The world is heavily reliant on fossil fuels and other energy sources that can be harmful and will only last so long. Solar power and hydroelectric power are two more promising alternatives, being abundant, renewable, and cleaner than the currently used methods of production.
Solar power is the conversion of sunlight into electricity using a medium like solar panels. Hydroelectric power is the production of energy using water in motion, generating electricity using a turbine to channel the energy of flowing water. They are both renewable and clean sources of energy.
In a growing world, the use of exhaustible resources like fossil fuels is an increasing worry. However, energy sources such as solar and hydroelectric power provide a solution, making it worth the time to read and learn more about them.
Solar and Hydroelectric Power
Put simply, solar power is the use of solar energy, the light, and heat from the sun, to generate power. To accomplish this, there are several methods, with the most common utilizing solar panels, with the end goal being the conversion of solar energy into electricity.
Hydroelectric power works on a similar principle of harnessing nature. Hydropower, the driving force behind electricity production with hydroelectric power, comes from the energy contained within moving or falling water. Hydroelectric power encompasses all methods of gathering said energy and converting it into electricity.
As stated above, both forms of production rely on the principle of harnessing nature. Because of this, they share a few characteristics that make them stand out from other energy production methods, namely that they are clean and renewable energy sources, able to be harnessed indefinitely.
Clean and Renewable Energy
Two of the most important factors for both solar and hydroelectric power are that they are clean and renewable. Considering how big a part these two traits play, what do they actually mean?
Clean energy, also known as sustainable energy in some cases, is any energy that is classified as an energy that can be used now without affecting the future. Essentially, it is energy with limited negative impact, including but not limited to:
- Environmental Impact
- Economic Impact
- Socio-Cultural Impact
Then there is renewable energy, a term often used interchangeably with clean energy. However, there is a difference. Renewable energy is an energy source that replenishes faster than it is consumed, without any requirements for sustainability. Therefore, while they are often associated, energy can be one without the other.
The incredible thing about solar and hydroelectric power is that they are both clean and renewable. Considering how important those traits are to the two types of power, it is a good idea to keep them in mind going forward.
Harnessing the Power of the Sun
It is hard to think of something more powerful than the sun, one of the things responsible for our very survival. However, the truth is actually even more astonishing. Each hour, the amount of solar energy that hits the Earth is around the amount needed to meet the entire world’s electricity needs for an entire year.
By the nature of its abundance, solar energy has the potential to sustain humanity, but it is not that simple. There are many factors to consider with solar power, including the technology required to convert the solar energy into electricity and the obstacles that must be navigated to make it widespread.
The Current State of Solar Power
Worldwide, solar power is doing better than ever, seeing rapid growth from the early 2000s. In fact, from 2010 to 2019, the use of solar power increased by over 40 times in the US, becoming a far more widely used source of power. However, despite those staggering numbers, it only makes up a small percentage of global power production.
In the US, solar power only accounts for around 3% of the total amount consumed. A few other countries that utilize large amounts of solar power are:
- China, with 3.9% of its electricity coming from solar power
- Germany, with 8.6% of its electricity coming from solar power
- Honduras, with 14.8% of its electricity coming from solar power
Clearly, the amount of energy needed impacts the percentages, but even looking worldwide, the total percentage of electricity produced by solar power comes out to around 3%. Why is that? In part, it is due to the methods and requirements involved in the production of solar power.
When people think about solar power, they are likely thinking about photovoltaic systems. In a photovoltaic system, light is converted directly into electricity using certain materials. Primarily, solar cells are used to capture and convert solar energy from sunlight without the need for further trouble, an example of which is solar panels.
Some examples of where you might find photovoltaic systems being utilized are:
- Floating on water
- Spacecrafts and satellites
- In large clearings (solar farms)
Photovoltaics is the conventional form of solar power, with two of the major forms of implementation being the use of residential homes and solar farms. For residential homes, solar panels are installed on the roof, where they begin to absorb solar energy and convert it into electricity that is either used directly or fed back into the power grid.
