When most people think about renewable energy sources, they think about solar power first. After all, it’s the most popular source of alternative energy nowadays. But what is solar energy, and why does it matter? Let’s explore…
Solar Energy Explained
When we think about solar power, we usually think about solar cells, which convert sunlight directly into electricity. But that’s not all there is to it. When most people think about solar energy, they think about the Sun. But that’s not the only thing that makes solar power unique. When the Sun shines on a solar cell, it creates heat. The hotter it gets, the more electricity you can generate from it. But that’s not the case with all solar power. There are various ways to generate electricity using the sun’s rays even when it’s not directly shining on the solar cell. Let’s explore…
There are two main ways to harness the power of the Sun independently of one another:
- Photovoltaic solar cells (PV cells)
- Thermoelectric generators (TEGs)
Let’s explore each one in detail.
PV Cells & The Sun
PV cells and the Sun are pretty much synonymous nowadays when it comes to renewable energy. But that was not always the case. Remember: the PV cell was originally developed to protect military equipment from damage or destruction during a nuclear war. In a nutshell, PV cells harvest the Sun’s energy and convert it into electricity even when the Sun doesn’t shine directly on them. So basically, when the Sun does shine on them, they absorb the light (give or take a few nanometers) and create electricity.
PV cells can come in all shapes and forms, but they generally consist of a layer of plastic with very small (and preferably transparent) crystals placed on top. The plastic protects the crystals from breaking or chipping, and the tiny surface area of the individual crystals determines how much electricity they can generate. When sunlight is not available for long periods of time (like during a cloudy day), the crystals can become quite hot, which can lead to damage.
Since the invention of the PV cell, many materials and processes have been developed to make them more efficient and cheaper. As a result, we now have the ability to generate electricity from the Sun even when the Sun is not Shining directly on us. This largely explains the boom in popularity that the PV cell has seen nowadays.
But sometimes the Sun does shine directly on us, which provides us with the highest peak electricity generation rate. In that case, we either need to be located in a region with plenty of sunlight or need to install a solar panel to collect the Sun’s energy…
TEGs & The Earth’s Axis
Just like with most anything else in science, there is more than one way to generate electricity using the Sun’s power. For our purposes, let’s explore one of the basic ways, which is similar to the way that a solar panel works. In the Northern and Southern hemispheres, the Sun’s rays are typically not directly overhead, so even when the Sun is shining, it is not directly hitting the ground and therefore not directly impacting solar power generation.
To capture the maximum amount of energy from the Sun, we need to harness its rays in a way that takes advantage of the fact that the Earth is a rotating planet. As a result, in the Northern and Southern hemispheres, the Sun’s rays primarily fall on the northern and southern latitudes, respectively. And just like with a solar panel, these are the regions with the most electricity generation potential.
In addition to solar cells, which we’ve already discussed, TEGs directly convert heat into electricity without any additional components. TEGs generally consist of four materials:
- Thermoelectric material
- Peltier TECs (thermoelectric cooler)
- Heat sink
Just like with solar cells, materials science has advanced significantly since the days when TEGs were first invented. As a result, we have materials that are much more efficient at generating electricity than those original TEGs. But the basic design principle behind TEGs hasn’t changed. Essentially, when electricity is not generated fast enough to meet our needs, we use natural gas to fuel TEGs instead of the traditional fossil fuels such as oil and coal.
And just like with solar panels, gas-powered TEGs have a number of advantages. First, they are much more efficient at generating electricity than other forms of renewable energy. Second, the fuel is relatively inexpensive and available worldwide. Third, they are much more environmentally friendly than other traditional sources of energy.
All in all, TEGs are a great choice for those seeking renewable energy sources because of their efficiency, low price, and environmental friendliness.
But which option do we prefer? Although solar power generation is most often associated with clean energy, it is not the only option available to us. Even in areas where the Sun is shining, there are still clouds in the sky. And as we’ve discussed, the Sun is not always shining in a given region.
Therefore, when we are seeking clean energy, it is best to look at all the options available to us rather than just picking one. If we compare the cost of solar power generation to that of other renewable energy sources, we find that solar power is indeed quite a bit more expensive. But if we compare the cost of operating and maintaining a traditional energy source to that of solar power, then the cost of solar power becomes more favorable. This largely explains the boom in popularity that we’ve seen for solar power in recent years.
Choosing Your Energy Source
When choosing your energy source, you really have two options to choose from:
- Fossil fuels
- Renewable energy
If you value the ability to generate electricity quickly and also want your electricity to be clean, then you should go with renewable energy. Even if you live in an area where the Sun is shining all the time, you should still go with renewable energy because the ability to generate electricity quickly is not dependent on constant sunlight. As a result, even when the Sun is not shining, you can still generate electricity using renewable energy sources…
On the other hand, if you want your electricity to be cheaper than that produced by traditional energy sources, then you should go with fossil fuels. Even when the Sun is shining, traditional energy sources are more efficient at generating electricity and are therefore cheaper…
In both cases, make sure that your chosen energy source is truly renewable or sustainable. In some cases, what seems to be renewable may, in fact, be unsustainable. For example, sugar cane is often mistaken for a renewable energy source because it can be grown again and again. However, this type of plant is actually quite harmful to the environment. Another example is hydroelectric dams, which produce a lot of electricity but also kill countless amounts of fish and other aquatic life. Be mindful of the impact that your choice will have on the environment.