Inverter Systems

Staying efficient - staying green

A solar inverter or PV inverter is a type of electrical converter which converts the variable direct current output of a photo-voltaic solar panel into a utility frequency alternating current.

What does that mean to you?

Any solar panel system is only as strong as its weakest link and this is the most important part of your set up. Over several years like any kind of electrical appliance it loses efficiency. All this means is you are losing generation power and your system is not as effective as it once was. By losing efficiency the number of units you generate decreases, in correlation so does the amount you return on your FIT (Feed in tariff).

How will this benefit you?

There are many different factors that come into the equation when considering if a new inverter would really benefit you as all systems are different. You have to consider how old is your inverter? Is it a traditional string system? Have you changed any other parts of your system i.e. had issues with your inverter and had it replaced on your warranty? Maybe added voltage optimisation to your mains electric or added optimisers to your panels?
Most people change their inverter every 3-10 years depending on the quality of the current inverter to allow extra benefits from high powered systems such as micro inverters or SolarEdge which are both leading performance set ups designed to allow the panels to work in parallel rather than in series like a traditional inverter.
Depending on roof type, shading or general personal circumstances we advise to switch over with our in-house scheme of a buyback to save  customers money in the long run or if the old system has simply broken, we would recycle as well.

Inverter Types

String Inverters 

A string is a chain of panels connected together in series. This is the most basic inverter system. All the panels in a string must be at the same pitch and orientation, otherwise there will be inefficiencies in the system. Many string inverters have 2 or even 3 MPPTs (Maximum Power Point Tracking), which means that you can have a different string of panels on each MPPT. This could work well for an east/west set up.


One of the disadvantages of string inverters is that if there is a fault or shading on one panel in the string, it will affect the performance of all the panels on the same string. In a microinverter system each panel has an inverter all to itself. Each panel is therefore isolated so any faults or shading will be isolated. As microinverters are often hooked up to the internet, problems with specific panels are quickly and easily identified, saving a huge amount of investigation time.

Optimised Inverters

A hybrid of the microinverters and string inverters, separates the two jobs of an inverter. There are optimisers behind each panel which carry out the role of MPPT therefore isolating any shading or fault issues. These optimisers are connected to a central inverter which can work more efficiently as it is always presented with the same voltage from the panels (string inverters have to deal with variable voltages). These systems are also internet connected which allows pro-active maintenance. So if there’s a fault, your installer will get an email alert and can respond quickly and accurately. 

Contact Greenstars

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