Many homeowners with solar panels eventually ask whether they can expand their system.
The rising cost of electricity or investment in new technologies like electric vehicles or heat pumps can lead to a sudden increase in energy bills, and solar panel users often find themselves wondering if a larger solar array may help to ease the burden.
The good news is, in most cases, it’s possible to add more solar panels to an existing installation.
However, it may need some adjustment to your existing system, too.
How do solar panels work?
Solar panels are made up of photovoltaic (PV) cells, usually made from silicon. When sunlight hits these cells, it knocks electrons loose and gets them moving. That movement creates an electrical current.
This current comes out as direct current (DC), but your home runs on alternating current (AC). An inverter sits between your panels and your home’s electrical system and handles that conversion, turning the DC electricity into something your appliances can use.
The more panels you have producing that current, the more electricity your system generates. So, in theory, adding panels to an existing installation sounds straightforward. In practice, there are a few things that determine whether it’s actually feasible.
Your inverter is the main consideration. Every inverter has a maximum capacity, and if your existing one is already running close to its limit, it may not be able to handle the output from additional panels. Your roof space, its orientation, and your DNO’s approved export limit can all play a role, too.
So, the good news is, you can often add more solar panels. Many existing systems can be expanded successfully.
Additional panels may be used to increase daytime generation and your reliance on the grid during these hours. This can be particularly useful if the electricity demands in your household have grown since your original installation. New appliances, growing families or new home offices can all lead to changes in your household’s electricity usage.
The rest of this blog explains the best way to go about adding more panels to your existing solar installation.
Check for roof space and suitability
The first step you need to take is to question whether this is a practical option for your house.
Do you have the space available on your roof for additional solar panels?
Are the unused sections of the roof facing in a suitable direction?
Is it removed for shading such as nearby trees or buildings?
A poorly positioned panel may not perform as well as you’re hoping, and it may take longer to pay back the money you’ve invested. So, it’s important to be realistic about the available space from the outset.
Can your inverter handle more panels?
The inverter is the part of your solar system that turns the electricity from your solar panels into electricity your home can use, but it has limits to how much generation it can process at a time.
If additional solar panels push it over that limit, you may find you need to replace the inverter, or purchase an additional one.
This is one of the most common reasons why adding more solar panels might require a redesign of your set up.
Will your battery system need upgrading too?
If you already have battery storage, more panels may charge it faster. If your existing solar array isn’t charging it fully, additional panels may offer extra stored energy.
However, if battery capacity is small, extra solar may still be exported unused. This means it will take longer to pay back your investment.
This can be an important consideration if your use is heavy in the evenings, when generation has stopped and export prices are highest. You might want to opt for additional battery modules or a larger battery.
DNO permissions and grid approval may apply
Adding additional panels will change how much energy your system generates. The body that manages electricity use in your local area is known as your Distribution Network Operator. They’re responsible for the cables and other infrastructure that bring electricity from the grid, into homes and businesses.
If change the capacity of your system, you may need to notify them or any changes, or even ask permission to go ahead in the first instance. In many cases, a professional solar panel installer (like us) will take care of this on your behalf, but it’s important to find out what is needed from you upfront if you’re considering adding additional solar panels to your home.
It may also be worth checking if the changes will affect your export tariff, as some schemes have specific rules around system changes. Again, your installer will be able to offer tailored advice according to your setup and tariff.
Is adding more panels always the best option?
If demand for electricity in your household has increased and you’re no longer able to generate enough to cover your day to day needs, then yes, adding more solar panels might be a good option for you.
It’s also important to consider your other options. Sometimes better returns can come from:
- Adding battery storage
- Replacing an old inverter
- Improving system monitoring
- Changing your habits to use more daytime generation
We can offer advice on where the best investment might be according to your system, to ensure everything is working safely and as efficiently as possible.
How can Electrical Innovations help?
If you’re thinking of expanding your solar array, Electrical Innovations can assess your existing system and advise on whether expansion is the right choice for you. We’ll take you through the whole process from design to installation and handle the paperwork and safety checks on your behalf.
We’ll be sure to let you know if you’re going to need upgrades to your existing battery or inverter and make sure you’re getting the best value from your solar set up. So, if you’re a homeowner in Derby or the surrounding Midlands area looking to get more from your existing solar system, why not get in touch for tailored advice about the best way to extend your installation?