Solar farms are similar but on a much larger scale. With a solar farm, an area of land is cleared, and massive solar panels are installed, which serve the same function as residential panels. However, the panels for solar farms tend to be larger and more efficient, providing more energy for a lower price and at the cost of less total space.
Concentrated Solar Power
Concentrated solar power (CSP) is solar power generated through the use of mirrors and lenses, which concentrate sunlight into a single receiver. To do this, a large amount of space is required, and a complex setup of more complicated panels is needed. Additionally, it does not operate on the same principle as photovoltaics.
Concentrated solar power generates electricity through heat, not the conversion of sunlight. Ordinarily, this is accomplished using a steam turbine or another similar heat engine. The concentrated sunlight is fed into the receiver, converted into heat, and subsequently converted into electricity.
CSP’s benefits are substantial. Like photovoltaic solar power, CSP provides a great deal of electricity when the sun is out during the day. Combined with a tracking system, which allows it to absorb as much energy as possible throughout the day, it can display some incredible results. However, it can also continue producing energy at night.
Since CSP relies on heat and not the sunlight itself, it can use various methods to store heat during the day and continue using it as needed. Of course, CSP comes at a cost, which is that it is more expensive and often experiences more technical difficulties than photovoltaic systems.
Obstacles to Solar Power
Solar power is underutilized, or so it seems, but there are some big reasons that solar power is not as widespread as one might expect, especially in the US. Mainly, the costs and overall inefficiency of solar power keep it from growing even more rapidly.
- In the United States, one of the major obstacles is the power grid, which remains unchanged despite its long life. Because of this lack of change, the grid is not set up to handle renewable energy sources like solar power. Considering most solar power is fed directly into the grid after its creation, that poses a problem.
- Changing the power grid is not a cheap project, but neither is solar power in general. In fact, the average cost for a residential setup is anywhere from ten to thirty thousand dollars. While there are incentives, the price does not change drastically either way. The large-scale solar farms suffer from the same problem.
- Inefficiency is also a major problem, referring to the fact that most panels do not capture more than 20% or so of the solar energy hitting them. Therefore, more space is required to produce significant results, a definite problem when more panels mean more money and cost is already a big enough problem.
Solar Power’s Weaknesses
It is clear that solar power has many strengths, but a lot of what makes it great, such as the renewable component known as the sun and the high output in certain situations, also hold it back under certain circumstances. For instance, the fact that it is so reliant on the sun can be a problem.
The sun is only out during the day, meaning there is a limit to the amount of solar power that can be produced, even when using CSP and storing heat. However, the rise and fall of the sun do not prove to be the only detracting factors. Other factors also lessen the efficiency of an already inefficient method, including:
- Indirect Sunlight
While these factors do not negate solar power production, they do hurt it. Even with built-in sunlight trackers and increased efficiency, they will always be a problem. Plus, the amount of energy produced poses a problem, mainly with storage. After all, the US power grid does not store energy, and homes cannot do it either, not without a battery.
Solar Power’s Environmental Impact
Solar power is a clean, renewable energy source, but that does not mean that it is without any environmental impact. While the production of electricity using solar energy has little to no direct impact, there are factors involved that do. Among these, land requirements and the impacts of their initial creation stand out.
Solar power often uses a large amount of land, especially when utilizing solar farms, also known as solar power plants. The same is true for CSP, which relies on clearing out a large section of land and concentrating sunlight into one point, which must be unobstructed. Therefore, the ecosystem in the area is always impacted.
Another potential problem with CSP is the actual light that is being focused towards the receiver. While not directly harmful to the environment, the beams of light have been known to kill birds and other animals that come into contact with them, which could potentially disrupt migration, among other things.
Furthermore, while the generation of solar power has few impacts, the production of solar panels and the often necessary batteries do have some environmental impacts. The long-term environmental impact is greatly lessened when using solar power, but it is not eliminated altogether.
