solar cost estimator

Today, we review the Solar Cost Estimator and online solar calculator. While the most recent official data from the DOE-funded Lawrence Berkeley Labs found that the average cost of solar panels per watt in the US is $3.34/watt, prices from solar cost comparison marketplaces like show the actual average residential solar panels cost is now $3.18 per watt.

For an average-sized residential solar power system of 6kW, this is a cost of $19,080 before the federal solar tax credit, or $14,119 after claiming the tax credit.

How do you want to view our solar panel cost data?

Solar panel cost by system sizeSolar panel cost by stateSolar panel cost by solar panel manufacturerCurrent offers on residential solar panels in your city

What is included in ‘solar panel cost’?

We compile solar power cost data for complete solar power systems that are professionally installed by licensed solar companies. The equipment and installation, in addition to the permitting and inspections by the city and your utility, are all handled by the solar company and are thereby included in the price. More »

Solar panel installation cost by system size in 2020?

Below is the current average price of solar panel installations for the most common residential solar systems installed, sized from 4 kW to 20 kW.

Solar Cost Estimator

System size*Average cost
per watt
Average Cost
(showing after tax credit)
show before tax credit
Savings on
your home
(25 years)
4 kW$3.66$10,827Calculate
5 kW$3.50$12,965Calculate
6 kW$3.37$14,974Calculate
8 kW$3.19$18,864Calculate
10 kW$3.05$22,607Calculate
12 kW$2.93$26,058Calculate
20 kW$2.79$41,346Calculate

* What is a kilowatt and what is a kilowatt hour?

By entering your zip code into the solar power calculator below, you can easily find out how many solar panels you need for your home. You’ll also see live solar prices in your city for the recommended solar system size for your home.

Enter your zip code and power cost to calculate the right system size for your home and see live current solar offers in your city

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Average solar panel cost in each state in 2020?

If you prefer to view solar power system prices specific to your city or region, you can select your city below.             Select state                             Alabama                             Alaska                             Arizona                             Arkansas                             California                             Colorado                             Connecticut                             District of Columbia                             Delaware                             Florida                             Georgia                             Guam                             Hawaii                             Idaho                             Illinois                             Indiana                             Iowa                             Kansas                             Kentucky                             Louisiana                             Maine                             Maryland                             Massachusetts                             Michigan                             Minnesota                             Mississippi                             Missouri                             Montana                             Nebraska                             Nevada                             New Hampshire                             New Jersey                             New Mexico                             New York                             North Carolina                             North Dakota                             Ohio                             Oklahoma                             Oregon                             Pennsylvania                             Puerto Rico                             Rhode Island                             South Carolina                             South Dakota                             Tennessee                             Texas                             Utah                             Vermont                             Virgin Islands                             Virginia                             Washington                             West Virginia                             Wisconsin                             Wyoming                                   Select city          See my Location

(If your city is not listed, try a nearby city or view information for your state)

StateAverage cost
per watt
Cost of 5kW system
(showing after tax credit)
show before tax credit
lifetime savings
New Jersey$3.07$11,420$143,955
New Mexico$3.44$12,457$66,748
New York$3.34$12,943$137,512
South Carolina$3.81$14,911$87,565

Show all states

Average solar system cost for installed systems using each of the best brands of solar panels in 2020

Below are the solar panel costs for systems using the 15 most frequently-installed residential solar panels. This list also includes the most efficient solar panels on the market, which is likely the reason they are the most commonly-installed.

Panel ModelWattageEfficiencyLowest Cost Per Watt
(installed system)
(showing after tax credit)
show before tax credit
Average Cost Per Watt
(installed system)
(showing after tax credit)
show before tax credit
Q.PEAK-G4.1 30530518.30%$2.00$2.60
REC290TP2 BLK29017.40%$2.06$2.76

Why do we use ‘cost per watt’ as a way of measuring solar power system costs?

Solar panels are priced by the watt. “Cost per watt” is used when talking about the relative value of residential solar systems, rather than “total cost” because it allows us to compare systems of different sizes.

