PV Gap

Derek Said:

Does A solar panel have the capacity to run a Factory? If so How Much Would It Be?

We Answered:

You'd need a very, very big solar panel (or lots of solar panels) to run something as big as a factory. But the exact size/number depends on the size of the factory and what it does. Your first step would be to calculate the factory's power needs, including heating, lighting, appliances, machinery etc. How much electricity do all these draw and for how long per day?

See this article, about a factory which runs on solar power. Note that it is a large flat building, so it has a very large roof in proportion to its volume. Almost all of that huge roof area is taken up with solar panels: http://www.architectureweek.com/2002/082…

Michele Said:

Will my 18watt solar panel charge a car battery and how fast?

We Answered:

welcome to the wonderfull world of solar!
you probably have a 12Vdc 18 Watt solar panel, to figure out its charging amps capability we do this equation
Watts/Volts=Amps
18watts/12Vdc=1.5Amps

this is a conservative figure, since solar panel ratings are calculated using winter time sunlight, sunny locations and more daytime hours will give you higher amps.

a typical good condition car battery is rated at 40Ah (Amp hours).to find out the charge time, we use the following formula;
Amp Hours/Amps=T where T is time in hours
40Ah/1.5A=26hours

this is charge for a single battery, two batteries will double to over 52 hours.
lets compare to charging a battery with your car, a car alternator puts out about 60 amps but usually run about half capacity.

40Ah/30amps=1.3Hours!
An alternator is far more efficient so charging with a small solar panel is best as an alternative or for low power applications.

As far as using an inverter to power a TV, we can calculate how long the battery will last by using the original formula.
a typical 19"tv will use 70 watts

70watts/12Vdc=5.8A
40Ah/5.8A=6.9hours

this figure is by drawing all the power from the battery, voltage inverters have a safety feature that will not let you discharge your battery all the way, so 40Ah battery will power a 19" tv for about 4.5 to 5 hours.