PV Technology
THE DIFFERENT TYPES OF MODULES & CELLS
Not all PV Panels are
created equal!
Your choice of photovoltaic panels will have an impact on the ongoing performance and annual output of your PV System. With a wide selection of panels available on the market, varying in quality and performance just as much as they do in price, choosing your panels can be daunting. There are a lot of factors to consider when specifying a technology such as roof orientation, roof pitch, available area, budget, your desired annual yield, phew, the list goes on.
But don't panic - we can help. We regularly review and assess new products on the market, we listen to your requirements and preferences and we advise on a suitable technology to ensure that you have the right product on your roof.
Comparing photovoltaic technologies
Solar PV panels are manufactured using one of four different types of photovoltaic technologies: Hybrid, Monocrystalline, Polycrystalline and Amorphous. Each technology has different characteristics but they all work by converting light into electricity (read more about how photovoltaics work). There are three main factors to consider when specifying a solar pv panel: how it performs in all light conditions, how much area is required and of course, cost.
The performance of a pv panel is measured in kilowatt hours per kilowatt peak (kWh/kWp), which translates as the number of electrical units of energy (kWh) the panel will produce at maximum output (kWp), or in other words during the brightest sunlight. While this is a good measure of performance, it isn't the full story. Each technology performs differently in certain light conditions and considering our UK climate, overall performance becomes a significant factor.
Graph illustrating comparitive outputs of typical pv technologies based on amount of solar radiation
The rated performance of a photovoltaic technology at full output does not necessarily reflect it's performance in less favourable light conditions. Hybrid technology is the best all round performer and will generate more elelctricity in lower light conditions than other technologies. Monocrystalline and Polycrystalline panels have a mid-range performance and are the most common type of photovoltaic panels. Amorphous technology, a flexible technology also known as Thin Film, is the least efficient technology requiring a significantly larger area than the other photovoltaic technologies.
The amount of space you have available for pv panels can also influence which type of technology you choose. More efficent panels generate more power per square metre than less efficient panels - ideal when your roof is small or partially shaded. The efficency of each technology can be measured by the maximum output per square metre area of photovoltaic cells.
Figures are based on a typical panel size for each technology. PV Systems are modular so can be any size or shape.
The four photovoltaic technologies
There are four main photovoltaic technologies to choose from and each one has different characteristics. We can advise you on which technology is right for your roof and we'll assess the economic payback period so you can evaluate the cost of each technology yourself.
Hybrid modules contain a layer of both amorphous and crystalline cells providing best all round performance. Although more expensive, they provide much better output per m2. This is particularly useful when the roof is limited. Compared to other technologies, Hybrid PV Panels will generate more kilowatt hours (electrical units) per year so you will benefit from additional FIT or ROC payments, reducing the payback period of your system and putting you in profit sooner.
Hybrid Photovoltaic Panels
Cottage, Pembrokeshire
Monocrystalline photovoltaic cells are cut from a single crystal of silicon and are generally considered to be the workhorses of the PV market due to their high efficiency and dependability. They can be distinguished by their uniform appearance and are usually dark blue or black in colour.
Monocrystalline Photovoltaic Panels
Two storey house, Bristol
Polycrystalline cells are cut from multifaceted crystalline silicon and are distinguishable by their crystal-like appearance. Polycrystalline panels provide slightly lower annual output than monocrystalline panels, but they are in turn slightly less expensive.
Polycrystalline Photovoltaic Panels
School, Belfast
Amorphous PV, also known as Thin Film is made entirely differently from the crystalline modules and the annual output tends to be much lower. Amorphous panels, while having a good performance, have a low efficiency and require significantly more space to achieve the same comparitive output as other technologies. This also makes them expensive and generally unsuitable for most buildings. They are however, flexible so can be used in many more applications, such as shingles, curved roofs, bus shelters and portable solar panels.
Amorphous Photovoltaic Panels
Carport / Garage