Here at SolarReviews, we are seeing homeowners who search for competitive quotes finding solar panel costs per watt as low as $2.26 in some states. While cost is not the only factor to consider when buying solar panels for your house, the decision to install them is primarily a financial one. Therefore, obtaining the best-possible system cost is important in order to minimize your solar payback period and maximize your solar savings.

Calculate how many solar panels you need to power your house and compare prices

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What factors affect the cost of solar panels for your home?

There are many factors that affect solar panel installation costs with regard to specific homes, including:

The location of your home

The location of a home affects the cost of installing solar in a few ways. Because the average cost per watt for solar systems varies throughout the country, it leads to different solar system costs. Not only that, the amount of sunlight each location receives affects system output and dictates how many solar modules you will need, which, in turn, directly affects the total system cost.

The amount of electricity your home uses

A house that uses more electricity will need more solar panels. Although solar panels do get cheaper on a per-watt basis, as the system size gets bigger, the overall cost of the system increases, as well.

The type of solar panels and inverter you buy

There is a significant difference in cost between the top-rated solar panels and brands that are perceived to be of lesser quality. The same is also true for inverters. For example, a 6kW solar system using Sunpower or Panasonic solar panels can be as much as $5,000 more expensive than a solar system using Canadian Solar Modules.

The relative ease or difficulty of installing solar panels on your home

If your roof is particularly difficult to install solar panels on, say, if your home is three stories high or has a roof with a 45° pitch, it will take longer to install the panels and do the wiring.

Calculate how much power solar panels will produce on your home

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Learn more about how much solar panels will cost for your house with our solar panel cost calculator

Our solar power calculator, originally developed with funding from the Department of Energy, is the easiest way to determine the solar panel installation cost for your home because it only requires the input of your address and monthly power spend. From this information, the solar calculator knows your utility company, your electric rates, and how much power you use. It will tell you:

  • Step 1: How many solar panels you need to power your house?
  • Step 2: Roof space: How many solar panels will fit on your roof and where will they go?
  • Step 3: How much your solar panels will cost, and how much they will save you?

The solar panel calculator will assume you want to install a solar power system to offset 100% of your energy use. This is because net metering laws limit the size of eligible solar systems to a system producing a similar amount of energy as your house uses.

Are individual solar panel prices still falling?

The median cost per watt for residential solar energy systems has dropped about 70% since 2000. However, in the last few years price decreases have slowed and are decreasing at a rate of about 5% per year.

It is unlikely that we will see steep or sudden falls in pricing again because at the wholesale level, individual solar panels are now only in the range of $0.40 per watt to $1.10 per watt (depending on the quality of the brand of solar panel). As of 2020, the federal solar tax credit has reduced to 26% and will go away completely in 2022. It is unlikely we will see any cost reductions that would be large enough to offset the loss of the tax credit. This means that waiting to install solar panels for your home seems unwise.

How to calculate solar panel cost for your home without collecting power bills?

While there is data on average electricity use of homes in each state and how many solar panels are needed to power an average house in each state these averages are of little use, as most people considering solar tend to have electricity usage that is almost double their state average.

Our solar panel calculator provides an easy estimate of the number of solar panels needed to power your home. All you need to know is the amount of your energy bill for the last month and your utility company.

The solar power calculator produces a ballpark estimate just from an average monthly power spend.

Does how much power solar panels produce in your city affect the cost of solar for your home?

The National Renewable Energy Laboratories (or NREL) have produced sophisticated and accurate data that shows how much electricity solar panels produce (in kWh) for over 1,000 weather locations throughout America. This is why almost every solar energy calculator uses the NREL PVWatts data for their solar panel kWh production calculations.

Enter your zip code and average monthly power spend to estimate how many solar panels you need for your home

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Will solar save you enough to get a short payback period on the upfront cost of a solar panel system for your home?

The solar savings estimator will also calculate how much solar will save you. The size of your solar savings depends largely on how expensive utility electricity is in your region, what the future rate of utility price inflation proves to be, and of course – how much power you use.

Solar payback periods can now be as little as 5-6 years, leaving homeowners installing solar to enjoy 20 years or more of free electricity once the panels are paid off. The solar calculator will work to determine your solar payback period.

Here is an example of how much a financed 6kW solar system in California saves a PG&E customer with a $168 current electric bill.


