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Solar Panel Kits

Frances Said:

if i buy 2 solar panel kits of 45 watts each how much would i making in kwh?

We Answered:

Others above have covered the calculations quite well.

For a real world data point, each 1000 watts of solar array in my area of northern California produces about 2000 kWh of energy per *year*.

Those little 45-watt kits from Harbor Freight, Northern Tool, etc., can be fun, but they have amorphous silicon panels, and from what I've heard, are very optimistically rated. One guy who analyzed the kit said that the panels actually returned more like 5 watts each in bright sun, for a total of 15. Also, those kits are designed to charge a lead-acid battery, and provide stand-alone electric power. They cannot be connected to hosue wiring. Given the inefficiencies of storing energy in a battery, I suspect what you would get is enough to run a laptop for maybe a couple hours a day, or a small compact fluorescent bulb for twice that.

Raul Said:

Are the $200 DIY Solar panel KITS legit?

We Answered:

I just looked at what you are referring to.

In short, the answer is a resounding NO.

They are only 4.5 - 12 watt max sub units that can produce that only under the absolute best of conditions. Additionally, in order to make any real use out of them, you would have to take anywhere from 8 - 10 of the larger units to store enough to run only minor electronics for a while. Say you wanted to run one brushless motor for 1 hour. You would need to store the equivalent of 36 volts at 600 watts. These panels will let you store enough for an 1/8th charge, at max capacity for a day, on an average auto battery.

It's not worth it unless you create a full array.

Jeffrey Said:

Can a 18W solar panel kit used for Metal Stand fan?

We Answered:

You would need to know how much power the fan uses, it may say on the label on the back how many volts and amps (multiply them together to get watts). Also, is the fan AC powered (plugs into the wall outlet) or DC powered (can be run off a 12V battery, like plugging into the cigarette outlet in your car)?

If it is AC powered, you would need to charge a battery and convert it to AC with an inverter.

Charlene Said:

Can a Harbor Freight solar panel resist hail?

We Answered:

I have one up and it hasn't destructed yet. It does what they say. I have it connected to 2 5 volt golf cart gel cells in series. You would need about 20 of them to power most things directly.

Gerald Said:

Are there problems adding other charging units like wind power to a Harbor Freight Solar Panel ChargeControler?

We Answered:

Hey Me, what are you using for battery storage? If I understand the harbor freight kit properly, it does not have a battery included, or it is a very small sealed AGM type battery. If that is the case, don't bother adding another source of charging power, you'll just fill that battery up faster and still have no place to put your excess energy. If you have a good sized deep cycle battery or two hooked up, my suggestion is simply get a wind turbine that has it's own charge controller, most of them do. Then wire it straight to the battery bypassing the harbor freight unit. A good example would be Southwest Windpowers Air 403, puts out up to 300 watts, although in ideal conditions on a tall tower, but has its own internal regulator, like a car alternator. So the two wires coming down the tower go straight to the battery, and the turbine is already prevented from overcharging anything.

In most wind/solar power systems, the charge controller is the achilles heel. It is the one thing that breaks down first and causes the most problems. We've been living in a wind and solar powered home for years now, I can speak from experience on this. We've not purchased the HF kit because the panels are not built as robustly as they need to be to be mounted on the roof of a home in all weather conditions, and the wiring harnesses are not designed for permanent installation, to be sunlight resistant, etc. Also the electronics are not UL listed to my knowledge, so they would not be legal for in home installation either. They are terrific little units to make small amounts of power in a portable application, like camping, or a remote shed for example. Adding another source of power to be fed through the existing controls of that kit would be like welding a bed on the back of a Ford Pinto in order to use it as a pickup truck. My suggestion is to have a good sized battery pack, like a pair of Trojan T-105 golf cart batteries (220 amp hours) then get a small turbine with its own regulator, and wire it straight to the batteries. The batteries will happily take a charge from either source, or both simultaneously, that's how our home works. If you really want to do some shopping for this stuff, get a subscription to Home Power Magazine, they regularly run articles on all the available panels, turbines, controllers and othe components to home power systems. If you subscribe, you can use their website to review archived articles in past issues that have all the write ups you're looking for. Good luck Me, and take care, Rudydoo

Harvey Said:

I have just read an ad for Power4Home solar panel kit. Has anyone actually bought this kit/books. Is it a scam?

