800 for all the parts total a side from the solar cells. I have 140 3×6 cells I should be buying another 60 and want to make a panels that will charge car batteries. I need to know what parts and equipment I will need aside from the solar panels to to charge them. Equipment that that tells me how much power is flowing and if the batteries are charged are not. Thank you all for viewing my question I am very appreciative to all who help and answer.
-John

the wattage of your power converter will depend on how much power you want to be able to use at any given time. buy one as big as you can afford, you could always add another converter in parallel later if the first one you buy isn’t big enough. the power converter will be used to convert the 12 volts from the batteries into 120 volts to power light, etc. solor panels should produce 12 volts and basically directly connect to the batteries.

Hi, i need help to determine parts required for a complete solar project for my seniour Engineering designing class.The panels have to be integrated with special mirrors to enhance production of power.
I need a list of all the parts required.It should include all the sensors and stuff.

It’s your project, you should do the work, but you have the order wrong.

first task is to develop a set of specifications, such as voltage, current, time, amount of sun.

then do a design based on those specifications

Then develop a parts list based on the design.

PS, most solar cells and panels have max temperature limits, and using mirrors may exceed those limits and cause damage.

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