Optimised vs String solar panels: which is better?
If you’re thinking about installing solar panels, you might be wondering about the different solar panel set-ups available.
From price, efficiency, performance and maintenance, here are some of the main pros and cons of string solar panels vs optimised solar panels.
See the difference at a glance
| Feature | String inverter system | Optimised system |
|---|---|---|
| Lower upfront cost | ☑️ | |
| Each panel performs individually, reducing impact of shading / debris. | ☑️ | |
| Higher energy generation and financial savings | ☑️ | |
| Panel-level monitoring & easier fault detection. | ☑️ |
String inverter solar panels
String solar panels are the type of solar panel technology that has been on the market for the longest. It involves the panels being connected in one electrical ‘string’, with all power going into a central inverter. The inverter converts the solar power from DC to AC so it can be used in your home or exported to the energy grid.
Pros
- Lower cost: string inverter solar panels are some of the cheapest options available
- Bigger choice: there are a large number of manufacturers and installers to choose from.
- Simple set up: with only one inverter, string solar panels are quick to install and maintain.
Cons
- Lower output: panels in a string system are only as efficient as the lowest performing panel. So if one panel is in the shade, faulty or covered in dirt or debris, the full string will generate less. This will affect your bill savings and your export payments.
In optimised systems all panels perform individually, protecting generation.
- Less flexible design: some string inverter systems require panels to be installed at very similar orientations to make sure they work efficiently. This can limit the number of panels you can install, or impact how the solar array would look on your property.
- Shorter lifespan: you’re likely to need to replace your inverter after 10-15 years, in comparison to the 20-25 year lifespan of an optimised system.
- Less insurance friendly: insurers give string solar panels a lower reliability rating than optimised systems, because they’re associated with a slightly higher risk of fire. This could increase your home insurance premium, or even limit the amount of insurers that will cover you.
- Increased maintenance costs: if there is an issue with a string system, it’s impossible to know which panel is underperforming without a physical check. This can prove costly and timely.
Optimised solar panel systems
In an optimised solar panel system, each panel has an optimiser fitted, which allows them to operate independently and maximise your solar output; as well as one central inverter. Not only do optimisers enable each panel to generate more energy, they also provide a detailed level of performance monitoring – helping you to spot and resolve under-performing panels more easily. Here’s a full list of the pros and cons.
Pros
- Enhanced solar generation and earnings: adding an optimiser to each solar module allows it to operate independently of the others. So if one panel in the array is shaded, the output of the others isn’t reduced as well. This leads to higher generation and annual savings.
- In-built safety features: optimisers can monitor the performance of each panel and automatically detect faults. SolarEdge systems also offer enhanced safety features such as SafeDCTM, which reduces the DC voltage down to safe touch levels, to enable safe maintenance.
- Insurer friendly: Optimised systems meet the latest insurance and fire safety requirements, including RC62 fire regulations.
- Performance monitoring: view the generation levels of your system as well as the performance of individual panels, making fault-detection easy.
- Easy to expand: if your household energy needs change, you can easily add more panels or a battery onto a SolarEdge optimised system.
- Long term warranties: SolarEdge offers lengthy warranties on power optimisers and inverters. Their customer support team can also help diagnose and troubleshoot any issues remotely.
Cons
- More expensive than installing a string inverter system on its own.
Most of the systems we install at Good Energy are SolarEdge optimised systems. We find this gives most customers the best balance between upfront cost, and yearly return on investment.
Deciding which solar panel system is right for you
As part of your solar consultation, our team can talk you through the best options for your home, depending on the space available for your install, your budget and household electricity needs.
