3KW Solar System Review

25 Aug.,2025

 

3KW Solar System Review

Agreed with the 100w panels. Perhaps some of the worst $/watt that you can find today.

The growatt will need north of 30v but less than 150v on PV input. so you have a huge range to work from. Higher voltage pannels (larger watt) in parallel will result in better performance vs a bunch in series.

600w PV on a 3kw system with a 200ah battery .... napkin math for this says peak sun days 5hrs *600w = w per day you'll make. /24v = 125a. or about 2 days to charge if you didnt use any power from the inverter.

What I'm trying to say is unless your physically constrained with space (like on the top of an RV or something) your system is going to perform a lot better on 2x that PV or more. (the 24v growatt supports up to 2k)

the pannel cost is also the least $/watt your going to spend. With used pannels often going for $.4/w or less.
I just want to run a freezer, a refrigerator, a washing machine, dryer and a garage opener, all of them inside my garage. Thanks
Ummm... unless half those appliances are propane you're not going to have enough battery capacity to run that much. The 200Ah battery will et you about Wh of power, the Growatt is going to want Wh of that per day just to exist leaving you about Wh.

Have you done the Power Audit and checked to see how much each of those uses on a daily basis? I think you're going to be unpleasantly surprised at how much battery capacity you're going to need.

Also assuming that the dryer is an apartment 110v style and you're not going to need 220v split phase for that which would require another Growatt and another Wh per day of battery.

Your argument for the 100w panels is quite valid though, it all comes down to density and if you're buying new retail the 100w panels tend to actually be the better bang for the buck. Where you can really save cash is by going used. As an example, last fall I bought a pallet of 23 200w used panels from Watts247. The shipping was $300 at the time, but divided over the 23 panels each 200w panel ended up costing $53. Plus side, $53 for 200w. Down side, glad I had a full size pickup truck!

I would recommend doing everything you can to max out that PV input, you're going to want ALL the watts, especially if/when you have to add new batteries.

How Much Does A 3kW Solar Power System Cost? - SolarReviews

A 3 kW solar system will generate between 260 and 415 kilowatt-hours of electricity per month, depending on where it is installed. That’s about $50 worth of electricity. 

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Installing a 3 kW solar panel system won’t cover the entire electricity bill of most homes. But, it can be an option for people who want to install solar panels on a tight budget or for those who don’t use much electricity. 

A 3 kW system will cost about $6,300 to install, including the federal solar tax credit, and will pay for itself in just under 11 years.

How much does an average 3kW solar system cost?

Because 3kW systems are relatively small, they can be much more affordable than larger systems. 

With the average cost of solar at $3.00 per watt as of December , a 3kW solar power system in the US will cost about $9,000. With the federal solar tax credit factored in, the solar system price drops down to about $6,300.

It is important to keep in mind that the above cost is the average, many states offer different state or utility-based solar rebates, like feed-in tariffs or net metering. Because of this, the cost of solar varies state by state, and we’ve listed out a few states to compare. 

State

Average cost of 3kW solar system before tax credit

Average cost of 3kW solar system after tax credit

California

$8,040

$5,628

Florida

$7,740

$5,728

Texas

$8,310

$6,150

North Carolina

$7,470

$5,528

Arizona

$7,920

$5,861

New Jersey

$8,340

$5,828

Massachusetts

$8,610

$6,027

Georgia

$6,990

$4,893

New York

$8,580

$6,006

Can you finance a 3kW system?

You can finance solar systems if you do not have the cash to pay in full, which allows you to own your system while paying it off and get long term electric bill savings. 

The following are the most common ways homeowners finance their solar systems:

  • Solar loan: A loan you take out for the purchase and installation of solar panels so you can invest in a solar system without paying lots of money upfront.

    If you want to learn more, please visit our website 3 kW On Grid Solar System.

  • Solar lease: You pay a fixed monthly or annual payment to your solar installer and you do not own the solar panels.

  • Solar power purchase agreement (PPA): You pay on a cents-per-kilowatt hour (kWh) basis for the energy your solar panels produce. It’s similar to a solar lease, just with different payment terms.

How many solar panels are in a 3kW solar system?

3kW systems are small and usually have between 8 and 11 solar panels.

The actual number of solar panels within a 3kW system depends on the wattage of the solar panels. Higher wattage panels are more efficient than their lower-wattage counterparts. Typical panels have wattages of between 275-400 watts.

For example, if you install 300 watt solar panels, you will need 10 panels to generate enough electricity for a 3kW system. 10 panels should be able to fit on most homes and will help offset your electricity costs. 

See how many solar panels you need to eliminate your electricity bill

How much roof space do you need for a 3kW solar system?

A 3kW solar panel system will require less than 300 square feet of space on your rooftop.

Southern-facing roofs are ideal, and keep in mind that the actual square footage required will depend on the wattage, or efficiency, and the dimensions of the panels you install. 

High efficiency solar panels will create more energy in a smaller area. So if you do not have about 300 square feet of roof space to spare, higher efficiency panels can help you utilize the space you have for a 3kW solar array.

How much power does a 3kW solar system produce?

A 3kW system will produce about 260 - 415 kWhs of electricity a month, meaning the amount of energy produced ranges from 3,120 - 4,980 kWhs a year. 

Being that the average US home’s monthly electricity usage is 893 kWh, a 3kW system might not be enough to eliminate your utility bill entirely. 3kW systems generally just help offset electricity usage and will not cover the entire electricity bill.

The amount of sunlight your home state gets also determines the amount of solar panels you will need. If you live in sunny Arizona, a 3kW system will get you much further than if you live in rainy Washington. 

Calculate how many solar panels you need to cover your power bills

How much can I save with a 3kW solar system?

The electric bill savings from a 3kW solar system varies widely from state to state. This is because your power bill savings depend on how much energy is produced and how much electricity costs. 

For example, if your 3kW solar system generates 415 kWh a month in Florida, it will save you about $46 per month. A system installed in Massachusetts (where electricity is very expensive) that produces 415 kWh would save a homeowner $79 per month. 

The table below lays out estimates of how much a 3kW system can save in various states:

State

Estimated yearly savings
from 3kW solar system

California

$542 - $866

Florida

$343 - $547

Texas

$343 - $547

North Carolina

$344 - $550

Arizona

$380 - $605

New Jersey

$490 - $783

Massachusetts

$593 - $946

Georgia

$359 - $573

New York

$550 - $875

The payback period for your solar panels, or the time it takes to pay the system off and get completely free electricity, depends on your state incentives.

Your payback period will be shorter if you live in an area with additional solar rebates like solar renewable energy credits (SRECs). Find out what your estimated payback period is for a 3kW system in your state here.

How do I find the right installer for a 3kW solar system?

If you are looking for off-grid options or are interested in installing solar panels yourself, it is possible to buy a DIY solar kit to install a 3kW system. A DIY kit costs about $5,000, making them slightly cheaper than the installed price you will get with a solar company.

But, many times you will need the help of a solar installer or a licensed electrician for proper solar installation and to pass inspections. All of that extra work can cost more than having a licensed solar installer install your panels.  

For more information, please visit 30 Amp Solar Controller.