3 kW Solar Systems (Cost, Energy Production & More)

In this EcoWatch guide on 3kW solar panel systems, you’ll learn:

  • How much roof space you’ll need for a 3kW solar system
  • Whether a 3kW solar system can power your entire house
  • What type of energy savings you can expect from a 3kW system

This guide has helped thousands of homeowner’s save money when going solar by helping them find the size that best meets their energy needs. Let’s get started!

Ecowatch Author Kristina Zagame

By Kristina Zagame

Updated 9/27/2022

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Will a 3 kW Solar Panel System Work for Your Home?

As a homeowner, you may be looking to install a 3 kW solar energy system because it’s more budget-friendly or because you don’t have a lot of roof space for more solar panels. Or maybe you’re looking to install an off-grid solar system in a remote area.

Installing a solar photovoltaic (PV) system is a smart and sustainable solution that may save you money on electricity. However, the upfront cost of a solar installation is not cheap, and the more solar panels you need to power your home, the more it’s going to cost you. We’re here to help you figure out if a 3 kW solar panel system will work for you.

How Much Does a 3 kW Solar System Cost?

Based on the U.S. average cost of solar of $2.66 per watt, a 3 kW — or 3,000 watt (W) — solar system costs an average of $7,980, or $5,905 after factoring in the 26% federal solar tax credit. The solar tax credit is expected to drop to 22% in 2023, so the sooner you buy your solar panels, the more you’ll save.

Keep in mind that your solar system price will vary based on many factors unique to your home, including the cost of energy where you live, what brand of solar equipment you buy and if you’re planning a DIY installation or letting a solar installer handle the job. There are also financial incentives and rebates available for renewable energy systems that may reduce the cost.

Here’s a look at how much a 3 kW solar power system would cost in the top 10 states for solar energy:

State Average Cost Per Watt Average Cost of 3 kW Solar System Average Cost of 3 kW Solar System After Tax Credit
California $2.73 $8,190 $6,061
Texas $2.69 $8,070 $5,972
North Carolina $2.54 $7,620 $5,639
Florida $2.53 $7,590 $5,616
Arizona $2.61 $7,830 $5,794
Nevada $2.52 $7,560 $5,594
New Jersey $2.77 $8,310 $6,149
Massachusetts $2.94 $8,820 $6,527
Georgia $2.55 $7,650 $5,661
New York $2.95 $8,850 $6,549

This cost estimate includes the installation of your solar PV system and all of the basic equipment that comes with it — solar inverters, connectors, panels, mounting equipment, etc. Any additional equipment, like a solar battery for energy storage, will raise the cost.

How Much Energy Does a 3 kW System Produce?

On average, a 3 kW system will produce roughly 375 kilowatt-hours (kWhs) of electricity per month, or between 4,000 and 5,000 kWhs per year.

Just like with price, the amount of energy your solar system produces will vary depending on where you live. That means a 3 kW solar panel system in sunny Florida is going to produce more energy than a 3 kW system in Oregon, despite them being the same size. With that said, solar panels are still worth it in less sunny states, they may just not save you as much money.

Can a 3 kW System Power a Home?

Once again, the answer depends entirely on location and how much energy a household consumes. Technically, a 3 kW system could power an entire home, but it’s unlikely because areas where solar panels are most efficient also tend to be areas of high energy consumption.

Let’s take Phoenix, Arizona, for example. A 3 kW system in Phoenix may produce around 430 kWh of energy a month, which is an above-average production rate. However, the average Arizona homeowner uses 1,114 kWh of energy a month, which is also above the national average (829 kWh).1 So, even though solar panels are more efficient in Phoenix, a larger system — around 11.5 kW — would be needed to completely offset energy consumption for the average household.

The best place for a 3 kW system would be somewhere like Hawaii, where panels can produce a lot of energy but homeowners don’t consume a lot of it. According to the Energy Information Administration (EIA), the average Hawaii household only consumes 537 kWh of electricity each month.2

Determine Your Home’s Energy Needs

To accurately find out if a 3 kW solar panel system can fulfill your household energy needs, you need to figure out how much solar power you need to power your home.

The best way to do this is to connect with a solar installer to get a home assessment, but you can also estimate based on your electricity bills, energy needs and available roof space. Here are the general steps:

  1. Calculate how much energy your home uses
  2. Assess your roof space and the amount of sunlight your home receives
  3. Figure out the specific yield of solar panels in your area to estimate system size
  4. Check the wattage of the specific panels you intend to purchase
  5. Divide the wattage of your system by the wattage of your panels

For more information, check out our guide to determining how many solar panels you need.

