Adding Solar Panels to an Existing System in 2022 | EnergySage (2023)

If you’ve gone solar, you’ve already decreased (or possibly eliminated) your electricity bill. But you may want to add more solar panels to your existing system; your solar panel system could be undersized to begin with, or you might have increased your electricity usage since installation due to new additions to your house, new appliances, or adding an electric vehicle (EV) purchase.

The process for adding additional panels onto your existing system isn’t going to be the same as when you were originally shopping for a solar panel system. As you’re investigating your options, here are a few key factors to keep in mind.

Factors to consider for adding new solar panels to an existing system

If you want to add solar panels to your existing system, here are a few things to keep in mind:

Energy needs

How many additional solar panels do you need? This is going to be the first question to address, as it will affect both your system design and the cost for the add-on project.

(Video) Can I add solar panels to my existing system?

The number of panels you need to add onto your system will depend on a number of factors, including your electricity bill post-solar, where you live, the equipment, and your system design. If you have your electric bill information since going solar and can provide it to your installer, they should be able to determine how many additional panels you will need given your unique situation. If you’d like to start calculating this number on your own, check out our guide to calculating how many solar panels you need.

Space for new panels

Do you have enough space to install additional solar panels? If you have a rooftop system with constrained space, the answer may be no. Ground mount systems can be a bit easier to add onto because property owners with ground mounts typically have a lot of sunny land available for install.

That being said, if you’ve run out of roof space to install additional panels, that doesn’t mean you should give up. You can always investigate installing supplemental solar arrays on other structures on your property, such as carports, sheds, or gazebos.

Solar panel upgrade and compatibility

What panels were used in your original installation, and does any component require an upgrade? Your solar panels will continue to generate electricity for more than 25 years, at which point you might see more significant dips in production, so it’s unlikely you’ll need to replace the panels of the original system. But still ask your installer to check everything, including the racking and wiring.

(Video) Adding solar panels to existing systems

When adding new panels, it’s a good idea to install the same type as your original array if possible. This ensures everything will match aesthetically, and has the same power outputs and efficiencies as your other panels. If you’re unable to install the exact same panels, you should still look to install new panels with the same or similar power output – otherwise you could damage your existing array.

Inverter replacement

Is your inverter large enough for the additional panels? Depending on how much more new capacity you add onto your system, you may need to replace your inverter. When an installer sizes your central inverter, it’s based on the power output of your panels. Because the direct current (DC) electricity being produced by your panels is being converted to alternating current (AC) at the inverter, the power rating of that inverter can be a bit smaller than the panels because of the energy loss that occurs during the conversion process. If you’re adding quite a few panels and your entire solar panel system is much larger than the original size, it may generate more electricity than your pre-existing inverter can handle.

Add-on projects are a bit easier if your original solar panel system uses microinverters as opposed to a power optimizer or string inverter system. Because microinverters are located at each individual panel, you don’t have to worry about inverter capacity issues and can just install additional microinverters with the new panels.

Installer to add on the panels

Does your original installer do add-on projects? If so, it’s going to be the easiest to contact them first to see if they can do the work. They will already be familiar with your system and property and will be best equipped to add more panels onto their own handiwork.

(Video) Understanding Solar Batteries - A Beginner's Guide - 2022 Edition

That being said, this may not be an option for you if you had a bad experience with your original installer, or if they’ve since gone out of business. You can always shop around for a new installer to do the work when it comes adding more panels onto your solar array but may have a harder time finding a solar company to do the work. Some installation companies that will avoid doing add-on projects for installations that aren’t their own. This happens for two major reasons: they don’t want to deal with conflicting warranties on the overall installation, or the size of the project isn’t large enough. A lot of installation companies won’t want to encounter disputes down the line about whose job it is to fix a part of the system, especially because the original work is not their own and they can’t stand by it.

With regards to system size, many installers have a minimum system size they will install for their own profit margins. A typical add-on project may be installing only a few panels, which will mean much less profit than they would see on a standard residential installation. Depending on their resources and installation calendar, many companies will choose to focus their efforts on larger projects.

Permitting and interconnection

Will installing additional panels on your property require pulling additional permits, or submitting additional interconnection documentation to your utility company? This can depend on a number of factors, including how many additional panels you’re adding, whether a new inverter is required, and your local area’s permitting requirements. If you are adding more than a couple kilowatts (kW) to a system and have to replace your inverter, it’s more likely that you’ll have to submit another interconnection application with your utility company.

Any installer you’re working with for an add-on project should be aware of any permits or interconnection requirements and will help file for these as well as part of the overall cost of the add-on project.

(Video) Installing Solar Panel System on a "Solar Prepped RV"


If you’re adding additional panels onto your system, you may not be eligible for some of the same incentives (such as tax credits and rebates) that you claimed when you originally installed your system. Many incentives are only allowed to be claimed once per property, or once per person.

Performance-based-incentives (PBIs) can be a bit complicated when it comes to add-on projects. Because the incentive amounts are based on how much electricity your system is generating, you may run into some complications if you have a new inverter and have to re-file for interconnection.

Always have a conversation with your solar installer about what incentives you will and will not be eligible for when it comes to your add-on solar project, and talk to a tax advisor or accountant when it comes to questions regarding tax credits you may be eligible for.

Add solar panels to an existing system on EnergySage

With any solar project, big or small, it’s good to shop around. By signing up on the EnergySage Marketplace, you can receive multiple quotes to compare costs for solar. If you’re looking to add panels onto your existing system, note that in your account, along with information about your existing system (equipment, system size) so that installers can provide you with the most accurate quotes possible.

