Global energy consumption is rising at an accelerated pace. In 2023, this growth was at the rate of 2.2%, compared to a 1.5% yearly average between 2010 and 2019.
This faster rate of energy consumption is primarily driven by China, which, at +6.6%, was twice its 2010-2019 average. Other contributors include India, Iran, Brazil, the UAE, Algeria, Vietnam, and Indonesia. In contrast, energy consumption declined in Japan, South Korea, South Africa, and the EU and remained stable in the US.
Overall, global energy consumption has increased by about a third since 2000. Currently estimated to be 580 million terajoules, this annual global energy consumption is further projected to reach 740 million terajoules by 2040.
However, the most concerning part is that the vast majority of this energy—83%—comes from fossil fuels, with oil being the biggest energy source, followed by coal and natural gas, which emit enormous amounts of CO2 into the atmosphere.
This calls for an urgent need to innovate in green energy. While renewable energy is expected to grow, this increase is a mere 4 percent, bringing it to 6% of global primary energy use.
So, against this backdrop of a global need to transform the energy system, solar energy has emerged as a potential game-changer. This is because the energy generated by the sun has the potential to power the entire world and more.
Earth needs only a couple of hours of solar energy to provide the entire world with the energy it needs for a full year.
It is also the cleanest and most abundant renewable energy source available. Moreover, it carries the advantage of decarbonizing, reducing energy costs, having a much lower environmental impact, and offering greater energy access and security.
Of course, there are several challenges associated with harnessing solar energy; otherwise, we would already be utilizing it extensively. Besides the primary challenge of solar intermittency, since the sun doesn’t shine all day, there are additional challenges related to location, storage solutions, and the technology required to harness this energy.
When it comes to harnessing solar energy, there are a few ways to capture solar radiation and convert it into energy.
One method is to use active solar energy, which involves using electrical or mechanical devices to convert solar energy into another form of energy actively. This is achieved through photovoltaics (PV) or Concentrated Solar Power (CSP).
In PV, sunlight is converted into electricity using semiconductor materials that exhibit the photovoltaic effect. PV technology is more commonly known as solar panels, which is a collection of solar cells, each containing a semiconductor that creates an electric current by absorbing sunlight.
In CSP, lenses and mirrors focus sunlight from a large area into a much smaller one to generate electricity. Solar furnaces, which include different types, including solar power towers and parabolic troughs, are an example of concentrated solar energy.
Another method is to use passive solar energy, which doesn’t use external devices but rather takes advantage of the local climate. For instance, designing a building to get desirable amounts of sunlight and constructing buildings with thermal insulation are examples of this method. Other examples of this method include cool roofs and green roofs.
However, this is not the end of techniques for utilizing solar energy. Given its vast potential, researchers are always exploring novel ways to capture solar power and convert it into useful energy, as well as to make it cost-effective and more efficient so that it can actually be useful in our daily lives.
Generating Solar Electricity From Phones & Cars
Researchers from Oxford University recently made an interesting development in the field of solar energy technology. Under this technology, solar electricity can be generated from the surfaces of cars and mobile phones.
Source: Oxford University
Yes, you heard it right: instead of installing lines and lines of silicon-based solar panels, one can generate increasing amounts of solar electricity simply through everyday objects.
This innovation is made possible by a new power-generating material coated on the surfaces of these objects. The light-absorbing material is thin and flexible enough to be applied to just about any surface. This revolutionary approach involves stacking several light-absorbing layers into a single solar cell.
For this, scientists from the Physics Department of Oxford University pioneered a technique that enabled them to harness a wider range of the light spectrum, generating more power from the same amount of sunlight.
The material, thin-film perovskite, has also been independently certified by the National Institute of Advanced Industrial Science and Technology (AIST) of Japan to deliver more than 27% energy efficiency. These numbers match the performance of silicon photovoltaics, which are traditional, single-layer, energy-generating materials.
According to the researchers, after just five years of experiments using the multi-junction or stacking approach, they have increased the power conversion efficiency by approximately 21%. This means that from an initial efficiency of around 6%, they can now convert over 22% of the energy from the sunlight.
With the material already reaching close to the limits of what today’s single-layer photovoltaics can accomplish, Dr Shuaifeng Hu, a Postdoc Fellow at Oxford, said:
“(Their technique) may enable the photovoltaic devices to achieve far greater efficiencies, exceeding 45% (in the future).”
