Bifacial solar panels, possessing that added advantage

Gazing at the impending trend of bifacial solar panel, as a replacement for the existing traditional and conventional solar panels, the solar industry feels, it’s time for India’s transference into a self-sufficient solar country, by not completely generating power from coal and fossil fuels.

Bifacial solar is gaining the momentum among the solar industry. Since the solar industry is seeking to get more production from the solar technology, there is an inclination on having a bifacial solar as the bifacial cells allows the panel to generate power, from the sun light from both the sides, unlike the traditional panels, that absorbs powers only from the top of the panel that is more exposed to the sunlight. The bifacial cells let you preserve an additional 5 per cent to 15 per cent of the energy generated throughout the day.

Rating: Bifacial vs mono-facial panels
When it comes to rating the two panels, N. Yuvaraj Dinesh Babu, Senior Advisor, EY India, is of the opinion that bifacial panels are better than the mono-facial panels. He says, “Any new technology associated with increased efficiency and economical power generation will be a boon in solar sector. Deployment of bifacial panels on a large scale basis is already happening in USA, Europe and Middle East. Believe India has some projects too but not of large scale yet.”

One the same view, Siddharth Gangal, CEO, The Solar Labs, says, “Since the traditional solar panels can absorb light only from one side, the can be no absolute comparison of the existing conventional panels with bifacial solar modules. Moreover, to create a solar panel these solar modules are placed together in a periodic array.” The amount of electricity generated depends on the sunlight absorbed which in turn depends on the number of photovoltaic cells. With more number of photo voltaic cells more sunlight can be absorbed and hence a greater amount of electricity can be generated.

Avishai Drori, CEO, SolAround Solar is a bifacial supporter. He says, “We believe bifacial modules are a much more potent industry development accelerator since they provide much higher energy density and essentially produce more energy per square meter installed, making the cost of energy cheaper.”

In the purview of the increasing popularity of bifacial solar modules, Ivan Saha, BU Head of Manufacturing & CTO, Vikram Solar opines about the need to evolve the technology to harvest the solar energy, if we really want to replace the conventional fossil fuel based energy by bifacial solar panels in the near future”.

The determiners
The Bid of Materials (BOM) for bifacial installations is considered today higher than that of the mono-facial systems due to required adjustments, but, these price differences will zero down once bifacial technologies become mainstream. However, the comparison between the two is not straight and is based on various factors.

Energy efficiency
Envisioning bifacial solar panels as a one of the important aspects in the near future, Drori says, “Bifacial modules generate 10-30 per cent more energy than regular (mono-facial) modules once properly installed. It possesses additional advantages in grid balancing and extreme weather conditions such as snow and desert environments where their energy gain can be even higher.”

Gangal talks about how bifacial module manufacturers claims that if these bifacial panels are installed on a highly reflective surface, they can increase the power generation up to 30 per cent, because of the extra power generated from the rear. However, Gangal also points out that comparing the two doesn’t really cater to the cause at large, because of their varied absorbing and functional patterns. He says, “Traditional solar cells, because of the junction, have limited efficiency. Conventional solar panels are estimated to reach up to 33-34 per cent, but rarely any commercially available current solar panel achieve this.” Additionally, traditional solar panels can only capture sunlight from one side of the panel. This means that the efficiency is also determined by the solar panel positioning, which decides how much sunlight is absorbed throughout the day.

However, terming bifacial modules as a disruption in the Indian solar industry, Sunil Rathi, Director, Waaree Energies, says “The bifacial modules are equipped to absorb solar energy from both sides. The generated output from such modules, is up to 30 per cent more efficient than traditional mono-facial modules. In traditional modules, the reflected light from the ground leads to an increase in the internal temperature of the module.”

Furthermore, “Maximising energy efficiency significantly contributes to reaching climate change targets and achieving environmental sustainability. This is now of paramount importance considering population growth is expected reach nearly 10 billion by 2050, and India’s population is due to surpass China’s, Drori added.

Adding to the output and preserving capacity, Saha says, “The bifacial PV module offers greater energy output (approximately 10-25 per cent) when compared to conventional mono-facial PV modules (whether mono or poly crystalline) due to its ability to harvest sun’s energy on its front as well as its backside. All it needs is a subtle tilt of the installation adjustment and a reflective surface (like snow, desert etc.).”

