How Much Power Does a 15kW Solar System Produce? -
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How Much Power Does a 15kW Solar System Produce?

Short on Time? Here’s The Article Summary

The article discusses the details of a 15kW solar power system, including its power generation, space requirements, and cost. It explains that a 15kW system can generate 15,000 watts of power, roughly equivalent to powering 500 laptops simultaneously. However, various factors like weather, temperature, and equipment affect actual power output. The article also compares the power output of a 15kW system to a 7kW system, highlighting that a 15kW system can produce around 60kWh per day. It mentions the importance of considering efficiency and ways to maximize a solar system's efficiency, such as using LED bulbs and adding insulation.

Regarding installation, it explains that a 15kW system typically requires 50 to 60 solar panels, depending on their efficiency. Lower-end panels may need up to 63 panels, while higher-efficiency panels may require only 44 panels. In terms of cost, the article mentions that the average installation cost for a 15kW system is around $2.93 per Watt, totaling approximately $43,950. However, with a 30% federal tax credit, the cost can be reduced to $26,370. It also provides price ranges for 15kW systems in various states, noting potential incentives and rebates available.


Solar panels and systems are available in various sizes and outputs. Depending on our needs, we may need solar systems that produce as little as 4kW or as much as 15kW.

Here, we look at how much power a 15kW solar system can generate, how much space it’s going to take up, and how much money you’ll be spending on an installation.

The Total Amount of Power Generated

how much electricity does a 15kw solar system produce

What does it really mean when we think of a 15kW solar system? A solar system that can produce 15kW (kilowatts) of power usually does so instantaneously. Is it the same as what a 5kw solar system can run or even a 10kW solar system?

To get an idea of how big this solar system is, compare it to a laptop. Laptops use about 30 watts when they’re plugged in and powered. With a little bit of math, we figured out that a 15kW solar system is able to power 500 laptops simultaneously. 

This is because 1kW equals 1,000W. In other words, a 15kW solar system produces 15,000 watts. Powering all those laptops is entirely possible - in theory. 

Realistically, there are loads of variables that play a part in how much power can be generated from a 15kW solar system. Things like the weather, temperature, wiring, solar panel soiling, and equipment all affect how much electricity can actually be produced. 

How much power does a 7kW solar system produce per day compared to a 15kW solar system? As a general rule of thumb, a 7kW solar system should produce between 30kWh and 40kWh every day whereas a 15kW system can produce an average of 60kWh each day.

According to the National Renewable Energy Lab, it’s recommended to shave off 14% of total electricity production to account for all the different variables causing these losses. So, in practice, a 15kW solar system will only put out 12.9kW in total. 


how much does a 15kw solar system cost

Before you start dismantling your installation or cancel your order, let’s remind ourselves that a 15kW solar system can still do a ton of stuff. 

For example, Colorado. There, a 15kW solar system generates around 12,907kWh every year. The average amount used annually is 8,256kWh, which means that a 15kW solar system produces enough power to cover close to 160% of an average home’s electrical usage.

Although, we need to point out that most utilities limit the size of solar systems to cover only 100% to 120% of a home’s electricity usage.


Having a solar system installed is a good financial decision and there are numerous other things you can do to maximize the efficiency of your system. 

A few things you can do to save even more money on electricity involve the rest of your home. This includes swapping out the incandescent light bulbs for LEDs, adding insulation to particular areas in your home, weather stripping around windows and doors, and even installing low-flow faucets.

how much is a 15kw solar system

These are just a few things you can do to get the most out of your electrical usage, and along with a solar system, you’ll save tons of money in no time at all.

A good idea is to see whether or not you can get a rebate on your energy audit. A technician comes to your home and inspects your windows and doors for leaks, and runs tests on insulation levels while also checking the HVAC (heating, ventilation, and air conditioning) for inefficiency. 


How Many Solar Panels Are in a 15kW Solar System?

Now that we’ve explored how much 15kW really is and how much a solar system like that will produce, how big is the installation going to be? The size of a solar system like this is primarily determined by the efficiency of the solar panels themselves. On average, that number ranges from 50 to 60 panels. 

There are levels of efficiency homeowners can go with when purchasing solar panels, and the level of efficiency directly corresponds to how many panels you need to produce 15kW.

Lower-end solar panels are generally capable of 14.5% efficiency and generate 240W each. A solar system as big as 15kWh would need as many as 63 panels to produce that output. 