Besides energy efficiency, the versatility of the material is another crucial factor. The material is ultra-thin, just over one micron (0.001mm) thick, which makes it nearly 150x thinner than a silicon wafer. Si wafers generally have a thickness between 0.5mm and 400 microns (0.4mm), while the 2 and 25 microns range is used for specific scientific purposes.
This thinness of the new material means it can be applied to not just any common object and buildings but essentially to almost any surface, as opposed to the existing photovoltaics.
By having the new materials used for coating, Dr Junke Wang, noted that:
“(They’ve) shown we can replicate and out-perform silicon whilst also gaining flexibility. This is important because it promises more solar power without the need for so many silicon-based panels or specially-built solar farms.”
This new approach is expected to make solar the most sustainable form of renewable energy and further reduce the cost, which has already fallen by as much as 90% over the last 14 years.
According to the World Economic Forum, in 2010, it cost a global average of $378 without any subsidies to generate a megawatt hour of electricity from solar photovoltaics, which came down to just $68 in 2019. Solar energy is now cheaper than coal and nuclear and almost as economically efficient as onshore wind. While wind energy has also seen a decrease in cost during this period, nuclear and coal have either increased or recorded a slight drop.
Now, innovations like thin-film perovskite promise additional cost savings by reducing the need for silicon panels and purpose-built solar farms.
According to the researchers, this latest innovation can become its very own industry to manufacture materials and generate solar energy cheaply and sustainably by using existing objects.
‘Artificial Leaf‘ to Produce Clean Fuel
Scientists are not only making it possible to generate solar electricity cheaply using everyday objects, but they are also rewiring photosynthesis and, in turn, revolutionizing how we generate clean fuels.
In 2019, researchers from the University of Cambridge set a new benchmark when they successfully had an artificial leaf creating syngas simply by using sunlight, carbon dioxide, and water.
Source: Cambridge University
Syngas is a gas made from fossil fuels, a mixture of hydrogen and carbon monoxide, and is used to create plastics, pharmaceuticals, fuels, and fertilizers. Since we are used to producing products that we consume every day, it’s crucial that we find ways to “produce it sustainably.“
So comes the artificial leaf, which is a carbon-neutral device powered by sunlight that does not release CO2 into the atmosphere. What’s more, despite running on sunlight, the artificial leaf still works efficiently on overcast and cloudy days.
Inspired by photosynthesis, a natural process by which plants use light energy from the sun to turn carbon dioxide and water into food, the researchers combined two light absorbers on the artificial leaf with a cobalt catalyst. When immersed in water, one of the absorbers produces oxygen with the help of the catalyst, while the other carries out the chemical reaction, reducing water and CO2 into hydrogen and carbon monoxide, which form syngas.
Because the light absorbers work even under low levels of sunlight, this technology can be used all day long and anywhere in the world.
While other artificial leaf devices have been developed, the Cambridge researchers noted that they only produce hydrogen, unlike their own device, which can produce syngas due to the combination of materials and catalysts they used.
The material used for the molecular catalyst was cobalt, which is lower-cost, abundant, and better at producing carbon monoxide than other catalysts like platinum or silver.
Meanwhile, their light absorbers were made from perovskite instead of silicon or dye-sensitized materials. Perovskite light absorbers provided a high photovoltage and electrical current to power the chemical reaction, which reduced CO2 to CO.
The next step after syngas is to develop a sustainable liquid fuel as a substitute for petrol. Instead of making syngas and then converting them into liquid fuel, the study aims to make the liquid fuel itself one step from carbon dioxide and water.
With electricity only able to satisfy a fraction of total global energy demand, synthetic petrol can be a vital development, said senior author Professor Erwin Reisner from the Chemistry Department at Cambridge, noting the “major demand for liquid fuels to power heavy transport, shipping, and aviation sustainably.”
Over the last few years, Reisner has been working with his group to develop a new artificial leaf that can immediately produce clean ethanol and propanol without first producing syngas. This has been achieved by developing a copper—and palladium-based catalyst.
The paper’s first author, Dr Motiar Rahaman, said:
“(Being able to) produce a practical liquid fuel just using the power of the Sun” (makes this) an exciting advance that opens up whole new avenues in our work.”
For now, the device is only a proof of concept. The researchers are working to optimize the leaves to better absorb sunlight, refine the catalyst to convert more sunlight into fuel, and ultimately make the device scalable to produce large volumes of fuel.
Professor Reisner was actually awarded a Royal Academy of Engineering Chair in Emerging Technologies earlier this year. The £2.5 million award will enable his team to enable the lab-to-market transition of solar chemical technologies.
