What wattage of solar panel do I need?

Question

What wattage of solar panel required to power household things with that require a larger amount of energy?

Example: Computers, Small appliances

Answer 1

Look at you electric bill it will tell you what your daily usage was last month.

This will tell you what wattage of solar panel you need.

Answer 2

That's kind of an open ended question. I use a 15 watt solar charger to keep my trolling motor running, but I have two batteries and I only run it on weekends in the summer. Where you live will determine how much you can generate in a day. The appliances you are running have a vast range of power needs. Calculate the power needs of the appliance (check the energy star label) then buy according to the need. If you are in a situation like mine you can get by with a small panel and ample storage to cover the intermitent need. If your need is constant such as for a refrigerator or a computer which is always on, you need to generate ample power to both run the appliance during sunny times, as well as to charge batteries to run things when sunlight is not available. Check out the systems at Northern Tool. You should find what you need.  

Answer 3

around 50 watts

Answer 4

I have a solar setup. Pix at the link below. You can either do as I have and use batteries with an inverter, or go with a grid tie.

It isn't practical to power appliances directly from solar. If you want to run them at night or when it's cloudy, you need batteries and an inverter.

The second link below will walk you through sizing batteries and inverters based on how much power the appliances use and how long you want to power them.

It isn't cheap and doesn't pay for itself. I did my setup because we were completely without power for 3 weeks after the last hurricane and couldn't get gas for generators because the hurricane damaged pumps at the port.

Answer 5

how many watts are they?

you'll need to create 110 AC, so you'll need the equipment to do that.

how are you going to get the power to them?

through the house circuit?

then you'll need to power everything that's connected, and turned on.

now the way that's done around here is to connect it to the utility lines, and have the utility act as a reservoir.

in that case, you pay a lot to set it up, and probably never really recover all of the investment, but your bills will be lower.

Answer 6

Powering your own home with solar power will not be close to efficient. Your variation in demand will be very great, far greater than the daytime variation of solar panels.

Even if you were planning to power a remote campsite you would need to plan for a lot of storage capacity compared to solar panels.

A way to find out how much you need is to start with a storage and inverter large enough when fully charged to run all the things you want to power, but not necessarily all at the same time. You charge the battery on the grid. Now experiment with using a cheap battery charger to keep the battery charged.

How much current do you need to keep the battery charged, and have them stay charged when you use the charger for only 3 hours a day? If you need to run a 10 amp charger 3 hours a day, then you need a 10 amp solar charger. That would be 120 watts of panels.  If you need a 10 amp charger for 6 hours a day, you need a 20 amp solar panel, or 240 watt.

Because solar panel is expensive, you will want to undersize that component. So perhaps buy less at first and only increase it as you see need.

Now how many hours of effective capacity do you get from a solar panel in the middle of winter?

http://www.solarcraft.net/sun-hours-map....

You may get more or less than 3 hours of rated capacity depending on where you live.