How Much Solar Power Do I Need

Sally Said:

how much solar power do I need?

We Answered:

The computer and TV will be the big energy drainers when they’re on. Maybe you would use a computer with a tuner card in our computer as your TV, to save space? A flat panel display uses a lot of power because of its backlight. If you get a modest laptop, it might use 50 watts. You can get a computer that uses 7 watts, or even 1 watt, but that type will be very limited (uses flash instead of a hard drive). I’d allocate 1 kWh a day for the computer/TV.

If you have money, you can buy a SunFrost refrigerator, and use maybe half a kWh a day.

Again, if you have money, you can invest in LED lighting. Something like

http://www.ledwholesalers.com/store/inde…

uses 3 watts, and provides enough light to read by. 4 of those, 12 watts – maybe 0.1 kWh a day.

400 to 500 watts of panel should cover you for that kind of situation, just to pull a wild number out of the air. If you have a list of your appliances, try asking the question on the Northern Arizona Wind and Sun forum, where more experts are in attendance.

Note that if you use a cheap, crappy old refrigerator, you could easily use 30 times as much electricity per day. I was surprised that one of those little 4-foot high dorm refrigerators uses almost as much electricity as a full size. Because of poor insulation, it can run all the time.

Edward Said:

How much solar power do i need to power an led bulb?

We Answered:

It depends on the type of LED you are using (voltage, colour of light, etc.) You should figure on about 0.05W for each LED you want to use, but check the data sheet for the LED first.

Most solar systems have a battery that is trickle charged by the solar panel and this powers the bulb. This means that if a cloud passes the sun your bulb won’t dim. Standard solar panels output 5V or 12V and the power depends on the size of the panel and the efficiency of its manufacture.

You should be able to get a solar panel that outputs a few watts cheaply at any hardware store.

Megan Said:

how much solar power do i need to power a house?

We Answered:

A typical US home will need a 3KW system, if the home is connected to the grid you can install a smaller system that will offset only part of your consumption. For DIY (buy the kit and install it yourself) you may assume $5 per watt ($15,000 for a 3 KW system), but you can claim 30% as a federal tax credit and depending on where you live, many states grant tax credits or other incentives

View this 2 pages to get more details on the system sizing and the tax benefits:
http://www.solar-energy-for-home.com/res…
http://www.solar-energy-for-home.com/ene…

Leslie Said:

how much power do i need from my solar panels?

We Answered:

Very simple. Look at your bills from the past year and calculate how much power you used and see what you need to cover that usage. How are we supposed to know how much power you use? Maybe you live in a 1bdrm trailer or a 6000 sg ft house with 20 kids. Oh and remember a few things. There is more to ‘ going off the grid ‘ than just solar panels. When the panels work depends a lot on your climate. They kind of suck on cloudy days or if you live in the artic with 6 months of darkness.Also , you need an area for the (not so cheap) storage batteries. Learn to live by cooking with gas or wood as hydro is limited , so is heat. How do you plan on heating your home /water/ refrigerators and freezers? Off the grid means a lot of compromise. Even the amount of time you can spend on the computer asking these questions. You may be limited to no more than 1 hr per day. Off the grid also includes removing any electronic influence. No cell phones , tv (cable/sat) internet. Grow your own food and live off the land. The amount of solar panels you would need to maintain even a current lifestyle as most of us know it would probably require at least 1/2 acre and the cost would take at least 15-25 yrs to recover. You really need to spend more time into looking at what the cost versus return is. Like I said before. Look at what you use and see what it takes to get that from your panels. You will be shocked. Currently the panels are very good. But they cannot produce what the average home needs per day every day, they are support systems. Much like a fire place. Now they are nice to have and are very efficient. 50 yrs ago you used to toss in 2-3′ logs about 6″ around into the only heat source in your home. A fireplace. And it sucked more cold air into the house than the heat it produced. History has a way of repeating itself. This stuff was out almost a decade ago, they just didn`t have batteries then