We Answered:

Sounds like a variation on Earth4Energy. Here are some comments from other victims, I mean, customers:…

We have commercial solar panels on our house, so I feel I have a good understanding of what's involved in making a reliable, practical panel. It's beyond my skill, probably beyond most people's. Certainly not an easy project.

Rene Said:

What SOLAR PANEL kit do I need?

We Answered:

You need a lot of money.
It's difficult to even fit enough panels on a normal roof to supply the average usage of an American home.
You need to figure out your daily usage in watts. The average home needs anywhere between 2500 and 6000 watts at peak times of the day.
You would need a significant battery bank as well, so that you had enough power through the night.
A standard panel is around 2' x 4 ' and produces between 60 and 240 watts in bright sun, (depending on the quality of the cells, which increases cost per panel)
There's also the issue of how much weight your structure can handle. You might need to put some of them on a stand in the yard. Or specially design your home to support the weight.
Most roofs are designed to handle the load of a few feet of snow.

Ok so lets add that up. If you were very conservative and kept it under 3000 watts at any given time, leaving enough to charge those batteries as well, AND you bought the highest grade panels, 3000/240 = 13 panels. That's 104 square feet of panels.
Now hopefully you live in a warm climate like southern California, and plan to use a wood/pellet stove for heat. What about hot water? What about cooking appliances? An electric range needs about 3600 watts at 240 volts to operate the oven, and each burner is between 1200 and 1800 watts depending on how large it is. A standard microwave is around 1200 watts. Some more. A vacuum is 1460 watts. A blow dryer is 1500 watts, a Clothes dryer is as much as 6000 watts.
You have to really consider how much power you actually need at any given moment. And then how much reserve power you will need. You might also want a back up generator for cloudy days...

You might do well to include some wind power to supplement your panels.

But for starters, figure out how much power you currently use.
A quick, but inaccurate measure would be to look at your bill and divide the total electric KWH by the days of the month and then by 12 hours. And then multiply by 1000 to get average watts per hour during the day.

Then figure out how much money you want to spend...
If you do it yourself you won't get the tax credit (if that's still actively available) For that you have to get an engineered system made of UL approved parts and installed with permits and inspections.
In most places you're required to do most of that anyways... although many people get away without the hassle.
There's a lot of dangers to consider though, Know what your roof can support. Some panels weight as much as 60 lbs each. Know how to size your wire. Know how to handle batteries and where you can safely store them (not inside, they release toxic fumes)

Many solar distributors have estimating programs that will give you an idea of average sun production for your yard, and what the optimum orientation for the panels are.

My dad uses motors to tilt his along with the sun on his peak. I don't know how effective that is at making it worth while.

He also buys low cost panels that aren't UL approved. Right now he gets an average of 1500 watts during the day with about 11 panels. But he's just inverting it into his house power with a grid tie.
You would need a special kind of inverter, and a charging monitor to keep your batteries safe.

I would also consider a meter that tells you how much charge you have and how much power production you have available to use, you wouldn't want to overload the system.

Personally I want to get property with flowing water on or next to it, that I can place wheels into.
I've seen quite a few designs for home made wind generators, and I want to work with hydrogen as a storage medium.
I could use the green energy to perform electrolysis and design a generator that runs on hydrogen, (of those PEM fuel cells seem to be the most efficient although they're really expensive right now...)
If I could make enough hydrogen, I could also use it for heat, hot water, and cooking.

Discuss It!