Photovoltaic Research Hopes to Overcome Key Challenges From Cost to Durability
The push for greener technology, namely solar, has led researchers to investigate cheaper, more efficient, and durable photovoltaic (PV) technology; however, there are still many challenges to overcome.
Recently, there has been a surge in the development of photovoltaic technology, fueled by the need for cleaner and cheaper energy sources.
A high-level representation of a PV system. Image used courtesy of the FSEC Energy Research Center
Photovoltaic technology-related developments are essential for solving some common challenges with solar panels, including instability and degradation, power conversion efficiency, durability, and manufacturing costs.
This article aims to explore these challenges and some recent studies seeking to solve them.
The Need for Newer and Higher Performing PVs
Photovoltaic technology has evolved since its invention at Bells Laboratories in 1954.
From a total global solar power capacity of 1 megawatt in the 1980s, the technology has experienced exponential growth to hundreds of gigawatts, with a corresponding cost reduction. The excessive emission of CO2 and other greenhouse gases into the atmosphere is a key reason for continuous research into cleaner energy sources.
Unlike hydrocarbon energy sources, PV technology could efficiently meet the growing demand for cleaner and environmentally sustainable energy.
Many countries, including the US, plan to switch from conventional electrical grid-based power supply to solar power. However, there must be a concerted effort in PV technology-based development, innovation, installation, and policies to achieve this unprecedented feat.
For example, engineers can significantly minimize material requirements and fabrication costs by opting for thin-film materials.
Key Challenges of the PV Industry
Photovoltaics offer several benefits to modern-day residential and commercial applications, including:
- Low installation and maintenance costs
- Noise and air pollution-free
- Minimized dependence on non-renewable natural resources
- High return on investment
- Reduced greenhouse gas emissions
Common problems with photovoltaics, particularly solar panels, include:
- Potential induced degradation (PID) effect
- Snail trails
- Electrical issues
- Roof issues
- Inverter faults
- Hot spots
- Delamination and internal corrosion
Along the lines of PID, the voltage difference between earthing and the solar panel can be a typical cause. Since PID causes the primary power circuit to produce partial voltage discharge, it can adversely affect solar panel efficiency, performance, and lifespan.
Similarly, micro-cracks, which are tiny and visually unnoticeable solar panel cracks, can pose significant problems to the photovoltaic system functionality. Although these cracks seem harmless at first glance, they can expand over time to cause irreparable damage.
Moreover, snail trail contamination, resulting from micro-cracks and defective silver pastes, is a common cause of solar panel performance-related issues and failure.
Faulty wiring, oxidation, loose connections, and wire corrosion are some electrical issues that can affect the efficient production of electricity in photovoltaic systems.
A rule of thumb to avoid these issues includes employing the services of a licensed electrician for installation and maintenance purposes. Just like electrical issues, professionals must supervise the installation of solar panels to minimize and eliminate any roof-related challenges that may occur.
Additionally, seemingly harmless birds can nest beneath solar panels and cause avoidable damage. Thus, extra measures must be put in place to avoid this situation.
Aside from solar panels, inverters can generate faults that can adversely affect the efficiency of the entire photovoltaic system. Inverters convert solar-generated direct current (DC) to alternating current (AC) for various residential and commercial applications.
Like every other electrical appliance, inverters are susceptible to wear and tear. Consequently, while engineers are trying to improve the functionalities of solar panels, they must also consider the durability of inverters to achieve higher efficiencies and durability in photovoltaic systems.
Eliminating Shorter Operational Lifetime in Photovoltaic Cells
In addition to continuously improving existing photovoltaic technologies, researchers are developing newer ones to meet the growing demand for high efficiency, low cost, and high operational lifetime.
A University of Michigan-based research team recently published one such study where they identified the need for organic photovoltaic (OPVs) cells with a longer operational lifetime.
By switching from fullerene acceptors to physically modified non-fullerene acceptors (NFA), the team maintained a high efficiency of 80% in OPVs while extending their intrinsic lifetime to over 5.6 x 104 h, which is equivalent to 30 years.
Cross-section of a physically modified OPV. Image used courtesy of Kan Dang and the University of Michigan
Although NFAs are typically highly efficient, their weak bonds cause photovoltaic cell degradation when exposed to UV (ultraviolet) rays from sunlight.
Consequently, the team studied this sun-induced degradation and physically modified the cells by incorporating several protective layers into their design, including sun-blocking zinc oxide, carbon-based IC-SAM, and a 2 nm-thick C70 layer.
After further tests on these improvements, the team discovered that the OPVs exhibit high efficiencies at a longer extrapolated operational lifetime.
A Cost-effective, Efficient, and Thermally Stable Perovskite Solar Cell
A team of researchers at the University of Queensland recently published another notable study on photovoltaic technology performance improvements.
A cesium-doped perovskite solar cells. Image used courtesy of the University of Queensland
Professor Shapter, the team lead, noted achieving efficient, stable, and low-cost replacement of conventional silicon-based photovoltaic cells as a key objective of their research.
According to the study, perovskite solar cells (PSCs) can achieve higher efficiency and thermal stability than silicon-based cells when doped in cesium (Cs), a nanomaterial modification alkali metal.
The researchers reported exceptional results in PV technology, with improvements in solar cell efficiency, thermal stability, and cost.
All in all, as the push for greener and more energy-efficient technology starts to take precedence, researchers like those mentioned, are working on taking PV technology to the next level. With this focus in mind, more and better PV technology is sure to start trickling down the pipeline.
Featured image used courtesy of the University of Michigan
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