PV Gap

Brett Said:

how many windmills/solar panels would be required to replace fossil fuel generators in the US?

We Answered:

There is no alternative energy that will even come close to replacing fossil fuels.
You can add up all the solar, wind geo-thermal, ocean wave and any other alternative energy source you can think of and it would not equal 1% of what fossil fuels do.
The only real answer is to increase oil production in the USA right now and work on developing a new energy source for the future, because it could talke 20 years to come up with something.

Francis Said:

How to charge batteries with a 110V 1A Solar Panels?

We Answered:

Hey Arkundapur, I am not from India, but I have heard of those type of panels before. So I'm taking a chance that you don't mind if I answer you from the Midwest United States. Those are unusual panels, but there were a few made with specs similar to that. They were primarily designed to charge a battery bank with the use of a Maximum Power Point Tracking charge controller, or MPPT. This type of controller can take a fairly large range of input voltage, such as 90 to 150 volts DC, and convert it to 12 or 24 volts to charge a battery bank. The batteries then feed an inverter. MPPT Controllers came out about 10 years ago or so, they can increase the efficiency of your solar electric system if they are installed correctly, and they are quickly becoming the standard for solar electric systems today.

You can take a panel like this and directly connect it to a battery, and it will feed the 1 amp it is rated for into the battery. The panel voltage will simply degrade to whatever the float voltage on the battery is during charging. You don't have to be concerned about, "Over Volting," the battery, but it is a pretty inefficient way to charge your battery with this panel, you will be wasting over 90% of the charge capability of the panel, unless you wire your batteries up for about 90 volts DC.

I don't believe anyone is making panels like this anymore. Most people installing MPPT controlled solar systems today simply wire an appropriate number of standard 18 volt panels in series to get the ideal voltage for the controller they have selected. At one time this created problems when one or two of the panels wired in series was being shaded and the others had good sun, but most panel manufacturers are installing a bank of bypass diodes into the panel junction boxes now to avoid this problem today, so there isn't any need to build high voltage panels anymore.

If you have a battery bank you are trying to charge with these panels, I would suggest simply shopping for an appropriately sized MPPT charge controller for your system and wire it up according to the instructions in the controllers manual. Make sure you are reading the data plate on the panel correctly. The voltage rating should be, "Open Circuit Voltage," and the amp rating should be, "Short Circuit Current." If it is indeed a 110 volt open circuit voltage, then you need a charge controller that can work at that voltage, and be selectable to the battery voltage you are planning on using. Check out Home Power Magazine for good places to buy a controller, they are at Homepower.com. Good luck, and take care