How Much Can You Save on Your Electricity Bill With a 3 kW System?

While a 3 kW solar system may not eliminate your utility bill, it can significantly reduce it. We’ve found the average U.S. homeowner would save $594 per year on electricity expenses with 3 kW of solar, based on the average utility bill of about $120 per month.3

This savings estimate doesn’t take net metering into account, which is a system by which homeowners with solar can earn credits from their local utility companies for any electricity their panels generate and send to the local power grid. If net metering is available in your area, you will be credited for your surplus energy in one of two ways:

  • Net metering at retail price: You get full credit for each kilowatt-hour sent to the grid. For example, if you’re charged 16 cents per kWh consumed, you’ll get a credit of 16 cents per kWh exported. This type of net metering is required by law in 29 states.
  • Net metering at a reduced feed-in tariff: Surplus electricity sent to the grid is credited at a lower rate. For example, you may be charged 16 cents per kWh for consumption but paid 10 cents per kWh exported. Feed-in tariffs and other alternative programs are used in 17 of the states where retail-rate net metering is not mandatory.

Note: This is just a simplified example — the exact kWh retail price and solar feed-in tariff will depend on your electricity plan.

Payback Period

The basic formula for calculating a payback period for solar panels is to divide the cost of the system, including tax rebates and financial incentives, by the annual amount you’ll save on utility bills. This will give you an idea of the number of years required for you to “break even” with your solar panels.

While the exact length will be unique for everyone, we’ve estimated that it will take roughly 10 to 14 years to pay off a 3 kW solar panel system. But again, these numbers are averages and can vary greatly depending on your energy usage, the cost of solar where you live and your solar financing method.

3kW solar panel systems

How Many Panels Are Needed in a 3 kW Solar System?

The number of solar panels needed for a 3 kW system will range from about 9 to 12 panels depending on the type of solar panel you choose. Keep in mind that the average solar panel is 65 by 39 inches or roughly 17.5 square feet.

Monocrystalline or “mono” solar panels are the most efficient and have the highest wattage, followed by polycrystalline and then thin-film. The best solar panels on the market have an output of around 350 W to 400 W each, but the output of less efficient panels can be as low as 250 W.

If you’re looking to buy a 3 kW (3,000 W) system and you’re buying solar panels that have an output of 350 W, you’ll need about 9 panels. Your formula will look like this: 3,000 W / 350 W = 8.6 panels.

Although the cost of solar panels is lower if you choose a lower-efficiency model over a pricier high-efficiency one, remember that the total amount you pay for your solar energy system may come out to be the same or higher because you’ll have to buy more panels. Also, if you’re looking to install a rooftop solar panel system, keep your available roof space in mind. The average solar panel is 65 by 39 inches, which is roughly 17.5 square feet.

Find the Right Installer for a 3 kW System

Most solar companies are capable of installing any size system, but you will want to choose the best solar installer in your area for the job. Here are a few factors to look out for when choosing a solar company:

  • Availability: Even big-name solar companies tend to only serve about 25 states maximum (with the exception of SunPower). If you live in one of the top states for solar, you’ll likely have plenty of options. On the other hand, if you live in an area where solar energy is still budding, you may only have a few solar installers near you.
  • Solar costs and financing: Different companies have different solar financing options. You’ll want to find the one that works best for your family’s budget.
  • Consultations: Many solar companies will offer a free home consultation or evaluation, or at least some sort of free estimate based on the specifics of your home. We recommend getting solar quotes from at least three companies to compare prices. And be sure to ask about any discounts, rebates or sales the company may be offering.
  • Warranty: Solar panels are a hefty expense, so you’ll want to make sure that investment is protected. Make sure to choose solar panels that have at least a 10-year warranty, as that’s the industry standard. However, most of our top picks for solar companies have warranties that last up to 25 years.

FAQs: 3kw Solar Systems

Below are a few questions EcoWatch readers regularly send in when considering 3kw solar panel systems. If you have anymore, do not hesitate to contact us at contact@ecowatch.com!

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Kristina Zagame

Kristina Zagame is a journalist and content writer with expertise in solar and other energy-related topics. Before joining EcoWatch, Kristina was a TV news reporter and producer, covering a wide variety of topics including West Coast wildfires and hurricane relief efforts. Kristina’s reporting has taken her all over the U.S., as well as to Puerto Rico and Chile.

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