Solar panels falling under the mid-range category are 16% efficient and produce 265W per panel. You’d need close to 57 panels to generate 15kW. In general, many homeowners go with mid-range panels like the 100W Inergy Solar Storm because they balance cost with higher efficiency levels. 


how many kwh does a 15kw solar system produce


Finally, solar panels in the higher efficiency ranges are able to generate close to 345W per panel. Because of this higher output, you’d only need 44 solar panels to make up a 15kW system. 

So, we can see that when it comes to solar panels, homeowners have a few routes they can choose to go with. It all comes down to personal choice - and the size of our wallets. 

How Much Space Does a 15kW System Need?

The typical size of a solar panel is around 65 inches tall by 39 inches wide, which covers a total area of 17.6 sq. ft. per panel. Put a few of these together, let’s say 57 panels, that would equal 1 003 sq. ft. in total. Just imagine ten Honda Accords parked in a row - now, imagine them parking on your roof.

We know that none of our roofs have that much space in one area but with the use of micro-inverters, this dilemma can be dealt with. Micro-inverters optimize each panel individually, making it possible to put solar panels practically everywhere on your rooftop. 

When using micro-inverters, panels need to be installed in groups of three panels or more, they can face different directions and be tilted to various angles. Micro-inverters are more expensive than regular string inverters but when there’s only so much space on your rooftop it’s much better to go micro. 

Cost of a 15kW Solar System

According to a report made by the National Renewable Energy Lab in 2016, the average installation cost for personal-use solar is $2.93 per Watt. 

Installing a 15kW solar system could see you paying as much as $43 950 in cash. Yikes! That’s quite a load of money, fortunately, there are ways to knock that price down a few notches. 

The first thing you should be aware of is that homeowners that buy their own system get a 30% federal tax credit. Using that immediately would bring down the cost to $26 370.

how much does a 15kw solar system produce

For example, how much does a 4kw solar system cost according to this statistic? Before the tax credit, it would be $11 720, and around $8 200 after applying for the tax credit. You can apply the same math when figuring out how much a 6kw solar system costs.

That’s better but we can go further into detail. Let’s take a look at how much electricity is produced and what it would’ve cost if you had to buy it straight from the utility. 

We know that the 15kW installation in Colorado generates 12 907 Watts every year, so we’ll use that in our equation. Colorado’s utility prices are generally $0.12 per kWh, which makes the cost of buying 12 907kW around $1 564.

Solar systems typically last between 20 and 30 years, we’ll go down the middle and say that our 15 kW installation is going to last 25 years. 

Throw in the 0.08% annual efficiency drop, and at the end of 25 years, our 15kW installation will have generated 319 596kWh in total. 

Now, imagine buying 319 596 kW from the utility. Since utility rates climb at a rate of 2.5% each year, it’s another factor coming into play. 

Buying 319 596 kWh from the utility over the course of 25 years would set you back $52 870 in total. Subtract this from an initial investment of $26 370, you’d end up saving $26 500. There are probably a lot of things we would do with over $25,000 in our back pocket, right?

However, you could always avoid the initial investment cost by financing it through a loan, lease, or PPA but your savings will be lower. Of course, you’ll still be able to save a few thousand this way, too. 

Solar Panel Installation Costs Across the U.S.

Not all of us live in Colorado, though, and it’s important for us to know how much we’ll be paying in our own states. 

what can a 15kw solar system run

Here’s a list of price ranges from several states across the U.S. that show the gross cost for a 15 kW solar system in each state. Bear in mind that the federal tax credit for solar panels hasn’t been deducted here:

  • Arizona; from $40,950 to $50,850
  • Florida; from $33,000 to $45,900
  • California; from $39,450 to $49,350
  • Maryland; from $36,450 to $46,650
  • Massachusetts; from $42,600 to $52,200
  • New York; from $39,300 to $57,000
  • Washington; from $37,350 to $47,850
  • Texas; from $38,550 to $46,950

Also, depending on the state you’re currently living in, you might have access to solar incentives or rebates from the government or local utilities. 

There are some states that also have a market for solar renewable energy certificates or SRECs, which allows you to earn an extra income by selling the SRECs generated by your solar system.

You could also sign up for a solar panels affiliate program that allows you to refer anyone to buy from a particular solar shop and earn commissions.

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Article by

Alex S

Alex is a co-founder of Shop Solar, a company that he established in 2018 to revolutionize the solar industry by simplifying the process and making it more simple and cost-effective. Under his strategic leadership, Shop Solar has grown into a comprehensive one-stop-shop, empowering over 40,000+ customers to access top-quality solar and storage solutions, comprehensive information, intuitive tools, and professional installation services.

With a passion for innovation and sustainable energy, Alex has successfully expanded the business's reach and impact, serving as a driving force in the company's growth and development. You can browse best seller's here.

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