While the Reisner team works on making its product scalable, Yimin Wu, an engineering professor at the University of Waterloo, released another paper around the same time as the Syngas research. This paper also created an ‘artificial leaf‘ that inexpensively converted harmful CO2 into a useful alternative fuel.
Again, inspired by the process of photosynthesis, the artificial leaf produced methanol and oxygen, unlike the natural lead, which produces glucose and oxygen.
The key ingredient here was cuprous oxide, an optimized red powder, which was designed to have particles with eight sides. It was the result of adding copper acetate, glucose, sodium dodecyl, and sulfate sodium hydroxide to water heated to a specific temperature.
When mixed with water and exposed to CO2, it acted as a trigger for another chemical reaction, producing oxygen and converting CO2 into methanol. A solar simulator was used to beam white light. As the solution was heated, the reaction collected methanol, which evaporated.
Quantum Dots to Create Double-Pane Solar Windows
Another development in this field has been quantum dots, which are small semiconducting particles in the 2-10 nanometer range. Their small size gives them unique electronic and optical properties, making them versatile.
In research at Los Alamos National Laboratory, quantum dots were embedded in window glass to generate electricity. These ‘designer‘ quantum dots absorb sunlight and convert it into energy without affecting the transparency of the windows.
This innovation essentially allows entire buildings to become solar energy generators without needing traditional solar panels, which are costly and take up a lot of space.
Source: Los Alamos National Laboratory
According to lead researcher Victor Klimov, quantum dot-based double-pane windows provide a novel approach to reducing cost thanks to the strong performance that can be achieved with these “low-cost, solution-processable materials.“
This new method does not replace current PV technology. Effective sunlight collectors are simply added to the existing solar panels. They can also be integrated as semi-transparent windows into a building’s architecture.
While current photovoltaic panels achieve an efficiency of around 25%, quantum dots offer the potential to surpass this by using carrier multiplication.
A typical photovoltaic solar panel absorbs one photon of light and releases one electron, which becomes energy. However, through carrier multiplication and incorporating magnetic manganese ions, quantum dot-based solar panels produce more than two electrons for each photon they absorb.
However, at the core of this technical advancement is “solar-spectrum splitting,“ which separates the processing of high- and lower-energy solar photons.
This was achieved by incorporating ions of manganese into quantum dots to serve as highly emissive impurities. When quantum dots absorb light, the impurities are activated, which leads to the manganese ions emitting light at energies below the absorption onset of quantum dots.
Now, to transform a window into a tandem luminescent sunlight collector, the researchers deposit a layer of quantum dots doped with highly emissive manganese onto the surface of the front glass pane. Meanwhile, a layer of quantum dots with copper indium selenide was deposited on the back pane’s surface.
This way, the front layer absorbs the visible blue and ultraviolet portions of the solar spectrum while the bottom layer picks up the rest. Once absorbed, the quantum dots re-emit photons at a longer wavelength. The re-emitted light is guided by total internal reflection to the window’s glass edges, where the integrated solar cells collect the light and convert it to electricity.
In addition, Klimov’s team is also exploring how quantum dots can be used to produce ammonia, which accounts for over 2% of global energy use. In this particular application, they are using quantum dots and sunlight to generate “free electrons“ instead of light via photoemission.
Now, let’s look at two major companies in the solar energy space.
#1. NextEra Energy
Known widely as a leader in renewable energy space, NextEra Energy posted a net income of $552 million and adjusted income of $865 million in Q2 2024.
They added 3GW to their renewable energy capacity, including significant solar developments, projecting an upward earnings trajectory through 2027 with expectations of adjusted earnings per share rising annually.
#2. First Solar
First Solar specializes in manufacturing solar panels and providing comprehensive photovoltaic power plant services. Their innovative use of thin-film semiconductor technology distinguishes them in the solar industry.
Financially, First Solar reported revenues of $3.56 billion and net income of $1.02 billion in the last fiscal year. Their focus on sustainable technology and international market expansion underlines their strategic position in the solar sector.
Conclusion
These latest innovations mark a big and important step forward in realizing the full potential of solar energy. Solar energy is a clean and renewable resource that offers a powerful alternative to fossil fuels, which pollute the environment.
With global energy demand expected to increase in the coming year and sustainable solar energy available in abundance, it is imperative to use this limitless source of clean energy. However, solar power currently accounts for a really low (single) percentage of total global electricity generation from all sources. This underscores the urgent need for continuous research, development, and collaboration between government and organizations to really drive solar energy usage forward and power the entire world.
Click here for a list of top solar power stocks.