Your full guide to Solar Panels

19th Jan, 2026

The solar panels mounted on your roof are the beating heart of the solar system on your home or business. With so many manufacturers and models out there it can be daunting to know whether you are getting the right panel for your property.

Hopefully in this guide we will be able to answer some of the questions which you might have about panels and give you some examples of our favourites that we are installing currently.

How panels have developed

Panels have come along way since we started installing back in 2014. When we first started the average panel rating was around 250W. We are now installing 470W panels and this keeps rising incrementally as technology advances.

Its not only the rating of the panels that have moved on but the aesthetic too. You rarely see any new installations using silver frames and blue cells anymore (polycrystalline). Panels are predominately black frame, black back sheet and black cells (monocrystalline).

Types of Solar Panels

The two main types of solar panels used in the UK are monocrystalline and polycrystalline.

Polycrystalline

These panels are made by melting multiple silicon crystals together which gives the panels a slightly blue tint. These panels are generally cheaper but less efficient.

Monocrystalline

Monocrystalline are the most used panels on roofs today. These panels are made with single crystal silicon which gives them a solid black darker look. These panels are more efficient with a rating of 17%-24%.

Stringing

Panels are mounted on your roof. Which fixing system we used depends on if your roof is pitched or flat and what type of roof covering you have. To find out more about this check out our article on Fixings Systems.

Panels are divided into strings. A string is a set of panels which are traditionally connected into one another in series with two dc cables (a positive and a negative) running into the inverter. Strings are organised based on a few factors.

Orientation: Panels on the same roof pitch with the same orientation and access to light are grouped together in strings. Systems with multiple roofs will be split into multiple strings.
Number of Panels: Using inverter manufacturers guide lines the number of panels per string will be chosen to best suit your layout and make sure your system is performing at its best.
Panel Size: Different panels have different voltages which can affect how many panels you put in a string.
Shading: If a string of panels is affected by shade during parts of the day by surrounding obstructions getting the right string configuration is key to boost the performance of your system. Optimisers can also be used which helps panels deal with shading. Learn more about Optimisers here.

Your specific layout will depend on how your solar system will be strung. The team at Helios will do all of this during the design phase of your solar installation. With over a decade of experience there is nothing we haven’t come across before and we can advise you on the best fit for your property.

Check Out our go to panel we are installing at the moment:

Aiko Neostar 2S 470W N-Type ABC, 54 Cell, Mono Glass All Black, Gen 2