Bifacial vs HJT Solar Panels - A Complete Comparison for Indian Conditions

Solar technology has changed significantly, and the people who are building homes and businesses today have a very important choice to make when it comes to investing in renewable energy: whether to invest in bifacial or heterojunction (HJT) solar panels. Both technologies are important improvements in comparison to the traditional monocrystalline and polycrystalline panels, and they perform well in various conditions with a different financial implication. It is important to know the difference between them in order to maximize your solar investment, especially in the Indian climate.

What Are Bifacial Solar Panels?

Bifacial solar panels are a revolutionary technology that focuses the sunlight on the front and the back of the module. Whereas conventional mono-facial panels absorb light on the front side only, the bifacial panels make use of the reflected light of the surrounding surfaces, be it white gravel, sand, concrete or even snow. This is a two-sided energy capture system that makes them more efficient at about 22 percent in comparison to 18-20 percent in conventional panels. Bifacial panels cost approximately 28 per watt in India, which is fairly high end relative to ordinary panels.
​
The actual benefit of bifacial technology is seen in certain environmental conditions. The bifacial panels have been demonstrated to have 15-20 percent better energy yields than the monofacial counterparts in studies in Indian states such as Rajasthan and Gujarat which have sandy soils with high light-reflective characteristics (high albedo). Bifacial technology is especially appealing to ground-mounted systems and solar farms where the ground surface is free to be covered with light-colored materials.

Understanding HJT (Heterojunction) Solar Panels

HJT technology is a hybrid technology, crystalline silicon is used together with the thin-film technology to develop high levels of efficiency. HJT panels today provide 24-25 conversion efficiencies (research grade cells make 27). This increased efficiency is due to their distinctive structure: HJT cells employ a thin film of hydrogenated amorphous silicon to passivate the crystalline silicon substrate to minimize electron-hole recombination losses that afflict conventional cells by a large factor.
​
The difference in HJT is their high bifaciality rate of more than 95 percent versus the 70-85 percent of bifacial. It is possible to say that, even in a typical installation, HJT panels are able to produce meaningful electricity on their back side. Also, HJT panels have a better temperature coefficients (approximately -0.26%/C) and hence are more efficient in hot climates in India which experiences temperatures in excess of 40 C on a regular basis. They also exhibit very low degradation rates of only 0.5 per cent per year, as compared to 1- 2 per cent per year of traditional panels.

Read More: Topcon Vs Bifacial Solar Panels

Direct Comparison: Which Suits Indian Conditions Better?

HJT panels have been shown to be more efficient than bifacial panels in most cases. The 24-25 efficiency of HJT compared to the 22 of bifacial is a significant benefit. But efficiency is not the sole factor that can be used to come up with the optimal decision to Indian installations.​

In high-albedo states such as Rajasthan, Gujarat, and Telangana, which have a sandy soil and a dust-reflective surface, bifacial panels may produce 10-30 percent higher energy than the usual panels because of the ground reflection, which may reduce the efficiency advantage of HJT. Bifacial panels would be of more cost-to-benefit in these areas because they are cheaper and still able to trap a lot of reflected light.​

However, in urban rooftop applications in metros such as Delhi, Mumbai and Bangalore, where the ground reflection is low, HJT panels can offset their higher cost by being more base efficient and showing outstanding performance under diffused light conditions, which is the main issue in India during the monsoon season. The high temperature coefficient of HJT also implies that it does not lose efficiency during the hottest seasons of the year.

Also Read: Which solar technology will be the best in 2026? HJT vs TOPCon 

Degradation and Longevity

One of the factors that are not well considered but are critical is long-term reliability. The degradation rate of HJT panels is only 1% during the first year and then it decreases to 0.35 percent per annum. This guarantees your system 90 percent of the rated capacity after 15-20 years. Bifacial panels are very strong, but generally exhibit a higher degradation rate. In installations with 25-30 years, HJT has a higher stability, which will result in much more cumulative energy generation.

Bifacial panels are priced around 28 rupees per watt whereas HJT panels are priced at a higher price, which is usually 30-35 rupees per watt. Nevertheless, HJT has higher efficiency and reduced degradation which can lead to higher ROI in the long run, especially in low-albedo urban environments. Bifacial panels have advantages of good performance in situations where ground reflection is preferred, and thus they are most suitable in commercial solar farms that have optimized ground cover.

There is no universal superiority of technology. Use bifacial panels when setting up a ground-mounted system in sandy areas where the reflection of light is high. Choose HJT panels when you are installing a rooftop system in a city or a place that may have suboptimal surface reflection because their increased base efficiency and greater operation in a mixed light environment will provide better returns throughout the lifetime of the panel. This is an investment decision you should consider in regard to your particular geographic location, type of installation, and long-term energy objectives.