However, Yuvaraj Babu, views the apparent shift, a quite differently. He says, “Since the new technical energy models haven’t yet incorporated the required essential parameters like Albedo – the measure of ground reflectance, for bifacial panels, which would comprehend with the Indian conditions. Albedo among other essential parameters, have a significant effect, while analysing the performance of a bifacial panel, in terms of the mono-facial panels.”

Furthermore, “Maximising energy efficiency significantly contributes to reaching climate change targets and achieving environmental sustainability. This is now of paramount importance considering population growth is expected reach nearly 10 billion by 2050, and India’s population is due to surpass China’s, Drori added.

Cost benefit
There is also a notable cost benefit in the case of bifacial modules, as they utilise glass, which costs 20-30 per cent cheaper than the transparent sheets used in the traditional modules. Lastly, taking into account the topographical diversity, as well as the variety in climatic conditions, Rathi says that it is imperative to create maximised output in limited spaces. The module is apt for both commercial and residential projects, especially when space allocation is a challenge. Thus, bifacial modules are touted to be the future of the solar industry, and are significantly better and more efficient than traditional modules.

It is a notion that installers normally prefer traditional modules to bifacial modules for ground mounted installations because bifacial modules require a higher tilt angle. Gangal says “As the cost of the module mounting structure drives up, the number becomes quite significant in installations of 100 MW. Project cost increases significantly with a small increase in individual MMS cost. As of now, traditional modules appear to be cost effective for large ground mounted installations compared to bifacial.”

The in-design
In contrast to traditional cells, which use polycrystalline materials, most bifacial solar panels use mono-crystalline cells. Alongside the clear light pathway on both sides of the panel, the mono-crystalline material enables the light to be absorbed from either side of the cell, and it is expected that the overall efficiency of the mono-crystalline cells can be up to 30 per cent, which is greater in commercial applications. The exact amount is unpredictable and variable depending on the surface that they are installed on. Most of the solar light is absorbed by the front side of the solar panel whereas rear side are capable of absorbing between 5-90 per cent of the light absorbed by the front of the solar panel.

Setting-up an ideal pricing
Setting up a model cost for a bifacial module, is quite a task, because, bifacial modules claim an increase of up to 30 per cent power in comparison to traditional modules but not guarantee an exact percentage. Noting the hidden difference which may someday create financial imbalance if not addressed, Gangal insists on balancing the high initial cost of bifacial modules, increasing the amount of preserved power is highly recommended. He further adds, “Bifacial modules are not recommended for flush-mount systems, because then there is not enough room to reflect light onto the backside. Even with a light-coloured roof, there still isn’t room for reflection. The demand for bifacial modules is quite limited in comparison to traditional modules.”

Drori is of the opinion that the working pattern of bifacial is highly advanced and costly, in terms of traditional PERC panels, and hence the overall economics, considering the performance and O&M aspects must be established in India.

Are bifacials here to stay?
While discussing the future in India, Yuvaraj Babu highlights, “I strongly believe the market will soon turn towards bifacial panels. At the same time the traditional panels will have its own market given the varied site conditions in India and especially in the rooftop solar sector.” A clear winner between the two in the present scenario is difficult to be predicted but future of bifacial modules seems to be bright.

The traditional panels will have its own market given the varied site conditions in India and especially in the rooftop solar sector.
N. Yuvaraj Dinesh Babu, Senior Advisor, EY India

Bifacial modules are a mush potent industry development accelerator
Avishai Drori, CEO. SolAround Solar

The bifacial PV module harvest sun’s energy on its front as well as its backside and offers greater energy output than conventional mono-facial PV modules
Ivan saha, BU Head of manufacturing & CTO, Vikram Solar

Bifacial modules utilise glass, which is 20-30 per cent cheaper than the transparent sheets used in the traditional modules
Sunil Rathi, Director, Waaree Energies

The demand for bifacila modules is quite limited in comparison to traditional modules.
Sidharth Gangal, CEO, The SolarLabs