The future of solar power is limitless. Considering how much solar energy the sun gives off, there is a nearly inexhaustible source of energy and, by association, electricity. The overall growth of solar power depends on a few factors, however, including:
- Land availability
- Reduction in cost over time
- Increased efficiency and storage
Mostly, it boils down to how quickly technology grows. Efficiency, both in the amount of energy captured to the size of the panels, will impact both cost and how much land is needed. Additionally, battery technology and the integration of storage into the US grid will both impact how much solar power can be created and used.
However, in the immediate future, further growth seems inevitable. Countries worldwide are turning to renewable energy sources, and solar power is one of the fastest-growing. In fact, there are many who believe that solar power may account for over 10% of our total energy consumption a few decades down the line.
Harnessing the Power of Water
Few sources of power are as old as hydropower. While electricity is important now, with hydropower being turned into hydroelectric power, it has long been a part of humanity’s power solutions. An example of this is the water wheel, the origin point of the more complex modern process.
Around 71% of the Earth is composed of water, which gives a good idea of just how abundant a resource it is. In fact, it is a resource that is heavily utilized. However, to produce hydroelectric power, running or falling water is required, as are large installations and the technology that gets it going.
The Current State of Hydroelectric Power
Hydroelectric power is present in large-scale across the world. In the United States alone, it produces over 6% of the total energy consumed and stands near the top of renewable energy sources. It is a major source of power in other countries as well, with a few producing large amounts of hydroelectric power:
- China generates nearly 20% of its power using hydroelectricity
- Canada generates nearly 25% of its power using hydroelectricity
- Brazil generates over 60% of its power using hydroelectricity
While the world as a whole only produces around 17% of its energy from hydroelectricity, it is the most widespread renewable energy source around the world. Even in the United States, where the total percentage is lower, it accounts for a large portion of the overall renewable energy produced, at around one-third.
While the details of any setup or system differ, hydroelectric power is produced by a series of basic steps, which revolve around the utilization of water, turbines, and generators. The steps are:
- Water is fed towards a water turbine
- The power of the water turns the turbine, producing mechanical energy
- The turbine is connected to a generator, which turns that mechanical energy into electricity
From there, the water cycle takes care of the rest, ensuring that the supply of water does not run out and allowing hydroelectric power to be produced consistently.
Hydroelectric dams are the largest contributors to hydroelectric power, particularly in the US. A hydroelectric dam works by storing a large amount of water behind it and releasing the water as needed. It produces hydroelectric power by utilizing that process, taking advantage of the discharge process.
The specifics are quite similar to the basic principle, where the water being discharged flows through a spillway and is fed into a water turbine, which proceeds to turn the power of the quick-moving water into mechanical energy. Then, it comes down to the generator converting that to electricity.
For a hydroelectric dam, the biggest factors for the amount of power produced are the size of the dam and the amount of water present. The larger a dam, the more room it has to “drop” the water, increasing the power behind it and increasing the total hydroelectric power output.
While no longer as popular a choice, pumped storage is another type of hydroelectric power production. Pumped storage works by pumping water into a storage reservoir at a higher elevation during times of low electricity demand, such as at night. It is then saved for times of higher demand.
When demand is higher, the water flows downhill from the reservoir, utilizing hydroelectric generators at a dam to produce electricity. The two types of pumped storage systems are:
- An Open-Loop System: Open-loop systems have a consistent source of water that is pumped to a higher elevation and stored. Usually, the water comes from the water that has already passed through a dam, being pumped into the storage reservoir afterward.
- A Closed-Loop System: Closed-loop systems are not connected to a dam but rely on two different reservoirs, one at a lower elevation and one at a higher elevation. Water is pumped up from the lower reservoir and then flows back to it to produce electricity. These systems are often isolated from running water.
Running Off a River
Known as run-of-the-river hydroelectricity, this option also involves a dam of sorts, just in a different way. Instead of having to build a massive dam with reservoirs and water storage, this hydroelectricity production method relies on a waterway’s normal movement, utilizing it directly.
