The growing popularity of bifacial solar photovoltaic (PV) modules is changing the solar industry and more than ever, home owners who are interested in going green are keen to understand the benefits of bifacial PVs over traditional ones. Key players such as LG Solar, Longi and Canadian Solar have already started to manufacture these PV modules on a large scale in preparation for this next wave of solar panel technology. In this article, we will explain the technology behind bifacial PV modules and the pros / cons of installing these systems.
Bifacial solar panels are almost the same as normal ones, except for a few but significant structural differences that make them unique and beneficial at the same time. As you already know, sunlight strikes only one side of traditional solar panels. This is because the back is covered by an opaque sheet. Hence, they produce power using only the front side. This is where bifacial solar panels differ. Bifacial solar panels have their backs covered with either a transparent sheet or a have a double glass panel. This makes reflection possible, hence, there is energy production from both sides, increasing the total power output by as much as 40% under optimal conditions.
The higher that a bifacial module is tilted, the more power it produces because reflected light can reach the backside of the cells. Bifacial modules work the best on flat commercial rooftops and ground-mounted arrays because of the amount of reflected light and the availability of space for tilting the modules.
For normal households where roof space can be limited, the higher output of these modules means that less space is required to achieve the desired generation over the traditional monofacial ones. However, obstacles behind and around the bifacial panels and dark bitumen roof membranes will reduce the amount of light being reflected to the backside of these panels effectively reducing their additional power generation which these panels are designed to achieve. The supplier of these panels should be able to use computer aided layout & design tools with 3D shade analysis to ensure that homeowners interested in investing in bifacial modules can evaluate the benefits of this technology.
Bifacial modules so far are more expensive compared to traditional PV modules per Watt peak installed but we can expect prices to fall as the technology becomes more mainstream. One main disadvantage of bifacial PV modules is that the peak system power size declared to the local Regulator is the nominal power of the module without the additional power of the modules expected from the to reflection. This means that the feed in tariff which is based on a capping of 1600kWh per kWp installed does not apply for the additional power generated by the system due to reflection. This additional energy is therefore sold to the grid at €0.0725 instead of the applicable feed in tariff. Owners who on the other hand select own consumption or invest in battery storage will however gain more from the additional energy generated.
To sum up, solar energy is becoming one of the cheapest and most efficient ways to produce power. It is the most practical way of power generation that can happen at a residential scale. Bifacial solar panels are a great way of boosting the benefits from solar but they are suitable for everyone. Call us on 20102121 today for a free consultation today so that we can assist you in deciding which technology works best for you.