The most efficient solar panels on the market today function at about 22-30% efficiency.
That means, out of the 100% potential energy from the sun that lands into a solar panel, only 30% of that power gets converted into electricity.
But things may soon change.
With solar innovations getting launched one after the other, these biggest breakthroughs in conversion efficiency are solar, so good.
Where the Limits Exist?
How efficient are solar panels commercially available today?
In reality, anything over 20% is brilliant. However, the average efficiency rating of many conventionally produced solar panels is just hitting a range of 15-19%.
Why do solar panels reach only one-third of their full potential? Three factors have been scientifically proven to reduce solar panel efficiency: energy waste, excessive heat and the limited types of solar panel
Challenge #1: The Shockley-Quiesser Limit
Not all photons are created equal.
In 1961, physicists William Shockley and Joachim Quiesser calculated the maximum efficiency of a solar cell at 33.7% and why that limit? It has to do with the sun’s wide spectrum of photons.
Meaning, not all photons the sun emits are capable of exciting Silicon electrons.
In fact, 20% of the sunlight that falls on a solar cell does not contain the required 1.1 electron volts to knock loose an electron and create electricity.
While some are too energetic. So most of the photons that a solar panel absorbs get lost in transmission which results in wasted energy.
Promising Innovation: Carbon Nanotubes and Multi-junction Solar Cell
NovaSolix is growing carbon nanotubes to harness a broader range of energy from the sun’s full spectrum and convert that into electricity.
Using a rectifying antenna, this raises the conversion efficiency to 90%.
Meanwhile, the U.S. Department of Energy (DOE) and Spectrolab have also announced that they have produced a “multi-junction solar cell” that can also capture more energy from a greater portion of the sunlight’s electromagnetic spectrum.
These new highly efficient units are superior to conventional silicon cells with a 40.7% conversion efficiency.
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Challenge # 2: Excessive Heat
Fact: Solar panels work in cold weather.
In Alaska, where the average high temperature is 70 °F and the average low is 0 °F, solar panels have been deployed to cut on fuel costs for generators and lower down electric bills.
It might be news to many, but solar panels work fine, whether in colder climates or cloudy skies.
On the contrary, solar panels may reach temperatures of 60 degrees on any given sunny day which can decrease energy output from 12 to 16 percent.
As research shows, excessive heat is the real culprit in reducing solar panel efficiency.
Promising Innovation: A Solar Panel that has its own Cooling System
Researchers from the Brunei University in London are developing a tubing system that can be integrated into the Photovoltaic Cells. The goal is to innovate on the feature of self-cooling to dramatically increase the electrical output of the cells.
Keep Reading: Pros and Cons of Solar Energy
Challenge # 3: Limited Type of Solar Panels
How efficient are solar panels in terms of the technology used?
Common types of solar panels are limited into three technologies: Monocrystalline solar panels, Polycrystalline solar panels and Thin-film solar panels.
Monocrystalline Solar Panels deliver the highest efficiency rate of more than 20% since solar cells have been manufactured from the purest silicon. However, this also the most expensive panel.
Polycrystalline Solar Panels are manufactured from melted fragments of silicon which give solar panels an efficiency rate of less than 20. But this lowers the cost of solar panels.
Thin Film Solar Panels are less efficient than Monocrystalline solar panels since these are manufactured using cheaper photovoltaic substances as cadmium telluride, copper indium gallium diselenide, and amorphous thin-film silicon.
Moreover, their lightweight and flexible bases are ideal for portable solar panels. The efficiency rate however fluctuates from 15 to 22%.
Promising Innovation: Perovskites
To compromise on cost, flexibility and efficiency, scientists are looking at another category of compounds as alternative solar cell material, like Perovskites.
A study backed by the U.S. Department, the National Science Foundation and the Skolkovo Institute of Science and Technology among others is trying to make Perovskite a viable technology to commercialize solar panels with increased efficiency.
How efficient are solar panels going to be?
Currently, the highest rated solar panel efficiency of 30% is tested at standard test conditions and everyone knows that’s not enough.
In a market that is getting more and more competitive, the world needs less expensive yet more efficient solar panels that can survive extreme conditions. How far along is that? Nobody knows for fure.
But change is just like the sun, it may halt for a time but it’s not going away. Change is coming.