Buying a home solar power system can be a very exciting experience, but don’t get too carried away by advertising. Be sure to focus on the important aspects of your purchase as it’s a substantial investment and one you’ll be living with for a long time. The following are some buying solar tips on what to look for when purchasing a system.

Buying solar tips: Solar quotes online


Ask friends, family neighbours or colleagues who have had solar PV systems installed. Often the best buying solar tips com from right in your neighbourhood. They’ll be able to tell you about their experiences and perhaps alert you to any problems they experienced. Problems that you’ll be able to avoid. Learn more about potential issues in our consumers guide to solar power – avoiding tricks and traps.

Length of manufacturer’s warranty

Take note of what guarantees the manufacturer offers. If the manufacturer is reputable and the warranty period on the panels is substantial (at least 25 years) you would naturally expect your solar system to last long for a long time, long enough to pay for itself and make you a profit. However, for a warranty to be honoured, the manufacturer needs to be still operating. So, be cautious of brands without a track record in Australia.

Have realistic price expectations

If you are paying substantially less than many other similar size systems quoted, you may find poor quality equipment and/or poor installation work. Quality equipment and installation isn’t cheap and, like all other purchases, you often get what you pay for.

Compare components and warranty periods and check into the company providing the installation. While large, well established companies can pass on substantial savings due to increased buying power, other companies often reduce costs by cutting important corners.

Solar panel certifications

This applies to all solar panel purchases, but especially to the purchases that could attract a government rebate. The certification on solar panels indicates the type of testing that they have undergone. For instance, TUV IEC 61215 confirms that the solar panels have gone through testing by an independent laboratory and have met their advertised specifications. Other certification types are often self-assessed. Therefore, they rely on the company being honest in what it claims.

Decide on the type of panels

It used to be the case that if you had limited roof space you would need highly efficient (and very expensive) mono-crystalline solar panels. This is rapidly changing with advances in polycrystalline panel technology and some thin film technologies. Still, even if you have ample roof space you may still want to consider panel sizes vs. output. Filling up your roof with inefficient panels will affect your ability to add more panels at a later date, and does not maximise the power output of the space.

It’s also important to bear in mind that regardless of claim, no solar panel technology will produce a significant amount of power in full shade. Learn more about monocrystalline vs. thin film panels.

Solar panel mounting

Make sure that the roof, ground mounting or tracking system is engineer certified for the area you are in. For example, if you live in a cyclone prone area make sure the mounting system  and mounting brackets are also cyclone rated. Quality systems are wind certified. After all you do not want your system to take off during a wild storm . The mounting system is a very vital component and some suppliers skimp on this item. Make sure you ask about wind certification, warranty arrangements and get copies of relevant documents.

Solar inverter efficiency

A power inverter is the box between the panels and your appliances that converts DC electricity from solar panels to AC suitable for use in your home.

Not all solar inverters are equal and inverter efficiency will have a direct impact on the amount of time it takes for a system to pay for itself. Look at the inverter efficiency before purchasing a system. Obviously, the more efficient the inverter the better. Less electricity will be wasted as heat during the conversion from DC to AC. Industry leading solar inverters for grid connect systems in Australia include SMA, Sungrow and Fronius. Be cautious of  generic type brands.

Get a few solar quotes

It always wise to gather a few solar quotes when making a major purchase as you will find that prices vary widely between providers. But don’t be just swayed by price as inferior components can reduce the up-front cost of the system. However, they may wind up costing you more in the long run in terms of reliability and efficiency.

Buy solar power at discount prices

Avoid high pressure sales people

High pressure sales tactics are unfortunately common in the solar industry. Try not to make decisions on the spot, just ask the person to let you consider the offer. If it’s as good as they claim, it will still be a good deal tomorrow. Pressured decisions on the spot often turn out to be less advantageous in reflection.

High pressure sales people are only one of the pitfalls that may await you when you shop for a solar power system. Learn more about the potential issues and how to avoid them in our consumers guide to solar power – avoiding tricks and traps.

One of the best buying solar tips is to make sure to use an accredited solar power system installer, certified by the Clean Energy Council.

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