PV Gap

Rafael Said:

how much watt of solar panel do i need for a 10watt LED bulb?

We Answered:

You must first determine for how long do you need the light to be on.

Second the wattage of the solar panel will determine how many electrical units will be generated in each day, i.e more the wattage more the units generated. Plus you must take into account the efficiency of the solar panels & the charge controller so the cumulative multiplied effect will give a different result.

Normally the led's can work on AC as well as DC Supply, so i feel you wont be needing an inverter.
Take a look at the LED Bulb's voltage & current ratings.

Once you know the current then get the time of keeping the LED Light on
multiply it & you will get your Ampere Hour rating of your battery. You may add some 10% to 20% to it to account for the losses in the wires and giving it more autonomy during the days when there is low or no sunshine.

Additional accessories i suggest,
photocell : this automatically will power up your led lamp once the sunlight incident on it reduces below a particular threshold.
Also have reflectors installed before you install your LED lamp, this will ensure good light quality


www.solarenergyexplorer.com/solar-elec…

Frances Said:

What's a 10 watt solar panel capable of running?

We Answered:

A 10 watt 12 volt light bulb, provided the panel voltage is 12 volt. If it is simply a 0.5 volt panel, then you have about 20 amps, but you may be restricted to a lamp with a 0.5 volt rating.

Leah Said:

10 Watt solar panel question?

We Answered:

Watts is a rate, watt hours is a quantity. Compare with mph is how fast you go (the rate), and miles is how far you went (quantity). Going 60mph for 1 hour, you will have gone 60 miles. rate x time = quantity

A 10W panel will charge a battery at a rate of 10W. In one hour, it will have supplied 10 watt hours (wh).

If your computer draws 100W, to run it for 8 hours requires 800wh.

To look at the big picture, look at your electric bill, the electric company charges you in watt hours, or kilo watt hours (1000 watt hours). If you have a bill for 1000kwh in a month, your houses draws an average of 1388W (1388W x 24 hours a day x 30 days = 1,000,000 watt hours or 1000 kwh.

There's a lot of really good information and free videos to help learn this stuff at http://www.altestore.com/store/Books-Cla…

Linda Said:

how can a solar panel under 10 watts not overcharge a battery?

We Answered:

Ben, Amy is quite right, but to better understand this, there is no 10 watt limit. That number gets thrown around in discussion a lot because people are generally trying to keep things like car and trolling boat batteries charged. Most of those size batteries have capacities around 50 to 100 amp hours. Using the 3% rule, a 50 amp hour battery can be charged at 1.5 amps continuously without any problem. A 10 watt rated panel will put out about .75 amps, since most 12 volt nominal voltage panels are wired for 17 volts. We use this same principle on two of our DC systems here, the one running the barn, and the small one we keep in the house to run our DC loads. In both cases we have 4 golf cart batteries wired for 12 volts, so the pack has a capacity of 440 amp hours. Again, using the 3% rule, we can run up to 13 amps into them without a charge controller. Both of them charge on a KC-120 panel, with a maximum amperage of 7.2 amps. They have been running this way for years with no problem.

If you don't want to take our word for it, check out a book at the library called, "The Complete Battery Book," by Richard Perez. There is an entire discussion on this concept. Richard happens to be the founding editor of Home Power Magazine, another really great publication on all the nuts and bolts of renewable energy, and quite worth the subscription price. Take care Ben, Rudydoo