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How much do commercial solar panels cost?

November 16, 2020

As you might expect, the answer to this question is far from straightforward. The cost of a commercial solar array is subject to several important variables, and this article will look at some of them (note that this article is not an exhaustive list).

Variable 1 -

System Size

Commercial solar panel installations are modular, they can be designed and sized to suit the operation of the business that they are being connected to.

Broadly speaking, there are four limiting factors when deciding on a system size –

  • Roof/land size – self-explanatory really; you can only install panels if you have the space. BeBa specialise in systems that cover a minimum area of roughly 150m2.
  • Electrical demand/profile – in order to maximise the return on investment, the system should be sized to maximise self-consumption. Whilst you can export your surplus power to ‘the grid’, it is bought at a fraction of the cost you pay to import the power. BeBa will always carry out a forensic analysis of your energy demand before proposing a system size. As a rough rule of thumb – if you are keen to maximise return on investment – a system should have a self-consumption rate of at least c. 80%
  • Grid capacity – in almost all instances, your system will operate in parallel with ‘the grid’. Accordingly any system must be approved by them for connection to their network and for permission to export your surplus power. BeBa will make representation to your local District Network Operator on your behalf as part of the feasibility stage of a project. In some instances, even if you have plenty of space and plenty of electrical demand, ‘the grid’ could impose a restriction on the size of the array
  • Budget – as is the case with most investments, budget plays a huge role. That said, there are several ways to fund a solar project including one option that requires no capital outlay whatsoever.

Variable 2 -

Roof Type/Mounting Area

The way in which the solar panels are mounted to your roof/land can have a dramatic impact on cost. The panels and mounting system need to withstand everything that Mother Nature can throw at them so it is critical that they are held in-place securely for at least 25 years.

Again, broadly, speaking there are 4 types of commercial roof, each requires its own type of mounting system –

Metal – the mounting system is fixed to the roof only.

Fibre-cement – the mounting system is fixed through the roof sheeting and into the main substructure of the building.

Kalzip – typically seen on curved roofs, the mounting system is clamped to the standing seams of the roof.

Flat – the mounting system is anchored to the roof using ballast (typically blocks or other weights).

For ground based systems, there are normally two types of mounting system -

Piled – the vertical posts mechanically piled straight
into the ground.

Concrete – concrete is used to fix the posts into place.

Variable 3 -

Solar Panels

The big one.

There are hundreds of different types of solar panel on the market – each with their own unique characteristics.

Most differences are subtle; the main difference – and the one that will dictate the cost of the panel – is the amount of power the solar module is capable of producing at any one time.

How do you know which module is right for you? 

Ultimately it comes down to the amount of space you have available on your roof or on the ground. If you are not short of space, and your limiting factor is the amount of solar energy you can consume at the point of generation, then you might opt for a panel with standard efficiency – c. 20%. If, however, space is your limiting factor, you might wish to consider a solar panel that has a higher efficiency rate.  Bear in mind however that the most efficient panels on the market today are over double the cost of standard panels.

Variable 4 -


To optimise or not to optimise…..that is the question.

Like solar panels, there are many different types of inverter, and the differences between inverter are subtle.

The main difference with inverter technology comes down to system optimisation. To decide whether or not you should optimise, and pay the premium that comes with it, you must first understand a little about how a solar array performs. Most solar arrays group their panels together in ‘strings’ of c.24. This arrangement means that each solar panel in a string can only perform to the level of the lowest performing panel. In real terms, this means that even a small amount of shading on a panel has the potential to dramatically reduce the output of the system over time.

By adding optimisers to the back of the panels, each panel is able to operate independently; shading will therefore only affect the panel that is shaded. Bear in mind that choosing to optimise your array will increase the cost of the system and introduce additional potential points of failure.


Having operated In the commercial sector for over 10 years BeBa energy have the knowledge and experience to analyse all of the critical variables before suggesting the appropriate system specification.

Call us today to see how your business can benefit from solar power.