This option is considered far more environmentally friendly than a traditional dam, but it comes at a cost. Namely, the power produced is far less, and without the storage and control provided by a dam, it displays far less impressive results. Even with the addition of small storage stockpiles added in, it does little to match the larger dam.
There are a few exceptions, however, which are when run-of-the-river systems are paired with a powerful waterfall. An example of this is Niagara Falls, which adds a level of power and “weight” that is otherwise lacking when using this method. After all, hydroelectricity depends on the power of water, meaning more power is more electricity.
When talking about water, nowhere has more of it than the ocean. Therefore, where hydroelectricity is concerned, it is a huge area ready to be exploited. However, there are more difficulties when dealing with the ocean. One is cost, while another is putting theory into action. A few hydroelectric power options for the ocean are:
- Tidal Power: Tides flow in and out, causing water levels to rise and fall. This method seeks to take advantage of those periods to create electricity. It works by utilizing a turbine, moving it naturally with the rise and fall and producing electricity with a generator like a dam.
- Wave Power: While the direct power does not match up to that of tidal power, utilizing the ebb and flow of waves is another serious possibility. There are different techniques, including submerged systems and those utilizing pneumatic force from air, but they all utilize the turbine and generator framework.
- Thermal Energy Conversion: Relying on slightly different principles, utilizing different temperatures and steam to turn a turbine and produce power. While not as tested as other options, the potential among all the different forms of hydroelectric power is stunning.
Obstacles to Hydroelectric Power
Hydroelectric power relies on water, and there is plenty of water, or is there? That is one of the biggest obstacles facing hydroelectric power. Water is a valuable resource, particularly water from rivers, which is where most dams are built. Because hydroelectric dams can lower water quality, they may not always be ideal.
High initial costs are another concern. While hydroelectric power does not require a fuel source, aside from moving water, they are not terribly expensive to maintain. However, the building of a hydroelectric power system is incredibly expensive, requiring a great many considerations, including:
- The building of a reservoir
- The building of a dam
- The displacement and payments to people living in the area
Technology is another obstacle, especially for ocean-based systems. They require a great deal of innovation before they will be ready to provide a sizable amount of power, and this will take time and resources that may be difficult to come by.
Negatives to Hydroelectric Power
Much like solar power, hydroelectric power requires a large amount of space, which means displacing wildlife. Not only that, but there is the further issue of affecting the life of fish and other habitats that live in the water source in question. A few of the ways hydroelectric dams can impact wildlife are:
- Obstructing fish migration
- Impacting fish populations
- Changing the water temperature
- Changing the river’s flow
Such changes can harm species in the water and on land, and it can also impact humans as well. People may be required to relocate due to the land requirements and safety issues involved in storing such large amounts of water. A worst-case scenario could mean major floods, even for those that are outside of the danger area.
Additionally, the loss of land has other impacts, such as eliminating large amounts of agricultural land or natural resources, hurting the economic state of an area.
In its current state, hydroelectric power is likely to decline as time goes on. While hydroelectric power has potential, the easiest sources are mostly tapped out, particularly in more developed countries, such as the US. With most of the best sites taken, many others lack the potential to be worth the costs, financially or otherwise.
Moreover, ecological issues are more severe with hydroelectric power than some of the other forms of renewable energy. Even innovation is limited where traditional dam-based hydroelectric power is concerned, making other forms of energy production more valuable as future prospects.
However, there are options remaining. In particular, underdeveloped countries might have significant untapped hydroelectric power options. There are also ways to utilize small-scale, less environmentally impactful hydroelectric power systems, those relying less on stored water and large dams.
Perhaps most important, though, are the ocean-based systems. While the future of hydroelectric power looks limited, that is mostly due to the technology involved. If there is a breakthrough that allows such projects to become more feasible, it could become one of the largest energy producers worldwide, with the entire ocean up for use.
Solar power and hydroelectric power are both clean, renewable energy sources that harness the power of nature to provide electricity. Whether it be utilizing the power of the sun or water, they are both incredible choices with exciting futures ahead, having the potential to change the way we generate power forever.