(Video) Should You Expand Your Existing Solar Energy System?


Is it possible to add more solar panels to an existing system? ›

Providing you have the space, and we can work with the grid it is entirely possible to add more solar to an existing system. The equipment need not be the same as originally installed so, for the most part, it would be treated as a brand new installation.

Is it worth adding extra solar panels? ›

Adding more solar panels to your system will increase the amount of energy your home produces, and if you have extra space on your roof, installation can be a relatively simple process.

Do I need to tell my electricity supplier I have solar panels? ›

First off, you can still switch gas and electricity suppliers when you have solar panels or generate your own renewable energy in another way — but you must switch to an eligible supplier. When it comes to your Feed-In tariff, it's Ofgem that sets the rates for the schemes.

Are there any grants for solar panels UK 2022? ›

Yes, you can get a grant for solar panels in the UK to help reduce the cost of your energy bills by up to £1,000 annually, or even a fully free solar PV panel system. There are currently 3 available solar panel funding options that you may qualify for.

Can I mix 100 watt and 200 watt solar panels? ›

The short answer is, yes, you can mix solar panels that have different wattages. But it is not usually advised, because mixing different wattage panels reduces the efficiency and power output.

Is there a limit to how many solar panels you can have? ›

You can have more than 4kWp.

It's a very common misconception that domestic Solar PV systems are limited to 4kWp. This myth was driven by two factors. Firstly the tariff used to reduce for installations above 4kWp, not so any more, it's the same between 0-10kWp and actually goes up for installations over 10kWp.

Do solar panels decrease property value? ›

According to Zillow, homes with solar panels sell for approximately 4 percent higher on average than homes without solar energy. That means an added value of about $9,200.

Do solar panels devalue your house? ›

found that installing solar panels on your home does not negatively impact the value of the property. Eight per cent of estate agents involved in this research said they thought solar panels increased property value.

Do solar panels increase house price? ›

Yes. The research indicates that solar panels add around 4.1% to a home's value – which means you could make tens of thousands of pounds. That makes sense, too: who wouldn't want to buy a home with better energy efficiency than the average property, that can save you money on your energy bills every month?

What are the 2 main disadvantages to solar energy? ›

Solar Cons
  • Standard home solar does not “work” at night.
  • Home solar panels are not attractive.
  • DIY solar installation is difficult (if not impossible) for most homeowners.
  • Not every roof configuration is ideal for maximum solar power generation.
  • Solar manufacturing is not good for the environment.

Can I run my house on solar power only? ›

With a modern solar energy system, including power storage, you can definitely run a whole house completely on solar power. Today's high-efficiency solar panels and solar batteries make it cheaper than ever before to power an entire home exclusively using solar energy.

Why are my solar panels not saving me money? ›

Your Home Is Using Too Much Power

If your solar panels are not reducing your bill, it can be because: Your system is generating less electricity than you use. You're using too much electricity at night when panels aren't generating it. Too many appliances or devices are plugged in.

Can you piggyback solar panels? ›

What about connecting multiple solar panels to one battery? You can connect them in parallel, providing your battery management system can handle the maximum input power.

How can I increase my solar panel output? ›

The 6 Best Ways To Improve Solar Panel Efficiency
  1. Buy one of the more efficient solar panel models. ...
  2. Buy panels with High Concentrated Photovoltaic (CPV) Cells. ...
  3. Avoid installing solar panels in shaded areas. ...
  4. Get an expert to install your solar panels. ...
  5. Clean your solar panels.

Can you have 2 solar system on your house? ›

You can add a new solar system, although two systems working side-by-side can make adding batteries and backup trickier. The benefits of this third approach: With a new system, you get a separate warranty. Installing a new solar system may be cheaper than upgrading.

Can I add more solar panels to my Sunpower system? ›

If your panels are 10 years old or more, you probably won't be able to add modern panels to your existing system. Solar technology is changing rapidly to become more efficient and easier to control, so adding new panels may not be possible with the infrastructure already in your home.


1. IT HAPPENED! For Only $0.22/w, Tesla 4.0 solar cell Can blow your mind!
2. The Best Solar Battery Backup in 2022
(Solartime USA)
3. Solar Panels - Do They Make Financial Sense in 2022?
(Electric Vehicle Man)
4. Can you add solar panels to your existing system?
(Panasonic Business Solutions)
5. My Actual Costs to Expand My DIY Rooftop Solar Array for MORE POWER!
(Anthony Dunster)
6. I Added 11 More Solar Panels. Was It Worth It?!
(Epic Homesteading)
Top Articles
Latest Posts
Article information

Author: Horacio Brakus JD

Last Updated: 02/18/2023

Views: 6000

Rating: 4 / 5 (71 voted)

Reviews: 86% of readers found this page helpful

Author information

Name: Horacio Brakus JD

Birthday: 1999-08-21

Address: Apt. 524 43384 Minnie Prairie, South Edda, MA 62804

Phone: +5931039998219

Job: Sales Strategist

Hobby: Sculling, Kitesurfing, Orienteering, Painting, Computer programming, Creative writing, Scuba diving

Introduction: My name is Horacio Brakus JD, I am a lively, splendid, jolly, vivacious, vast, cheerful, agreeable person who loves writing and wants to share my knowledge and understanding with you.